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Bonneville Salt Flats Discussion => Build Diaries => Topic started by: Old Scrambler on May 22, 2011, 07:32:17 PM



Title: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on May 22, 2011, 07:32:17 PM
Hello to the group......or hopefully a few of you experts.  I visited the salt-flats for 5 days during the 2009 BUB event and got to meet several teams........most notably for me was Tom Mellor and his Trident.  I loved it but did not intend to return until I came up with a change of plans in the fall of 2010.  I had a basket-case '62 Cub that I thought would make a good looking flat-track replica to use as a pit bike.  I am mostly an idea person with only basic skills regarding mechanics and none for metal fabricating.  I don't like electronics and I can't do body work.  What I have done is research the basics and locate the local professionals to handle the things I can't do. About the fanciest wrench I own is a ratchet and socket set, and I can do a little polishing.

OK, enough about what I can't do........or don't know how to do...........I have been riding motorcycles since 1966.....mostly HONDA but a few others along the way including a '57 T110 Chopper. I used a 650 single dual-sport for a pit bike on the salt in 2009.

Back to the Cub..........I noticed that a few others had built replica flat-trackers so I decided to do something different.  My local machinist and biker expert agreed to work for SMALL $$$ and together we would build a bike to compete at Bonneville.  I figured for once in my life I would do something for real instead of just watching and dreaming.  The Cub seemed like a practical way to go fast slowly........ha ha.

I starded with a frame and motor but soon learned a later model had better main-berings. In November I started hunting for parts. By January  I came across a modified head and had gotten to know the bBritish suppliers so well that they had sent me Christmas cards. Hear is a look at the basic motor build........... 


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on May 22, 2011, 08:25:10 PM
The motor has been together since February and numerous parts have been gathered to put together a modified frame.........I am running 21" wheels front and rear...........extended the swingarm using two originals and some bracing.........found some 30mm Ceriani forks.........and now fabricating alloy oil and gas tanks.  I would post more pics but the computer tells me this file name is already used.......help!


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Koncretekid on May 23, 2011, 10:23:48 PM
Hey Old Scrambler!
Your motor is looking great.  You know you'll have to run against the 250's at BUB and SCTA, but if you use the stock venturi sized carb and a stock type exhaust system, I believe you can run M-PP (no record showing in 2010).  That is, modified frame with stock engine.  Internals can be modified as much as you want as long as you use the stock cases, cylinders and heads.  Just a thought.
As for posting more photos, you should be able to just log into the forum, and click on reply to your own post.  Don't try to change the subject line; just add in more text and click on "Additional Options", and add your new photos.
Tom


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on May 25, 2011, 12:35:53 PM
I know how to go slow........but I don't know how to add to my own posts........several attempts tell me the file has already been posted.


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Seldom Seen Slim on May 25, 2011, 01:23:31 PM
If, for instance, you're trying to post a photo - the file name may have already been posted by you -=- like maybe as a different photo but the file name got reused.  In that case you're usually best to post the photo to a file sharing site (Photobucket, for instance) and then link the photo into your post.  I've often tried to simply rename a photo (when presented with the "filename already used" message) only to find that I still can't get it to post.  So -- the Photobucket trick will work for sure.

If you're new to photobucket (or that ilk of sites) drop me a note and I'll try to walk you through the process.  Best -



Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Nortonist 592 on May 25, 2011, 04:34:21 PM
There is no modified frame / production engine class.  If you run a modified frame with a production engine you will be runnng against modified engines.  Also as you are running a Triumph engine you will have to run a Triumph frame to be in the modified class.  Page 114.


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Koncretekid on May 25, 2011, 09:02:00 PM
In the BUB rules, it only says you can't run a production motor in A, APS, or S (page 44).  A friend of mine holds the 250 M-P record on an RD250 modified frame, stock engine, so I guess that's allowable. There are actually lots of examples in the BUB records, including some with MPS-P. I admit I haven't studied the SCTA rules.
Tom


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Stan Back on May 25, 2011, 09:34:29 PM
With only a little bit of study, you'll find a class (maybe not presently occupied) for perhaps anything.  It must be kinda a sport to pick a new un-occupied class every year.  Four miles and you're done.  the big complaint is you have to actually fit in, unlike other places.  But there's plenty of holes.  Fill one this year, paint the seat green next year -- new class.

(Too many cervezas?)


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: wobblywalrus on May 25, 2011, 09:48:13 PM
Our team ran modified partial streamliners with production engines in the AMA class in MPS-P.  The rules are clear and easy to follow.  "Modified" chassis rules supplemented with "Partial Streamlining" rules and the motor meets "Production" rules.  There is a lot of freedom in this class to build a nice and affordable lake bike.


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Nortonist 592 on May 26, 2011, 12:22:26 AM
Sorry I was thinking of SCTA rules.


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on May 26, 2011, 09:59:21 AM
Great Discussion............I need to do more reading.............trying more pics.........your comments are welcom regarding rules for my hoped for build to meet the M-PG class......



Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on May 26, 2011, 11:18:36 AM
Thanks to SSS...............(http://i928.photobucket.com/albums/ad125/ddweinhold/Tiger%20Cub/Jan2011Cycleproject004.jpg)
(http://i928.photobucket.com/albums/ad125/ddweinhold/Tiger%20Cub/MVC-001L-1.jpg)
(http://i928.photobucket.com/albums/ad125/ddweinhold/Tiger%20Cub/DSCF4101.jpg)
(http://i928.photobucket.com/albums/ad125/ddweinhold/Tiger%20Cub/DSCF4380.jpg)


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Seldom Seen Slim on May 26, 2011, 11:30:23 AM
Scrambler:

Next we'll work on putting some comments and maybe some blank space between the photos -- but you've got the basics down now.  Quick learner. . . :lol:


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on May 26, 2011, 01:16:18 PM
Since SSS was so helpful..........I'll try a few more............
This is the rear wheel modified from a Honda XL350 front
(http://i928.photobucket.com/albums/ad125/ddweinhold/Tiger%20Cub/DSCF4382.jpg)

The fuel tank mock-up...........will have a Monza cap but need to get the carb mounted before final design
(http://i928.photobucket.com/albums/ad125/ddweinhold/Tiger%20Cub/DSCF4402.jpg)


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Seldom Seen Slim on May 26, 2011, 01:52:19 PM
Wow, I'm impressed.  He learns quick for a guy that brags (in his online name) that he's an old guy.  Looks like a fun project, too.


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: beerbellykelly on June 05, 2011, 03:51:47 PM
like the build-also glad to see i,m not alone in the 'fill the workshop up to the roof' school of thought. :-D

when we were kids,one of the local racers used  cub motors-we saw just about every trick he knew,and learned a few things.one that stuck with us was his pushrods-he used the stock ends and a very thin wall aluminium tube,before he assembled them he inserted timber dowels down the tubes to give rigidty-we,d never seen wood in such a high revving engine.sounds whacky but he won lots of club races.
all that work saved maybe 4 grams of weight,ANY advantage he had over the pack was a winning move as far as he was concerned.
best of luck with your bike,like all the one off stuff.


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on July 27, 2011, 04:43:21 PM
Its been a while and I've been away including a van trip to Yellowstone Park to visit our daughter in Idaho...........Dave Murre has been building the Cub in between customers and Al from the Advanced Landspeed shop has been helping by sponsoring parts at cost.  Anyhow...............IT RUNS........The motor was started on July 22nd and has only a minor oil leak...........I was away at a tractor show with one of my brothers........but Dave & Al phoned to let me know it was a success.

So.......we plan to make it to BUB and see how much fun can be had by going fast...slowly!(http://[IMG]http://i928.photobucket.com/albums/ad125/ddweinhold/Tiger%20Cub/DSCF5163.jpg)[/img]


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: fredvance on July 27, 2011, 05:34:14 PM
A Triumph with an oil leak. :roll: You're kidding.


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Koncretekid on July 27, 2011, 06:26:38 PM
.....minor oil leak.......just marking its territory!

Glad to know you're going to make it to BUB.  Got to love those old singles.  Look me up.

Tom


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on July 27, 2011, 07:43:47 PM
I know........just one little oil leak.......so far!  But it was a new part..the oil pipe to the head...........ordered a another new unit from the UK........(http://i928.photobucket.com/albums/ad125/ddweinhold/Tiger%20Cub/DSCF5164.jpg)


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: 55chevr on July 27, 2011, 09:08:43 PM
Oil leak on a Triumph. Unheard of. Next thing you will say is that there is an electrical problem.


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on July 28, 2011, 11:59:57 AM
The spark is provided by Chevy, Suzuki/Geo, Yamaha & Honda............and the degree wheel is from Norton-Villiers..........Those comments about Lucas electrics aren't jokes!


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on August 03, 2011, 05:15:28 PM
My sister-in-law has started a page for the us on facebook.....SALT TEAM ADVANCED LANDSPEED...........21 days to complete the build and pack to leave for BUB.........(http://i928.photobucket.com/albums/ad125/ddweinhold/Tiger%20Cub/DSCF5262.jpg)

(http://i928.photobucket.com/albums/ad125/ddweinhold/Tiger%20Cub/DSCF5261.jpg)


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on August 08, 2011, 08:19:57 PM
Day by day things progress...........lots of welding has now allowed the bike to roll off the bench for some testing.........Dave Murre, my all-around bike builder, thought that passing a 'can you lift it' test should be 1st on the list...........

(http://i928.photobucket.com/albums/ad125/ddweinhold/Tiger%20Cub/DSCF5293.jpg) 


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Unkl Ian on August 08, 2011, 09:36:56 PM
The spark is provided by Chevy, Suzuki/Geo, Yamaha & Honda............and the degree wheel is from Norton-Villiers.



Very interesting.

Chevy HEI pick up ?
What else ?





Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on August 11, 2011, 11:39:22 AM
I'll let Dave do the talking / showing about the electrics at BUB...........The 12V dry-cell battery is beneath the seat. The oil tank is an altered A-C bottle........the catch-tank was a formula bottle..........and the 21-inch wheels are from XL185 and XL350 Hondas but only the rear brake is active.  We are using the front speedo drive for early testing. The handgrips have Kevlar compound and the foot-shifter is now a rear-set on the left. The only secret is the source of the front fender........yet to be mounted.  The electric tach has a separate battery for memory.....and I still have to lose a few more pounds to squeeze into the borrowed leathers!


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on August 17, 2011, 09:46:50 AM
The first test ride went GREAT!..........A little fine tuning and shift-linkage to work on, but the Cub rolls straight and easily gets up to moderate speed.  Now for more time on the motor to set the rings and a couple of oil changes. Now if only I can find the decals I've been collecting for some decor.............???
(http://i928.photobucket.com/albums/ad125/ddweinhold/Tiger%20Cub/DSCF5311.jpg)

(http://i928.photobucket.com/albums/ad125/ddweinhold/Tiger%20Cub/DSCF5310.jpg)

(http://i928.photobucket.com/albums/ad125/ddweinhold/Tiger%20Cub/DSCF5309.jpg)


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: saltwheels262 on August 17, 2011, 06:12:17 PM
old scrambler,

nice build.

what diameter and wall thickness aluminum tubing are you using
for the fuel tanks ? length ?

also curious as to the volume of 1 of them. looks like a gallon and a half or more per side.

need to do a tank for the new kneedragger. I'm done with in frame tanks.

franey


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on August 18, 2011, 02:32:06 PM
Thanks for the nod...........The tank holds just under 2 gallons. It was made from a 5-inch diameter 'pipe' taken from an intake-stack off of a tractor-truck.  It was halved and expanded with a 2-inch flat-strap. The ends are 1/4-inch stock for strength because the tank is part of the frame geometry forming the upper head-stock brace. The size of the carburetor access tube was not known at first, but we needed to be sure the tank held 5-liters when finished. Dave Murre did the welding and fitment.......the cap is from Johnny Rocker in the UK.


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: saltwheels262 on August 18, 2011, 06:23:37 PM
okay, thank you.
4 gallons will be plenty for that motor.

so it's  non aluminum?

bf



Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on August 18, 2011, 06:51:25 PM
Its a single tank just under 2-gal. and is all aluminum.........the 1.6 qt. oil tank was made from a condensor bottle salvaged from a car.  Here is a pic of the underside............

(http://i928.photobucket.com/albums/ad125/ddweinhold/Tiger%20Cub/DSCF5264.jpg)


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Koncretekid on August 19, 2011, 07:53:02 AM
Great looking bike,
2 gallons should be plenty.  I made two or three runs at Loring, went back to the gas truck, and we couldn't put in 1/2 gallon.  I really like your pile of spare parts on the floor.  No doubt enough parts to build another bike.  Bring your buddy Dave along - - I want to see if he can lift my bike!

Will see you at BUB.

Tom


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on September 03, 2011, 08:56:10 PM
We had a great time on the salt!  The bike ran very well and we apparently have moved the 250cc M-PG record up to about 82.6 mph. Speed Team Doo had not yet run when we left for home. Look to Facebook for the Salt Team Advanced Landspeed for many pics and comments. I just arrived at home so I have a lot of things to do. Everyone from my team was very impressed with the great people they met on the salt........that includes YOU!


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Koncretekid on September 03, 2011, 10:34:02 PM
Dennis,
It was great to meet you and your mechanic, Dave.  Congratulations on your record runs, the bike couldn't have looked any better!
Tom


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: wobblywalrus on September 03, 2011, 11:21:48 PM
Congratulations.  It was nice to meet you and see the Tiger Cub.  It is a professional looking little bike.  Welcome to the fraternity of Triumph racers.


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Bruin on September 05, 2011, 05:23:47 PM
Dennis - Tucker here.  Congrats on the new record.  You did really great!  I know how good it feels to set a record.  I had bike issues but did manage to make 2 1/2 runs on the last morning.  Once we figured out the bike, it ran really well.  You've set the goal for next year.  Hope you're back in 2012 for a little friendly competition. 


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on September 05, 2011, 09:09:17 PM
Thanks Tucker.  Yes, it feels good but has not totally set in.............maybe I'm getting old???  The Cub really ran better than my builder, Dave Murre, expected. We only have 201.44cc so a little building may be in order.


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: wobblywalrus on November 30, 2011, 10:06:57 PM
Dennis, in a previous post on another build you mentioned how smooth your engine is with a small flywheel.  There might be another benefit - a reduction in non-aero losses.  Vibration is the frequent acceleration of a mass for a very short distance.  It takes energy to do this and the engine supplies it.  The mass cannot be accelerated if it is restrained so it does not move.  This means the force creating the vibration does not need to be eliminated if the parts subject to vibration can be braced so they are stationary.  The best solution is to balance everything so the vibration causing forces are not present.  Your little flywheel might be doing the latter.

This was told to me many years ago and it seems to make sense.  I am not a physicist -  so I could be wrong.   


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: wobblywalrus on April 02, 2012, 11:00:59 PM
Dennis, you will like the book on drafting you ordered from based on info in Sumo's build diary.  A peculiarity of a technical education when I had mine was the hard work of engineering, such as dimensioning, fits, tolerances, limits, etc. were taught in drafting classes.  The material in the back of the book about detail and assembly drawings are a must read part.  Especially useful are the sections about tolerance distribution and accumulation.  We do not manufacture the things we use on our bikes.  We do draw stuff up for others to make.  The techniques in this book are taught to both machinists and engineers.  It is a common language.


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on April 03, 2012, 08:26:15 PM
The closest I ever got to being an engineer was when I ran out of parts in my older brother's Erector Set before I was ten years old.  When I was about 13 I de-coked (didn't know the term then) our Lawson motor. Then my mother sent me off to a private school to become a teacher or a minister........(was in sales & marketing; then became a commercial appraiser)......so engineering books were not available.  I have always loved the simple motion of a lever. Then I fell deeper in love with levers coupled to springs! So now I am planning my retirement life to get back to doing things I enjoy. When I finish reading the book I will give it to Dave Murre, my very reliable engine builder.  He already knows this stuff but I figure if he has a book on his shelf then others will place more trust in him.


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on September 03, 2013, 01:11:36 PM
So its been a long time since my last post in this thread............something to do with a new computer that has new rules about posting pics. Anyhow..........WE HAD A FANTASTIC TIME AT BUB 2013.

We brought the same basic Triumph Cub chassis but with a new motor and added partial streamlining. The new motor was measured at 236cc but we calculated it to be 243cc.  We had a tech problem with the extended swingarm..........apparently the AMA does not accept a magazine article as a reliable reference regarding the standard wheelbase of a Triumph Mountain Cub.............so we had the swingarm marked according to the standard Cub wheelbase which only left a half-inch of adjustment. Thank goodness for half-links :-)

We were competing in 250cc MPS-PG. After several practice-course runs with plug-chops on Sunday, we had our 1st and best run early Monday at a top speed of 89.339 mph.  The average should be about 88.74 mph for a substantial increase to the AMA record. We had plans of removing the fairing and running to up our existing M-PG record of 82.5 mph but decided to leave that for next year.

My trusted builder, Dave Murre, headed up my pit crew along with two new members who very possibly will be back with bikes of their own 8-) Tom (new record and fastest B50 in the world), Bo & Gretchen, Tom Mellor (now in the 200 club) & Crew, some crazy guys with fake steel valve-stems and 12v meters that register 1.3v apart from each other :roll: Peter with the red hair, the blind riders group, Speed Team Doo, and many others stopped to say hello.

As I gather my pics, I'll try to post a few...........especially the dimples on the intake valve stem.


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Cereal KLR on September 03, 2013, 09:28:07 PM
Hey that was us with the fake steel valve stems, and multimeters that were voltage adverse  :cheers:

It was great pitting next to you and talking Cubs with Dave. Congrats on the record!


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on September 06, 2013, 02:21:52 PM
Cereal.............We will be back next year. I'll bring my own multi-meter :lol:

You guys were a great resource.............and so where several others.........helmets, jets, half-links, and twice someone took down our canopy while we were in line for a run to save it from the wind. I hope to be that helpful someday :-)


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Cereal KLR on September 06, 2013, 09:10:48 PM
Glad you will return next tear, will see you there. We grabbed your canopy just as it was going over the truck at one point, the folks to our left did the same for us too. Who ever invents a secure 60 mph ezup will be rich.


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: wobblywalrus on September 27, 2013, 12:04:10 AM
Dennis, your record is on the list.  Now you can wait for that special flat envelope to come in the mail.


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on September 28, 2013, 12:44:04 PM
Thanks for the heads-up :-D :-D :-D

We think we have identified the so-called 'rev-limiter' that makes top-gear on the Tiger Cub feel like a Sunday Ride. We believe our spark is not hot enough at full-load. The GM electronic ignition is a total loss system and this year we only had about 1-amp of power coming from a 12v EV02 BALLISTIC battery meant to run a 50cc scooter. We are thinking we may need a 4-amp or higher battery to assure a full coil load at high-rpms.  The motor pulls into the mid-7000 rpm range in 3rd but only climbs to about 6500-6700 rpms in 4th.

Any thoughts..................


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Freud on September 28, 2013, 02:25:11 PM
Use less gear.

FREUD


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Koncretekid on September 28, 2013, 03:47:31 PM
Thanks for the heads-up :-D :-D :-D

  The motor pulls into the mid-7000 rpm range in 3rd but only climbs to about 6500-6700 rpms in 4th.

Any thoughts..................
Dennis,
Why only 7000 rpm?  I've heard that BSA 250s can rev easily to 10,000 rpm.  I am using a 250 crankshaft stroked to 75mm (is your stroke just 70mm?) and I can rev easily to 8500, even with a much bigger heavier piston.
Tom


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on September 30, 2013, 08:35:03 PM
We tried a larger rear sprocket and ran slower...........at the same max rpm in 4th. Each tooth is roughly 2 mph.  We are fairly convinced its the ignition system........so hunting for a replacement.  We got this far on used parts .........even my new leathers were an ebay close-out :wink: Time to get serious.  We are thinking of adapting a mag system from a Honda CRF-series bike.

Tom.........we agree the motor should easily rev into the 8s.................Current bore is 69.3xx mm and the stroke is standard at 64mm. 

Maybe I just weigh too much :-D :-D :-D


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: wobblywalrus on September 30, 2013, 08:44:58 PM
What about a beefier battery or an ignition system that uses less juice?


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on September 30, 2013, 08:55:34 PM
No battery equals another lb. or 2 off of my belly :lol:

Yes, the coil, modulator and battery all have to be in sync...........but a mag will give us all the spark we need and will run off of the crank, instead of the timing side.

Just exploring for now..........open to ideas..............


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Koncretekid on September 30, 2013, 09:33:35 PM
Dennis,
Insufficient amperage will definitely limit the rpms.  To try it, hook up a voltmeter and run the motor up thru the rpms as you watch the voltage.  I've had it happen to my CB350 roadracer.  The motor would rev to 8,000 and just stop there.  Turned out to be a faulty battery, which started at 12v and dropped to about 9v at 8,000.  New battery, problem solved.  (I seem to be a slow learner.)
Tom


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on October 04, 2013, 07:55:28 PM
Tom...........I just began to learn about these things at age 64.........talk about slow :lol: :lol: :lol:

More juice is planned for 2014.........in more ways than one :-D :-D :-D


Title: Re: TRIUMPH TIGER CUB - HONDA CB750
Post by: Old Scrambler on May 29, 2015, 09:35:53 PM
2014 was an expensive experiment at the salt. With so little opportunity to get runs in, I tried to run the Tiger Cub only to find frozen shift-linkage. So it got repaired in a few minutes but I had quickly substituted my new build so the Cub never made a run :-(

The new bike is a CB750 sohc put together from a mix of parts and some left-over racing pistons. Dave and I built the bike to compete in the Classic category and proceeded with a plan to break it in at the salt. We were way off on carb-tuning and timing............so not much to talk about.........until I figure out how to post the dyno-charts from yesterday's session at a local shop.  More later..............someone is calling my name :-D


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on May 29, 2015, 10:46:42 PM
The bike as it sat in line at 2014 BMST
(http://i928.photobucket.com/albums/ad125/ddweinhold/CB750%20Classic%20Bonneville%20Racer/2014%20Salt%20Flats%20051.jpg) (http://s928.photobucket.com/user/ddweinhold/media/CB750%20Classic%20Bonneville%20Racer/2014%20Salt%20Flats%20051.jpg.html)

Its a 1mm overbore so legal in the Modified Classic 750 class. Now we are a lot closer to knowing what we have:
(http://i928.photobucket.com/albums/ad125/ddweinhold/CB750%20Classic%20Bonneville%20Racer/002.jpg) (http://s928.photobucket.com/user/ddweinhold/media/CB750%20Classic%20Bonneville%20Racer/002.jpg.html)

Plans are now underway to take both bikes to Bonneville for the BMST............... :-) :-)


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: wobblywalrus on May 30, 2015, 05:23:02 AM
Dennis, try dropping your needles one notch.  It might get rid of some of that dip in mid range power.


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on May 30, 2015, 10:09:27 AM
Needles on the RS34s are in the middle slot..................if anything I would lower the clip to raise the needles..............they have a long slender tip and then an abrupt taper that effectively closes the main when at rest. Right now the mid-range is good if the throttle is rolled on rather than yanked to WFO.


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on August 06, 2015, 04:31:20 PM
Just to let you know we are still working and planning to attend BMST...........the Tiger Cub should be READY with minor mods and a NEW battery........now playing with timing.

The Honda CB750.........I call it the CBR for Classic Bonneville Racer.............has a new megaphone muffler; new intake stacks; and a revised air-intake system with only a screen in the box. We tried a lot of different ways to get an effective ram-air system to the box..........but too many seams and joints caused leaks...............This box retains the OEM intake on the bottom. If the new side intakes work, the bottom could be taped shut. The carb-bowl vents will go to the lower part of the box.

A few pics just to give you an idea of what this motor is all about................

(http://i928.photobucket.com/albums/ad125/ddweinhold/CB750%20Classic%20Bonneville%20Racer/IMG_3391.jpg) (http://s928.photobucket.com/user/ddweinhold/media/CB750%20Classic%20Bonneville%20Racer/IMG_3391.jpg.html)

(http://i928.photobucket.com/albums/ad125/ddweinhold/CB750%20Classic%20Bonneville%20Racer/IMG_3303.jpg) (http://s928.photobucket.com/user/ddweinhold/media/CB750%20Classic%20Bonneville%20Racer/IMG_3303.jpg.html)

(http://i928.photobucket.com/albums/ad125/ddweinhold/CB750%20Classic%20Bonneville%20Racer/2014750bike012.jpg) (http://s928.photobucket.com/user/ddweinhold/media/CB750%20Classic%20Bonneville%20Racer/2014750bike012.jpg.html)

(http://i928.photobucket.com/albums/ad125/ddweinhold/CB750%20Classic%20Bonneville%20Racer/2014Augcycle007.jpg) (http://s928.photobucket.com/user/ddweinhold/media/CB750%20Classic%20Bonneville%20Racer/2014Augcycle007.jpg.html)

(http://i928.photobucket.com/albums/ad125/ddweinhold/CB750%20Classic%20Bonneville%20Racer/2014July750017.jpg) (http://s928.photobucket.com/user/ddweinhold/media/CB750%20Classic%20Bonneville%20Racer/2014July750017.jpg.html)


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Koncretekid on August 06, 2015, 07:26:03 PM
Looks good, Dennis.  Looking forward to seeing you guys again.

Ram air?  My bike actually ran with the ram air up to about 133 mph; then just wouldn't go any more.  I decided that there are probably too many variables like position of intakes, size, corners, and air box size and shape.  Today while waiting for ignition parts, I cut the suckers right out of my fairing and tomorrow I'll fill in the holes and paint some eyeballs or something where the holes used to be.

Tom


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on August 06, 2015, 07:41:18 PM
We need to get together and have good discussion about the ram-air. I have discussed it with 2 engineers. Our biggest problem was the OEM frame :-(

Dave Murre is not making the trip this year. So parts may be flying :lol: I will have Jerry from Colorado Springs to help...........and 2 or more spectator friends along for the ride.


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: fordboy628 on August 18, 2015, 06:58:09 AM
Scrambler,

What is the exact displacement of your Honda engine?

Just a SWAG on my part:

@ 76.2 rw bhp, (from your PhotoBucket pic), guessing 780cc's (?!?) equals 97.7bhp/liter, not too shabby for air cooled at the rear wheel.

Where does the written 98 crank bhp number come from?

In my world, 76.2bhp x 15% drive train loss (at the most) = 87.6bhp or 112.3bhp/L, pretty good.

98 crank bhp requires a drive train loss % of 28.6%, seems kinda high to me.

JMHO, though.    Punch in your exact displacement and re-calculate these numbers to be precise . . . . . . . .

Also:  Your a/f ratio needs to be lower between 4000 & 5600 rpm to tune out that "dip" in the power curve.    Unfamiliar with those carbs, but it looks like a needle change is in order . . . . . .   or at least "alteration" of the existing needles . . . . . . .    Are your carbs perfectly synchronized?   That can play he** with a/f.

 :cheers:
Fordboy


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on August 18, 2015, 10:48:57 AM
Original motor was 736cc...........1mm overbore = 762cc

The 98 was a guess by the dyno tech........from a H.D. shop

We had 50-psi in the tire and noted significant slippage and peeled rubber on the dyno........the tire was quite hot :-o

The tech was short-shifting...........I have no intention of letting the rpms drop below 7500 when changing gears on the salt :-D

The 34mm carbs feed 33mm ported intakes and ported head/trimmed guides. We may have a case of 'big-carb-itis' causing a loss of flow across the needle-jet when shifting gears. Our thoughts were to grab as much of the available air as possible to get enhanced chamber-filling/pressure. 31mm Exhaust valves lead to polished exhaust ports and a 4-1 header. The dyno-test showed improvement after removing a straight-pipe from the header. We have since added a reverse-cone megaphone......no baffles. We also gained HP when the air-filter was removed.........and significant (5-HP) when the timing was advanced several degrees from stock.   

We will continue to play with a ram-air design and we are always open to critique and HELP :-D :-D :-D


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Rex Schimmer on August 18, 2015, 01:25:02 PM
Scrambler said:
"
.......and significant (5-HP) when the timing was advanced several degrees from stock. "

This is a pretty common occurrence with hemi style combustion chambers. The large "chunk" of piston that it required to get some compression interferes with getting the incoming mixture to swirl and reduces the combustion process efficiency which then requires additional ignition lead to compensate. Also the extra piston area and material adsorbs heat which reduces engine power. I also notice that with your head/bore set up there doesn't appear to be a squish area which can also assist in combustion efficiency. Still pretty impressive for an early Honda 4 cylinder engine.

Ram air is not something that can be measured on a dyno and as Tom's experience has shown what may "look" like it should work can sometimes be a step backward. I call this OIA, optically intuitive aerodynamics, i.e. "if it looks good it will be good"! The basics of ram air is that you need to take the high velocity incoming air and slow it down which increases the pressure and will provides air at an the increased pressure to the engine. This requires an inlet that starts small and then increases in cross section at a gradual rate until the air velocity is reduced sufficiently to provide increased air pressure. Not an easy task on a bike like yours but something that could probably be done.

Great project and good engineering! Keep us up to date on your progress.

Rex    



Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: wobblywalrus on August 18, 2015, 08:36:57 PM
Ram air was something I monkeyed around with in the 1970's.  A main jet sized for running into a cool headwind was a lot different than the one needed for a warm tailwind.  Sidewinds had their own bizarre effects.  It was impossible for me to make use of the concept in the varied environments encountered on race days. 


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on August 19, 2015, 11:05:41 AM
Thanks, Rex.............all helpful info.............I have extensive research into the air-intake designs on modern bikes.............and will continue to work on stabilizing the air in a box before it goes to the carbs.........I have the advice of an air-flow engineer that round tubes and intakes have significant drag, while rectangular or square tubes and intakes only have drag at the corners. 

I have a plan for a big-bore that should have significant squish-band. I take particular note from the positive comments because I wanted to try to exceed what numerous other builders have done to these motors in the 750cc level of competition.

Bo............I am told by everybody's best friend GOOGLE that ram air becomes modestly effective at 100-mph and SIGNIFICANTLY effective above 150-mph. 


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: panic on August 19, 2015, 04:41:20 PM
Excellent work, best of luck!

Based on your photo, I'm not sure your side positioned air intakes are "visible" outboard of the slipstream from the chassis ahead of it. I'm guessing that (as seen from above) they are inboard of some component shapes in both directions.
All fluid transfer depends on pressure differential - high to low, nothing else. If they're not in a high pressure area (relative to the box interior) you have nothing except engine vacuum. You may need an entry device far away from the box (and suitably ducted).
Have you done any yarn or smoke tests?


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on August 20, 2015, 02:14:29 PM
Panic...........thanks for taking an interest :-) :-)

The bottom of the box has a rear-facing intake about 3/4-inch tall by 3-inches wide. Its design was different from all other CB750 models and helped to move the red-line on the standard F2 and F3 models from 8000 to 8500 rpms. The outer 'add-on' ducts are indeed slightly in-board of the outer edge of the motor block. I have shaved the head fins to match the block. My knees are pressed against the rear edges of the airbox and feel quite a bit of air-pressure when over 100-mph.........that could disappear when at higher speeds. The effort was only to catch 'some' additional air but not to expect any ram-air affect.

Last year we had two 1-inch hoses, one on each side of the neck, with flared 'bell' intakes, leading along the frame (wide tank tunnel) and then formed into a wide-radius 180-degree bend and stuffed into the bottom intake. We had a new K&N filter in the box. It seemed to work but when I shifted from 3rd to 4th at 9,500 rpms (about 113 mph) the motor bogged and would not recover. I backed off on the throttle and saw no improvement.  We changed jets and made one more run with even worse results.  On the subsequent dyno run (no hoses) the motor struggled at 9000 rpm and showed rich on the A/F.............we removed the bottom of the box and filter and showed immediate improvement with the motor running clean and clear into the mid-10,000s.............then we moved the timing a few times until we found the sweet-spot and the motor ran crisp, clean and QUICKLY up to 11,300 rpms.   


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: tauruck on August 20, 2015, 10:07:05 PM
I built an air box for my Sportster bobber but as the bike wasn't a runner at the time we tested it on my buddy's bike.

He's a qualified HD mechanic, did all the courses etc. but is also a Chevy Big Block nut case.
He went up three sizes on the jets because the Dyna motor breathed too well with my contraption.

I'll shoot some pics and post them later.


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: tauruck on August 21, 2015, 09:17:25 AM
Here's the box sans the three metal rings that fit in the opening.


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: tauruck on August 21, 2015, 09:21:59 AM
I know it looks like something you might see on a Top Fuel or Funny car motor but it works.
No restrictive HD filter.
I used a breather fabric that we used on the Mazda Rotary race motors sandwiched between a metal mesh thing I thought up.


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on August 21, 2015, 08:06:45 PM
T. Thanks for the comment..............and pics..........Was the intake facing forward?  How did it perform on the street...........or wherever it ran?


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: tauruck on August 21, 2015, 08:20:14 PM
Facing forward and ran on the road.
This thing works but it was on a Harley.

I guess it might get clogged up on the salt but it was way better than the OEM HD "air box".
Each inlet is 38mm.


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: wobblywalrus on August 22, 2015, 12:11:00 AM
Dennis, the air horn should have rounded rather than a sharp edge, and it should be a harmonic distance from the intake valve seat at the peak torque rpm.   The butterfly or inside face of the carb slide is reflective.  It should be at a half harmonic from the intake valve face at the rpm when you want grunt at partial throttle.  The air going into the bellmouth should be as cool, calm, and clean as practical.  A proper air box will help.  It can hold the filter and have an intake where the air is cool.  Also, by virtue if it being a box, the air inside is calmer than on the outside, and this helps.   


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Peter Jack on August 22, 2015, 12:15:55 AM
Do you have a picture of the underside Mike?

Another nice piece of work by the way!  :cheers: :cheers: :cheers:

Pete


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on August 22, 2015, 11:21:18 AM
The custom-design Sportster intake is indeed very COOL.......LOOKING. It allows the carb to breath.............but it may be more of an 'anchor' than a helper on the salt at 'high-speed'.

Bo...........all good info...........but I don't plan on having any 'slide-obstruction' when at WFO :-D  The dyno tells me the box with air-cleaner was very restrictive. The attempts on the salt-runs indicated rich conditions and that gear-change transitions need to be at higher RPMS in the upper gears.............maybe I need a closer-ratio set of gears or a six-speed :|

Three of us went to a Steam & Tractor Show yesterday............found a genuine JAGUAR wrench and took a few pics of a 100-HP Steam-Tractor rolling through the power parade and later operating a saw-mill. 


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: SPARKY on August 22, 2015, 01:02:34 PM
What no   :-o  threshing machine   :roll:


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: wobblywalrus on August 22, 2015, 06:03:06 PM
Those things I listed are items to check in the air box.  Many air boxes have two chambers separated by a plate or wall with a hole or slot in it.  The compartment with the intake bell mouths is often a Helmholz resonance chamber and it resonates at a desired frequency to accentuate the intake harmonics.  The other chamber holds the filter.  It may be that one or more chamber resonant harmonics are wrong for your application.  Put some hard boiled eggs or tennis balls in the box.  This will change the harmonic resonance.  See if the problem goes away.  Like Peter says, a picture will help.  I think I remember how those boxes look, but that is many years ago.       


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on August 23, 2015, 11:42:55 AM
Sparky..............Threshers are too COMMON to discuss in the Mid-West :lol: ............5 or 6 were operating at this show.  The older wooden-threshers are somewhat unique to see :-)

Bo...........we have removed the inner plate from the F2-F3 box that sealed against the top of the air-filter and had an somewhat 'oval'-shaped intake. It really shrouded the #1 & #4 intakes and was sized for the stock 31mm 'pinched' carbs. Our modified box is just a shell with a screen between the halves. I am working on a design that would basically invert the upper-half of the box below the frame rails.........then set a separate box on top of the frame with intake ducts leading from the steering neck, an internal filter, and down-tubes connected stabilized air to the lower box. It would work a lot easier if I used a Special Construction frame............but I want to see it happen in the Modified class. 


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: wobblywalrus on August 24, 2015, 04:14:46 AM
Methinks that plate with the hole in it is for Helmholz resonance.

Resonance works to push or pull air/fuel mixture into the combustion chamber through the valves.  It also can make the carbs see Goofus if big pressure oscillations occur over the needle jet.  The venturi vacuum that pulls the fuel or emulsion out of the bowls is altered.  Sometimes it happens with air boxes that the resonant frequencies inside the box and inlet tract confuse the carb metering.  That might have happened when the plate was removed.

Plenum volumes can be calculated by PipeMax or other formulae.  That will give a good idea of where to start when designing the box volumes.     


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on August 24, 2015, 11:54:24 AM
The Honda plate was designed to hold the shape of the air-filter that was designed in 1967-68 and used on 28mm carbs.  The intake area was cluttered with two cross-members that held centering-guides for the through-bolts that held the lower part of the box to the upper.

On a modern box, a similar 'restricter' plate is noted with shorter intake-stacks on #1 & #4 to allow more air-space for balanced air availability to each carb-body............the box remained the same as the bikes transitioned from vacuum-carbs to fuel-injection. On our build we feel that most of the Helmholz (if not all) is negated by the hoped-for positive air-pressure feeding the box. We have attempted to negate closed-valve harmonics from reaching the carb venturies by extensively porting the 'roof' area of the head.

I can see that more than 1 or 2 visits to the dyno will be made before we set the final design. BTW.......we will attempt to use two or more high-speed thrust-fans (furnace fans.......not leaf-blowers) to feed ducted-air to the box when in the dyno-room. The fans have reostat-controls for needed CFM to simulate cylinder-fill requirements at high-rpm.     


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Koncretekid on August 25, 2015, 02:41:11 PM
Funny you mentioned leaf blowers.  I was thinking of bolting one onto the front of my bike (without the fairing) to pressurize my airbox as sort of a joke.  Two throttle cables and and with the carb vents and gas tank vent connected to the airbox, the gas should still flow.  I would still be in the 650cc class if the leaf blower was under 50cc, but I guess I'd no longer be considered pushrod! Now I have another year to think about it.
Tom


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on August 25, 2015, 06:52:39 PM
Tom............the leaf-blower turbo-test is a U-Tube wonder..............Good info if you poke around looking for Formula 1 Intake design; and F1 Air-Box design..................lots of talk and engineering...........but closes with the catch-all; the harmonics don't matter at WFO :-D :-D :-D :-D

As of now, my opinion is a sizable box needs to be slightly pressurized with sufficient intake capacity to maintain the amount of air the engine requires as it is drawn through filtered intakes to a second chamber feeding the carbs.  The very slight amount of positive air-pressure is significant when measured against the LOSS of air-pressure when traveling at speed.


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on September 20, 2015, 07:03:18 PM
I was invited to display my Land-Speed bikes at a 'Gather on the Green' event at a resort in Elkhart Lake during the Road America VSCDA and Fall Festival event on Saturday, September 19.  I talked with numerous racing fans and competitors and was pleasantly surprised at their knowledge of the poor conditions and mining issues affecting Bonneville. 


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: wobblywalrus on November 28, 2015, 11:24:33 AM
Dennis, look in the Nov/Dec issue of Classic Racer.  There is an article about Rex Wolfenden and T-Rex Racing Developments.  They do a lot of work on early CB750's for the classic bike racers in Australia.  The pictures show some parts that might help you like lightened cranks that are reworked to reduce windage.


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on November 29, 2015, 10:03:38 AM
Bo............Good to know :-)

APE in the US will supply lightened and balanced cranks for the sohc CB750 motors. OR, Dave Murre, my builder and tuner, may want to shave a few ounces from each weight for my planned larger displacement motor. 

https://scontent-lax3-1.xx.fbcdn.net/hphotos-xfp1/v/t1.0-9/12191594_815741615230134_7915338662756175088_n.jpg?oh=2d7e3ee04f21a2c55013ff3bdb16e3d8&oe=56CF8E90


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on August 19, 2016, 09:29:05 PM
A few days to go before we leave for the 2016 BMST and the bikes are tuned and ready to go :-D The Classic Bonneville Racer has a few additions including a ram-air system.

(http://i928.photobucket.com/albums/ad125/ddweinhold/CB750%20Classic%20Bonneville%20Racer/IMG_4802.jpg) (http://s928.photobucket.com/user/ddweinhold/media/CB750%20Classic%20Bonneville%20Racer/IMG_4802.jpg.html)

(http://i928.photobucket.com/albums/ad125/ddweinhold/CB750%20Classic%20Bonneville%20Racer/IMG_4804.jpg) (http://s928.photobucket.com/user/ddweinhold/media/CB750%20Classic%20Bonneville%20Racer/IMG_4804.jpg.html)

The Triumph Cub looks the same as before but we think we have solved its performance problem........although it holds two records. In top gear the motor was just purring along as if on a Sunday drive. I was about to take it for a spin on a dyno, but we checked the timing and found it was about 5-degrees less advanced than we thought it was set at. So all is adjusted and it runs stronger and revs higher........but starts harder (my leg) and now marks its spot because the primary case did not seal as well as it had been.

We plan to be busy with two bikes and 4 classes............kinda fitting 2-years of excitement into one event :-) :-) :-) :-) :-) :-) :-) :-)


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: wobblywalrus on August 19, 2016, 10:51:27 PM
Looks good, Dennis.  Make sure to yell us how it goes.


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on August 20, 2016, 09:33:14 AM
My confidence is on the optimistic side :-) Bo, I am expecting to see you at the salt........I may need a 'pusher' to help with the Triumph :lol:


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: astek on August 21, 2016, 10:58:51 PM
Bike looks bitchin Old Scrambler! Wish you good luck and look forward seeing you at the Bonneville AMA speed trials.


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: wobblywalrus on August 21, 2016, 11:21:23 PM
Dennis, I will not be at the salt this year.  It looks like a couple of cams need to be designed and ground for the Triumph before it does any racing.  Progress is being made. 


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on August 22, 2016, 09:03:27 AM
Thanks, Astek..............Packing the trailer with plans to leave on Wednesday for arrival on Friday.

Bo........I'll try to take some notes for you :wink: :wink: :wink:


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on September 04, 2016, 07:54:40 PM
Success :-) :-) :-) :-) Well, sort-of...............My 750cc sohc Honda-four got me a record in Modified Partial Streamlined Classic Gas at 137.699 mph...........top speed was 140-mph on a separate run but my battery failed and I could not back it up :x  Without the fairing I also upped the record by 5-mph to 130-mph :-)

The Triumph ran into wire-harness failure so I parked it and went home a day early to catch the Chief Blackhawk AMCA meet in Davenport Iowa. 


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: wobblywalrus on September 04, 2016, 09:53:20 PM
That reads like success.  Two records.  Good job.


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Bruin on September 10, 2016, 11:03:52 PM
Sounds speedy. Sorry I missed you. Do you run a total loss electrical system, battery without the drag of a generator?


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on September 12, 2016, 09:50:07 AM
Total loss L-I unit...............When fully charged its good for 4 runs on the International course. I could have idled home on the battery, but not enough juice for full noise on the 5th run. I use a Deltron (Battery Tender) unit and like the 4-post design and that it does not require a special charger.


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Bruin on September 12, 2016, 10:55:35 AM
I'm looking at dropping my tank to the floor so it will need a fuel pump. The fuel pump I have on hand is a 12v model and the bike is CDI with 6 v for lights. So a total loss 12v battery will power the pump. I think the pump draws 3 amps so a 15 amp hour battery should run 5 hours-ish. I figured I carry a spare battery. I have found a solar powered trickle charger and I thought that might keep it topped off when not running at sunny Bonneville.


Title: Re: TRIUMPH T20 CUB - MODIFIED
Post by: Old Scrambler on September 12, 2016, 01:37:02 PM
We have a solar unit for the daytime, and a standard charger in hotel-room for when I REMEMBER to bring the battery with me :wink:

I see several riders using a modern Suzuki fuel pump for its low-amperage and sufficient volume without 'blowing' the fuel-lines.


Title: Re: TRIUMPH T20 CUB & HONDA SOHC CB750
Post by: Old Scrambler on October 26, 2016, 02:14:02 PM
So we got the motor on the CB750 together and gave it a trial run. All is good with no apparent damage to any components after our record runs 8-) 8-) 8-)  Plans are to fashion a new and improved tail-section to 'close the hole' more effectively. While that is being accomplished, Carol and I have decided to do some traveling to see some far-away places. Our first trip was to visit several national parks in California and Utah. Upon our return to Plymouth, (sold our house and moved to an apartment) the mail-lady brought me a letter from our State Governor. He was congratulating me for setting records at Bonneville..........Wow.....it must have been a slow news-day for him to do that :lol: :lol:..........but I do know that he occasionally rides a bike 8-) 8-)

A few short trips are planned to visit our daughters and then..............we hope to travel with our RV to Alaska for several months in 2017. We will tow a trailer containing a UTV and a bike. One of many things on my 'bucket-list' is to ride the Haul Road to take a swim in the Arctic Ocean. If we like what we are doing, we may not be back to the salt until 2018. But the bikes will be ready, just in case :-) :-) :-)