Author Topic: Help the new guy build a LSR Honda CB550f!  (Read 11017 times)

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Offline Peter Jack

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Re: Help the new guy build a LSR Honda CB550f!
« Reply #15 on: May 14, 2011, 08:17:57 PM »
For Bonneville you shouldn't have to worry about the weight, in fact weight is often your friend. This is unlike any other form of racing and if you've participated with any other form of racing first the weight issue can screw with your mind. Lots of guys carry a fair bit of extra weight on the swing arm. Everywhere else they worry especially about unsprung weight. Go for it, be safe and have fun.

Pete

Offline Milwaukee Midget

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Re: Help the new guy build a LSR Honda CB550f!
« Reply #16 on: May 14, 2011, 08:28:25 PM »
Remember - you're at 4400 feet, and I assume normally aspirated.  The head will need to breath well.  Don't let the mixture go lean on the high end. 

It's hot and dry out there - except when it's cold and wet. :-D

"Problems are almost always a sign of progress."  Harold Bettes
Well, I guess we're making a LOT of progress . . .  :roll:

Offline Gu11ett

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Re: Help the new guy build a LSR Honda CB550f!
« Reply #17 on: May 14, 2011, 09:16:12 PM »
Get a rule book, look at your classes and the safety items. Maybe you will or will not be competitive in your class, but you can be safe, have a lot of fun and learn a thing or two.

Enjoy the ride

Offline wobblywalrus

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Re: Help the new guy build a LSR Honda CB550f!
« Reply #18 on: May 16, 2011, 12:29:09 AM »
Trevor, sometimes it helps to find a person who runs an engine like yours in a higher state of tune, such as blown, fuel, turbo, etc.  They can tell you how to set up your motor for reliability.  That is what I did.  I built the lower end to work reliably with lots of power first.  The adding power part is happening later when I get the money.     

Offline oz

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Re: Help the new guy build a LSR Honda CB550f!
« Reply #19 on: May 16, 2011, 06:50:04 AM »
Hi Trev
You go for it buddy I am using a 20 year old CBR Motor in my project it aint as old as yours I know but old hat by any stretch of the imagination.
As the project progresses there is less and less of the original motor left things get modified or replaced with more up to date equipment and little by little it gets stronger,faster,better......hmmm sounds like the beginning of the six million dollar man and sometimes I reckon thats what it costs me.
Regardless, to get to Bonneville on something you have built yourself is no small acheivment whatever you build its the journey and the experiances you have that count!

Good Luck Oz
Newcastle born and bred a City built on Coal and Steel and a people built of stronger stuff

Offline Stainless1

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Re: Help the new guy build a LSR Honda CB550f!
« Reply #20 on: May 16, 2011, 08:36:35 AM »
Weight good airflow and compression are necessary when racing on the salt.  It will be a 3 mile drag race.  You said you were shooting for the Bub, so the rules are online.  You might want to consider Run Whatcha Brung... for your first outing on the salt.  It will give you a taste of salt racing while not costing you a fortune.  You run for 2 miles on that one IIRC.  You could ride to the event, race and ride home. 
One of the fast cars one the salt ran an old 500 four Honda motor...  Lingua Bros. & Father M. Lingua 08/91 223.071, but I know Mark went over 250 several times so don't get discouraged. 
Stainless
Red Hat 228.039, 2001, 65ci, Bockscar Lakester #1000 with a little N2O

Offline V8Pinto

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Re: Help the new guy build a LSR Honda CB550f!
« Reply #21 on: May 16, 2011, 01:01:20 PM »
I'm going to second what Stainless said on weight, good airflow, and compression being your friend.  Also, the BUB run what ya brung class would be a great intro for you. 

Focus on making the machine reliable and getting your whole entire setup together.  Entire setup = everything from the ice chest, trailer, to the racing tires and tools.  So much of Bonneville is just making it to the starting line - there are a million things to do before you get there.  Definitely get a rule book, figure out your tow vehicle (at BUB you don't need one), where you're going to stay, how you're getting there etc.

There is a wealth of info out on the net on the CB series bikes (I love those bikes).  If you can find any way to increase the displacement towards the class limit, that would help you out the most.  Weight is good, especially over the rear tire and hidden from the wind within the confines of the chassis. 

Have someone take pictures of you in a race tuck on the bike from all sides in that badass room/shop of yours (I love that!).  Then look at what sticks out.  Walk around and see what doesn't look aero and what you can improve and do those things.  Then do it again...and again....and again...
Shane
V8 Pinto on juice
Hayabusa on the brain
Twin-Turbo F150 4x4

Offline V8Pinto

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Re: Help the new guy build a LSR Honda CB550f!
« Reply #22 on: May 16, 2011, 01:05:15 PM »
and say goodbye to the nice finish on any metal parts.  The Salt will lay it's claim to your treasured cycle.  Get some SaltAway and use it but the bottom line is, that bike will never be the same.
Shane
V8 Pinto on juice
Hayabusa on the brain
Twin-Turbo F150 4x4

Offline kerncountykid

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Re: Help the new guy build a LSR Honda CB550f!
« Reply #23 on: May 17, 2011, 12:42:13 AM »
Thanks for the encouragement everyone, lots of good advice, I read every bit of it. Further reading on unsprung weight was especially interesting. I'm chipping away at it every day and will post back as I move forward. Getting an outline for the motor currently so I have something to talk about with the machinist.

Also good advice considering the surrounding arrangements like trailer and sleeping. I slept in an alfalfa field and behind a row of bushes last time I rode through Utah on my 550  :-o

Offline Nortonist 592

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Re: Help the new guy build a LSR Honda CB550f!
« Reply #24 on: May 17, 2011, 01:42:20 AM »
Hi KCK,   Welcome.   Don't mind the naysayers.   Go with what you have.  If Burt Munro had listened to the naysayers we'd never have heard of him.  This is still an amateur sport but there are those who have taken the fun out of it.  No record, no fun.  I'm running a mid 80s (don't know for certain and could care less) Weslake.  Its outdated but its fun (not to mention four records). 

Just two things.  Weight.  At Bonneville its basically irrelevant.

                        Drag.     Its everything when you run a small displacement engine.

Hope you make it to Bonneville this year.  And the best of luck with the build.
Get off the stove Grandad.  You're too old to be riding the range.

Offline maguromic

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Re: Help the new guy build a LSR Honda CB550f!
« Reply #25 on: May 17, 2011, 02:25:58 AM »
Have fun building it, the road to to get their is just as fun. Tony
“If you haven’t seen the future, you are not going fast enough”

Offline JimL

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Re: Help the new guy build a LSR Honda CB550f!
« Reply #26 on: May 18, 2011, 01:45:36 AM »
Being of a certain age (I was at the American Honda Convention when the CB500-4 was introduced to the dealers), I've played with some of that era stuff.  One of the things we learned about the old 2-valve engines (keeping in mind that the CB500 was essentially 4 SL125s, sort-of), was valve float as the exhaust side of the head heated up.  This showed up when I was running a stroked and bored SL100 in the 125 class on 1/2 mile ovals (I was young and skinny, and....yes....we just rode around wide-open throttle, kind of like Bonneville!). 

Anyway, the solution was to dish and polish the exhaust valves (lightening and improving gas flow to reduce the heat in that area).  That was a "no cost" project, involving chucking them up in a drill press and using a Dremel tool to slowly dish the valve while it was spinning.  Without that step, the exhaust valve would tap the piston before the end of a 16 lap main.  At that time we had no options for valve springs...and no money to spend on such stuff.  Note that the valve contact condition never happened in a "heat" or an 8 lap "semi".

For cams, we simply had the base circle ground down about .040" and surface hardened.  Nothing fancy....just our best guess, which worked out OK.  Now you can probably get a WEBCAM cheaper than doing your own.

We often ran Mikuni 28mm carbs, with the slide cutaway hand ground to lean out the part throttle enough to "get by".  28s were easy to come by, as the Yamaha guys were putting on GYT kits and throwing the original carbs away.  We also ran the original points ignition with the spark  advance welded full up, to prevent the rattling and bouncing at very high RPM.  Ditch the flywheel and run constant loss battery.

We had good luck with Powerolls exhaust tuning (which was pretty similar to the pipes you see on old CR77 kitted Super Hawks.)  I've made my own megs by gore cutting thin wall tubing, then using lots of hose clamps to close the taper before spot welding between the clamps.  You'll find good length info on the internet.

Maybe some pretty cheap fun!

Offline Dr Goggles

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Re: Help the new guy build a LSR Honda CB550f!
« Reply #27 on: May 18, 2011, 02:54:52 AM »
Pretty much nailed it there for you KCK.

What a great board this is....
Few understand what I'm trying to do but they vastly outnumber those who understand why...................

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Offline wobblywalrus

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Re: Help the new guy build a LSR Honda CB550f!
« Reply #28 on: May 19, 2011, 02:09:25 AM »
Trevor, it was experience with those old Hondas that taught me to pay attention to valve spring tension.  A strong spring will make the rocker follow the cam and the valve will close gently.  The rocker will not follow the cam if the spring is weak and the valve will slam shut.  Eventually something will break.  Excessive heat will partially anneal a spring and make it weak.  I carefully checked the springs during every tear down.  I still do on all engines I take apart.

Our shop bought big barrels of 20-50 Castrol GTX mineral oil.  It went into all of the Hondas.  We did not have any oil related troubles with the street and dirt bikes, with two exceptions.  A couple of fellows ran the Honda 350 fours as production road racers.  There were a lot of problems with the top ends.  Cams, rockers, and cam bearings as I remember.  The problems went away when we tried synthetic oil.  An expert with engines and oils helped us figure this out.  One thing he mentioned was to use a thinner oil.  He said the engines would run cooler.  His reasoning was that there is less heat producing internal shear in the oil as it is moves about and there is greater oil flow to carry heat away from critical parts.  We switched from 20-50 to 10-40 or 20-40.  This was a long time ago and I do not remember exactly.  This is something I do to this day.  I avoid excessively thick oils.

Synthetics are not all equivalent, I learned the expensive way.  The oil in a Honda needs to have an additive package for the transmission gears and minerals to keep the cams in good shape such as zinc and phosphorous.  A lot of car synthetics do not have these additives.  An oil made for motorcycles with integral transmissions is best.  Those Hondas worked well after we figured out their quirks. 

Offline kerncountykid

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Re: Help the new guy build a LSR Honda CB550f!
« Reply #29 on: June 04, 2011, 09:54:31 PM »
Didn't wan't anyone to think I fell off the map. I have a blog....

kerncountykid.blogspot.com

... that covers about the first year with my travel bike Dee Dee. There was another whole cross country trip and thousands of miles through the south. That bike was stolen a couple weeks ago and it has grinded the bonnie bike to a halt. No racing on the salt with my grandpa this year, no cross country trip. Can't even get around as I don't have a car during the day. I'll come back to this in a couple months when I find a replacement (not that that is really possible) and begin duplicating all the custom travel items I had on Deed's. Thanks for all the help so far.