Landracing Forum
Bonneville Salt Flats Discussion => Build Diaries => Topic started by: JimL on May 22, 2011, 11:21:11 PM
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Last years bike reworked to run against my 144.360 MPH record
- Engine moved forward 9" to get more weight on front wheel (last year bike lost steering at any speed over about 150 MPH)
- Engine tilted forward to uncover primary drive and trans gears (last year gears were submerged, high drag)
- 6 gallon water tank added ahead of engine, with single radiator behind engine. More weight on front wheel and better cooling.
- Reversed water flow in cooling system (engine, to radiator, to tank, to pump, to heads)
- Larger Mikuni Pro Series TM carbs. These are machined by Mikuni for much higher flow than last years carbs.
- 3/8" removed from mid-step header length to help power above 10,500 RPM
- Higher final drive gears (has 2.22:1 versus 2.33:1 last year). I have more available if it will pull, last year ran 10,500 RPM at 3/4 throttle.
- Bike lowered 2" and rear suspension has new down stop.
- Tailpiece narrowed and flushed for better aero.
- Fairing will be 2" narrower around engine (narrower overall width).
More pics when it gets closer.
Regards, JimL
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It is nice to see that you are still building bikes. Good luck. That machine sure looks complicated.
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Thanks....it doesn't look so bad if I turn off half the lights in the shop and kinda "squint". I've learned you can tell when you're about done....you run out of space for more stuff! Here's a pic of the other side.
JimL
ps ---you can seen how far I moved the engine....that empty tab next to the tach drive/cable is where the forward upper bolt was located last year (nut with an exhaust tab located at it).
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Hey Jim
i got the fuel tank bottom made for yer buddy.... Do you wanna pick it up for fitment and outlet bung location?
kent
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Will do....also will have your axe ready. Will try E-flat tuning (down 1/2 is easier on the fingers).
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Jim,
Is that basically a modified CX-650 motor? You know it's hard for us old timers to use the word "Honda" and "Pushrod" in the same sentence! Makes my poor old BSA look like an antique (or I guess maybe it is an antique.) Then there's Tom Mellor's Triumph Triple antique........ Will you be at BUB as well? I won't be able to make it to SCTA.
Tom
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Yes, it is a CX650 (674cc) bored to 680cc. I also have a pair of destroke crankshafts about finished that will build 648cc engines using my same parts. Shouldn't be any noticeable difference in power.
I'll only run Speedweek...many folks on the car side I like to visit.
Regards, JimL
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Hey Jim
So you are sticking with the single engine
And you have sorted out the fairing
G
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Been loaded up for awhile....decided to put together the destroked engine for 648cc, in case I can raise my record or the 680cc engine breaks :-P. The destroke engine uses similar pistons with the pin moved down 1.5mm (3mm destroke). This was a difficult process because of a mixup on the cranks, and one is unuseable due to cracking. The engine swap will require using the left case from the 680cc engine, which has my chain drive conversion. I'll also have to swap the clutch, because I only have one Barnett package.
I don't expect the 648cc engine to run much slower....only 30cc difference from what I ran last year.
Pic shows the front fairing rework and how far I've lowered the bike (suspension stops are on the forks). See you there, JimL
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Looks great Jim!
I always enjoy following your builds. :cheers:
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Jim,
Is it legal to be ready this early!? I am thrashing on an air scoop for Steve Nelson's V4/FL lakester and he is thrashing to get the motor together and hopefully we will get it in the car early this week so I can fit the scoop. Aug 12 keeps getting closer and the "to-do" list gets longer. One of the thing you learn quickly is that they will start the races even if you are not there!!!
Great looking job on the faring looking forward to seeing you in a few weeks.
Rex
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I am just catching up to the fresh work on the bike.... looks great.
good luck!
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Rex....kinda don't have a choice this year. My retirement hits right on Bonneville so some things had to be ready ahead of time. This might be (knock on wood) the first time in my life that I get to arrive early....instead of day(s) late. The only year I remember getting a Saturday run was 1969.... not a very good batting average since! Of course, come to think of it, I was unemployed at the time, having just returned from Nam and had not started looking for work.
Strange loop, how this life stuff goes around in a big circle. Anyway...I keep going to the shop and firing it up to be sure it still sounds good. I'll probably have dead batteries by the time I get there :-P.
JimL
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Jim,
Congratulations on retiring!!! I retired last year and can tell you it is great. Now you can spend all of your time in the shop!!
Rex
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Jim,
Congratulations on retiring!!! I retired last year and can tell you it is great. Now you can spend all of your time in the shop!!
Rex
Rex,
"all of your time"? Have you no "Honey do" list?
Seriously, I too am enjoying my retirement. Sometimes I wonder how I ever found time to go to work.
Jim,
Could you please bring a spare set of bodywork for me to try? I guess that will be next years project.
Tom
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I would love to retire but the damn job keeps the cash rolling in. The available time to work on the machines would be welcome but the projects need to be funded.
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Nice to see you back jim looking good!
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Just a quick note to thank all the folks who stopped to chat in impound. We had some good luck, despite wind and weather, and got to spend every day (from Saturday) in impound. It's a lucky event when you don't need to set up a pit.
Results were a 154+ APS-PG-750 record for me, a 158+ APS-PF-750 record for my son, Marc, and a 133+ MPS-PG-650 record for my friend Dan Wagner. Marc did a great ride, despite leaning the bike into the wind....all the way down to a bent exhaust pipe and ground heat wrap. Dan pulled the record up with one of my de-stroked "680-to-650" engines (my 750 engines are a little small). His engine is 647cc and made the record with 4 bent intake valves and a cracked head (on the first pass....yes...my fault).
Perhaps next year some much stronger 650 class engines, for both bikes, and then a full 748cc from my current 680. As we used to say in Colorado, "God willing and the creek don't rise."
Also a big thanks for all the great SCTA folks, especially the MC tech/impound staff. Everyday, non-stop, always patient and fair.
Thank you, gentlemen!
Have a great build year, everyone, and hope to meet you again. JimL
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Congratulations future neighbor, it was good to chat with you in impound.
Don
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Thanks, Don....also good to finally meet you and see your project. We'll be in touch shortly.
JimL
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We were down the row from you a few spots on Sunday in impound and I meant to come and say hello but we got busy tearing down the motor, congratulations on a very succesful week at Bonneville, 1 record is great, I can't imagine what 3 would be like. :cheers:
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Thanks! You did well, also. It is pretty amazing how the time completely fills up in impound. :?
We'll cross paths again, I'm sure.
Regards, JimL
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Jim, I talked with you for quite a while in impound. I was very impressed with your build. Made me think about yanking the motor out of my drug from the bushes CX 500 and turning it sideways. Thanks for all the tips you gave and the wonderful impression you left on me. Congratulations on such a great speed on a pushrod bike. Hope to see you next year.
David
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Good to visit with you, too!
A follow-on to the orange bike and Dan Wagner's 650 class bike.... I opened the engines to see where the horsepower had slipped away and found intake valve contact on all the engines (valve reliefs are out of position about .040"). The leaking valves explain where the high RPM power was failing us, this year. I was kinda' puzzled why this thing couldn't get past 160.....like they say, "there's always a reason for everything". :oops:
My goof (not double checking the valve fit) ruined one head, so that is already out (with another casting) to get sorted. One intake valve hit hard and square enough to crack both sides of the valve guide boss, into the water jacket. That cylinder was swallowing water on both runs.
Off to get new pistons started, tomorrow. We also learned we're too low on compression ratio, so that will be going up (on both the 680cc engine and the 647cc engine). Maybe next year we can go a little faster....the closer I get, the more I find out I don't know!
Now all I have to figure out is why the bike goes fastest (by 8-9 mph) in a headwind, compared to sidewind or almost no wind. I must have something goofy with the aero, but right now it makes no sense.
regards, JimL
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Jim -- can you post some pictures of the fairing? It has a nice look to it.
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It is the AirTech Charlies Toy package (fairing, tail piece, and front fender). The tailpiece is modified with a piece of Kent's Electric bike tail, turned upside down and bolted in. If you look in old postings for 1350cc Pushrod Bike, you'll find the build diary when this bike started out as a twin engine (that failed during initial run). There are many pics throughout that diary. Maybe this will get you there:
http://www.landracing.com/forum/index.php/topic,7416.0.html
This sure has been a lot of fun.
Regards, JimL
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that is one of Kents ... nice stuff ... thanks for the link.
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Way to go Jim good on ya!!
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Thanks, OZ,.....pulled down the orange bike today....got some wear showing in a few places. I guess it's turning into a high mileage vehicle! :wink:
I did find another broken head.....these castings are a little thin and were certainly never meant to make this much pressure. I'm hoping to find some more junkers, over the winter. First find a place to live, second find bikes to tear apart!
Simple plan, don't you think? As daddy always said, "Time flies when you're confused!"
JimL
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If you have trouble finding parts drop me a line thet were very popular over here as dispatch bikes hence there are loads in the breakers for peanuts.
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Thanks Oz....other life stuff to work out, right now. We got good news on one head....the lines in the ports were scribes from the porting measurement, not cracks. The water in that cylinder/head was the combination of head jacket water (trapped behind part of the head gasket) and salt....this fuzzed up the chamber and made it look like the engine had ingested water. A pressure check of the head found it OK. The water happened when I pulled the head in impound....and we don't have any coolant, so the water/salt react very fast. Live and learn, I guess.
Addendum to the orange bike story....I always find a way to embarass myself, and this year is no exception. You see, after my first pass we were impound at a little over 150...obviously undergeared with 40 teeth on the rear sprocket. We pulled the rear wheel, got the 38T out of my stack of sprockets, ran the next morning at 159.6 and figured "that's all there is".
Yesterday, back at the shop and unloading stuff...I find a new, unused, never had a bolt on it, 38T sprocket?! Wait a minute....I only have one...went to look at the bike and sure enough, I'd put a 36T on it (good for 174-180 with a lot more engine!). That's why the bike quit accelerating in 5th gear and never ran where it should have.
Wow....blew all those runs for a dumb mistake. :oops:
Regards, JimL