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Discussion Starter · #1 ·
Last years bike reworked to run against my 144.360 MPH record (APS-PG-750 class = modified frame, partial streamlined, pushrod, gas, 750cc).



- 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.

- 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).

- Additional aero work will be done under/around rear wheel

- Front fender will be reinforced and side-vented to prevent front wheel washout I experienced last year.



More pics when it gets closer.

Regards, JimL
 

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Discussion Starter · #2 ·
....one more thing you might notice in the left side view: Water flow is now reversed (Dedenbear Chevy Sprint Car electric pump now pulls from the tank and pumps into the heads, down through engine, and out of water pump housing, to top of radiator.



JimL
 

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As always Jim you are making the CX/GL world very proud! I'm sure this year will be a great success with all the improvements over last years two motor design that left you scurrying to get to speed weeks. Keep us updated on the ultimate success of your runs. I have no doubt you'll break your own record. Good luck Jim!
 

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I always get excited when this time of year comes, Jim. You are keeping this legacy alive in a new form for us. Good luck and godspeed.



Joel in the Couve
 

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What, just one engine this year -- where's the challenge in that?




Good luck, and keep us posted!
 

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Jim,

Congratulations, I think you may very well break the "real" pushrod 750 partial streamlined record this year. Its difficult to know exactly when the record was last held by a pushrod powered motorcycle, but in the Bonneville 1973 Records and Rule Book, there is a Triumph listed in class MPS-AG at 145.650. I am sure overhead cam and two stroke motorcycles took that record sometime in the seventies. It is too bad those old records set by pushrod engines were never reinstated. When it was decided to include pushrod engine classes in 1990 (to offer the Harley guys some means of setting "world records"), there was no way for us to determine when each record was last held by a motorcycle using a pushrod engine - the records of engine type were not kept, and records of engine make were not even always available. Looks like a fun and successfull project. Keep us posted...
 

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Discussion Starter · #11 ·
Actually, T. Mellor has a 750cc pushrod Triumph Triple that ran 180-190 at the BUB event. His aero is really beautiful. Not sure I'll ever get there with this undersize engine in a heavier, bigger bike. If it stays together, I'll see what it'll do.
 

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Actually, T. Mellor has a 750cc pushrod Triumph Triple that ran 180-190 at the BUB event. His aero is really beautiful. Not sure I'll ever get there with this undersize engine in a heavier, bigger bike. If it stays together, I'll see what it'll do.


That is very impressive on gas from 45 cu in. I wonder how fast the Big D triple went in its heyday on gas...
 

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That is very impressive on gas from 45 cu in. I wonder how fast the Big D triple went in its heyday on gas...
I roadraced with Jon Minono in those days when he rode the Big D bikes. I don't remember any 750's being that fast and I don't remember them ever racing a 750 on gas on the salt. Even back 20 years ago I think they all had turbos, but they were very fast.



Tom Mellor's bike is really impressive for its speed and streamlining. I think Jim mentioned that Tom's speed came on the long course. I think he ran about 159 unstreamlined and 180 with the fairing. That is smoking fast for a pushrod 750! When you look a the new GSXR-750 and see that it "only" runs 168mph with 127hp probably at sea level (June 2011 Cycle World), then it makes Tom and Jim's performance at altitude, with about 82 horsepower really impressive.
 

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any updates Jim?
 

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Discussion Starter · #16 ·
Yes....hope to take some pics this weekend. I was going to do that last Sunday...up until about 1:40PM. That's when I reached down and picked up a piece of sheet metal work I'd been grinding on. It appears our brain gets "stupid" after we eat lunch. My thumb is still bandaged, and there will be quite a bit of burn blister to heal through. Here's a link address to my "bandaged thumb"....on-stage later that night, not playing or singing very well!! http://vimeo.com/24732823




The bike fired up perfectly on the new carbs, and sounds completely healthy. I'm fitting up all the "inspection" bits; countershaft chain guard, improved kill tether, etc. It looks like I need to go another inch lower in back, and about 2 inches lower in front. I'm thinking I'll start off without the front fender....it really spooked me, last year, when the front end blew away at speed. I need to go straight before fast.



thank you, everyone, for the interest and kind words. I hope it stays fun for all of us!



JimL



ps ---earlier in the morning, I learned that the smell of wood smoke should NOT be ignored just because it seems to be coming from your bike. Fortunately, the small fire, on the table...under the bike....started by a little "tack welding", went out by itself. Isn't working on motorcycles a great adventure??!!
 

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Jim,

Good luck on the improvements. I'm sure you'll get it tuned in this year to blast the records again. It just sucks that it takes a year to do the fine tuning runs.



Feel lucky it was only wood smoldering. Years ago I cut some metal over my 55 gallon trash barrel with a cutting torch. I had forgotten I had a large pile of magnesium shavings from lathe work in there. Needless to say it was a spectacular fire that I had to drag outside while it burned out. S*#! happens as they say!




Looking forward to the pictures. But when speed weeks is over I would like to talk to you about the cams and heads for a super street motor I plan to build for a full on hand built cafe racer if you don't mind.



Larry
 

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Discussion Starter · #18 ·
Found a way to reinforce the front fender internally, and also made a full length panel for the exhaust side of the fairing lower. Took a pic of the new tach location (lots of fiberglass dust to blow off). Also making a panel to close the front of the fairing a little better. This panel will fit pretty close to flush....still needs a little shaping for fender clearance, but I put a limiter on the fork travel today (about 1" total travel, front and rear).
 

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Looking good Jim. I'm surprised the stock tach is enough for the motor. What is the top end rpm range that you end up running?
 
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