Topic: Bonneville

[Don R]

 I saw a pic on Instagram of a cb750 sohc at Bonneville today, does anyone know details?

[Don R]

https://www.instagram.com/p/CSQ_asAHcer/

[Old Scrambler]

1220cc with a bottle................went 148 and then slowed on 2nd run.................Old Bike Barn is rider.........I am now trying to help, but its difficult with a fat rear tire.........

[samm_j2]

Why is there difficulty with a fat rear tire? How wide is it??

[johno]

wish it was in my shed 

[Don R]

 Well, that's living the dream. I hope they get it going.

[Jerry Rxman Griffin aka MuthaF'er]

Is that the one that Kenny was playing with?

[Old Scrambler]

Fat tire woes..........less than 1-inch width is touching the earth..........no corners on the salt ......no need for brakes except in the pits .....the excess tire width graps air and creates side-wind vortexes that have the speed effect of riding with a 2x6 across your rear >: ......and some of that air is compressed against the salt surface which creates lift ...........to which some of the riders complain about losing traction and so they add lead-ballast..........that's what I see and try to avoid.

No runs for the 1220 bike as numerous other glitches were solved and a lot of down-time on the salt due to a fatal crash, a car fire, and then a spectacular endo-crash with moderate driver injuries...........tomorrow begins racing at 8-AM

[desertrefugee]

148 and no fork brace...?   

[samm_j2]

Old scrambler, thanks for sharing. That makes total sense.

[Stev-o]

My buddy is on the salt, waiting on an update from him.

[Don R]

 That's my dream.
  I changed the efi on the dragster to run on the existing tune above 6K rpm so it doesn't continue to adjust going down track and cause a break out.  I turned it off and back on to make sure my changes were still there, then everything was at Zero. I thought I had erased the entire tune up. one more try and it is back. thank goodness.
  EFI would have to be the hot setup at Bonneville's density altitude. It can adjust on the fly.

[Old Scrambler]

1220 bike ran at 147 with mild NOX.......will run again in the AM. Effective altitude under a cloud was 6,800-ft.......at the timing tower and in the sun it read 7,800-ft........so EFI may help on a slow bike ...........88-year old rider on an old Indian went down at low-speed as he exited the course.........no reported serious injury.

The salt is excellent............BMST begins in 19 days and I'm almost ready

[dragracer]

Is that the one that Kenny was playing with?

No Jerry, that bike was built by an acquaintance of mine. Tim Papinchak.  It was originally built for either hill climb or dirt drags. He did make a few dragstrip passes and then parked. Put it up for sale afterwards. Its got a big valve, straight spirit head with Lectron carbs, stroker crank.

[Stev-o]

My buddy is on the salt, waiting on an update from him.

Heard from him last night, the car ran 135, the record for their class is 140mph.  It's a 300ci flat head Ford in a custom chassis putting out 300hp.  They changed the axle ratio and hope to set the record today.



The car was built by Rex Rod, Duncan is part of the crew, and it was painted by Martin Bros [Iron Resurrection]

[Don R]

 I checked on running our dragster on the mile. The cost of tires, wheels, gears and safety equipment changed my mind. We run a 12 bolt in it so the gear change becomes a thing too. The 4% torque converter slip at 180 I could live with. It could run as a lakester but I wasn't really interested in a class record, I just wanted to go 200.

[Old Scrambler]

That car is one fine looking rig.........I have a pic or three

Don, I have talked with 2 'rent-a-ride' guys and both paid $10,000 or more to have a chance at a record.

The 1220cc bike seems to have a rev limiter at 9,500 when trying to go faster than 147...........Most of the small gremlins are cured, so tomorrow will attempt a 4th-gear run with 19-32 sprockets..........its still basically a drag bike with a dry NOX system and miss-matched parts in the head.

Nitro-methane 1000cc Vincent in a custom frame went 191-mph today..........tomorrow at 7:30 Alp gets to run to confirm the record He negotiated the sale of the bike to a museum collector during the build.

[maxheadflow]

Got a buddy, Jim Knapp, that is going to for the 4 wheel driven record on methanol.  He's still shaking out the bugs on his car.   

[Old Scrambler]

Speed Demon is in impound with a 460-something on his A-motor.........475 exit..............blew 2 motors so far

[scottly]

The 1220cc bike seems to have a rev limiter at 9,500 when trying to go faster than 147.

The great white dyno is saying the HP peak is at 9500 RPM. Hopefully the gearing change will raise the speed.

[Old Scrambler]

+1 Scottly..............Bear aka Old Bike Barn.....only changed down 2T on the rear....and then got his 150.something time slip.

Alp blew the lid from his fuel-pump while starting the bike ...........no run, but the little 'nickle-sized' lid hit a close-by on-looker and drew blood........he was standing in front of me.....so I later thanked him for taking the bullet. We were asked to NOT take pics of the blood on salt......later covered with oil-dry.

[scottly]

The 1220cc bike seems to have a rev limiter at 9,500 when trying to go faster than 147.

The great white dyno is saying the HP peak is at 9500 RPM. Hopefully the gearing change will raise the speed.

Dennis, I misspoke; the dyno is saying that the HP at 9500 is enough to push the bike through the air at 147, but the peak HP may be at a much lower RPM, especially with 1220 CC. The head, even modified, can only flow so much air, so the peak will be lower than a smaller engine with the same head. Your motor, for instance, had a peak at 9500 or so, IIRC. What was the RPM at 150?

[dragracer]

The 1220cc bike seems to have a rev limiter at 9,500 when trying to go faster than 147.

The great white dyno is saying the HP peak is at 9500 RPM. Hopefully the gearing change will raise the speed.

Dennis, I misspoke; the dyno is saying that the HP at 9500 is enough to push the bike through the air at 147, but the peak HP may be at a much lower RPM, especially with 1220 CC. The head, even modified, can only flow so much air, so the peak will be lower than a smaller engine with the same head. Your motor, for instance, had a peak at 9500 or so, IIRC. What was the RPM at 150?

This is a straight spigot, big valve head. I asked the original owner about flow numbers but he never got around to running it on a bench. I'd still imagine it can move a lot of air. He had a special cam ground just for this stroker.

[Old Scrambler]

The motor sounds very 'healthy'..............rider seems to shift too low......he said the tach was showing about 9,000 at 150 with the 19x36 sprockets..........its a naked bike so lots of turbulence and a somewhat fat tire. Flat bars keep the riders arms and shoulders in the air......but something is not allowing the bike to RUN.......at that gearing and with that size, 1220cc, it should be going that speed in 4th.  It may be that his tach is wrong because it sounds like barely 8,000 rpms when I'm standing a half-mile away. 

I'm now in Pocatello.........so no more info

[Stev-o]

That car is one fine looking rig.........I have a pic or three

I agree.   Got another update from my buddy last night:

"Damaged the motor and we are headed back to Texas. There's always next year!"

I'll see him next weekend and get all the details.

[Don R]

 Tuning for that density altitude is a challenge if you haven't seen it before. Most of us haven't.

[scottly]

The 1220cc bike seems to have a rev limiter at 9,500 when trying to go faster than 147.

The great white dyno is saying the HP peak is at 9500 RPM. Hopefully the gearing change will raise the speed.

Dennis, I misspoke; the dyno is saying that the HP at 9500 is enough to push the bike through the air at 147, but the peak HP may be at a much lower RPM, especially with 1220 CC. The head, even modified, can only flow so much air, so the peak will be lower than a smaller engine with the same head. Your motor, for instance, had a peak at 9500 or so, IIRC. What was the RPM at 150?

This is a straight spigot, big valve head. I asked the original owner about flow numbers but he never got around to running it on a bench. I'd still imagine it can move a lot of air. He had a special cam ground just for this stroker.

Frank, what do you mean by "straight spigot"?
The bike ran 147 at 9500, and 150 at 9000. The great white dyno says this engine makes more HP at 9000 RPM than at 9500 RPM, and the actual peak RPM may be even lower, given that it is a stroked motor.

[gschuld]

Straight port head.  This means the intake ports are modified to have them go from angled (needing angled boots to allow straight carb racks to work, to parallel to each other so the carb flow doesn’t take the turns you get in a stock setup.  Carbs need a wider rack spacing to compensate and use straight boots.

CycleX road race head was both straight ported and raised intake ports.

The pic below is an example of a straight port mod(RPE work in the pic I recall)

George

[Old Scrambler]

Observations regarding the 1220cc bike:

Based on the 'post' locations in the head-fins, this is NOT an F2 head or later K model. That leads me to think that the valves are not significantly oversized. Side-winder pipe is oversized vs. smaller diameter. The Lectrons are open with no air-filters, and appear to be no more than 31 or 32mm. The 'gas-tank' is a less than 2-inch square tube 'back-bone' so it may be starving at the 3-mile. May be 530 0-ring chain which takes a few horses to turn. Lots of nice looking weld around the jugs

I did not measure anything........just looking

[Don R]

 That's a pretty head, the last few horsepower are surely left on the table with the use of stock intakes and rubbers.  I've done a tiny bit of welding on cast and know what a challenge it can be.  Clean, grind, weld, grind, clean, weld, grind, etc.