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| Joined: | 03-12-2005 |
| Location: | Cary, North Carolina USA |
| Posts: | 339 |
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First session out we made it about 3/4 the way around Roebling Road and had a fire! The header wrap, which was soaked in oil form engine run in, finally got enough temperature in it to light the oil off. So, into pit road we go, trailing black smoke and flame, to get it extinguished. Driver was shaken but little damage done. We spent the next couple of hours getting the wrap off and washing off all the fire retardant in the engine compartment.
Second session we got a few laps in but the water temperature wouldn't stay down. It'd get up to about 210 or so, oil temperature the same, and I'd bring it in and shut her down. But, the laps I got in were good! Car cornered flat on 650lb springs and turns in sharply with low steering effort despite the 225-45-13 Hoosier race meats. Welded rear and panhard rod were planted solid as a rock, scary planted actually. I think this car will acheive some high corner speeds if she'll hold together. In short I liked it!
The third session was missed but we did get out the fourth session to collect more data. The engine Judson built pulls very smoothly and strongly and I was able to get in a couple of 80% laps running the car to 6500-7000 RPM. I've only driven one other JH, one with some sort of Paco stage two motor with Delortos, and this Stromberg carbed motor I have will walk all over that thing, no doubt about that. Torque was surprisingly pretty good throughout the rev range and top end power decent. I had it on the straight at 6000 RPM in 5th and it still pulled pretty good when the hammer was dropped, and at that point we're doing like 110-115mph or so.
The engine needs more sorting - carbs out of sync, timing is conservative at 10 BTDC, and we've not optimized cam timing, porting, etc. - this is just a first effort to get the little guy on track. But I am happy, Judson's motor is holding up well and I think will do the job! The engine has 75 psi of oil pressure at idle WHEN COLD, but once temps get up around 210 F we only get around 30-40psi at 3000 RPM and I don't like that. The oil pressure stays high when the temps are around 160-180F, but above that they drop off and drop hard. We also have some flicker on the gauge in long sweepers so we need some oil protection. I don't think we did any engine damage because I didn't hear anything bad and the lowest I ever saw, when bringing it back in hot at idle, was 15-20psi and that is about par for a 907 engine.
What we learned we need to fix is the following:
*More radiator - I've ordered a big aluminum radiator for a Ford and will make it fit for more cooling. That means I'll have a super nice 4 core brass stock one (converted to four core) for sale if anyone wants to upgrade their cooling system. It'd work great for a street car, but not for a race car that will spend 30 minutes at 5000-7000 RPM.
*More oil cooler - I tried the stock cooler but it isn't enough for race duty. If I can keep the oil cooler and maintain good pressure I'll be a lot happier driving the snot out of the car.
*Plumb Accusump for some oil safety in the turns.
All in all I am pleased. She weighed in at 2290 lbs with a 195lb driver (not me), so with me it'll be about 2260lbs with half tank of gas, just about where we want it since spec weight is 2240lbs. I plan to knock these issues out and have it back on track at VIR in two weeks! Here are some pictures:
Last edited on 04-26-2006 02:24 am by Ron Earp