i toke a 301 chevy out of 1 car an put it in a new car. before it woud turn 8500 to 9000 rpm ez. no changes where made to it except went from a std to pg. noe it will not turn more than 6000rpm in nutral. for 1 year i have been looking for the problem. i have changed dist, wires, plugs, intake carbs, valve springs, and rewired the car. i have been building cars for 40 years an this has me beat. thank you for any help u can give. o an there r no computers in this thing
It obviously wants a 4 speed behind it. if the transmission is the only thing you changed, that is likely where the problem is.
How was the exhaust in before car as compared to now car. Could be backed up by to small of a system.
Yeah that was what I was thinking too. Spinning an engine that high with no load is asking for a whole lot of trouble...
You don't give much detail on the equipment. If the powerglide is anywhere near stock maybe it is better that it doesn't turn that fast. Cast iron PG???? Later aluminum PG??? Built for racing??? An automatic is still pumping oil even in neutral is it not??
RPMs are not everything. A lot depends where his power and torque curves are. Once you get up past the peaks of those curves it doesn't take much to knock the rpms down. The engine will rev higher but you don't gain anything, the torque & hp drop.
the exhaust is the same, the pg is built for racing but no trans break, the converter is 3800 stall. the care is the one in my avatar. on the track ,under load it will only go 4000rpm. in nueral , 6000. before changing cars it would do 9000 ez
Squirrel probably nailed it, he usually does. The only other thing is the fuel system. Is that identical to what it was before?? Same pump??? Same size lines?? Plugged or crimped lines?? Junk in the tank?? Anything that might not allow enough gas flow??
You ought to take that 9000 RPM Chevy out of the car and put in a display case. I seriously doubt the 9000 RPM claim.
seriously? 9k on a sbc is not the big deal it once was... Hell there are a bunch of them around. Just because they don't have them in hillbilly country is no reason to be a **** to the dude... and just so you can see what one looks like...
I think the tach was hooked on the 6 cyl side before. I know this will start a firestorm but 9000 rpm??
Maybe somebody else will remember better than I, but, I think in the late '50's Isky had a kit for chevys and would guarantee 10,000 RPM.
Sprag in the converter? What does it flash to? How're you launching - stab at idle? reset your tach after a p*** and on the return road stop and whack it and then get off, the tach recall will show the flash rpm. How does the car push around the pit - can you do it yourself? What 60' do you get? Is is reverse manual valve body? Is there a brake in it but just not connected? What size valve spring? i know you said you replaced them, but i gotta ask that and cam lift. You get to 6k and then what? shift? how does it pull when it gets to high gear? Have you tried another converter? That would be my guess, a bad sprag esp if it pulls in high.
RPMing sbc's? I've sidestepped the clutch a 11K and that is no ********. One of my comp motors, i was match racing a guy and was pissed at the car and let it eat. The tach said 11K and i saw pics of it and there was only one slick left on the ground at the launch, the other three tires were in the air. I still have that motor if anybody wants to buy it - solid 850hp, 406".
Well....im the driver and I know for a fact the motor will do 9k. I lauched at 6500 and ran thru the traps withe the old car at around 8200 at 118mph. This new car acts like its got a rev limiter on it. Wont go over 4500 at the track. We put all new bigger fuel lines and system in it. We are at a lose. By the way .....Sam Cunningham laughed his '61 corvette with a 301at 9k setting a world record back in the 60s . He's in the NHRA hall of fame.
seriously? didn't NASCAR just limit RPM to 9500 in the last few years? I know about 5 or 6 years ago if it wasn't for the gear rule they would have been turning 11k instead of 10k. It's not rocket science, there are plenty of them out there.
Still thinking - sorry about the rpm sidetrack - you didn't replace the timing chain when you pulled the motor from the old car, sounds like retarded valve timing too. How about a compression test? All the holes 160ish? If the valve timing was retarded you wouldn't get decent compression. Or if you did a leakdown the exhaust valve would open way soon. Just trying to rule out engine health, if the engine is happy and ok, the car rolls around nice an easy, then it is ignition/transmission/torque converter. Have you tried another box? Do you have retard functions? are they grounded? not with just a zero chip either; when at rpm does the motor miss? msd distr? the purple wire on the pigtail should not go to the purple wire of the cable, if so polarity is backwards and at highish rpm it'll get stupid and miss. Thats it, i'm out of ideas, hope i did some good oj
Thanks oj. U given us some more things to look at. The old car had a 3speed stick in it and the motor ran great. We put a full race power glide and up graded some parts with new and now it run like ****. It s like it just hits a wall at 4500 on the track and 6000 in nuetral while trying to tune. Almost like a rev limiter.
Any of those things could be causing problems. Did you change everything at once? do you still have the old parts?
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