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HybridZ

350 with NO torque!


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What would cause a 350 to lose most of it's torque? bad rings, head gaskets, carb? All I can say is that this 350 is mated with a t56 and 3:9 rear end -- I should be able to waste the rubber in first if I floor it with the gearing, but I don't even get so much as a chirp. Even if I pop the clutch at 4000 rpm I'll get a half-second chirp. If this was a completely stock 350 under the hood I'd be able to lay down some mad marks :cry:

 

What are some possible causes of this? I'm going to do a compression test soon, when I have some time, and whatever else you suggest. It really stinks when you have a car that's 50 times slower than it sounds. Thanks in advance for any help.

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Are your throttle plates opening fully?

 

Not enough compression for the cam?

 

Timing is a more likely culprit, hopefully ignition, possibly cam. Is your mechanical advance working right?

First I'd verify TDC to be certain the damper ring hasn't slipped, then I'd check for full advance with a degree tape on the vibration damper (or use a protractor to mark the damper).

 

Smoke should be available at 4000 RPM.

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Guest Nic-Rebel450CA

I say timing or a slipping clutch. Do the RPMs climb even though the car doesnt move?

 

I agree that timing is probably the most likely cause. Power can disappear drastically if the timing is off.

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A good old fart hit an easy one with his first idea. I've seen many engine swaps where the guy hooks up the linkage from under the hood and hand operates it and stops there. Get some one to mash the gas from inside with the pedal. Look inside the carb and check to see if the plates are fully open. Just because you can open them from under the hood dosn't mean the complete linkage is working. Sorry, I meant A. G. Olphart. :oops: ( Warning: do not do this with engine running! Mike kZ )

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hope you get that one settled out, if the clutch isnt slipping, i would look and see about the throttle plates and the linkage, and possibly the timing.

 

I remember my old v8z, one thing it could do that my turbo car has trouble with was burning rubber, oh lord was it awesome.

A nice high rev shot and a sidestep, and it was sideways with billows and billows and smoke from both tires, as long as I could hold the gas down, the smoke would keep pouring, after a few seconds, I couldnt even see behind me, man it was great!!!!! with the turbo car, i do the same thing and get some rubber, then the car just hooks :cry:

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go through your standard check list,

 

check that theres spark at all the plugs and the plugs are burning cleanly

 

check that your getting the correct voltage at the coil/ignition and plugs are not loose and gapped correctly,

 

check that the wires and coil are not arcing or shorting out

 

check that the throttle linkage opens fully

 

look for coolent on the plugs or coolent leaks under the car

 

look for loose vacume hoses, crimped lines, ETC,

 

check your oil level is correct

 

do a compression test if anything looks bad on the plugs or engines seems to not be running on all 8 cylinders

 

look for rocker arms that are not moveing correctly,bent push rods, loose rocker arm studs, broken valve retainers, or valve springs

 

check that your getting good oil pressure at idle(pressure switch can turn off ignition)

 

check that cam and ignition timeing is ok/not changed (timeing light,

 

loose timeing chain on cam drive, check that the distributor has not moved, check with a timing light)check that the rotors not loose under the distrib. cap and the distrib. cap itself is not loose or cracked

 

check that you have not wiped a cam lobe, broken a valve spring or valve spring damper.

 

look for loose rocker arm adjustment

 

look for vacuum leaks

 

look for loose electrical connections, fan belts or accesories that might be having a bearing or electrical failure putting excessive drag on the engine

 

look for low fuel pressure/clogged fuel filter, bad fuel, water in gas, rust in the gas or just low on fuel.

 

look for plugged up air filter/bad pvc/egr

 

check catalitic converters not plugged/restricting the exhaust flow

 

check for moisture in distributor cap.

 

check that the damper on the crank has not come loose and moved the timeing marks on the outer ring by having the elastic break loose between the rings on a stock style damper or that the key in the crank has not sheared allowing the damper to move possition

 

do a CYLINDER LEAK DOWN test

 

make sure the fuel pressure is correct and the fuel supply system is working at 6psi-8psi before the pressure regulator and about 5psi-6psi at the carb

 

http://www.centuryperformance.com/timing.htm

 

http://www.centuryperformance.com/vacuum.htm

 

http://www.boyleworks.com/ta400/psp/distcurve.html (pontiac but info the same for chevy)

 

http://www.73-87.com/garage/101s.htm

 

http://www.73-87.com/garage/hei.htm

 

firingorder.jpg

fuel2.gif

 

look for spark plug wires that are loose or not correctly connected

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Thanks everybody -- I'm relatively confident that timing is the culprit. I'll be out there with a timing light this weekend. I've checked the throttle plates -- they're opening fully when the pedal is floored. The clutch is not slipping (yet), and I will need to check my timing advance, as that is another good possibility. Thanks for the reply grumpy, I was waiting for you to send me that 500 point checklist :-D . I've checked most of those things on your list, but there are a few I can run back by again. By the way, those centuryperformance.com links didn't work for me, but the rest did.

 

One other thing I've noticed is that my passenger side is running hotter than the driver side (exhaust from passenger side is hotter than driver side) -- what's a common cause of this? One other question, my aluminum heads have seen about 245 degrees and I'm afraid that they may be warped. Does anybody know how much aluminum heads can usually take? Once again, thank you all for the help. Hybridz kicks azz!!

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