1985foxbodyLX

Hey guys, I have something to pick your brain. I built a 1985 5.0 motor with twisted wedge heads, trick flows stage 2 cam, stock pistons, cam, and a reman crank. So i broke in the motor with out a problem, but at idle the motor moves around a little more than usual for a street, and strip motor. Around 2500+ rpm my whole shifter vibrates really bad. I put in new motor mounts, trans mounts, 2 balancers .50 imb., no miss fire going on, and my question is before i put in anothing new flywheel what are the chances of the crank being bad or the wrong imbalance? I forgot to mention it does it while driving, stand still, clutch in or out.

JIM5.0

Welcome to the board!

1985foxbodyLX

thank you

.boB

Sure, the crank could be the wrong one. Wouldn't be the first time somebody got the wrong part. Impossible to tell with it installed, though.

Use an infrared thermometer and see what the exhaust temps are from each cylinder. Some variabilty is pretty normal, but it shouldn't be huge. If one cylinder is significantly differant, that's where your problem is coming from.

Also, check your vacuum. If it's unusually low or jumps around, then you'll need to find out why.

When you assembled the engine, did you check P/V clearance at every cylinder? TW heads often don't mix with stock pistons, especially with added lift.

stdyhand

Was the rotating assembly balanced in this build? Just wondering if maybe thats where the excess vibration is coming from. I would check compression on all cylinders, spark, and make sure your getting fuel to each one, if it's FI.

Jabtyson34

Could possibly be fan wash if you run an open conical style filter.

TrimDrip

eh, you could try sticking a different balnacer and flywheel on it and see what happens. If it is the old type balancer, it can be modified to work. No ****, I have seen it done by someone smarter than me. Anyways, I can't see any reason why the trasmission would need to be in there as long bellhousing and starter is mounted if you want to give it a shot.