OK, this is the first time I have asked for help on the forum, but boy am I frustrated. The situation: 94 Vert with 40k on the engine and 75k on the car and transmission; the car/engine is a DRM 383 stroker that I purchased from the original owner about five years ago; I have put about 30k miles on the engine along with about 200 passes at the drag strip and the last 20 with 125 shot of nitrous (11.36 best time); it has aalways had vibration at about 5k; changed the clutch and flywheel about 700 miles ago (one year back); put dual mass flywheel in with a dual friction Centerforce clutch; put Redline in the transmission (I know...wrong fluid); ever since the new clutch I have had vibration at 3400 rpm; I talked with Doug Rippie last week and he said they balanced the rotating assembly so that a new flywheel could be used when needed but it would be neutral balanced - I assume this means it does not have to be balanced on the crankshaft and can be balanced independently of the crankshaft - right? (he also offered to pull it apart and take a look, at minimal cost, even though I am not his original customer, but it's too costly to ship it up North from here in BG); when we changed the clutch we put the same weights in the same position as the old flywheel - again now we have the vibration at 3k; another person who used a CF clutch said he had the vibration problem for about three thousand miles but it stopped and he thought it was due to the slidding weights on the CF; I have had enough. So now I have noticed some noise at the front of the ZF, and am sending it to ZFdoc in AZ. The question: I am attempting to get the flywheel neutrally balanced. I have fears that a) it can't be balanced and b) it still won't solve the vibration problem after having spent about $4,000 on transmission blueprinting (which is a good investment anyway for the drag strip) and fooling with the flywheel. If the crank is out of balance I'd have destroyed the bearings in the engine my now, I should think. Any thoughts would be extremely helpful.

 

It may be a long shot, but check your harmonic balancer. It could have slipped a bit and threw everything out of balance.

 

Thanks for the reply, but I forgot to mention that I have replaced that too.

 

So, this motor has always had a bad vibration at 5400 and after the clutch/flywheel the vibration is now at 3400? To me, it sounds like the engine was never properly balanced.....just a thought. After some abuse and 40k miles I would have to agree that the bearings, or even worse, the mains are damaged.

 

Your 383ci stroker got a internal balanced aseembly. Your after market flywheel, you have to remove the counter weight it will become zero balance. Your vibrition problem is sovled. Unless you have other problem.

This has happened to me in the pass.


Bruce
383LT1 Supercharged