Frustrated, discouraged and don't know what to do

[jhyder408]

I just did an engine install of a brand new GM crate for a friend. Got it all in, broke in the cam, got it some what tuned for a brand new motor, came back from a test drive and heard a bad knock. I had a hard time believing it might be a flex plate or loose torque converter but I jack it up anyways and re torqued the torque converter anyways and the knocking went away. Its worth double checking with a wrench not just your eyes or thinking it is tight. Good luck

[piecesparts]

Originally Posted by derotoreut

Well I want to thank everyone for their input and ideas into this noise problem. I finally solved the mystery of the engine noise. Well here goes...

As it turned out it wasn't any problem with the engine. Actually, Laston03 was pretty close with the solution. Because the noise was evident when it was brake-torqued, a friend laid down along side of the truck, looking underneath while I brake-torqued it (crazy huh?). What he found was sparks coming from the flex plate. As it turns out, when the truck was under load, the flex plate would flex enough that it hit the pinion gear on the starter. I would have never thought this would happen because I looked at this before. I have a Power Master high torque mini starter that was shimmed to manufacturers specs. Even though it was installed as suggested it still rubbed under load. Last night I removed the starter and looked at the gear. I found evidence of contact on the starter gear, but never could see any on the flex plate. The starter gear was worn slightly on the gear face. So I re-shimmed the starter back some more and what do you know? Problem solved.

Through all of this United Racing Engines (URE) has been excellent. When I originally heard this noise, they took this engine back and totally rebuilt it. They also upgraded the crankshaft and pistons and re-dynoed it for free. They covered all of the costs. Even when it was returned to me and I had the same noise (Duh!) they were there to support me. I feel foolish and embarrassed to even tell them what it was.

Well again I want to thank everyone that contributed to this solution. This site is awesome.

A common problem with the factory flex plates is that when the tranny is under load the torque converter balloons out. That will push the plate forward from the tranny. If you use a heavier duty flex plate that is sold by many suppliers that is rated for drag racing, that will solve that problem

[nos81z28]

I would make sure you used the correct torque convertor bolts.

[rcrahn]

Glad that you tracked down the problem. Your persistence paid off.

[derotoreut]

Originally Posted by piecesparts

A common problem with the factory flex plates is that when the tranny is under load the torque converter balloons out. That will push the plate forward from the tranny. If you use a heavier duty flex plate that is sold by many suppliers that is rated for drag racing, that will solve that problem

United Racing Engines used a brand new SFI Precision flex plate rated for racing. When I installed the engine I used ARP torque converter bolts. I wouldn't think the flex plate would move that much to hit the starter gear, but I guess it did.

[bollybib]

Just read thru this thread. Great info on tracking down noises. Glad you solved your problem derotoreut.

[CG]

Well I think we all know now a good place to have an engine built. Sounds like a very good upstanding place. I think you should post their website for a little free advertising for them.

Of course maybe you did it earlier ... I didnt read every post =)

[camarodude87]

glad you figured out your problem.