Hey guys,

I thought I would throw this out here, just to see what people thought. First of all, I will be pulling my engine, and rebuilding it, but I am curious about the following:

I put a S5 BNR stage 3 in my car, S4 NA block, with the modifications done to the LIM to mate up to the 6 port. I am using a Haltech E6X to control it.

I went to the track, and made a few runs down the 1/4 mile. I was very happy with the way the car was pulling all the way to redline and beyond. I had assumed that I would have some boost creep, but that didn't seem to happen. I was hitting about 8 - 9 psi. On my few passes, the car ran 13.8 at 104 mph. I am using a DIY 2A0 wideband, and at peak boost, afr's were low to mid 11's.

I then made a run and as I was coasting at the end of the track, the car stalled. I tried starting it, and finally did, but it wasn't running quite right. Brought it home, checked compression. Front rotor was 90 - 90 - 90. Checked rear rotor and it was 60 - 60 - 60.

Now obviously I am going to pull apart the engine and see what's up, but I was curious as to what would cause low compression on all faces in the rear rotor. The only other time I have seen something similar was when I spun a bearing on my TII engine. In that case though, I had lower compression on both the front and rear rotor. Is it possible that I flattened out the apex springs?

Any thoughts?

Thanks,
Greg

 

If you have low compression on every rotor face i would guess scored housing....

 

Hmmm... good thought! I am assuming a warped side plate may show the same symptoms?

 

Alot of things can definately cause alot of different problem to these wonderful engines !