OK.....

About a month ago, I had a backfire that blew up my intake manifold and busted my #1 piston. This past weekend after waiting for a aftermarket head gasket to get made for it to lower the compression I finally got it all put back together. The compression should be 9.5 to 1 now.

Anyway, I changed the piston, used the new head gasket, new timing belt, set the timing using the proper tools ( crank pin and cam block). Made damn sure my oil feed for the turbo was spitting oil. Started it and every looked and sounded good. Went to drive it was running rough as hell when I would give it gas. I didnt go over 3500rpm the whole time, but when I got back to the house, the freaking turbo was starting to glow red! Engine temp was good, oil pressure was good along with the oil temp. The one
CEL that did come on though was something about timing advace off b1. I was told that it seemed like allot of fuel was getting dump into the exhaust making it so hot or the the timing was retarded to much.

My buddy and I are both mechanics, but usually we work on his two muscle cars. So the DHOC timing thing was new to us. But like I said I did use the correct tools, had instructions and the #1 piston was at TDC. I can go more into how it was running, but would like to see if anyone as heard of this before. It ran allot better before taking it apart, even with the broke piston! And nothing was really changed except for the head gasket that is thicker. Im getting fuel to all the cylinders and the plugs are good also.

Well, just trying to get some ideas of what to look at.[???:)]

first thing is, you lowered compression. did you do anything with the tune? It'll cause alot of change in the a/f ration.

did you recheck your cam timing after running it? (your actually supposed to rotate the crank twice and recheck before starting it). If cam timing was set before the adjuster was adjusted your timing will be off also.

yeah, we rotated it more than a couple times to check it first. Everything was good with that.

Adjuster? Timing belt tensioner or something else?

And I was curious about how much the compression change would make too. Could it make a HUGE diff. in performance?

Posted via FF Mobilethink ill just try to redo the timing, tom said the vct is tricky. still wondering if the gasket is affecting anything

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When you check the cam timing, make sure to pull the intake cam ahead to the stop before trying the timing bar. The valve springs are normally stronger than the VCT hub spring and the cam will be retarded without you helping it forward. (at least my engine is this way) If you can turn the motor and get the bar in without pulling the cam ahead....you are off and the code will tell you that.

You did break both cam gears loose, yes? The thicker gasket makes the gears farther from the crank so you are guaranteed to be off if you don't start with loose gears.

The O2 sensor should accomodate the reduced compression no problems but the tune might run better with adjustments. Your thicker gasket has destroyed any squish band activity you had so the combustion will be slow and might need more timing. You'll find out soon how it runs.