Low Comp And Blue Smoke Only Sometimes?

[femno]

Cool. Yeah i agree with you guys as well on the blue smoke issue...but what about the intermittent low comp?

[femno]

Expert opinion needed:

Does this look like it could be a problem after some time?

Before:

After:

Notice a fair bit of the valve guide has been taken away during the porting job....

Cheers!

[hungry6]

Nar that shouldnt be the issue, but the porting is abit hrmmm, questionable. I would be inclining to say some sort of sealing issue with valves or minute crack in head, Im assuming this from the looks of the 'porting" works

[femno]

Well i was thinking that the shortening of the guide might have caused to premature wear on the valve stem, giving sideways play and then the valve not seating properly..?

Yeah i know the 'porting' is good hey

[proengines]

If the bottom of the guide is cut off at an angle it will wear quicker than one that is the right length and square on the end. The valve probably wont wear but the guide will. Saying that, it can still take quite a while for them to wear and if it was worn far ehough to affect the compression it would pour smoke out and make some valvetrain noise. Pull the exhaust manifold off and have a look down the port and you should see if there is oil runing down the guides. Check the turbo while you're at it, had one of my engines diagnosed by a supposedly reputable workshop with valve stem seal problems which have ended up being a turbo seal. A leakdown test is probably worthwhile first.

[femno]

Cheers for the input guys, i have some decisive info about this whole thing:

I just got back from my engine builder, i took out all plugs etc, cylinder 3 and 4 plugs were a little wet around the bottom of the threads, 4th plug was blacker than all the others, others were fine.

Anyways we chucked the camera down all the plug holes and found that all the bores are completely glazed, i saw for myself they look like chrome, no hone marks whatsoever.

The outer circumference of the 4th piston is clean as a whistle, the rest of it carbon, it seems this ring isnt sealing, and 3rd not as bad but still clean. Im thinking the others wont be far away. We had 4th piston up, cranked it down and we saw oil sitting at the top of the bore, it started running down the bore.

We also checked the valve stems while they were open, there was no oil on any of the stems.

My car has always blown a fair bit of black shit since the tune (never revved it over 4k or flat stick before the tune), but i didnt think anything of it because i thought it was right.

What the f**k has caused this to happen to my engine??