compresion fail...
 

finally getting around to getting my car running again after a year and a half. when i left it, it was smoking pretty badly when running at almost all times. oil smoke.

turbo DEFINITELY needed a rebuild as the shaft play was bad enough to have the compressor housing have some light scoring from the wheel, so that's been sent out, but i was hoping the motor itself was ok. finally gt around to doing a compresion check today. i was happy until i hit cylinder 4...

as you can see form my sig, it's a 1.6 greddy based setup with a begi DP and MSI. ran great at 14 - 15 psi, but the urge to crank it up a bit, (to 17'ish, maybe a little more) may have been thr straw that broke the camel's back...

could be valve related, or ring related, i suppose... might as well pull the head next time i can work on it and see what's up.

FML.

Attachment 197356

Ouch. I drew the line at 15 psi with my Greddy. Upgrade to a 1.8!

Did you have a dual feed fuel rail? I'm guessing detonation caused the damage in #4.

negative on the dual feed. i hadn't thought of that though.. 1 - 3 plugs looked pretty rich, though, and similar to 4... i didn't see anything BLATANTLY indicating det on 4... btu i guess i'll get a picture of it when i yank the head next weekend.

well if ya need anything I've got some stock internals and new rings I didnt use LMK

i'll keep that in mind. pm me a price shipped so i can run down my options this week and make a decision?

What do you think you might want? I've got a set of rods with good pistons attached and the bearings look good still you could possibly reuse them

when my car leaned out on nitrous valve was the first to go. i lucked out and bought a "replacment head" on ebay for 150 bucks and it showed with hks 256s in it 14.9whp gain with no other mods.

looks like the plan is to pull the head and hand it over to my fiance's dad so he can bring it to a machine shop he works with (he owns a used import dealership) to check out. if there's anything off-looking, they'll refresh it with oem-spec stuff and i can slap it back on with some arp studs and check the comp again (assuming the cylinder bores look ok when i pull it). if it still doesn't show decent comp, then i'll build the bottom end with some m-tuned or belfab rods.

my guess is the more likely culprit is the valve guides/seals, since all my plug wells had oil in them that looked like it had been forced through the o-rings on the valve cover side, and adding a tbsp or so of oil to cyl 4 yielded a 120 rather than the 90 i got when i tested it dry.

thoughts on this plan?