Wobble test and visual of the guide oil seal install.

 

I'll second that.

 

My guess also.

 

What about the coolant ? Did you find some oil in there ?

 

No... forget...

 

new numbers!
standard leak down
at 100psi
1--83
2--90
3--86
4--85
5--87
6--81
7--93
8--93

compression (cold/dry)
1--180
2--170
3--185
4--180
5--175
6--175
7--175
8--190

 

All the ones over 10% are really bad. When I did the 996 in the summer. Just from carbon build up on the exhaust valves, the leakdown was ~12%. And even with that, you could really feel and hear the air pouring out the exhaust ports. In your case, if all the noise is in the crankcase, the rings are leaking BAD.

 

A well sealed engine should have low, single didgit, leakdown numbers.

 

thats just the pressure, not the leakage rate. so 1 is 17% etc...

here is a thought. talked to the shop i got my stuff from and had work done at in abq.

if it was a crap guide it would leak on High rpm deceleration, high vac, suck oil in past the guide.
if it is bottom end, smokes on acceleration, positive crank case pressure, oil past rings.

 

I still think this an oiling problem other than rings or valves......Crankcase pressure, oil in intake......Something is wrong.

Since the problem is mostly the back cylinders...could you be pushing oil in through the "vacuum" connection to the brake booster....which sits in the rear of the intake?

You'd actually have to "work" at screwing up a head that bad to pass that much oil through a guide....and if the rings were that screwed up in those cylinders, the cylinder walls would look like they got attacked by a chainsaw....

 

amount of oil on the pistons still gets me SOOOOO
im going to button it up and drive it (not just idle)

get it NICE and warm and some good miles on it

let it cool for a few min. take out the "trouble" cylinders plugs and check oil amount with the Scope
let it sit for a few days and check again

also make sure intake valve is close, during the sitting period
pull the center plenum and use the scope to check the back of the valves for oil pools

ran the milage numbers. i have about 400 on this build. i might just have to drive the pig..

shop that did the head work was Competition Engineering in cali.

 

Ditto.

And put some NGK's in there! Bleh @ Bosch plugs.

 

+1
My bet is crankcase pressure. Open it up somewhere and run a hose to dump out the bottom and run it hard for a couple of miles and see what happens.

 

What's the crankcase venting setup? Someone mentioned it is not stock.

 

Provent. Kuhn's filter/scrubber in the full neck. It was hooked up to an exhaust scavenge to create suction. But vented to atmosphere right now. Ill post an update soon. I want to eliminate all possibilities before I take anything part I don't need too