madkaw

It’s oil

Well after trying about everything I could think of I pulled the head . I definitely have an oil control problem . Since this is a fresh assembly I must of got something wrong or something failed. I tried different valve guide seals on this build, but examining one of them I couldn’t say if it failed . Removing the head revealed a oil film on 4,5,6 with 5&6 being the worst. Maybe oil control rings broke, failed ? Im going back to the Ford valve seals, but really should pull a piston - ugh. Just weird it happened on the last three . Or is possible it’s just #6 and engine vacuum is dispersing it between the closer runners ? Learning a lot in this build - the hard way

I started a thread #6 fouling. I swapped to a zx dizzy and nothing changed

I will also say I’m a bit reluctant to swap the O2 sensor over for fear of ruining it with oil . Not sure what else it will tell me that nits obvious from the plugs at this point

Running rich from a dilution of mix from the seal leak possible?

FPR is after the the tail . I could split the batch. I have the hot running to the fuse box , just got lazy because MS said it was okay to run all 6 with one hot. Need to get sequential going , but this should work unless the demand can’t be met with a bigger engine . I do have some kind of oil issue from a seal or something . Maybe get away with swapping intake valve guide seal on #6 will help

So I pulled the intake and found and oily residue lining the intake runner of 4-6 . Looks like # 6 could have a bad oil seal . Maybe bad enough to foul the mixture . The plug always looked more like carbon fouling and brushed off pretty well with a wire brush so I didn’t suspect oil . Not sure if a bad oil seal would cause my bouncy vacuum readings unless I’m seeing this as a misfire . Hopefully the guide itself is not bad . I tried a different type oil seal instead of the Ford seal and I guess I didn’t get one right . I’m assuming the color in the plugs on 4&5 is from a small amount is containment from #6 oil getting sucked over from the plenum . The pic is brand new plugs ran in a warm up cycle- I know , not the best, but car is on lift . 1-3 looks clean and is running 13-14 AFR. 4-6 get progressively worse. Valve pic is #6 .

Pretty sure I can the cam timing right , but maybe time to check. Not sure how I could get 225psi on retarded timing

Sprayed it down and couldn’t find anything

I see as high as 10 at 1000rpm

Running a stock n42

Well it’s batch fire and I swapped the leads between 5&6 with no change .

So the intake was biased forward or backwards ? So are you saying this didn’t cause a vacuum leak but caused inconsistency in the runners ?

Running batch fire so all cylinders should be the same . plug shows carbon fouled - dry stuff that brushes off pretty easy .

L28 54/MN47 Short block is fresh for the most part. New bearings , rings rebuilt head 530 lift cam megasquirt 3 - NA It’s a long story but this is what I’ve done Compression test 220 + or - 5 all cylinders . Coolant pressure test - passed leakdown - less than 5% swapped coils , plugs, wires , injectors, injectors connectors . Checked valve lash - several times checked for vacuum leaks vacuum is about 9 at idle vacuum needle bounces badly - especially at idle . It’s hard to make out a reading. The MAP gauge on MS is not that erratic , but it isn’t smooth either . Is it possible to have a bad HG and still get 225 on a compression tester? Is it possible to have a broken ring and pass a leakdown ? Is it possible for either of these tests be mute under running conditions ? I am at a loss and ready to rip it’s head off but will take any last ditch efforts and thoughts .