oil on top of pistons after rebuild
#41
thanks for the post , all machine work was done the right way , i assembled the engine and checked everything before it was put together have installed factory valley pan hope to fire it up tonight will post results
#43
Well that stinks. I think you are missing something simple. Do you you know anyone at a decent auto repair shop ? Most of them now days have a smoke machine for checking for fuel system evap leaks etc. I know some guys have found some crazy issues with one of those machines.
#45
if you look at the pictures of my old gaskets above, it appears most of my oil was sucked out through the exhaust crossover. It appears that the bottom of the gaskets were compromised at the crossover and at a couple cylinder intakes allowing oil from the lifter valley to escape. Maybe try blocking exhaust crossover ports? I was losing so much oil I would only drive it around town or no more than fifty miles. Good luck,
#49
thanks to all who have replied with suggestions , no problem with engine breathers, no oil in pcv hose . am 100% sure it is oil , not gas . have given up on it for awhile . will post any new developments .
#50
Have you verified the oil drainback holes on both ends of both cylinder heads?
Really, the holes at the rear of the heads are the important ones.
Olds heads have a goofy, double-drilled hole--the hole has a "bend" in the middle The upper drilling intersects the lower drilling; and the holes are not overly-large to begin with. Excess oil from crappy lifters could overwhelm the drainback holes. The valve guides would end up flooded in oil. I reworked the drainback holes on my "C" heads using a larger drill bit, careful to not drill too deeply from the top or from the bottom.
As said in an earlier post, the crappy lifters could be a root-cause; if they're supplying excess oil to the valve train, you'll want to eliminate the source of the oil flooding, not "only" enlarge the drainback.
Really, the holes at the rear of the heads are the important ones.
Olds heads have a goofy, double-drilled hole--the hole has a "bend" in the middle The upper drilling intersects the lower drilling; and the holes are not overly-large to begin with. Excess oil from crappy lifters could overwhelm the drainback holes. The valve guides would end up flooded in oil. I reworked the drainback holes on my "C" heads using a larger drill bit, careful to not drill too deeply from the top or from the bottom.
As said in an earlier post, the crappy lifters could be a root-cause; if they're supplying excess oil to the valve train, you'll want to eliminate the source of the oil flooding, not "only" enlarge the drainback.
Last edited by Schurkey; August 2nd, 2020 at 10:29 AM.
#51
drain holes are good have changed lifters from ht 951 to a set from lunati , also switched to restricted push rods. have changed intake gaskets twice since then . am having intake milled down some more this week and try again .thanks for replying
#52
oil on pistons
another failed attempt , this time i had intake milled down 0.10 more , painted intake black along ports on both sides let dry , painted intake ports on heads red let sit until tacky . put on intake without gaskets torqued to spec, removed intake had a good pattern of red around all intake ports on manifold , not 100 percent but enough that the gaskets should have taken care of thought for sure problem solved . am at a total f#@king loss as to what is causing this , was thinking of tearing it down and having the block decked , its the only thing i did not have checked while at the machine shop . anybody have any thoughts on this , really appreciate every body who has replied to this post
#53
Are the intake manifold side of the heads square to the combustion chamber side ? Are the intake side milled straight when using the dowel pins as a reference line ? Do you have clearance between the bottom ends of the intake manifold and the top of the block ? Have you tried a different pair of heads ? Hold off decking the block for now.
#55
Have you tried a known to be good intake manifold yet ? I am trying to rule out things before you consider decking the block. It is puzzling.
#56
I feel your pain. I admit I have no idea where to go next, but will reiterate what cured my oil loss. I was losing up to a quart every 120 miles. Compression was excellent. Car ran strong with intermittent puffs of blue smoke but not a smoke show. I ended up pulling the intake and noticed the 404 type gaskets were all Pretty much compromised on the lower Edges of the gaskets. Almost like the oil was wicking up into the intake ports. I suspect maybe a higher than normal crankcase pressure? Not sure. Have a w30 PCv system with Pcv running from the manifold with two valve cover breathers. So I installed a valley pan gasket and ditched the rubber end gaskets, where they suggest a 1/4 “ bead, I used 3/8. Bead of ultra grey. I also put a bead around every port both sides of the vp gasket. Installed and let sit overnight, crossed my fingers and fired it up. That was over a month ago and after six hundred miles have not lost any oil except for the fact I keep checking it because I’m still thinking it’s going to be low today but nope. I’m not tooting my own horn, I’m just saying what worked for me. I hope you solve your issue soon. There has to be an answer. Good luck
#57
Old,
Where exactly are you at in Michigan ? I still think it would be a good idea to find a repair shop with a smoke machine and see if they will let you use it to smoke the engine. If it is indeed the intake gaskets it should show it pretty quickly. If you tell us where you are I can reach out through some of my connections and see if I can find a smoke machine you can borrow.
Where exactly are you at in Michigan ? I still think it would be a good idea to find a repair shop with a smoke machine and see if they will let you use it to smoke the engine. If it is indeed the intake gaskets it should show it pretty quickly. If you tell us where you are I can reach out through some of my connections and see if I can find a smoke machine you can borrow.
#58
Oil on top of Pistons
I tried a factory valley pan silicone both sides with same results hey Bill I live between Lansing and Flint off interstate 69 I really appreciate your help and interest in this matter
Thread
Thread Starter
Forum
Replies
Last Post