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after breaking in a 455 on a test stand i found my intake was leaking oil by the distributor , not enough silicone . removed intake to redo noticed the bottoms of both mr.gasket 404 gaskets wet with oil looked into all ports and every intake valve that was closed had oil on it. pulled plugs every cylinder has oil on top of piston , resealed intake with new 404s again ran engine 15 minutes pulled plugs still oil on pistons. removed swap meet performer intake ordered new one , installed with e brock gaskets , and gasacinch. ran engine again for 10 min,, pulled plugs same thing . engine is 060 over stock c heads and valve train. silvolite replacement pistons, cast rings . cam is hi flow ah 0.504 lift 284 duration both intake and exhaust. all machine work was done at a shop i have used many times , clearance was checked between bottom of valve retainer and top of valve guide no problems with valve seals . no oil is going through the pcv, i still suspect intake somehow but would greatly appreciate any thoughts on this before i pull intake again . also have mondello tray over lifter galley. valve guides are good . heads were milled .006 to clean up surface . do not no previous history of heads , engine runs great 20 in of vac on gauge at idle of 850 rpm
If you have good vacuum then you probably don’t have an intake leak. However, remove the intake, then set it on the heads without any gaskets. Run a feeler gauge around the top and bottom as much as possible to check for square. Then go from there.
If that doesn’t yield any possibility for error, then the only thing could be may be improperly installed rings? At some point you’ll need to look elsewhere if you’re sure of the other potential issues.
What intake? Has the intake ever been machined?
To back up what Mark said, look really, really closely at the front of the intake where it meets the head. With no gasket, do the intake and head surfaces perfectly align with each other? EVERY Edelbrock intake I've used in the past 20 years needed to be machined. I had several builds pull oil from the bottom of the intake/head surface because the intake wasn't machined right. I also had really good vacuum, but still pulled oil like crazy. The other painful thing is the gaskets showed good crush, but they still didn't seal. Machined the intake sides of the head and boom - worked great.
Have each side cut - 10 to 20 thou to start, maybe more.
have checked as you advised before installing new intake , could not rock side to side or end to end . could get a .005 feeler gauge in some spots . depended on how intake was sitting. lined up manifold even with machine marks that run the length of both heads just below rocker covers could slide 0.10 gauge along passenger side of intake if i tipped that side down a little below the line it was tight. i am fairly certain rings are installed correct if not why would i have oil on top of valves , there is no trace of oil in the intake runners or under the carb. if the 1st and 2nd rings were installed incorrectly. why would oil be getting past the oil control rings? reading ring instructions as long as the main ring ends are not over lapped there is no way to install them wrong that i see.all i know is something is wrong be it my fault or not . i appreciate your help and the advice you give . thank you
e brock perfomer intake i also have good crush marks on intake side of gasket not so prominent on head side. have installed several e brock torker intakes with no problems
Last edited by oldaman; March 3rd, 2020 at 06:54 AM.
Reason: description
have checked as you advised before installing new intake , could not rock side to side or end to end . could get a .005 feeler gauge in some spots . depended on how intake was sitting. lined up manifold even with machine marks that run the length of both heads just below rocker covers could slide 0.10 gauge along passenger side of intake if i tipped that side down a little below the line it was tight. i am fairly certain rings are installed correct if not why would i have oil on top of valves , there is no trace of oil in the intake runners or under the carb. if the 1st and 2nd rings were installed incorrectly. why would oil be getting past the oil control rings? reading ring instructions as long as the main ring ends are not over lapped there is no way to install them wrong that i see.all i know is something is wrong be it my fault or not . i appreciate your help and the advice you give . thank you
The source of "vacuum" is created in the combustion chamber, not the carburetor. The flow of air is from the carburetor toward the combustion chamber (cylinder), thats why you will find oil on valves and not the carburetor. I believe that Edelbrock intake manifolds should have the intake side machined lightly before using. I thought Oldcutlass (Moderator) posted a link about it at one time.
The second ring provides additional oil control. If it’s in upside down, and it’s a tapered reverse twist ring then the oil will get past that. At that point the compression ring is not made to handle that much oil.
I’m taking for granted the cyl finish is correct for the rings used as well.
However with all that, the valve guides/seals could still be suspect. I’d dive into that in detail first.
thanks mark did not realize 2nd ring played in oil control also , will check ring type , think there are cast stock replacement. shop said bore is finished for type of piston and rings . valve guides were checked two exhaust were replaced ,new stock umbrella seals on all.
How do the plugs look? If that much oil is getting past the rings to coat the intake port and valve, then the plugs must be swimming in oil. If they're just dark then that tells me that the oil is coming from the intake port. If they're wet and crusty then oil is coming from the bore.
I'll double down on the intake needing machining.
Remember that we're talking about the bottom joint - the one you can't see - inside the intake valley. Usually what happens is the intake is a bit too wide or the faces aren't quite flat, so the top joint - along the valve cover - looks tight, but the bottom joint has gaps.
plugs did not look bad a little dark am pulling intake tonight@ checking gasket pattern . bringing intake to machine shop tomorrow to be checked out . will post results . thanks a lot !
Olda,
A good test to check for the intake leaking is the following:
1. Take the pcv valve out of the valve cover and block the hose off.
2. Take the breather tube or breather out of the other valve cover.
3. Block off one of the valve cover holes, does not matter which one.
4. Start the engine and let it idle.
5. Take a can of gumout carburetor cleaner and squirt about a 5 second shot into the open valve cover hole.
If the intake is not sealed properly it will suck the fumes from the carb cleaner in through the crankcase and the idle will change a few seconds after you squirt the gumout into the valve cover.
Also you really should not have a vacuum on the valve cover hole. If there is a noticeable vacuum there then it almost has to be the intake.
I dont like the hard Mr Gasket intake gaskets. If you are not using the valley pan i would use the Fel Pro 1356, they are a little softer.
Had severe oil consumption on a fresh SBC rebuild to the point of oily tailpipes, umbrella valve seals turned out to be the problem. Positive seals fixed it. Are the valve stems loaded with oil under the seals but topside of the guide?
new intake was milled 0.10 set on engine with no gaskets fit good , installed ran engine 20 min shut off pulled plugs later in day still have same problem, removed intake everything looked ok , now what ? pulled headers have oil coming out exhaust ports, to be expected i guess . pulled oil pan and heads . removed pistons from # 1 and 2 cylinders all looks normal . measured oil ring rail gap was 0.30 expander gap 0.100. top ring 0.018 2nd ring 0.014. same reading both at top and bottom of bore
installed piston in bore upside down with just oil rings took 24 lbs to move it . poured clean parts washer solvent on top of a piston after approx 10 minutes it was dripping on the floor . also before tearing down i was rotating engine by hand trying to see if stock umbrella seal was covering guide when valve was fully open could not really tell as coils in the way . seems odd that most of the seals ride just under the retainer .any input is more then welcome as i am ready to start pulling hair out ... LOL
Location: Colorado Springs Colorado/Thousand Oaks Ca
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Originally Posted by oldaman
new intake was milled 0.10 set on engine with no gaskets fit good , installed ran engine 20 min shut off pulled plugs later in day still have same problem, removed intake everything looked ok , now what ? pulled headers have oil coming out exhaust ports, to be expected i guess . pulled oil pan and heads . removed pistons from # 1 and 2 cylinders all looks normal . measured oil ring rail gap was 0.30 expander gap 0.100. top ring 0.018 2nd ring 0.014. same reading both at top and bottom of bore
installed piston in bore upside down with just oil rings took 24 lbs to move it . poured clean parts washer solvent on top of a piston after approx 10 minutes it was dripping on the floor . also before tearing down i was rotating engine by hand trying to see if stock umbrella seal was covering guide when valve was fully open could not really tell as coils in the way . seems odd that most of the seals ride just under the retainer .any input is more then welcome as i am ready to start pulling hair out ... LOL
Replacing two valve guides and then using umbrella seals, this will be problem, not sayin its the only problem. I spend a lot of time on valve guide installations, bronze guides honed to size, carbon reliefs on the EX sized to .0018 Int .0015 on a iron head, blue positive seals. Generally I use a CHE 1/2 OD one piece bronze guide.
Last edited by VORTECPRO; March 27th, 2020 at 06:57 AM.
What type of rings did you use ? Double check to make certain they are in the correct grooves and that they are not installed upside down, especially the second ring. Can you post a real close up picture of the rings, especially at the agps ?
Valve stem seals will not cause that much oil to get into the cylinders. Most early engines did not even have seals and they didn't use a terrible amount of oil.
That is why i pulled it down as i was positive rings were installed correct. and they were. used Hastings 2m 661 rings , have a new set they measured the same . all guides were checked only two were slightly out .rinds are cast
Last edited by oldaman; March 27th, 2020 at 07:10 AM.
Reason: add details
Thats how it was installed . i appreciate your input
Any time. I just had to ask, I see everything here at times I am having a hard time thinking of where else the oil could be coming from. I use Hastings Moly rings 90% of the time and they are pretty bulletproof as far as sealing. Very tolerant of improperly finished cylinders also.
I couple of people have said that if the second ring is installed upside down that oil will leak past it. That is not really what happens. The second ring has a tapered face and it scrapes the oil off the cylinder as it goes down. If it installed upside down it will scrape the oil up instead and cause problems. Just wanted to clarify that.
A couple of people have said that if the second ring is installed upside down that oil will leak past it. That is not really what happens. The second ring has a tapered face and it scrapes the oil off the cylinder as it goes down. If it installed upside down it will scrape the oil up instead and cause problems. Just wanted to clarify that.
Actually it is what happens on the intake stroke. You have low pressure above the ring and higher pressure below it. Oil WILL get past it at that point.
Op you said .300 gap on the oil rails, is that true or did you mean .030?
Actually it is what happens on the intake stroke. You have low pressure above the ring and higher pressure below it. Oil WILL get past it at that point.
That does make sense and then it scrapes it up too I found out the hard way on a 305 Chevy engine I built a long time ago. I put one second ring on upside down. Could not figure out why that cylinder kept fouling the plug. Pulled it out an took it apart and that is when I found it.
The 455 in this post is making no sense at all. For oil to be sitting on top of the piston and running out of the exhaust port there has to be something seriously wrong and I bet it is something simple.
I agree that valve seals are VERY unlikely. As Billk stated, early motors didn't even use seals and Chevy used Orings for decades; but, I did have one SBC gulping oil with oil soaked exhaust pipes due to valve seals that were installed as part of an overhaul.
I honestly believe the engine would have used almost no oil without any seal. The seals were umbrellas and seemed to move up and down with the valve making it like a pumping action moving any oil under the seal toward the guide. Once changed to positive lock type seals the problem was gone.
I’m trying to find the thread. I had the same problem until I came across a thread about lifters several years ago. Found out the shop put Chinesium lifters in my engine. Put too much oil on top of the heads and leaked past the seals. Changed lifters out and problem solved.
Finally got around to tackling my oil consumption problem. Was losing almost a quart for every hundred miles, pulled the intake off and voila. No valley pan, gaskets were leaking especially around the exhaust crossover ports, cylinders 4-6-3 Installed new valley pan using copious amount of ultra grey sealant on the end rails and also put a slight coating on ALL ports on both sides of the gaskets. Overkill? Maybe. Drove the car for about a 100 miles so far with no oil or coolant loss.
thanks for the post i might try that as all else has failed , just put on a different set of heads seems to have slowed down but still present , i have two other 455 engines that are running just the ebrock gaskets that are recommended with no problems both have heat crossovers blocked . do not know whats up with this one , compression and leakdown tests were spot on
I found that when using composition gaskets with an aluminum intake manifold the intake bolts needed to be retorqued every couple months (3 or 4 times) until things stabilized.
I found that when using composition gaskets with an aluminum intake manifold the intake bolts needed to be retorqued every couple months (3 or 4 times) until things stabilized.
yes, I retourqed the manifold the other day and got a quarter to a half a turn on most of the bolts so I will definitely keep an eye on that
thanks for the post i might try that as all else has failed , just put on a different set of heads seems to have slowed down but still present , i have two other 455 engines that are running just the ebrock gaskets that are recommended with no problems both have heat crossovers blocked . do not know whats up with this one , compression and leakdown tests were spot on
, before changing the old manifold gaskets to the valley pan gasket my compression tests were spot on also,(did not do a leak down test) and the car ran very strong which made the problem even more perplexing. i have since drove about 300 miles combined highway and city since installing valley pan ,without losing a drop of oil. hope this info helps and hope you solve your oil loss issue
after breaking in a 455 on a test stand i found my intake was leaking oil by the distributor , not enough silicone . removed intake to redo noticed the bottoms of both mr.gasket 404 gaskets wet with oil looked into all ports and every intake valve that was closed had oil on it. pulled plugs every cylinder has oil on top of piston , resealed intake with new 404s again ran engine 15 minutes pulled plugs still oil on pistons. removed swap meet performer intake ordered new one , installed with e brock gaskets , and gasacinch. ran engine again for 10 min,, pulled plugs same thing . engine is 060 over stock c heads and valve train. silvolite replacement pistons, cast rings . cam is hi flow ah 0.504 lift 284 duration both intake and exhaust. all machine work was done at a shop i have used many times , clearance was checked between bottom of valve retainer and top of valve guide no problems with valve seals . no oil is going through the pcv, i still suspect intake somehow but would greatly appreciate any thoughts on this before i pull intake again . also have mondello tray over lifter galley. valve guides are good . heads were milled .006 to clean up surface . do not no previous history of heads , engine runs great 20 in of vac on gauge at idle of 850 rpm
I had a similar problem like you. A friend highly recommended me to this machine shop and he rebuild my engine. When I started the engine in my car, it was smoking really bad. Next door neighbors thought my garage was on fire. I took apart my engine to see what's the problem. Everything was fine and I finally realized that the guy did a cheap quick cylinder hone job. The cylinder didnt have the cross hatch pattern. It had an up and down pattern, looks like someone use a sandpaper and just scoff it up and down. I took my block to another machine shop and they did the correct hone job. My engine doesnt burn any oil again.
March 3rd, 2020, 05:32 AM
I am having a hard time thinking of where else the oil could be coming from. I use Hastings Moly rings 90% of the time and they are pretty bulletproof as far as sealing. Very tolerant of improperly finished cylinders also. 
I found out the hard way on a 305 Chevy engine I built a long time ago. I put one second ring on upside down. Could not figure out why that cylinder kept fouling the plug. Pulled it out an took it apart and that is when I found it.
