Oil Spraying Around Cyl 7 On Fresh Rebuilt 302.

Madlash93

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Hello, i'm new to these forums. Tried searching around and can't find my specific problem so I figured i'd make an account and ask away.

(Bit of back story, not exactly required to know the problem.)
I got this 86 mustang GT on trade for my YZF R1 a while back (the mustang didn't run when I traded due to them having a plate covering the MAF sensor, removed the plate and it fired right up and ran great..... it has stock injectors, i'd assume that plate was tricking the ECU into thinking it had different sized injectors). it also had a really bad vibration over 3Krpms, eventually the rear main seal went out so I replaced it, then it went out again a few weeks later, so I figured it was probably being caused by whatever is causing the vibration.
I then decided i'll just buy another 302 roller bottom end for $100 and slap everything from my current 302 onto it and that's what I did with a 1987 lincoln town car roller 302 flat top cast pistons and all (yes I checked the PTV clearance with a solid lifter, play dough, and old head gasket in place. not exactly sure how but the valves were fairly far away form the pistons after about 4 full rotations of the engine ((flat top 87 town car cast pistons, e303 cam, E7TE heads, Compcams magnum push rods can't remember the number listed on them)))

(problem)
Now to get to the problem at hand, I have all new bearings, all bolts threadlocked, all new quality gaskets, all bolts tightened to torque spec with the correct sequence put 500 miles of low load low rpm driving (about 3500rpm, 50% throttle at most) changed the break in dino oil out, put in mobile 1 full synthetic 5w30 with a new filter, drove another 20 miles to make sure everything was still ok as up to this point nothing was leaking at all... then i got on it a bit, pulls amazing, runs great.
So I decide to do a good run through a few gears, hard pull from second to 3rd, all is good, then at the top of 3rd I started seeing what looked like steam spraying up near the dip stick and it very lightly misted my window. ((I was driving with no hood when doing the pulls as I was to lazy to mess with the stupid screws that hold it on... it's not a hinged hood.))
I got back to the garage and looked, it dripped a small amount of oil under the car, but I couldn't see anywhere oil could have possibly been coming from, the dipstick was fully seated and oil free, the bottom of the dipstick where it goes into the block was also dry, but my spark plug heat shield was soaked in engine oil and it just ran down the side of the block... I can't see anywhere it could possibly be leaking but it certainly is spraying when under continuous heavy load.

(What I already tried)
I have tried a few things like cleaning the oil off the block, lying under it while a friend holds the rpms up around 4K to try to spot the leak, but it doesn't show up unless the engine is under heavy load for a bit of time.

I have since driven it a few times to see if I can recreate the leak, it does this every time. I can really get it to spray good while doing a burnout even when I drop the RPMs to 2K while doing a fully stopped burnout (oil pressure is pretty good, right in the middle during warm idle, probably about 3/4 with higher rpms.)

(Sorry... I just noticed how much I typed.)
Any ideas?

((yes the new bottom fixed the vibration issue I was having, the old bottom end has aftermarket parts that aren't balanced, or aren't balanced for a 50oz imbalance, the rear main bearing was oddly broken as well, not spun or cut up looking, but a chunk of it was missing, i'll have to take a picture of it eventually as i have never seen anything like it.))
 
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Davedacarpainter

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First off, welcome to stangnet.

Secondly, I'll move your thread to the tech subforum. The mechanics hang out there.

What head gaskets did you use when you rebuilt it and did you have the block and heads surfaces checked to be sure they're still flat?

A chunk of the rear main bearing was missing?! Yeah, that could cause a slight wobble.

Anyhow, post a couple pictures of where the leak is as well for us.
 

General karthief

wonder how much it would cost to ship you a pair
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Your oil pressure sending unit is on the drivers side, check it to see if it is loose or has a leak, stock or aftermarket oil gauge?
Dip stick tube goes into block just above the oil pan rail on newer blocks, not sure what year the change was, , older sbf had a dipstick in the oil pan, where is yours?
 

Madlash93

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Nov 19, 2016
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[/QUOTE]]
First off, welcome to stangnet.

Secondly, I'll move your thread to the tech subforum. The mechanics hang out there.

What head gaskets did you use when you rebuilt it and did you have the block and heads surfaces checked to be sure they're still flat?

A chunk of the rear main bearing was missing?! Yeah, that could cause a slight wobble.

Anyhow, post a couple pictures of where the leak is as well for us.

Thanks, I was a little confused about where to initially post.
The chunk of rear main bearing was missing from the original bottom end, I planned on getting the rotating assembly balanced and rebuilding it as well. I'm running a different bottom end from an 87 lincoln town car for now.
I used a ford performance HGs part M-6051-A302 (https://www.summitracing.com/parts/fms-m-6051-a302/overview/make/ford) and it these heads didn't leak while on the original block so i figured all was fine.
I'll post a few pictured and possibly a video in a few hours, im headed over to my step brothers (where we work on our vehicles) in a few minutes.

Your oil pressure sending unit is on the drivers side, check it to see if it is loose or has a leak, stock or aftermarket oil gauge?
Dip stick tube goes into block just above the oil pan rail on newer blocks, not sure what year the change was, , older sbf had a dipstick in the oil pan, where is yours?

The dipstick tube does go into the block on both of the blocks, I used "copper" RTV when I initially put the tube in.
I used thread locker when I put the sending unit in, checked it as well for any sign of leaking and it's not wet anywhere near the sending unit.
 
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Madlash93

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(checked the dipstick tube bottom and top, top is completely dry, bottom i'm not 100% sure since oil is all over the back left side of the block.) I also had the PCV valve in the black of the intake manifold (pretty sure that's what it is) blow off today so i'm lead to believe I have high crank case pressure and the oil is blowing out from the bottom of the dipstick.... though I have it sealed with RTV so wouldn't it blow out the top of the dipstick tube? ((freshly reamed and honed cylinders with new piston rings installed and clocked 180 degrees... so is high crank case pressure even possible unless I did something wrong?))

These are the only ways I can really get it to leak. ((I completely forgot to take a picture, though it wouldn't do much good now since the entire back driver side of the block is now covered in oil after recording the videos))



i'm also about 90% sure these aren't stock 302 pistons (from the original bottom end that shakes like crazy over 2.5K rpm) So I should probably get the bottom end balanced?

3D60M8h.jpg
 

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a91what

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Ok.. so that didn't help at all. At this point it does not matter what pistons you have in there, it runs.

High pressure oil could only come from an oil galley... period. unless there is detrimental damage to the block. then you would know it.
An oil leak like the one in the video where oil runs down all over the headers, is most likely the valve cover leaking.
 
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Madlash93

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Ok.. so that didn't help at all. At this point it does not matter what pistons you have in there, it runs.

High pressure oil could only come from an oil galley... period. unless there is detrimental damage to the block. then you would know it.
An oil leak like the one in the video where oil runs down all over the headers, is most likely the valve cover leaking.

(Sorry about it not being much help, I have no other way to record it since it only happens when under fairly heavy load, I could see if any of my friends have a gopro I can use to try recording it.)
It does seem like it could be from the valve covers, but with enough pressure to mist oil onto my front window? (I really don't get whats going on with this, i'll probably just drive it as is next summer and keep topping the oil up until i get the other bottom end balanced... or just do a 351w swap like a planned from the beginning.)
 

a91what

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You have no hood on the car... imo the oil smoke is hitting the windshield and leaving residue on there.

This could happen with even a catch can, the oil vapor condenses on whatever it hits.

Just look at the valve covers, are the rails on them wet? you said #7 cylinder it's not hard to miss the hole with cork gaskets. when you get on it oil backs up in the valve covers then spills out onto the header.
 
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90sickfox

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I've had the same set of blue neoprene valve cover gaskets on one of my motors for years. They're reusable from advance auto. Can't count how many times I had them off....still not a drip.
 

General karthief

wonder how much it would cost to ship you a pair
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Just my thoughts here. Overthink'n, have you pulled that valve cover? I'm bet'n on it leaking. Heres why I think so, idle or a little above some oil splashing around, the shoulder where the valve cover sits is higher and the oil is not high enough to go over the edge, rev it up and the oil gets to fly'n around and gets over the edge. Too easy to just check it out, pull it and se.
Or don't and be a rolling oil slick, not to mention smoking kills.
 

Madlash93

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I've had the same set of blue neoprene valve cover gaskets on one of my motors for years. They're reusable from advance auto. Can't count how many times I had them off....still not a drip.
I have these exact valve cover gaskets, same with my oil pan gasket.

You have no hood on the car... imo the oil smoke is hitting the windshield and leaving residue on there.

This could happen with even a catch can, the oil vapor condenses on whatever it hits.

Just look at the valve covers, are the rails on them wet? you said #7 cylinder it's not hard to miss the hole with cork gaskets. when you get on it oil backs up in the valve covers then spills out onto the header.

I didn't use cork gaskets on my valve covers. this weekend i'll take the valve cover gaskets off and possibly put a tiny bead of RTV on them though id rather not with these more expensive neoprene gaskets. It does seem like the only real thing that could be leaking though, i just don't understand why it wont do it at high rpm just free revving, only while under load... even low RPM under load.

Here are my valve cover gaskets
https://www.summitracing.com/parts/fel-vs13264t/overview/make/ford

Here is my oil pan gasket
https://www.summitracing.com/parts/fel-os13260t/overview/make/ford

Here are my head gaskets
https://www.summitracing.com/parts/fms-m-6051-a302/overview/make/ford

Here is my rear main seal
https://www.summitracing.com/parts/fel-2941/overview/make/ford
 

madlash93-2

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Update: I had a hole in my cylinder 7 piston, I believe I might not have shaved enough material off for the ring gap on that cylinder as it looks like the ring buckled and broke the ring land.
(Sorry about the new account but I have been trying to get a password reset email for a while and it won't come through.) So some new Pistons and rings later and everything seems fine, just gotta' put some miles on it now.
 

Noobz347

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Update: I had a hole in my cylinder 7 piston, I believe I might not have shaved enough material off for the ring gap on that cylinder as it looks like the ring buckled and broke the ring land.
(Sorry about the new account but I have been trying to get a password reset email for a while and it won't come through.) So some new Pistons and rings later and everything seems fine, just gotta' put some miles on it now.


I've sent you a password for your old account through private message.
 

Davedacarpainter

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Update: I had a hole in my cylinder 7 piston, I believe I might not have shaved enough material off for the ring gap on that cylinder as it looks like the ring buckled and broke the ring land.
(Sorry about the new account but I have been trying to get a password reset email for a while and it won't come through.) So some new Pistons and rings later and everything seems fine, just gotta' put some miles on it now.
See there, I hadn’t thought of a hole in the piston!

How’d the cylinder wall look?