440 under load oil leak

Just built a HP 440 cop motor with a new oil pan and all new engine gaskets/seals installed. Sandwich gaskets on windage tray etc. Does not leak parked. Does not leak at idle. BUT if you do a burnout or full throttle start, there is a speckled trail of oil on the pavement. I made sure PCV was not bottoming out on oil shield, still does it. My wrench thinks it is the pan rail. I may rig a GOPRO under it today. Just thought someone here may have had same experience. Thanks, Phish

Did you break it & to let the rings seat?

Yes we put zinc in it to break in cam (2 to 3k)for about 30 min and have been up and down the road a few times. No blowby or smoke out of exhaust. This is an engine oil leak when under power. Thanks

By the pic I only see a PCV valve on the passenger side and NO breathers. Under full throttle there is no vacuum to operate the PCV valve and with no breathers you're building internal pressure. You're most likely pushing oil past seals and gaskets. I'd install breathers in both valve covers to cure the problem.

I think you got the break in question because from what you describe it appears to be acting like the crank case is getting pressurized somewhat when you get on it hard.

Years ago I had one do that whenever I'd get on it hard. It would cause oil to seep through the windage tray gasket setup and sometimes would even blow a little through the valve covers. I was concerned I hadn't gotten the rings to seat properly and was starting to think I needed to start over.

See the picture of your engine could I suggest changing out the driver's side valve cover setup to a breather cap rather than the twist to close filler cap and see if that helps any. Also make sure you've a good strong vacuum signal where the PCV hose is hooked to the engine. You may even need to add a second breather cap.

Switching that stuff around stopped the problem for me and the engine ran great for years.

As said I would add a breather in the round knockout there showing on the rear half of the drivers valve cover for starters to get the system plumbed back to "normal" & see how it acts & I would clean the lower eng at the car wash & then romp on it & pin down exactly where it is leaking from & if needed put it up on stands & nail it to see where the leak is. Might be excessive blowby & you get ONE shot to have a good ring breakin/seal & there's a good read at www.mototuneusa.com & scroll down & read "breakin secrets". it's a motorcycle site but the principle is the same but hopefully a breather will take care of this for you.

Fixin' to go out and run it with the oil cap off. Back in a bit. Thanks

Agree that a breather is required even if this is not the cause of your problem

I never woulda thought, cajun engineering at its best!

In the past, I would try to put about 500 miles on a car so the rings can properly seat before getting on the throttle hard & heavy.

If the rings are not seated properly, blow by as mentioned above.

I do believe you guys solved it. The rings have not been broken in properly and it has no breathers. It is stripped for paint ie no lights or bumpers so really cant put any miles on it. Will put it back on lift, clean it up, install breathers and send it to paint prison. Break in miles after that. Thanks folks.

PS Did you know 29 Cajun names end in EAUX. Building this to run in Lemons 24 race so I hope I haven't hurt the rings. Baby has to run for 24 hours!!!! CAJUN PEAUX PEAUX

If you have a compression tester you can use it to evaluate your ring seating progress in each cylinder.

With the last engine I did, the numbers started out low & varied but after 500 miles the numbers were consistent & at the higher end of perfection.

the gist of the motortune article is that you have ONE IMMEDIATE shot to get an excellent ring seal with good blowby numbers as opposed to a good or mediocre one & their take is to load it HARD repeatedly by goosing it during breakin (helps cam breakin too). it is commonly thought that they will breakin further with some miles & I definitley dont have the last word on that yea or nay but I would read the article & see what you think.

If you can find one of the old Mopar bibles on engine building and proper break in procedures they tell you to take the car out as soon as the cam is broken in and run it in low gear, no matter what rear gear ratio, up to 5000 RPM at WOT and let off until it slows down in gear to a idle an do that 4 more times and then the same thing in 2nd gear 5 times and finally again in high gear. I watch the water temps and if it starts to get above 220 F I stop and let it cool down, they want you to cool it down rapidly by draining the radiator with a cold water hose in it after the final WOT blast also
That flat works very well

One additional thought: when you're adding breathers, be sure there's a baffle under it inside the valve cover. Otherwise you'll probably start accumulating oil in the breathers and that will eventually start messing up your engine compartment.

Ask me how I know this.

The break in procedure Cab describes is what I'd learned years ago, particularly with chrome moly rings. I believe the theory was you are heating them up good during hard acceleration, then cooling them somewhat with the deceleration and further with the temp cool down cycles . It always seemed to work for me plus it was great fun putting your foot in it to see how the engine felt.

I'd usually then take it a step further and go out on the highway and run 5-10 minutes at various speeds, then change up after a couple short blasts and coasts. I liked to do this for a half hour or so.

Once or twice I did see someone manage to glaze the cylinder walls during break in. It would be obvious there was a problem as they'd tend to smoke from lack of adequate oil control.

If I recall correctly, thinking at that time was cast rings didn't require such an aggressive break in procedure.

Guys we put it on the rack and found it. Split dipstick tube at bottom. We did install the breathers with baffles and did the 1st and 2ng gear WOT and deceleration breakin etc. Oil leak was not as bad but still a few drips. The split probably was spewing when I had the sealed VC's. This thread was perfect timing (pun as we put the ready to run MSD setup in it). This is a real E86 cop motor and I can just imagine when a young trooper was issued one of these in 1974. Big azz C body and we have 150 lbs of junk in the trunk; it will fry 'em stopped or rolling. Thanks again. Phish