Bought a 355 Race Spec engine as discussed before and had it installed. The engine was built 6 months before I received it and sat until I bought it. The builder went through everything and even re-ringed it prior to install. they also took the heads off and completely went through the engine to ensure there were no issues upon install.

With that said here are my oil leak issues. I think it could be that the rings have not seated yet as it only has 50 miles on the new engine. bad PCV valve or too much crankcase pressure causing the pan gasket to continue to leak.

Here is what I have done to date.

- After install pan leaked at the front by the timing cover.

- Replaced oil pan gasket first time using silicone on top and bottom of FELPRO gasket. Oil leaked out the front and rear of the pan.

- Next time replaced oil pan gasket again this time only using RTV on the corners. Oil leaked only out of the front of the pan.

- Third time changed the pan as well as the gasket used "NO RTV" pan leaked out the front again.

- Fourth time took the car back to the builder they put a Moroso pan on and replaced the FELPRO gasket. Oil is still leaking out of the front of the pan as well as in 2-3 spots along the passenger side of the pan.

FACTs:

- Oil drips are always about 2-4 drips per spot, does not leak while sitting overnight or when not running.

- After replacing the pan/gasket or any combination it does not leak after replaced while idling. After 2-3 times of idling it starts to leak as pressure builds up.

- There is oil leaking out of the PCV valve grommet you can even see where it runs down the valve cover. The PCV does rattle but I have not yet checked it for suction.

Does anyone have any thoughts on this I am totally stumped on this one!

Thanks

 

Are they pulling the engine to change the pan and gaskets? The surfaces need to be clean and dry for things to seal up well. It's hard to do that with the engine in the car but I'm sure that several here might disagree. I would think that this would be the builder's problem to solve. Excessive crankcase pressure from blow-by is not hard to diagnose. It seems to me that if the rings were that loose (low tension oil rings?) that oil would be making it to the plugs. Oil tends to find even the smallest gap to leak from inside or out.

 

Builder told me to check the PCV valve so I am going to do that tonight. They also told me to run it for a 100 miles or so to get the rings to seat, if that doesnt work they told me to bring it back.

Pan has been done all 5 times with the engine in the car with the expection of when it was rebuilt.

Still confused why oil is leaking out the PCV grommet onto the valve cover.

 

Oh I forgot I am running 10:5:1 compression with a PCV (drivers side) and a breather (passenger side)....if that matters.

 

Double-check the the back of the intake, around the distributor, dipstick tube, front seal, and valve covers. All of these can 'look' like a pan or rear seal issue.

 

Dis, dipstick tube, and valve covers are spotless. Its almost as if there is too much crankcase pressue. So as the pressure builds it has to go somewhere and in return goes out the pan gasket. I really dont know totally confused.

But to date me and two other people have put on pan gaskets and everytime it leaks.

If thoes rings havent seated I would be sure to have some blow by.

Not sure just hoping someone had this issue before, and I hope its as easy as a bad PCV valve.

 

I doubt this helps but here is a picture of the setup.

 

Drivers side w PCV

 

Have you inspected timing cover for warpage where it meets oil pan? Clean surface? I went with a Milodon pan and 1-piece Fel-Pro oil pan gasket. Even with one-piece, I put a dab of black permatex on all engine facing corners of the 1-piece gasket so it gets into the cracks between block/main caps and block/timing cover.

How is the crank seal in the timing cover? Any indication oil is coming down the snout of the crank?

 

A) what material were the rings manufactured from? Some rings take longer to seat, find a long hill put the car in first and compression break down the hill a few times.
B) some times reringing is fine and other times the cylinders need bored and honed, don't know who built your 355" but assuming that they took it from 350" to 355" maybe it's all good there.
C) pull the pvc out with the engine running and put your finger over the bottom of the pvc valve, if there's suction then it's working, if it's working I would think that you shouldn't experience pressurization of the crank case.

 

I had similar problems with my new '69 Camaro until I put about 1,500 driving miles on the car.

 

It seemed like my 400" took for ever to seat the rings.

 

So before your rings seated did you have oil leaks?

 

A correctly built engine with the type of rings used today shouldn't really need any breakin, other than the cam (flat tappet).
The pressure in the pan is the same as the pressure under the valve covers and behind the timing cover. All those areas are connected and oil flows by gravity from those areas back to the pan. You could have blowby increasing internal pressures, but those pressures are not confined to the pan. Pressure in the pan should not force oil out since the level in the pan is well below the gasket.

 

do you have one of those high pressure oil pumps in it?

 

Only when my pvc wasn't connected and mostly valve covers. No issues now though. Everything I could find on the internet supports exactly what Bk has stated. So it had me worried for a while, but cleared up don't know how many miles it took as the odometer was dis connected. Made me wonder some about the hone as what I found on the net said that some rings take a different honing process to provide a different angle of the cross hatch( everything you read on the web has to be true right...lol ). But it cleared up.

 

I dont have a high pressure pump...its a stock pump with extended pick up for the deeper pan. I am going to check the PCV tonight when I get home after work. I am assuming there is something up there because of the oil coming out of the PVC rubber grommet....pretty sure it shouldnt do that.

Also I dont have the build sheet so I am not sure what rings went into the motor. These guys primarly build race engines so I would only assume that it was race spec equipment.

 

Ted

Timing cover looks good.....the builder checked it when they had the pan off last week. But the majority of the leak is coming from where the pan and timing cover meet in the front U of the pan.

 

Since you changed the pan and gasket. I assume it was done correctly, I think it's time to look elsewhere !!! Many times with nice clean oil, it will seep out of the valve cover and run down the side of the engine without you seeing it if it can get past the exhaust manifolds without burning. Then it hits the pan rail and can run all over!
You would blow the breather out of the valve cover before you would push past a siliconed oil pan gasket!
The last worst case scenario is a crack in the block. If this was your engine block that you had rebuilt, than you know if you blew a rod out the side but if this was a rebuilt core from someone else, you never know

 

I also had a small block 400 that had bolt holes in front of the block by the fuel pump. They were tapped so deep that oil started to seep out. I had to plug the holes with a bolt and Teflon tape. Rare but worth checking!