Oil Filter Plate

-

73smallblock

Well-Known Member
Joined
Nov 4, 2015
Messages
353
Reaction score
362
Location
PA
I have a friend who's just wont stop leaking. We have replaced the gasket twice and it still leaks. The engine is a fresh build with maybe 10 miles on it now. The block was tanked prior to the build. Is it possible the plate is bent in some way? Has anyone tried double gasket's with any success?

I am not talking about a 90* adapter, just the factory metal plate.

Thanks
 
I would remove the plate and look real hard for a chunk of old gasket on there.
 
I wouldn't double gasket it, check it for straightness or find another one.
 
Mine was leaking after my build and found that my high volume pump and 80psi pressure was too much against that factory plate. Just not enough holes.
 
I added additional holes in mine when i did my 360 yrs ago, seems to have help keep it alive after years of abuse.
 
I have a friend who's just wont stop leaking. We have replaced the gasket twice and it still leaks. The engine is a fresh build with maybe 10 miles on it now. The block was tanked prior to the build. Is it possible the plate is bent in some way? Has anyone tried double gasket's with any success?

I am not talking about a 90* adapter, just the factory metal plate.

Thanks
I used a Canton racing oil filter plate 22-575...end of problem.
 
Sorry crewchief, I should have quoted 73smallblock. I was wondering if he used a Magnum plate on an LA block. I think they different.
 
Sorry crewchief, I should have quoted 73smallblock. I was wondering if he used a Magnum plate on an LA block. I think they different.
No problem, I believe they are different. Canton's is a CNC-machined billet aluminum filter plate with an O-ring instead of a gasket.
 
There definitely is no old gasket on there. No, the original one was reused. not magnum. The block is an early 70's. I sent him a link to the Canton plate and he said he's going to order it tonight. It does have a hv72 pump on it, however I also have one and haven't had an issue. Maybe it's just one of those things.
 
I spent months trying to fix what I thought was a leak at the oil filter plate. I eventually found that it was the rocker covers leaking and it runs down the back and drips off the filter plate. the mopar performance covers need clearancing where they bottom out on the inlet manifold branches!
 
Did you use both gaskets ?

Both gaskets?

I ran my hand around the back corner of the head thinking it may be the valve cover but it appears to be dry. Wouldn't hurt to check again.
Thanks for the replies so far!
 
Yes, check EVERYWHERE
Wrap a paper towel around it, tape it off and go for a spin
Then remove the towel and see, is the oil on the inside or on the outside?

I THOUGHT I had a leaking plate
Even went with the Canton plate, and it still leaked...because it wasn't the plate, it never was

I had a bad rear main seal, and the oil fell onto the converter which swung it back up and guess where it landed?
 
I did most of the oiling mods listed in the sticky,and I also ported the pump and the passages,and I also opened the passages to my top end some,partly to ease the pressure, mostly to cool my springs,and you know that bolt that holds the plate on; there are two kinds; one with a 3/8 sq drive in the center of it, and the other has a hex around the outside. Guess which one is a restrictor; hyup the sq. drive one. I threw mine out and installed the hex drive. I might even have drilled the center out, but that was 20 years ago so I'm a lil hazy on the details.
The HV pump is a brute. Mine still blew the filter off; I thought the filter was a pos. But every filter I tried was same story. So then I took the 15W40 oil out, and tried a 10W30, and it still ballooned.
Soooooooo, I double-plated, double holed the plates, and end of problem.
And I still run the 10W30.


FWI
in the block, the large oiling passage from the pump has a cup-plug installed to divert the oil to the filter. And the oil then returns to the gallery above the plug. The passage has a step milled into it to stop the plug from going in too deep.
But there is no way to tell if it is in deep enough, except the experience of the installer to feel it stop, as he is driving in the cup. So far no problem; if not installed deep enough it becomes a restrictor to the entire oiling system, but the filter won't blow off and you won't see it on the pressure gauge.
But if the installer manages to drive it in too deep, then the pressure will back up and blow the filter off, and you still won't see it on the gauge, except perhaps if you knew what to look for.
There may be a depth spec for this cup-plug, but I don't recall ever seeing one.
The point is; that if drilling extra holes doesn't cure your plate ballooning, then you may have to dig deeper. If the plug is of the wrong size or type, or installed wrong, you could loose rod bearings, as the rpm goes up.

Furthermore, even with everything perfect, Guess what controls your oilpressure, before it blows the relief valve off; that's right internal clearances; mostly the main and rod bearings. So if you are running a straight 40 or 50 oil, and your clearances are very tight, the pressure is just gonna back up until it blows the relief valve........ and the filter plate could just be a tell-tale fuse.
 
Last edited:
Just the large outer gasket was used. Interesting to hear about the square being a restriction. His has the hex on the outside.
 
In some gasket kits there is a smaller round gasket that looks like it should go between the plate and the block where the hollow stud goes. Do NOT use this with the stock plate.
There are two diff thickness for small gaskets that comes in over haul kit thick for 90 adapter thin for stock
 
FWI
in the block, the large oiling passage from the pump has a cup-plug installed to divert the oil to the filter. And the oil then returns to the gallery above the plug. The passage has a step milled into it to stop the plug from going in too deep.
But there is no way to tell if it is in deep enough, except the experience of the installer to feel it stop, as he is driving in the cup. So far no problem; if not installed deep enough it becomes a restrictor to the entire oiling system, but the filter won't blow off and you won't see it on the pressure gauge.
But if the installer manages to drive it in too deep, then the pressure will back up and blow the filter off, and you still won't see it on the gauge, except perhaps if you knew what to look for.
There may be a depth spec for this cup-plug, but I don't recall ever seeing one.
Hey AJ, you would have to drive that plug several inches too deep the get it up into the upper flow passage that carries the flow out of the filter! So not very likely!

There may not be a depth spec, but it has been measured and reported here before (by myself and others).

And BTW, the HV pump only flows 18-20% more than the stock one, so is not any big deal at all. You may have had a combination of the extra flow AND the higher pressure relief spring, or more likely your relief piston was/s inverted or sticking and was not ever relieving the pressure. It takes well past 100 psi to blow even the cheapest filters gaskets... ask me how I know!
 
Sorry crewchief, I should have quoted 73smallblock. I was wondering if he used a Magnum plate on an LA block. I think they different.
Yes, the Magnum plate has less relief than the LA one, and will not clamp any where near adequately on the block gasket unless it is 'modified' in a press. The OP's friend's plate could well be bent or has been deformed. It works by the spring action of the steel against the outer gasket, but it is not spring steel so if pushed too far in the center, it will deform and then not put adequate pressure on the outer gasket.

I would not hesitate to put PermaTex #1 on a gasket like that. It might help.
 
Lots of great info! He has received the Canton plate and we are going to try that, just waiting for a warmer day. Temps here are not going to go above freezing for the next week and the car is in an unheated part of the garage.
 
Oh come on now! I've changed starters in 10F with howling winds, and snowmobiled in -35F all day. Where is the true gearhead spirit? LOL
 
-
Back
Top