Valve Cover Gasket Question (yes, another)

-
Duster_Dean

Duster_Dean

Active Member
Joined
Feb 15, 2023
Messages
43
Reaction score
24
Location
NEPA
Hi everyone,

I've reviewed many of the threads on this topic and be,ieve I have a plan to fix my issue.
I have a 1970 383 engine in a 1975 Duster. I replaced both valve covers due to leaks. The drivers side is fine, however the passenger side is still leaking slightly. The gasket used was a Fel-Pro PermaDry Valve Cover Gasket VS50145R from Summit Racing with no RTV.
I've pulled the offending cover, cleaned it down to bare metal, checked for warp around and near bolt holes (no warp) and cleaned it with CRC Brake cleaner. On the engine I've soaked up the oil laying in the head and then used CRC Brake cleaner on the mating surface to remove any oil residue. I have RTV ready.
After reading the different threads on this I ordered different gaskets, Mr. Gasket Ultra-Seal Valve Cover Gaskets 5877, but also have a second set of the original Fel-Pro gaskets.

My questions are:
1.) Which gasket, the Fel-Pro or the Mr. Gasket, would be better for this application? I know sometimes newer techology (gaskets) do not play well with older tech (engine head casting imperfections).
2.) Since the leaks were only coming from the bottom side next to the exhaust manifold, should I only use RTV there, where the leaks were, or should it be used all the way around?
3.) Confirm that I should 1st RTV the gasket to the cover first, and then 2nd apply the RTV to the gasket prior to placing onto the head (not RTV the head and then place the cover/gasket assembly onto it)
4.) Confirm that minimal, but sufficient amount of RTV should be used.
5.) How long should I let the RTV set-up before running the engine?
6.) Is retightening after the engine has reached normal running temperature needed? If so, while hot or after it cools?
7.) If still leaking after running (prior to retighening), will retightening help or is it a waster of time at that point?

Since this is the second time attempting to fix this I want to give myself the best chance of success - it's a bit difficult since I need to pull the distributor up a bit to clear and the rear bolt of the cover is tough to reach (BB never meant to go into a Duster).

Thanks in advance for your input and advice
Cheers,
Dean
 
Before I switched to the reusable steel cored rubber gaskets, I had always put a thin coat of rtv over the entire cork gasket on both sides and immediately installed them. I’d let them sit for about 30 minutes before I started the engine.
The rubber gaskets are expensive but they are reusable and don’t require rtv
 
Be sure to check that there’s no interference and that your valve covers are sitting as they should. When I changed from a single plane intake manifold to a dual plane I had the smallest oil leak that took some time to find where it was coming from. The dual plane intake was stopping the valve covers from fitting properly and I filed down a small notch on my covers. Right where the intake and valve cover meets you’ll see where I had to file it down.
As far as gaskets go I went with the Real Tennessee gasket and am leak free.

IMG_4245.jpeg
 
Make sure you flatten all the areas where the bolts are so they are not pulled down.

Use a quality thick cork rubber style gasket and contact cement them to the covers.

Do not and I say again do not use any RTV sealer on the gasket . Install them dry after you glue them to the cover.

This is the method we use and none ever leak.

Not only that we use them over and over when checking valve adjustment. Just don't over tighten them to ruin the gasket. Snug them down with a short 1/4 inch ratchet or small T-bar and go around them a couple times. The Head should be wiped dry with Thinner or reducer as the gasket should also be dry. Any oil between them will promote a leak.

Good luck also use the correct bolts not hardware store bolts with washers. If you need factory bolts I have them. I also have The later style triangle washers. But you can get them off any later engine 85-92 small block.
 
When u contact cement to VC, are u only.putting dabs, or a continuous bead?
Oldmanmopar said:
Make sure you flatten all the areas where the bolts are so they are not pulled down.

Use a quality thick cork rubber style gasket and contact cement them to the covers.

Do not and I say again do not use any RTV sealer on the gasket . Install them dry after you glue them to the cover.

This is the method we use and none ever leak.

Not only that we use them over and over when checking valve adjustment. Just don't over tighten them to ruin the gasket. Snug them down with a short 1/4 inch ratchet or small T-bar and go around them a couple times. The Head should be wiped dry with Thinner or reducer as the gasket should also be dry. Any oil between them will promote a leak.

Good luck also use the correct bolts not hardware store bolts with washers. If you need factory bolts I have them. I also have The later style triangle washers. But you can get them off any later engine 85-92 small block.
Click to expand...
 
Duster_Dean said:
Hi everyone,

I've reviewed many of the threads on this topic and be,ieve I have a plan to fix my issue.
I have a 1970 383 engine in a 1975 Duster. I replaced both valve covers due to leaks. The drivers side is fine, however the passenger side is still leaking slightly. The gasket used was a Fel-Pro PermaDry Valve Cover Gasket VS50145R from Summit Racing with no RTV.
I've pulled the offending cover, cleaned it down to bare metal, checked for warp around and near bolt holes (no warp) and cleaned it with CRC Brake cleaner. On the engine I've soaked up the oil laying in the head and then used CRC Brake cleaner on the mating surface to remove any oil residue. I have RTV ready.
After reading the different threads on this I ordered different gaskets, Mr. Gasket Ultra-Seal Valve Cover Gaskets 5877, but also have a second set of the original Fel-Pro gaskets.

My questions are:
1.) Which gasket, the Fel-Pro or the Mr. Gasket, would be better for this application? I know sometimes newer techology (gaskets) do not play well with older tech (engine head casting imperfections).
2.) Since the leaks were only coming from the bottom side next to the exhaust manifold, should I only use RTV there, where the leaks were, or should it be used all the way around?
3.) Confirm that I should 1st RTV the gasket to the cover first, and then 2nd apply the RTV to the gasket prior to placing onto the head (not RTV the head and then place the cover/gasket assembly onto it)
4.) Confirm that minimal, but sufficient amount of RTV should be used.
5.) How long should I let the RTV set-up before running the engine?
6.) Is retightening after the engine has reached normal running temperature needed? If so, while hot or after it cools?
7.) If still leaking after running (prior to retighening), will retightening help or is it a waster of time at that point?

Since this is the second time attempting to fix this I want to give myself the best chance of success - it's a bit difficult since I need to pull the distributor up a bit to clear and the rear bolt of the cover is tough to reach (BB never meant to go into a Duster).

Thanks in advance for your input and advice
Cheers,
Dean
Click to expand...


What brand of valve covers are you using???

When we installed the cast aluminum valve covers (I believe they were the M/T covers) they leaked... We installed 7 different types of gaskets on them including the fel-pro neoprene ones and they still leaked...

We talked to some others at the Mpoar Nationals that weekend and they told us that those valve covers are junk... We changed to a different brand and they sealed first time...
 
I found these, been using them for years, no leaks. They’re reusable.

IMG_5263.jpeg
 
Keep in mind that if the PVC system isn't working properly some gasket is going to push out somewhere.
 
krazykuda said:
What brand of valve covers are you using???

When we installed the cast aluminum valve covers (I believe they were the M/T covers) they leaked... We installed 7 different types of gaskets on them including the fel-pro neoprene ones and they still leaked...

We talked to some others at the Mpoar Nationals that weekend and they told us that those valve covers are junk... We changed to a different brand and they sealed first time...
Click to expand...

Krazykuda -
See below. The 'Mopar' cover is the one that was on the car and failed twice. I purchased the chrome stamped cover because I've heard before that the cast aluminum are problems.
To be 'safe' (?) I'm going to use the stamped cover instead of the flashy Mopar cover.
I'll gentle use sealer between the gasket and cover.
The concensus seems to be to NOT use sealer between the gasket and head surface (even though that is where it leaks) so I won't use sealer there.
If it works then I'll switch out the drivers side cover also.

I'll let you all know how it turns out!
Thanks again.

Duster valve covers.jpg
 
Duster_Dean said:
Krazykuda -
See below. The 'Mopar' cover is the one that was on the car and failed twice. I purchased the chrome stamped cover because I've heard before that the cast aluminum are problems.
To be 'safe' (?) I'm going to use the stamped cover instead of the flashy Mopar cover.
I'll gentle use sealer between the gasket and cover.
The concensus seems to be to NOT use sealer between the gasket and head surface (even though that is where it leaks) so I won't use sealer there.
If it works then I'll switch out the drivers side cover also.

I'll let you all know how it turns out!
Thanks again.

View attachment 1716112950
Click to expand...
It's difficult to get anything to stick to chrome. We have seen a few of our mopar cast timing covers chrome plated. Guess why they aren't popular and/or more often seen?
 
Duster_Dean said:
Krazykuda -
See below. The 'Mopar' cover is the one that was on the car and failed twice. I purchased the chrome stamped cover because I've heard before that the cast aluminum are problems.
To be 'safe' (?) I'm going to use the stamped cover instead of the flashy Mopar cover.
I'll gentle use sealer between the gasket and cover.
The concensus seems to be to NOT use sealer between the gasket and head surface (even though that is where it leaks) so I won't use sealer there.
If it works then I'll switch out the drivers side cover also.

I'll let you all know how it turns out!
Thanks again.

View attachment 1716112950
Click to expand...

Ok, follow up on the gasket and it leaks worse now than before - I resembled the old time mosquito patrol with a cloud bellowing behind me. Followed all directions to a 'T' inc;luding let it cure for 24 hours but no luck at all. Leaking along the bottom at the back I think, but air flow may have pushed it to the back. Next step is to take it to a shop - at least if it leaks I can take it back as many times as I need to.
 
Use the Blue Moroso or the black buna rubber coated felpro units. Always glue vc gasket to vc so you can check the valves and not waste gaskets. If you have too much oil up top or poor drainback in the heads you end up having to glue them on which is a PITA.
My blue Moroso gaskets have been on three engines over 20 years
 
Update - the way the oil was pouring out (there's a line going up my driveway and where the car sat for a minute) I have a feeling I pinched or otherwise messed up the gasket placement. It's like a puzzel trying to get the back of the right side VC on, working to get around the blower motor. My son (the mechanic) is going to help me this week and I'll post a follow-up after that.
 
The picture below explains the massive leak - must have caught the the gasket on the rockers trying to shoe horn the cover into place.
Well the chrome stamped covers were ****. The gasket surface wasn't nearly wide enough for the gasket. Must be china crap as it was also too short for the gasket - the same gasket that fit perfectly in the Mopar cast covers.

Avoiding tearing up the new gasket:
In the engine bay I moved everything that was in my way - heater hoses, distributor, coil wire, etc. and held them out of the way with bungee cords.
With an unobstructed work area I first glued the gasket to the cover (continuous bead after cleaning cover surface completly to metal) and then applied weight to it as I had read in another thread. I let it cure completly and cleaned out the holes where some rtv had pushed into.
With everthing out of my way i was easily able to place the VC onto the head without banging it around - letting the rtv cure helped as well since lite bumping won't move it like the picture below.
I have the screws all started and run down to the point they hit the cover.

Now I'm paranoid about how much to tighen the bolts, both initially and after a short test drive recheck. I can't get a torque wrench to the back bolt without using a universal, which I have heard will throw off the torque reading. I'm a typical 'over-tighener' which I know needs to be avoided. So, how tight is tight enough?
I guess we'll see!

Verdict to follow......

20230725_171907.jpg
 
A happy ending - test drive shows no leaks / smoking.
Thank you all for the advice and experiences with this!
 
You must log in or register to reply here.
-

Back
Top