Page 1 of 2 12 LastLast
Results 1 to 10 of 15
  1. #1
    Join Date
    Jun 2004
    Location
    Northampton
    Posts
    1,369

    Rocker cover gaskets, to seal or not to seal?

    Got some more metal reinforced neoprene gaskets to hopefully cure a small oil leak. So the options are:
    1 Don’t put anything on them.
    2 Stick gaskets on the rocker cover with Hyolmar to hold in place whilst fixing. Leave other side.
    3 Stick gaskets on rocker cover with silicone to hold in place then thin bead of silicone on the head.
    4 Another way?
    I’ve got Edelbrock alloy covers so they are quite true and flat but I think the weak point is the thin uneven rim where the gasket is mating to on the head. The width of this is about half the gasket width. (see photo).
    Thoughts please?
    Dek
    945C3776-DCEE-46B2-8329-4A57C495F9A2.jpeg945C3776-DCEE-46B2-8329-4A57C495F9A2.jpeg

  2. #2
    Join Date
    Jan 2005
    Location
    leatherhead,surrey
    Posts
    965
    i'd sikkaflex the rocker gasket to the head,and leave the cover plain - it'll create a sort of dam the oil has to get past to drip
    get it as oil free as you can before glueing.........brake cleaner/thinners
    neil

  3. #3
    Join Date
    Jun 2004
    Location
    Northampton
    Posts
    1,369
    Quote Originally Posted by neil still building it View Post
    i'd sikkaflex the rocker gasket to the head,and leave the cover plain - it'll create a sort of dam the oil has to get past to drip
    get it as oil free as you can before glueing.........brake cleaner/thinners
    neil
    Thanks. That’s certainly number 4. I’d be slightly concerned if I ever wanted to remove it though. That stuff sticks!
    Dek
    Last edited by Dek; 11-07-18 at 09:57 AM.

  4. #4
    Join Date
    Feb 2011
    Location
    Northampton
    Age
    40
    Posts
    3,397
    I'd stick them to the head with Hylomar Blue - looking at the head finish you want something with reasonable gap filling properties and that should tick that box.
    My DeDion build diary..
    Hon Sec of the Digidash branch of the Unpopular Kit Car Design club

  5. #5
    Join Date
    Apr 2004
    Location
    East Leake, Nottinghamshire, England.
    Age
    54
    Posts
    9,318
    I agree Hylomar blue to stick them to the heads but nothing on the covers. I have these on my engine and have nothing on it at all and they have never leaked at all.
    Martin

    351W 416.7 HP and 466.8 ft-lbs

    Running Mega Squirt and Edis 8


  6. #6
    Join Date
    Oct 2005
    Location
    Cape Town, RSA
    Age
    54
    Posts
    120
    Here is a new one (#5), which I am doing since 30 years: Silicone to valve cover and grease to head. We set valves after every run...
    Works without grease if you have a rubber gasket, as used in the 90s in the stock BB Chevy valve cover. Or the blue aftermarket one.

    Lasts a lifetime.
    Nothing is as it seems...

  7. #7
    Join Date
    Jun 2004
    Location
    Northampton
    Posts
    1,369
    Quote Originally Posted by aaronjb View Post
    I'd stick them to the head with Hylomar Blue - looking at the head finish you want something with reasonable gap filling properties and that should tick that box.
    Thanks Aaron, that’s what the chap at CM Frost, Dennington Estate, Wellingborough where I bought them advised. First time I’ve used them but would certainly go back. Very helpful. Get deliveries from the States every week. Have you used them?
    Dek

  8. #8
    Join Date
    Jun 2004
    Location
    Northampton
    Posts
    1,369
    Quote Originally Posted by TINKA View Post
    I agree Hylomar blue to stick them to the heads but nothing on the covers. I have these on my engine and have nothing on it at all and they have never leaked at all.
    Thanks Martin. I tend to agree any leaks are likely to be on the under surface between the gasket and the head. The trouble with my SBC heads is that the rim is a good bit less wide than the covers, hence less surface area to make an effective seal plus the edge is not flat but slightly curved, plus it’s not smooth! And with only 4 screws to hold it down there must be areas where there is not equal pressure. Apart from that it’s all good. With decent mating flat surfaces you can usually get away with a cork gasket but that wouldn’t be suitable for this. Even with the neoprene one it’s going to need some help. Last time I used silicone and if it is the rocker covers leaking (if) it hasn’t stood the test of time so keen to try something else. I notice it’s non setting but is it still advisable to stick it on the heads and leave overnight?
    Cheers.
    Dek.

  9. #9
    Join Date
    Jun 2004
    Location
    Northampton
    Posts
    1,369
    Quote Originally Posted by dominik View Post
    Here is a new one (#5), which I am doing since 30 years: Silicone to valve cover and grease to head. We set valves after every run...
    Works without grease if you have a rubber gasket, as used in the 90s in the stock BB Chevy valve cover. Or the blue aftermarket one.

    Lasts a lifetime.
    Thanks for adding to the list. I remember using grease on the old cork gaskets. I don’t intend having them off every run though, perhaps every couple of years.
    Dek

  10. #10
    Join Date
    Nov 2008
    Location
    Guildford
    Posts
    291
    I always use cork gaskets, but the approach may be possible with your gaskets. Spray top side of gasket with contact adhesive and locate it in the rocker cover, making sure bolt holes are lined up and all edges are in the right place. Turn around and put on flat surface with a weight on top and let cure over night. Use studs instead of bolts. Put studs into heads and then carefully put rocker cover ,with a light rub of oil around the bottom of gasket, onto the heads.Torque up the nuts to the correct setting, careful not to crush the gaskets.

    I have been told that the main reason leaks occurs if you try and put the gasket down first and then the gasket moves when you put the rocker covers on. I also dont like the idea of using some sort of sealer between the heads and gaskets. Its a bit of a mare when you come to change gaskets.

Page 1 of 2 12 LastLast

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •