Lotus Elan

cometic cam cover gasket

PostPost by: J J DIKKE » Sat Jan 18, 2020 6:56 pm

hello again, i think that i intend to use the cometic cam cover gasket on my twincam engines and not the cork standard type. could anyone give a view as to the type of gasket product i should use on each side of this type of gasket to avoid any oil leaks at all. thank you.
J J DIKKE
First Gear
First Gear
 
Posts: 17
Joined: 27 May 2018
Location: North of England

PostPost by: Grizzly » Sat Jan 18, 2020 7:23 pm

This has been covered before but i know this forums search engine isn't the easiest to find what your looking for.


So, the Cometic cam cover gasket is only usable in my opinion if you have first checked the head and cam cover is flat!! The cover does tend to warp and if there is any warpage you will really struggle to get a Cometic gasket to seal.

Thats why the cork gasket is good as it gives you a much bigger tolerance to warpage.

As for gasket sealer it depends how well you want it stuck....... i use a smear of permatex aviation sealer which does the job fine but i know a number of people that use permatex ultra grey, but it has been known to cause future cam cover removal issues and is a bit ott in my opinion.. Again it depends how flat your two mating surfaces are.
Chris
User avatar
Grizzly
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1964
Joined: 13 Jun 2010
Location: Cheshire/UK

PostPost by: Mazzini » Sat Jan 18, 2020 7:31 pm

And the D plugs have to align with the level of the head or it won't seal.

Stick with cork.
User avatar
Mazzini
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1899
Joined: 11 Dec 2010
Location: NE UK

PostPost by: Grizzly » Sat Jan 18, 2020 7:57 pm

O and i'd suggest replacing the rubber coated steel locking washers every time you remove the cam cover to prevent oil leaks from round the studs.
Chris
User avatar
Grizzly
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1964
Joined: 13 Jun 2010
Location: Cheshire/UK

PostPost by: patrics » Sun Jan 19, 2020 9:35 am

Hi
If you have a brand new head and cam cover it might work, but my experience on an old head and cam cover it was useless - don't waste your time - or your oil for that matter .

Regards
Steve
patrics
Fourth Gear
Fourth Gear
 
Posts: 542
Joined: 21 Sep 2003

PostPost by: J J DIKKE » Sun Jan 19, 2020 11:13 am

hello again, thanks for the info and opinions thus far these are good. i have a brand new 4k head on my newly rebuilt engine and i have had 3 of my cam covers skimmed to flat. i had considered using permatex aviation, form a gasket liquid on both sides of the cam cover gasket, either cometic or standard cork. i simply wish to be as sure as i am able that this expensive engine will not leak oil, at least from the area we are discussing at this point. i also have additional ideas in respect of the rubber/steel washers on the cam cover studs if any one may be interested. thank you, dennis.
J J DIKKE
First Gear
First Gear
 
Posts: 17
Joined: 27 May 2018
Location: North of England

PostPost by: JJDraper » Sun Jan 19, 2020 11:17 am

patrics wrote: but my experience on an old head and cam cover it was useless - don't waste your time - or your oil for that matter .


+1 on my +2 on this. Leaked appallingly at the 'D' plugs. Cometic thermostat housing gasket - brilliant and reusable.

Jeremy
User avatar
JJDraper
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1012
Joined: 17 Oct 2004
Location: Buckingham, UK

PostPost by: Davidb » Sun Jan 19, 2020 4:27 pm

JJ Dickk: Have you read through this thread:
viewtopic.php?f=39&t=45590

I ordered a sheet of the nitrile rubber but have not used it yet.
'65 S2 4844
Davidb
Fourth Gear
Fourth Gear
 
Posts: 871
Joined: 02 Jul 2009
Location: Vancouver, Canada

PostPost by: Elan45 » Mon Jan 20, 2020 3:23 pm

I wrap the D plugs w/ the plumber's teflon pipe thread sealing tape. Once around, maybe 1-1/2 times is all you need. The little bump on the D plug will push out through the tape and keep the plug from loosing position latterly. Don't wrap it too tightly. You want a small amount of build-up.

Roger
'67 Elan S3 SS DHC
'67 Elan FHC pre-airflow
'67 Elan S3 SE upgrade to 26R by Original owner
'58 Eleven S2 (ex-works)
'62 20/22 FJ (ex-Yamura)
'70 Elan +2S RHD
'61 20 FJ project
'76 Modus M1 F3
Elan45
Fourth Gear
Fourth Gear
 
Posts: 885
Joined: 23 Nov 2008
Location: Ohio, USA

PostPost by: Mazzini » Mon Jan 20, 2020 6:32 pm

Elan45 wrote:I wrap the D plugs w/ the plumber's teflon pipe thread sealing tape. Once around, maybe 1-1/2 times is all you need. The little bump on the D plug will push out through the tape and keep the plug from loosing position latterly. Don't wrap it too tightly. You want a small amount of build-up.

Roger


If I understand Jeremy correctly and I think I experienced the same issue, the problem is not the D plugs leaking on their circular face, but on the top surface. The Cometic gasket has no give in it, so if the top of the D plug is proud of the head face the Cometic gasket acts like a bridge and leaves an airspace underneath, that's where the leaks come from.
User avatar
Mazzini
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1899
Joined: 11 Dec 2010
Location: NE UK

PostPost by: el-saturn » Mon Jan 20, 2020 8:52 pm

i use a cometic at the bottom and a thicker cork type on top - no ltv, no mess - and open whenever i want to sandy
el-saturn
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1421
Joined: 27 Jun 2012
Location: switzerland

PostPost by: Rich » Mon Jan 20, 2020 9:44 pm

I have been using a Cometic valve cover on my twin cam with good results. Its definately and improvement over the cork seal.
Rich
First Gear
First Gear
 
Posts: 19
Joined: 29 May 2016
Location: Cincinnati, OH.

Total Online:

Users browsing this forum: No registered users and 15 guests