Aluminium Rocker Cover Gasket?

[Mike 77]

Hi please accept the naivety of this question as it's only my second post. I am trying to replace my cork rocker cover gasket with a silicon version as the cork one is seeping at one corner. Should I torque the rocker cover as per the workshop manual (0.15 to 0.3 kgf m) or should it be tighter as it's a silicon gasket?

[Motorsport Mickey]

Mike, I’ve used cork gaskets on Alloy rocker covers for years.

Clean off the Alloy cover with thinners and let dry. Wipe clean with dry cloth and wipe the alloy cover mating service with Wellseal and place the cork gasket in position on it. Turn the alloy cover over and place on a flat surface ( piece of glass on table does it) and place a couple of bricks on top of the alloy cover overnight. 
Wipe the top of the cylinder head where the gasket touches clean of oil and debris, and wipe the dry face of the gasket on the alloy cover with a spot of clean oil spread across the surface and round it… and bolt it on. It’s flat clean surface to… flat clean surface… why wouldn’t it seal even with the lightest of nip ups ?

If it doesn’t suspect the alloy cover is twisted, try and check it by smearing a wipe of oil onto the cleaned sealing surface leaving a “damp”residue on the bottom edge and place onto the  piece of glass used previously, check for confirming seal mark on the glass when you remove. 
What silicone gasket do you have ? You need one with a locating bead on it which fits to corresponding groove in Alloy cover… otherwise it’s like a greased pig !

 

Mick Richards

Edited May 18, 2023 by Motorsport Mickey

[Mike 77]

Hi Mick thanks for your prompt reply much appreciated. I have purchased a Moss Europe silicon gasket which I have attached to the Rocker Cover with Wynns Gasket Maker - with the curved edge against the Rocker Cover and so the flat edge will seal (hopefully) against the cylinder head. There was no locating bead so it was a bit of a faff to centre it on the Rocker Cover.

I will check to see if the Rocker Cover is not twisted - although I have attached the silicon gasket now! Should have asked for help earlier.

Will the torque settings be the same whether it's a cork or silicon gasket!

Thanks again.

 

Mike

 

[Motorsport Mickey]

Hi Mike,

The cork gasket is much firmer and when trapped between head and cover which are flat , doesn’t want to squeeze out much at all under torque.

 The silicone gasket has to be placed carefully and then tightened even more carefully. If the rocker cover is machined to match the profile it helps retain it, but on unmachined covers I tighten by hand and by eye checking along the edges until I feel it’s sealing.

Mick Richards

[Waldi]

Just a question:

Where can you buy a rocker cover with a locating groove for the silicon gasket, I have seen it mentioned before but never saw one?

Thanks,

Waldi

[TR NIALL]

24 minutes ago, Waldi said:

Just a question:

Where can you buy a rocker cover with a locating groove for the silicon gasket, I have seen it mentioned before but never saw one?

Thanks,

Waldi

Racetorations do one but you need Deep Pockets.

[Drewmotty]

You can get a local machine shop to mill a slot for you. 

[PodOne]

45 minutes ago, Drewmotty said:

You can get a local machine shop to mill a slot for you. 

Excellent idea! 

Just for completeness I siliconed the gasket to the rocker cover by firstly using masking tape inside and out for a neat finish and then placed a flat bit of glass with a heavy weight on top for 48hours. No sealing compound between head and gasket and tightened to around 10ft/lb. No leaks yet but then it hasn't been tested yet!

If it does it will get milled.

Andy

[Mike 77]

51 minutes ago, Drewmotty said:

You can get a local machine shop to mill a slot for you. 

 

[Mike 77]

Thanks Mick and all for the replies/advice much appreciated.

 

Mike

[Waldi]

10 hours ago, TR NIALL said:

Racetorations do one but you need Deep Pockets.

Thanks Niall,
I looked it up: it is made from a billet, which explains it’s price. It looks very well made.
Racetorations also say this avoids leaks through the wall, which can occur on a cast cover (again: according to Racetorations). 
I hope it has a baffle plate inside too to avoid excessive oil (mist) loss to the inlet plenum, as the original pressed steel item.

Here is a link: https://www.racetorations.co.uk/product/billet-aluminium-waterfall-rocker-cover-tr5-6/

Cheers,
Waldi

[Steves_TR6]

The Racetorations alloy cover actually uses an o-ring real 

my car came to me in 2012 with the racetorations cover but with a bodged cork gasket.

Darryl at racetorations sent me a new o-ring which i stuck in to the groove with a little instant gasket and then oiled,  it’s work perfectly ever since 

Steve

[Andy Moltu]

If you have an ally rocker cover you may well be able to get a groove machined in it to accept an o ring (3mm if I recall correctly) You can buy o ring in a suitable length, cut obliquely and stick together.

Not all alloy covers have enough meat to enable this.

[astontr6]

On 5/19/2023 at 5:42 AM, Waldi said:

Thanks Niall,
I looked it up: it is made from a billet, which explains it’s price. It looks very well made.
Racetorations also say this avoids leaks through the wall, which can occur on a cast cover (again: according to Racetorations). 
I hope it has a baffle plate inside too to avoid excessive oil (mist) loss to the inlet plenum, as the original pressed steel item.

Here is a link: https://www.racetorations.co.uk/product/billet-aluminium-waterfall-rocker-cover-tr5-6/

Cheers,
Waldi

Racestorations original aluminum rocker covers were porous! I had to have mine vacuum sealed and it leaked around the filler cap. To salvage it I had to have the neck taken out. Then counter bored and have a motor cycle oil tank filler assembly welded in no problems since. I was was not  impressed by Racetorations attitude to this fault? Custom service was not one of there good points.

Bruce.