silicone gaskets

[JonE]

http://www.ba7c.org/technicalArticles/ga...skets.html

Was thinking of making a sump gasket as per this article. Any people already done this... and can report worthwhile?

[Bob Culver]

Not relevant to the actual question, but to the article referenced. Thick hub gaskets cause the large wheel bearing to not be clamped, a prolific cause of these working loose in housing. (Ball wheel bearings will function for years with little more than  the races packed with grease. Unless wading  the original advice to pack hubs is obsolete.)

[Ian Williams]

Yes Jon and they work well on sumps.

[Bob Kneale]

Yes Jon and they work well on sumps.

I may have a declared interest, having written the original article, but having had to replace the silicone  sump gasket with a 'posh cardboard' version in an emergency, I have found the replacement item has resulted in leakage again. I will be replacing said gasket at the earliest opportunity.

Bob Culver's comment about hub gaskets is partly valid, but the gasket squishes down sufficientlly to take up the necessary clearance, and I've not had any problems with  material of that thickness.

It's a case of 'Horses for courses' and there are many situations (mainly high stress/temperature) where such materials would be obviously unsuitable - although I await with immense interest news of a silicone rubber head gasket

My source of supply of this material has seemingly disappeared of the radar (to my embarrassment) and I would appreciate any info on an alternative source.

I look forward to your comments - most of my posts seem to terminate subsequent threads. Please don't imagine me as some sort of guru

Used gaskets may need 'drying out' to regain their original dimensions, but this property seems to happen after about a week, and must be due due to solvent absortion or something!

Good luck with your endeavours

Bob

Hoping the appaling Cornish weather will end!

[JonE]

I went with black to better tie in with the engine bay.. :-)

https://www.ebay.co.uk/itm/201543352729 (note: it has been suggested that this - 1mm - is too thick and that 0.5mm would be better. Others experience?)

Wondering the best way to cut the itty bitty round holes...

Bob - I seem to remember having seem a proper supplier of silicone head gaskets on ebay - or was that perhaps block seal gaskets?

[Derek Sheldon]

Seven workshop for block to crankcase silicon gaskets, very good

[Ian Williams]

"Wondering the best way to cut the itty bitty round holes..."

With a ball bearing, just place it over the hole and give a crisp tap, alternatively you can use a wad punch.

[garryruck]

Not a silicone question but can anyone tell me if the cylinder head gasket is the same for the standard head and a high compression head. Thanks.

[Alan]

If you mean '37 v older heads, then they are not the same. The high compression one is thinner and the combustion chamber shape is different.

[Tony Press]

If you mean '37 v older heads, then they are not the same. The high compression one is thinner and the combustion chamber shape is different.

And make sure any modern reproduction gasket for either is the correct shape - some are incorrect and protrude into the combustion chamber which some (I believe incorrectly ) state leads to pre ignition.

Cheers, Tony.