#4 big end running?

[bmcecosse]

No need for any bodgery... Clean surfaces and good gaskets, that's all.
Smear of grease on the head gasket of course!

[JOWETTJAVELIN]

Hylomar is good and recommended by BMC in the shop manual on the main bearing cap - I used it there and haven't had any leaks!

The pros use it as my mate gave me some, his job is rebuilding engines!

[les]

Roy's probably right but using a thin film of sealant is just insurance against doing the job twice!

[bmcecosse]

BMC didn't need to do it twice. This very expensive business with theblocked oil way is exactly why it should not be used...ever.

[indian301]

There is nothing wrong with silicone sealant when used properly! When I was working on cars professionally ten years ago silicone sealant was the only gasket used on certain cars. Saturn for example uses silicone for the sump, timing cover, and rocker cover gaskets and there is no other option available. Nissan and Toyota use it in place of a water pump gasket. As long as the surfaces are clean and dry and the silicone is given the time to cure fully it is a wonderful product. I use it on my old Indian motorcycles and have never experienced a problem.

Dave

[bmcecosse]

They only used it because it could be squirted on by a robot........ A correctly assembled A series needs no sealants.

[MarkyB]

How it got past the filter is more interesting.
Also is there any more lurking about?

[bmcecosse]

It couldn't - ergo it must have gotten in to an oil gallery after the filter and before the main bearing gallery - most likely at the filter casing mount gasket....