Instant gasket users - Beware!

[Greybeard]

I'm currently in the process of applying a thorough coat of 'looking at' a cosmetically very nice AJS M31DL I bought a couple of months ago. Amongst the list of jobs was a clean-out of the oil tank and filters prior to refilling with synthetic oil (and removing the tap fitted in the oil line - I don't like the idea of the engine being fed via a 1/4 inch bore tap when it should be through a 1/2 inch pipe)
On removing the oil tank I was surprised to find that the fine gauze filter that should have been in the feed line was installed in the return pipe. I was also horrified to find that the end 1 1/4 inches of it was packed absolutely solid with fragments of instant gasket - a substance that I despise with a passion. Some of the pieces were of a size that could easily restrict or block an oilway. Lots of proddling with a wire hook aided by a high pressure airline eventually cleared it.
Hopefully the engine appears to have tolerated the situation thus far as both previous owners report favourably on its reliability over the last 20 years. With good quality Mobil 15W-50 circulating as it should I'm banking on that record to continue

Steve (wot's a life-long fan of Wellseal)

[Rob Harknett]

could be the modern oil has loosened all those particles. Should never use modern oil in an engine that has not been stripped and cleaned.

[Greybeard]

I've never been convinced of that scenario, Rob. I've remained convinced that the use of the word 'detergent' has generated a myth over the years that won't go away. Folk with far more knowledge of the oil industry than me have often tried to debunk it.
It's been hammered to death over the years, so little point in continuing it here

Steve

[Rob Harknett]

You show proof Steve.

[Greybeard]

I could say, you show me yours first, Rob - but that would be childish
After 40 plus years of being in and around engines of all ages/mileages Ive never come across anything to support it.
There is an article on the Real Classics site which has been posted several times on here. That article was written by an expert in the field and is well worth reading.

Steve

[ksj_LAPSED]

I get your point about half inch pipe but after the oil has travelled down said pipe it has to go through a tiny hole into the pump

[Rob Harknett]

I could say, you show me yours first, Rob - but that would be childish
After 40 plus years of being in and around engines of all ages/mileages Ive never come across anything to support it.
There is an article on the Real Classics site which has been posted several times on here. That article was written by an expert in the field and is well worth reading.

Steve

Perhaps I have been too careful Steve and took too much notice of the talk that modern detergent oils will loosen sludge etc. in dirty engines. I will however still stick to using only straight oil in my dirty old engines. I have never seen bits like you have in a filter.

[Greybeard]

Had the filter been fitted where it shouldve been, the chances are that these wayward bits of silicon would not have been noticed. All I intended to show was that lumps of instant gasket does break away and could pose a risk thats best avoided.

I have also used straight 50 Castrol in my roller bearing engines over the years, though with regular changes there shouldnt be too much chance of dirt building up

ksj - that's true enough. I just doesn't 'feel right' to add a restriction. I'm sure there must've been a reason to use 1/2 inch bore pipe if cheaper/neater 1/4 inch would have done the same job.

Steve

[leswaller]

I agree with Rob, a couple of years ago our VMCC section had a talk from the technical rep of a well known classic oils supplier. He was adamant that using a modern multi grade in an old engine that had been continuously run on old style mongrades was asking for trouble unless the engine had been cleaned out. In short the old type oils left a thick varnish like deposit on the insides of the engine which a modern multi grade containing detergent and other additives was likely to cause to peel off and go into the oil flow with potential blockages in the oil ways.

[Greybeard]

the technical rep of a well known classic oils supplier.

Playing Devil's Advocate, Les, he was hardly without a vested interest Did he provide tangible evidence to support his opinion? All I'm saying is that I have never come across the 'problem', nor have I spoken to anyone with first hand experience of it. There must have been hundreds of thousands, if not millions, of old engines worldwide that have been topped up/serviced with modern oils over the years and yet there has been no reported rash of engine failure as a direct result of it, nor of subsequent claims against the oil companies.

We seem to be getting into yet another discussion about oils again that will never be settled to everyone's liking. Personally, I'm quite happy for anyone to use whatever oil they choose, for whatever reason, in their own engines.
My original point was simply that instant gasket can block filters etc. and the evidence was supplied.

Steve