Stripped thread oilway blanking plug

[Old Dave]

The front oilway blanking bolt is leaking badly again. The bolt looks perfect and the threads in crankcase look poor. Not really a surprise is it?  The leak happened about 18 months ago and a new fibre washer and a very gentle turning of the bolt has held until now with regular checking.

I guess that a proper repair will involved heli-coil or similar and will be an engine out job?

Are there any sensible temporary solutions as I want to do the Staffs & Shropshire Spring run on Sunday which is about 100mile round trip? I have heard rumours of copper wire and aluminum foil, but I worry about putting "stuff" down into the oilway!!!

Advice gratefully received as always.

[Alan]

Hi Dave. Am I right in thinking it’s 1/4BSP? If so you might get away with replacing the plug with a BSPT one. Crewe Engineering Supplies should have them - across the roundabout from the retail park in Crewe

[Old Dave]

Hi Alan,

I can't get a good pic of it either end. Here is the bolt which takes a 3/16 Whit spanner and has a staight thread. The bolt section measures appprox 1/4" across the thread as you suggest.

So I guess this 1/4 BSP and the one you suggest getting is a taper version?

I will go to Crewe Engineering Supplies now.

Cheers Alan - see you Sunday all being well.

Dave

   

[Alan]

Dave. Not the plug I was thinking of. That looks like 1/4 Whit and it’s the oil jet blanking plug.

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As a temporary measure what you. Could do is wind order tape around the thread and jam. Cork between the bolt head and the cylinder block.

[Old Dave]

Hi Alan, Sorry my terminology is a bit lacking. Yes it the blanking plug over the oil jets.

It is BSF. We measured at CES with a thread guage. Very helpful guy

Sorry what kind of tape were you suggesting?

I do have fibre washers - will that do?

Cheers

Dave

[Alan]

Sorry it’s spellcheck that should be ptfe tape.

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Fibre washers will do fine and if you have a slightly longer screw that might help too

[AustinWood]

I made atemporary fix many years ago by bolting a clutch withdrawal lever on one of the block holding studs. This could go over the oilway plug and hold it in place. It leaked a bit but stayed in.

[Old Dave]

CES had some longer bolts - but how far can I go before causing problems below?! They also had stainless steel. I had heard of them but never been in - only 3 miles from home pf course.

I will go with the ptfe tape and fingers crossed Alan. Thanks

I like the lateral thinking Jim. One to keep up my sleeve.

[dickie65]

A Dowty bonded washer might well stop the leak as I suspect you are only talking 10 psi oil pressure.

[John Cornforth]

Hi

You could try a Dowty Seal instead of a fibre washer, Metric M6 will fit 1/4 inch OK. For those unfamiliar, this is a thin metal washer with a bonded rubber inner part.

If you prefer to stick with fibre washers, they can be softened a bit by soaking in water. The softening allows a better seal without excess pressure being needed.