SRM sump plate casting leakage problems

[a101960]

I have an SRM sump plate fitted to my engine and it is fixed into place with the SRM supplied socket head screws. Over a period of time the whole assembly  has become increasingly incontinent due to two main causes. The drain bolt washer is not sealing very well, and oil appears to be migrating down the screw threads. First the drain bolt.  Should I replace the washer with a new copper washer or a fibre washer? At the moment it is fitted with a dowty washer which I think is probably not really suitable for this task. Secondly I intend to replace the socket head screws with studs which I am led to believe are a better long term solution because they will prevent wear and tear to the crank case threads. The stud set that I have bought is stainless steel. I have read somewhere that stainless steel threads should be coated with copper slip to prevent electrolytic corrosion. Now the thing is, I want to ensure that the oil is unable to leak down past the threads, so instead of using copper slip would a thread sealant such as Permatex 59214 be an acceptable substitute? I propose to coat the gaskets with  Wellseal. Would that cause any problems when removing the sump plate when I do oil changes? I normally do this when I change the oil in order to clean the strainer. Finally, should I coat the exposed part of the studs with copper slip? I am thinking that stainless studs and an ally sump plate might just also suffer corrosion problems.

John

[a10 gf]

I intend to replace the socket head screws with studs which I am led to believe are a better long term solution because they will prevent wear and tear to the crank case threads

Yes !

Should I replace the washer with a new copper washer or a fibre washer?

Annealed (soft) copper is good. Any thread sealant should not be necessary unless there is some serious dents in the contact surface between bolt and sump plate that the copper washer can't fill.

[duTch]

 I agree with a10gf.
My Plungers stock Sump Cover stud holes are blind ie; they don't go through to the crank chamber so shouldn't leak anyway, but I recall discussion a while ago where other members do. You could poke a piece of wire up to find out?

 I was using S-cap screws, but replaced them with studs, but one decided to strip itself anyway , so I have a pack of helicoils to fix it when I'm in the mood.

[BSA_54A10]

Studs are the way to go.
Make sure that they will not hit the flywheel when done up tight.
They need to be 1 and 1 thread only longer than the thickness of the case.
Do them up very tight till the tapper at the end on the thred is embedded into the case.
As such they will neither leak nor come out.
Put an O ring under the nuts and tighten till the O ring is reasonably squashed.
This is generally tight enough to make a seal if you are using a good soft gasket and the O ring prevents the nuts from vibrating loose.

[Angus]

John
Where did you get the studs, I assume they are longer then the standard ones. I have a drain type sump plate that I have never fitted as the standard studs are to short and have not seen any longer ones around.

[Greybeard]

The studs have to have Whitworth one end and British Cycle thread the other. I have a feeling, (better check) that the rocker cover studs will work for this job.

[a101960]

Thank you all for your advice. Angus the studs are avaiable from here:

http://www.ebay.co.uk/itm/BSA-A-Series-Sump-Filter-Plate-Stainless-Steel-Studs/112010767298?_trksid=p2045573.c100033.m2042&_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D36886%26meid%3Db67209e1fc8142d989af15c235bb617b%26pid%3D100033%26rk%3D4%26rkt%3D8%26sd%3D381491860942

They are supplied as a set complete with nuts and washers. See the picture below. the studs are 1 1/4" long. I hope that helps.
John

[Billybream]

I to have the SRM sump plate and have used the socket head screws supplied but must agree studs are the way to go, another modification during next oil change. Thanks for the tip and link of where to purchase.

[terryg]

If you're thinking of buying studs, may I suggest costing some appropriate mild (or stainless) steel rod, dies and a die stock for comparison.

Give a man a fish and you feed him for a day, teach him to fish and you feed him for life - or something like that.

[ellis]

Regarding the SRM sump plug mine came with a thick nylon washer and has been leak free. Can't remember who supplied it. Stainless sump studs and stainless nuts need copper slip to stop the threads picking up. Hope this helps.

ELLIS

[Topdad]

This post caused me to check mine ,drained sump gave it a wipe and was very pleased that everything was dry. Been a bit incontinent of late, (the bike not me     ) so pleased after a 25 mile run out that there wasn't a drip in sight

[Butch (cb)]

I measured up and then had studs made in stainless by Barleycorn.

http://www.barleycorn.co.uk

[TimK]

If you're thinking of buying studs, may I suggest costing some appropriate mild (or stainless) steel rod, dies and a die stock for comparison.

Give a man a fish and you feed him for a day, teach him to fish and you feed him for life - or something like that.

I've been thinking of doing this and am happy that bog standard mild steel would be o.k. for sump plates and securing tinware, but what about barrel studs etc - would I need something a bit more exotic from the steel merchant?
Tim

[kiwipom]

hi Tim, I made my barrel studs by cutting correct bolts to size then putting whitworth threads on the cut end,cheers

[terryg]

Before I went wholly down the DIY route I bought some stainless barrel studs.  I'm pretty sure they were made, by a reputable supplier, from 303 stainless.  303 is one of the 'free machining' grades, kind to tools and nothing special in terms of tensile strength.