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MG Midget and Sprite Technical - What is the best way to a leak free sump?

Anyone has any suggestions on how to fit the sump leak free?
I have the rubber seals and new gaskets.
The reason I ask is that last time I fitted it, it was not leak free and I can't stand that.
Alex G Matla

Yes there is, do not put oil in it LOL. I am noy sure where I saw them but they make fastners for sumps that keep you from over torqueing and they lock in place so they do not loosen. it may have been on two guys garage, hope that helps.
ajs alan smith

Mig welder would probably work, maybe even Arc welder ...LOL.

Sorry!

Do you know for a fact that its leaking around the pan edge and not the scrol seal at the back of the engine....vary common, In fact its more un-common for the seal not to leak

Just from my own experiance if you pull the rear crankshaft main where that meets the block I had a lot of day light show though and even a rough edge...I used wet 80 grit sand paper on a sheet off glass with wd-40 as lube and sanded it down flat in a figure 8 motion....this was based on info from here on the BBS as well as from keith culver tech session in minimania.com I cant say if it solved it or not as I still dont have the engine running yet.

if it is leaking around the edge of the sump pan...you may have deeper issues such as over filing the oil pan or dreadfully speaking piston blow by.

But Id put a straight edge over the pan edge in multiple directions and look for distortions on the pan edge, then clean the mating surfaces and apply some peanut butter and lick the peanut butter back off....If you have no issue or 2nd thought with licking the butter off the surface, then its clean enough, if your afraid of what else you might also lick up...then you aint finished cleaning the mateing surface

Id do both sides of the gasket with a good RTV sealer made for oily surfaces...you will have to look for it but it is avialible....Id smear both sides and let it set up till tacky ...maybe 20 minutes then assemble but dont try to re-arrange the fit..stick and done is the idea, then torque it all up.

Prop
Prop

Alex

Permatex products are great...been using them for 40 years on things automotive & industrial.

They have a sealer for any type application.

Their Aviation Form a Gasket is an almost guaranteed no leak sealer, but difficult to remove the next time in.

I'm with Prop...check for true surfaces, then use RTV on both sides of the gasket.

Dave
Dave Rhine

Gentleman, thank you so far.
It's not leaking on the pan edges. I you straighten the edge and be sure the holes are flat then a gasket will work fine, bolts torqued to spec.

No, I mean the part around the cork / rubber seal, where the gasket and seal come together.
Should the gasket go over the seals?
I think not, but maybe it should?

And Prop, if you take of to much of the scroll seal it will not be round anymore and cannot seal, or even rub the crank at the bottom.
If you fit it with a feeler blade of 0,05 or 0,1 mm at both sides it should not leak. Mostly the problem with this type of seal is that it goes crooked when torqued.
Alex G Matla

I have always put the gasket over the seals, that is also how they are made. I put a small blob of Loctite Master Gasket in the corner where the main cap meets the block for the gasket and seal to but against. Never had any problem from there. Rear main slinger, yes when the engine is a bit tired and a bit of pressure to blow the oil through.

One thing I have encountered is main cap seals that are not the full width and do not fill the groove properly. As the groove housing is only spot welded on, the oil can get down the side of the seal and then seep out between seal housing and sump if this is the case.

A further point is not to trim the seal to flush with the sump - it needs a good 1/4 inch or so prutruding at each end to give good compression on the seal and get the intended fit. Seals made correctly will be the right length in this respect.
Paul Walbran

Thanks Paul.
This time I cut the gasket so it touches the caps.
And as for cutting the cork seals: I new that, the PO didn't.
Imagine my surprise when I lost all oil pressure on a highway trip.
I have fitted the rubber seals now btw.
Alex G Matla

Frankly, you could spend the next 10 years pulling the sump on and off..it will still leak. Acknowledge it, accept it and move on! Look at it the other way..you'll rust proof the underneath.

One thing to try, make sure your dipstick is fairly well sealed, that way you pull a small vaccum into the block and that helps limit the seal. Try pulling the vacum hose off and see the resulting leak underneath and you will understand.
Robin Cohen

I don't have vacuum on my engine, just 2 breathers on a catch tank. There's no vacuum on Full throttle anyway, so... :^)
Alex G Matla

i had the rubber seals be for i rebuilt my engine and they always leaked a little

now i have fitted the cork ones and cut the so they stick about 5 mm above the sump when not fitted.
i used a bit of hylomar blue to stick the gasket to the flange and it has not leaked yet.

i think the rubber ones harden over time while the cork ones suck up a bit of oil and stay in shape by that mutch longer.
Onno Könemann

Why not get rid of leaking A series and throw in a Kseries : not a drop of oil on my garagefloor!

the only place it can leak is between the Headgasket but that happens mostly in the inside of the engine so your still not bothered with liquids in the engineroom or garagefloor. ;)

Arie de Best

Onno, your's isn't running is it? 'Cause it will only leak at the seals with the engine running. unless you top up your valve cover with oil... :)

No, seriously, the last corky things that where in the gasket set where way to thin so I took no risk and ordered rubber ones from thijssie.

btw, how's the paint job coming on? rebuilding already?
Alex G Matla

With the engine upside down on the bench, the gasket ends go in the grooves in the bearing caps; I use Permatex #2 on the gasket, both sides; or, #2 on the block and grease on the sump face - this MIGHT make it possible to get the sump off leaving the gasket on the block! The cork seals are proud of the sump and compress onto the gasket ends. You don't cut anything, ever. Much harder in the car, but certainly possible. Be sure the flanges are flat and correct washers used.

FRM
FR Millmore

hmm paint
well a bit of construction work at Thijs stood in the way then i went on a holliday and since then it has been freezing so hard i am not going to try to work in a non heated garage.

but i'll start brining all the lose parts home and preping them one by one next week or so.
And next week my little sister is moving again and vacating an verry cold student room so my little electric space heater is free to work in the garage again.

so hopefuly it will be painted before spring (might have to take some time off work to get that done but i'll manage)
Onno Könemann

Ah.
And, fitting wing vents while you're at it?
If you can make a nice wooden template maybe we can do a joint effort? I can do the folding and welding at work.
Alex G Matla

But FRM, surely one has to cut the tips from the gasket, otherwise there will be a wrinkle against the cap.
Depends on the manufacturer maybe.
Alex G Matla

On the payne set, I simple placed the rubbers in the groves and cut the tips off flush. then RTV the composite gasket onto the block so the tip over laped the freshly cut rubber end then placed a big blob of RTV on the 4 corners where the gasket overlaped the rubber seal ...then applied the RTV on the rest of the gasket aand bolted the pan on after the RTV set up good and tacky

Prop
Prop

Alex -
The gasket tips "should" just touch the bottom of the grooves in the cap with the bolt holes lined up. And, they used to, when gaskets came from the real makers! Maybe no more, but that's how it is designed.
And Prop, cutting the ends of the cork or rubber just defeats the purpose of the design - the half circle seals are supposed to compress in the sump groove to seal all the way round. You might seal the ends with the RTV garbage, but it will likely leak elsewhere. I do not use RTV, ever, except on modern crap where the designers were slacking off and didn't do their job.

FRM
FR Millmore

I agree. No gooy substances should be needed for a proper designed AND well cleaned jointing surface.

So far my sump doesn't leak.
But then again, there's no oil in it :)
Alex G Matla

In my experience cork seals are preferable to the rubber ones. The cork ones readily collapse when torqued up and then swell slightly as they absorb a little oil. The rubber ones behave a little like door seals. They relax over time with repeated heat cycles, and I've found sump bolts that were initially tight can be nipped up three or four times as the seals relax and bed in. During this settling in time the sump can leak from both ends. This inspite of using RTV and trimming the seals 7mm proud and square to the seating face. After a couple of weeks of repeated tightening, the rubber ones will seal, but the cork seals never need this palarva.
F Pollock

"and trimming the seals 7mm proud and square"

I have pre-formed seals with something hard (metal?) in the centre, the cannot and need not to be trimmed.
Alex G Matla

I found it works best to use a small jack and board under the pan and hold the pan tight to the block while tightening the screws. That's when doing it with engine in the car.

Peter C
Peter Caldwell

Im must be headed for greatness,

Peter, that is exactly how I installed my pan this last time, Because I took someone elses advice and installed the engine 1st. without the oil pan to make the installation easier....But I did rtv my gaskets inplace 1st.

I had forgotten how tight a fit the pan can be

Prop
Prop

"I use hylomer"...risky stuff to use unless it's used very sparingly. You fine blobs or strings of it blocking all sorts of oilways. Albeit not a midget but a friend has a turbo go on a supra..cause was hylomer thread from the sump, that's why sticky stuff like wellseal are used, they don't set or break off.
Robin Cohen

Well, it appears the only real way to a leak free sump is to suck it...

I now have replaced my 45DCOE for my big twin SU's, and now I have connected the breathers to the carburettors. Not a drip...
Alex G Matla

good going alex,

scence Ive built my engine, its not dropped a tear of oil...Hope that holds after I start the car...LOL

Prop
Prop

At least you know the drain plug is sealing ok... :^)
Alex G Matla

This thread was discussed between 13/01/2010 and 17/03/2010

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