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Crank rear oil seal
Posted: Mon Apr 01, 2024 11:26 am
by BaritoneUke
Fitting the new improved rear oil seal is one job I need to do on my 10cg... I think machining is needed is this just making it flat or is there more?
Re: Crank rear oil seal
Posted: Mon Apr 01, 2024 1:16 pm
by philthehill
There is no machining needed with fitting the crankshaft rear lip seal but I would steer well clear of fitting a crank rear (lip) seal.
Unless the flywheel mounting flange is perfectly smooth or you have fitted a speedy seal sleeve the lip seal may well be torn to shreds very soon after you have started the engine.
Get the original set up with the return scroll working as it should and you will have no trouble......
I did have a rear lip seal fitted to my 1400cc 'A' Series but it was soon discarded and oil return enabled by the scroll.
Re: Crank rear oil seal
Posted: Mon Apr 01, 2024 1:33 pm
by svenedin
Some years ago I enquired of this modification to ESM and I was advised against it. I thought that was rather honest of them to not take my money. It would be a reasonable idea to check the condition of your engine breathing system. You might find that with the engine breathing working perfectly, you have no oil leaking.
Stephen
Re: Crank rear oil seal
Posted: Mon Apr 01, 2024 5:09 pm
by simmitc
I can only echo the above. The kit is not worth it. It sounds like a good idea in theory, but it does not solve the problem. The instructions (at least with one I fitted many years ago) gave very tight tolerances for the flange, and most crankshafts that I have measured do not meet those requirements. The instructions also required the copious use of a sealant material - not a good engineering solution.
With a good crank and bearings and the correct breathing system, you will achieve a much better "seal" than with the lip seal kit.
Re: Crank rear oil seal
Posted: Mon Apr 01, 2024 8:52 pm
by BaritoneUke
Thank you all, I'll save my money and try and get the scroll system working properly.
If it doesn't I'll fit a little catch tray underneath. This car is NOT going to leave embarrassing little deposits around

Re: Crank rear oil seal
Posted: Fri Aug 16, 2024 7:35 pm
by MMT1968
As many others I had the same problem to solve anyhow. But as my returning scroll on the crank shaft was badly worn and the parts of the block around it also I decided to use a lip seal conversion kit. …. And got the problems as predicted. At last I had to pull the engine out 8 times due to partly massive oil leaks. But now it is solved, not a single drop of oil is leaking out of the rear crank seal. And that’s not because there is no oil inside the engine.
My engine is a 1275 marina and the kit therefore is different from the others for smaller ones. The screws holding the seal housing to the block must pass outside the crank shaft flange which needs three recesses in the inner wall of the seal housing. These are very difficult to get sealed well at that point. I glued the lip seal in at last and filled these recesses with motor silicone. I also mounted a speedy sleeve and must say I‘m convinced it will never work without.
But! It will never work without a good or better perfect crank case ventilation system. I have tried all published versions but none did it’s job well enough. So I ended with the installation of an electric vacuum pump. That works perfectly. The amount of vakuum put on the crank case is easily adjustable and the ventilation hose is lead into an oil catch can. If the vacuum is adjusted correctly that catch can is completely dry.
Phil called it a bit of an overkill. Anyway, it works, so it’s fine.
So, if the original returning scroll is in a useful shape try to keep it and live with a few drops of oil under the car. That’s easier than having to face all the problems with a lip seal conversion kit.
After all this training I can pull the engine out in 1 hour now and putting it back in needs just 90 minutes.
Good enough for an amateur.
Chris
Re: Crank rear oil seal
Posted: Fri Aug 16, 2024 8:19 pm
by BaritoneUke
MMT1968 wrote: ↑Fri Aug 16, 2024 7:35 pm
So, if the original returning scroll is in a useful shape try to keep it and live with a few drops of oil under the car. That’s easier than having to face all the problems with a lip seal conversion kit.
After all this training I can pull the engine out in 1 hour now and putting it back in needs just 90 minutes.
Good enough for an amateur.
Chris
Still playing around with mine...as you do

My latest setup, which is promising, is based on Phil/BMC's recommendation in another thread, basically you have a breather pipe going from (ideally) the tappet chest into the inlet manifold with a restricted hole...16th of an inch or so to maintain some vacuum. And you block up the rocker cover breather. There's even a valve for this (PCS valve) but I haven't got around to that yet. But it's something to bolt onto my A series and I'm running out of things to bolt onto it, so i'm sure I'll get around to it soon.

(PS Congrats on getting the conversion kit to work. I wonder if anyone will try and replicate your solution.)
Re: Crank rear oil seal
Posted: Sat Aug 17, 2024 10:06 am
by MMT1968
Well, getting it to work was a hard job to do and there were several points I struggled hard not to give up and sell the whole stuff. But I‘m satisfied as it works now.
In my case I had no other option than trying to fit a lip seal. Finding another crank shaft in good shape for a 1275 marina engine may be possible somehow in England but in Germany it is absolutely impossible. One can do anything if money doesn’t matter but spending 2000€ for machining the crank aso in an engine worth 3000€ is useless to my opinion.
If anyone is interested in the vacuum pump solution just let me know. I post a pic showing it. The pump is located next to the carbs.
Chris
Re: Crank rear oil seal
Posted: Sat Aug 17, 2024 5:02 pm
by Sleeper
Oh dear.....

- servo.jpg (58.03 KiB) Viewed 4726 times
John ;-)
Re: Crank rear oil seal
Posted: Sat Aug 17, 2024 5:45 pm
by MMT1968
Why, it works well this way also. For what reason should be the reaction valve orientated this way? In my e-type it was just upright.
Chris
Re: Crank rear oil seal
Posted: Sun Aug 18, 2024 10:33 am
by Sleeper
To prevent air in the fluid being trapped ( highest point ) in the cylinder( slave cylinder in diagram ) and air valve..
John ;-)
Re: Crank rear oil seal
Posted: Sun Aug 18, 2024 12:35 pm
by MMT1968
Thanks John. I usually bleed my brake systems by putting a vacuum on it and suck the brake fluid through. I never had trapped air in the brake system that way exept after working on it. But after that the system needs bleeding anyway.
Chris