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Is this a modification
Posted: Wed Jan 06, 2010 8:45 pm
by SvMinor
I have a small oil leak at rear of sump between it and rear engine end plate.I was lookin on BM site under oil seals and this part came up.only thing is I didnt remove one of these when I removed the old crank.so is it a modification part or an essential one.
http:
www.morrisminorspares.net/shop_item.php?id=2596
Cheers Mark
Posted: Wed Jan 06, 2010 8:50 pm
by bmcecosse
Your link not working - but there is a modification available that puts a seal on the crank. General opinion is that it's not much good........ Is that what the link is pointing to?
If there is any pressure in your engine - it will push some oil out past the labyrinth 'seal' on the crank tail. So - best plan is to ensure NO pressure - in fact - some vacuum is good! Connect the rocker cover breather directly to the vent pipe on the SU carb - if it's not there already!
Posted: Wed Jan 06, 2010 9:03 pm
by SvMinor
http://www.morrisminorspares.net/shop_item.php?ID=2596
This is the link hope this one works
Crankshaft rear end oil seal.
I fitted the Dual oil and water gauge(got the adapter for the temp sender from a mini spares site) and the oil pressure reads 60 when driving.then it goes down to 45 at idle
Posted: Wed Jan 06, 2010 9:12 pm
by bmcecosse
Link better - but goes to blank page. But yes - you describe the after market modification seal. It's not oil pressure - it's crankcase pressure that's the problem - from blow-by on the pistons. Test is - hot engine - idling - remove oil filler cap and rev up. Is there a plume of smoke/fume ?
Posted: Wed Jan 06, 2010 9:27 pm
by SvMinor
Cant understand why the link is not working this time ,I copied and paste it to the post.
What happens/does this mean if the is a plume of smoke/fume?
Is it normal?
Posted: Wed Jan 06, 2010 9:31 pm
by bmcecosse
It's not 'normal' - but it is unfortunately common! It means combustion gases are getting past the piston rings - in other words - the bores/pistons/rings are a bit worn! Not to worry - if not too bad it can be contained with good breathing.
Posted: Wed Jan 06, 2010 9:40 pm
by SvMinor
Thanks Roy
Posted: Wed Jan 06, 2010 10:28 pm
by SvMinor
[quote="bmcecosse] Connect the rocker cover breather directly to the vent pipe on the SU carb - if it's not there already![/quote]
Not sure about this Roy,Take a look at these pics and tell me what to do if its right or wrong<br>

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Posted: Wed Jan 06, 2010 10:45 pm
by rayofleamington
there is a modification available that puts a seal on the crank. General opinion is that it's not much good........ Is that what the link is pointing to?
The seal is fine, but the installation is not ideal - it requires the surface of the crank to be in very good order to perform a task for which it wasn't intended. If the flange area is a good surface finish and free of damage then the seal performance will be good.
The other part about the installation id that it requires a flat surface across the back of the block and the main bearing endcap - which is likely to need the endcap to be machined in situ (ideally by doing complete engine strip and rebuild).
However, this may be completely missing the issue!!
If the rear of the sump is leaking, it will cause oil to dribble in this area also.
Posted: Thu Jan 07, 2010 1:30 am
by mike.perry
Back to the oil pressure, 60psi running and 45psi on tickover is perfectly OK, especially on a hot engine.
Rear crank seal
Posted: Thu Jan 07, 2010 6:47 am
by Declan_Burns
Try running the engine with the car over a pit, having cleaned off all the oil and grud beforehand. This will help to locate the actual source of your oil leak(s). If you have to replace the sump gaskets, I would recommend using the spridget 1275cc synthetic rubber seals instead of the cork seals. This worked for me as I tried cork several times without success. Thoroughly clean and degrease all surfaces and use high temperature silicon allround allowing it to cure properly before starting the engine. Check also the tappet chest seals. Again could be cork but there are modern neoprene seals available. The 1275 seals have to be cut back slightly-takes only a few minutes with a hacksaw. There is a wire insert which is best dressed with a file after cutting. They fit very snugly. It certainly solved my problem. I could not get the cork to seal and after several attempts finally used the rubber. Some have no problems with the cork.
I also fitted the OB rear seal mod-but that means gearbox or engine out. I would try sorting the breathing first as mentioned above.
I fitted it last year and it does work. You do get the odd drop seeping through but I mean a drop or two a week. This is because the seal is not fitted over a machined surface. Don't underestimate the work. It means gearbox, clutch, flywheel and backplate out-or engine out or both and there are so many other parts worth replacing simultaneously that it all adds up. I can send you the fitting instructions if you want. I think the seal kit was about 52 GBP at the time. I've done about 4000 miles since I fitted the seal and as I mentioned very very little oil seeps through. Although we couldn't machine the flange surface professionally in-situ we did smooth it off as best as possible. A belt from a belt sander turned inside out and a cylindrical grinding stone or similar as a drive shaft in an electric drill, while an assistant slowly cranks the engine with the plugs out. It calls for elbow grease but we got it fairly smooth. Perhaps that's why it worked in my case. It is a last resort job.
Posted: Thu Jan 07, 2010 8:40 am
by SvMinor
How do I sort out the Breathing?
I see what Roy is saying but.I dont understand.
Can someone explain it by looking at the pics please.
Cheers Mark
Posted: Thu Jan 07, 2010 10:23 am
by bmcecosse
Your rocker breather is going to the air cleaner - here it experiences very little 'suck' - and it deposits fume/oil all over the outside of the paper filter = not good! The later SU carb has a brass pipe on the side - leading directly into the inlet tract. The breather pipe goes on there - gets more 'suck' - and the fumes go sytaright into the engine - NOT all over the air filter. So really - you need to source a later SU with the vent pipe. Known as HS2 SU ! I have in the past fed the fumes directly into the inlet manifold - by drilling/tapping a hole and installing a fitting with a 1/8" diameter hole in the middle. This works very well indeed - slight upset to the idle, which can be balanced out at the carb - no fumes and no oil leaks! <br>

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The brass tube is seen sticking up at 45 degrees.