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Posted: Thu Feb 19, 2009 9:09 pm
by bmcecosse
I assume this is cylinder pressure - and at 125 psi that's very low - (although 9 bar is ~135 psi) BUT, they have probably been made low with special 'low compression' pistons because you have a supercharger.
Crankcase pressure is seen by taking the oil filler cap off when the engine is hot and idling - if there is a plume of smoke/fume - that's crankcase pressure caused by gases blowing down past the rings into the crankcase. It will cause oil to leak out at every possible orifice ! New rings may cure the problem, for a while.

Posted: Fri Feb 20, 2009 9:05 pm
by olskool
ok well here is wear im at this engine has not been modified for the supercharger the supercharger was designed for the 948 whihc means bigger displacment lower boost as matter of fact at 5000 rpm i have no boost so the sc is going for a rbuild and we are probably going to make a smaller pulley for it so it will actually boost

that being said this should be normal comperssion engine now it is low on oil so when i put more in it its my understanding my value will change but im not looking for much over 150 psi. but this even on all cylinders no diffrence at all.

the 1275 has a this canister on the timing cover for crnakcase pressure we do not have that it was taken off and the smaller engine timing cover used so we had clearnce for the supercharger belt

Now im thinking thats a crucial to this engine.

question now is is this thing neccasry this canister thing that was on there before

If so what does it do how is it designed can i just make a couple holes in the currnet timing cover run hoses to a remote canister one for supply one for retrun kind of like an over flow but with purpose of venting the case or this a one way valve that lets only pressure and no oil through if so i can do that to just wondering

we have no idea were the orginal cover is or the webber carb setup it had before the supercharger those two items are missing in action

Posted: Fri Feb 20, 2009 9:20 pm
by Mogwai
the 1275 has a this canister on the timing cover for crnakcase pressure we do not have that it was taken off and the smaller engine timing cover used so we had clearnce for the supercharger belt
that would explain the oil leak, the canister on the timing cover is the breather on a 1275. it also has a gauze in it to help separate any oil & act as a flashback arrester

Posted: Fri Feb 20, 2009 10:11 pm
by bmcecosse
There's nothing fancy - it's just a can with wire. Arrange good breathing from the rocker cover and add your own breather tube to the timing cover - and if there is a hole with cover plate for a mechanical fuel pump on the block (manifold side - low down near the front - sometimes used for oil return from superchargers) - that hole can also be used to make an excellent breather.

Posted: Sat Feb 21, 2009 12:10 am
by Kevin
Hi olskool glad you pinned it down as I did wonder hence my earlier post here is a picture of one for my 1275
<br>Image<br>
Originally it was round but often it hits the fan blades so there are 2 options it can either be flattened or as in this case cut down to the outlet remove the gauze and rewelded so it looks a bit neater than the other method, so as long as you create a version of this it should do away with your problem. Also as a matter of interest the 1275 engine doesn't have a breather on the rocker cover.
And to put it in the words from one of my books.
Do Not be tempted to use the standard Minor timing cover on the 1275 engine as it pressurises the bottom end of the engine and will cause strange oil leaks

Posted: Sat Feb 21, 2009 11:54 am
by bmcecosse
But it's a really good idea to add a breather to the rocker cover (or simply use an early rocker cover with breather) in addition to the timing case breather! At least in Mini applications they had another breather on the transfer case - and even then - rocker cover breather is still very popular too.

Posted: Tue Feb 24, 2009 4:19 pm
by olskool
cool good deal then when i saw the pic of the engine as it was when it got here i saw that and started thinking i bet thats problem i can fix that easyily im going to replace the front seal cause i doubt its worth anyhting now, is there a spin on oil filter adapter for this motor and if so were can i find it

Posted: Tue Feb 24, 2009 5:34 pm
by bmcecosse
There is a spin on adapter kit - or use the bits from a Mini if you can find one. But there's really nothing wrong with the old cartridge filter and many of us just stick with that! No need to spend money on the spin-on type - it's not any better technically.