1275 head

[moggyminor16]

hi all well the traveller has been standing for some time as yet again had to go away and the trav sat about
she has started to leak oil from the rear oil thrower
so may decide to replace it again with a 1098 as want to change the diff and gearbox at some stage
i am asking will the head from a 1275 fit on to a 1098 as its unleaded
any answers greatfull
any tips would be greate for the running gear as need better top end
thanks all

[bmcecosse]

I've replied to the main post about this - BUT - the reason your 1275 is leaking at the rear will be because of excessive pressure in the crankcase - from blow-by on the rings. But if you have sufficient suction on the engine - it should be fine. Use a rocker cover with a breather pipe - and connect it to the brass vent pipe on the side of the carb - to suck the evil fumes away!

[mike.perry]

Sorry to disagree with you Roy but the crankcase pressure on a 1275 needs to be sucked out via the breather on the timing chain cover into the carb. Unlike the 1098 and earlier engines there is not enough internal clearance to allow the pressure to escape into the rocker box.
I have a breather outlet on my alloy rocker box which is not connected at the moment. When I find that T piece I know I put somewhere safe I will plumb the rocker box vent pipe into the timing chain cover vent pipe which is cinnected to an ECV as my carbs do not have the breather pipes. I will then see if that reduces the drips.[frame][/frame]

[bmcecosse]

Sorry to disagree with you - but this is EXACTLY how I did it - very successfully - on my 1340 Mini. And it had NO timing case breather. There is plenty of room past the 8 pushrods to clear away any amount of fume and pressure. I led the rocker pipe into a 1/8" diam hole in the inlet manifold - and it cleared up ALL fume/blue smoke/oil leak problems. Before I did this the engine was really quite bad for all these things - this is a cure that WORKS.