33 replies to this topic

[Cooperman]

I've seen it said that it is best to offset bore if going to +60 as the gap between 2 and 3 is getting rather small. As it happens I have just gone to +60 (no offset boring) and am struggling with the gasket seal between 2 and 3. However, my initial look with a straight edge suggests the top of the block at this vital place is not as flat as it should be.

So if you are going to the trouble of boring an old block to +60, check the top of the block is in perfect condition while you are at it.

I never offset bore at +0.060" and have never had a gasket problem, except when Payen produced those 'duff' gaskets a couple of years ago. The gasket of choice these days is the BK450.
Yes, when building a fresh engine, always skim the block deck after the trial build, even if by only a couple of thou.

[MRA]

Dilligaf, you may be thinking of Mini speed...... and numerous owners had nothing but issues with these pistons in a Mini

[MRA]

Not naming and shaming..... if we don't try these ideas we would never get anywhere, by all accounts they produced well, just didn't like the revs longer stroke more inertia etc...... whereas the ford engines are pretty short on the stroke side of things.

[1977 Loud_Mini]

Bit of an update, i've managed to get hold of a vernier guage from college actually So today i've been measuring the bores. It kept coming up with mixed readings but got the guage centred in the bore and got some readings eventually, they are as follows:

No.1: 73.52mm
No.2: 73.51mm
No.3: 73.50mm
No.4: 73.52mm

It seems as if the pistons would be just about a perfect fit and that going by the ring gap measured in the bore it would seem the rings are too small but i'm not sure?
Anyway i've added a pic of the big end bearing shell to show the condition and type they are. Oh and a quick one of what it looks like at the moment with the 998.

Evan.