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Working on it

Bored now

Lintilla's rebored engine block

I picked Lintilla's engine block up from Minisport in Padiham this morning. The cost for the rebore and skim seemed quite reasonable to me, and it looks like they have done a good job (though I won't know for sure until I reassemble it). I was surprised to learn that they had to bore it out by 40 thou' - four times as much as usual - to get rid of all the scoring. Unfortunately I had already ordered a set of +10 pistons from ESM, so those will have to be returned and I won't get the +40 ones until Tuesday. I think they must have put it through one of those industrial dishwasher machines after machining it because it is virtually spotless with no sign of any swarf or grinding dust. I shall have to give it a nice coat of BMC engine green!

I've calculated the new engine capacity with the quadruple-rebore and it's gone from 1098cc up to about 1132cc, so an increase of about 3%. Probably not noticeable in terms of engine power.


After painting:
WOOF!!!! :D
You want to bore those two blocked water jacket holes out though.. surprised you didn't do that before skimming. I've lost gaskets before due to the pressure building up in the blocked-off passages in the head (for some reason, the head holes never seem to clog up in the same way.)
My rebuild 948 needs the same treatment.
They aren't blocked with rust or anything - the block was made without those holes. I'm not sure why but I presume the designers had some reason for it.
Thinking about it, those holes are probably blocked so as to prevent water coming into the front of the block from the pump going straight up and out of the front of the head without cooling the back of the jacket.
:( I don't know the 1098, but I strongly suspect there would be no difference in the cooling.. If you look at the ones that have already been drilled, they also resemble iron. I've no idea why it does that, but both my blocks have done the same in the past. Check the head for corresponding holes- I don't think those holes are meant to be blocked up like that. I've certainly lost a head gasket through making exactly that assumption in the past.