2 replies to this topic

[Raz]

Hi guys need some info ....I have just baught an engine i was told it is an 1100 with omega pistons and a kent 266 cam it also has Lumenition ignition the person i got it from wasent sure if the head had been modified anyway .....I have taken the head off and found it has been gas flowed to a high standaed it also has 1 1/4 inlet valves and double valve springs and the combustion chamber is very highly polished it has also been skimmed the number is 12A1458......i have measured stroke and its 84. 26 the bore width is 64..6 the pistons are dished but havent got a makers name on them the bore is like new no wear at all .....Ok what i need to know is has this engine been rebored and is it an 1100 unit and if i add the following what sort of hp i can expect carb Hif 38 alloy inlet cooper bigbore exhaust ..... finally i paid £82 for the engine do you think it was worth it mind i had to pay another £30 to collect it got it off ebay

cheers Raz :grin:

[Guess-Works.com]

The standard head for an 1100 is 12G202, 12A1458 is a std 998 head, but by the sounds of it if the inlets are 1.1/4" then they are bigger than normal (1.1/16") the exhausts are 1" as standard, from the sizes you have provided for the bores would indicate an 1100 (or 1098).

As an engine the 1100 is much torquier (?) than a 998, and personally I like them as a small bore. setup with a sympathetic LCB and inlet with an HIF38 would be a nice runner.

Don't know about the omega pistons, not sure they made small bore ?? The only real true way to find out what's what is to strip them out...

[Dan]

The 12G202 was the head for the 1100, as in the BMC 1100 standard engine. 1100 engines fitted to Mini and Clubman always used the same head (and all other components except crank and pistons) as was being fitted to the 998 of the time.
65.567mm pistons are standard in an 1100, and 83.72 is the stroke. So this sounds like a pretty standard engine allowing a little measureing tollerance.
Your modified head explains the over sized valves I would think. 1100 pistons are available from plus 20 to plus 60 if you do want to re-bore. You would need to measure the pistons a lot more accurately to know if they are oversized or not but they should have an oversize number stamped in the crown if they are.