Outer Limits 4x4 Board

Is heat fitting rimmed liners in an aluminum block, mainly the rover 3.9, absolutly necessary. I understand that many aluminum race engines here in the states use rimmed liners that are not heat fitted. Is this necessary only for straight liners or both?

Thanks,
Tim

Steel liners and aluminium "aluminum" blocks have a different rate of expansion, so as the block gets hot the hole ID gets bigger quicker than the OD of the sleeve. If you could press in a cold sleeve in a cold block , by the time they were at operating temp the sleeve would be flopping around.

So they heat the block to 100C and put in a cold sleeve so that when the sleeve heats to the same temp as the block it has a tight interference fit.
AFAIK it makes no difference falnged or otherwise. the flange means the head gasket bears on the flange , so even if the block has a leak it goes nowhere.
Regards Philip A