Interference engines or not?

[c_lee]

I have had a tendency to assume that all B200E engines in the 240's are the same - but it seems they are not.

I have two owner manuals for 240's - one for the 1988 model year and one for the 1990 model year.

Compared them today re B200E specs.

On comparing the two manuals there appear to be several differences relating to B200E engines of different years.

1/ maximum torque revs
2/ compression ratio
3/ recommended fuel octane requirements

There may be other differences too.

Colin

[Michael J]

Originally Posted by rustytoba

... a near flat cylinderhead design and have recessed pistons to accomodate the valves, this design could be considerd non-interferance, as the piston crown at TDC and the valves fully opened there would be no collision.

Normally if there are cut-outs in the piston crowns it's a sign that it is an interference engine - the recesses are because the valves are opening early and closing late, possibly with significant 'overlap' in the timing. The point being that if your belt snaps when a valve is fully open there will not be sufficient room when the piston moves up to the top of its stroke even with the recesses.