03-08-2018, 07:28 AM
I recently stumbled across a copy ot the Haynes Owners Workshop manual for the Merlin engine. An interesting photo was of mechanics lowering a block onto pistons. Presumably the vast number of workers already accustomed to this on their Sevens represented a signifiant wartime contribution!
A few car makes in the 20s and 30s had fixed heads so there was other scope for the method.
My father working alone always used this method; the original robust 5/32 rings assisted. I have used both; now many cheat by ommitting the baffles. I recall a work colleague telling how they spent an hour or so lowering a block; then dicovered they had fitted it back to front.
Perhaps surprising in view of the very high cyl pressures but Merlin pistons seem to have a 2nd skirt oil ring.
A few car makes in the 20s and 30s had fixed heads so there was other scope for the method.
My father working alone always used this method; the original robust 5/32 rings assisted. I have used both; now many cheat by ommitting the baffles. I recall a work colleague telling how they spent an hour or so lowering a block; then dicovered they had fitted it back to front.
Perhaps surprising in view of the very high cyl pressures but Merlin pistons seem to have a 2nd skirt oil ring.