The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => A7 & A10 Engine => Topic started by: bobber on 27.06. 2013 11:50

Title: A10 piston height
Post by: bobber on 27.06. 2013 11:50
hi,can anyone with this engine rebuild queery.
i am in the middle rebuilding a friends 1958 A10 engine which was just a box of parts,
when i fitted the barrels i notice that the piston top edges (dished pistons) are not flush with the barrel top,they are approx one sixteenth inch below barrel at tdc ,is this acceptable for the engine to run ok.
if it is i would assume that i would need to add that one sixteenth onto the mag timing tdc clearance.?
if it is not acceptable for engine to run like this would it be a case of wrong pistons or wrong conrods ?
any help on this matter would be gratefully received,
cheers
bobber
Title: Re: A10 piston height
Post by: muskrat on 27.06. 2013 12:05
G'day bobber, welcome aboard.
They'd be low comp about 6.5:1 and from memory (very bad) sit at that height. Timing height is from TDC so it doesn't matter if the piston is 1/2" down the bore if it's TDC.
Cheers
Title: Re: A10 piston height
Post by: bobber on 27.06. 2013 19:26
hi muskrat
many thanks for your quick reply,and clearing up that problem,
cheers
bobber