A series engine horse power.

[amgrave]

Just been reading up on A Series engines on t'internet and found an article stating what cars they were fitted into. It says the 1098 engine as fitted in a moggy was also used in the Sprite and Princess to name a few and the quoted hp was 55/56 whereas in a moggy it is 48 hp. Anyone got any idea how this higher hp was achieved and is the info correct.

[liammonty]

Yes, it's correct. I'm fairly certain it was achieved through the use of a 3:1 exhaust manifold and twin carbs (with associated manifold), plus a 12G295 head in place of the usual 12G202 - those were the obvious differences on the engine I had. I believe the cam was the same. Uncertain about CR differences.

I think that those higher output 1098s all had the larger 2" main bearings too.

[philthehill]

Only the 10CC prefixed engine number had the 2" diameter mains and that engine was primarily developed for the then Formula Junior (single seat race cars under 1100cc).

[bmcecosse]

The 295 head is worth at least 4 bhp, the better exhaust 1 or maybe 2, and the tiny twin carbs also 1 or 2 - mainly because the inletmanifold is not heated! The twins were on ly fitted to make it appear 'sporty'. No one would buy a sports car that didn't have the essential ( for Pub Points ) twin carbs.... There would have been more power if they had fitted a 1.5 SU on an unheated manifold.....