Twin HS2 carbs
Posted: Mon May 08, 2023 3:49 pm
My Traveller has a 1275 Midget engine, with the 1 3/4" single SU. Like my late father's 1275 Midget, it has a Peter Burgess "Econotune" head, which is basically just gasflowed. The Midget has the standard twin HS2 carbs. Both have LCB exhaust manifolds, straight through exhausts and K&N filters. When set up, on the same rolling road, both gave 77bhp BUT the Morris had a mechanical cooling fan, whilst the Midget had an electric one. That suggests the Morris is effectively giving a few bhp more than the Midget.
Since inheriting the Midget, I have found it noticeably more flexible and it pulls better from low rpm (It's a bit over 2 cwt lighter, so not that much). It isn't quite so eager at the top end and I'd prefer it if the Morris were the same. I have a spare set of SU HS2, complete with manifolds and have a mind to try them on the Morris. However, the exhaust comes out less steeply and I suspect would foul the carbs and certainly the heatshield, which acts as the anchor for the throttle return springs. I think the servo may be a tad close too. Has anyone fitted twin HS2 carbs to a Minor and what inlet/exhaust manifolds did you use?
Since inheriting the Midget, I have found it noticeably more flexible and it pulls better from low rpm (It's a bit over 2 cwt lighter, so not that much). It isn't quite so eager at the top end and I'd prefer it if the Morris were the same. I have a spare set of SU HS2, complete with manifolds and have a mind to try them on the Morris. However, the exhaust comes out less steeply and I suspect would foul the carbs and certainly the heatshield, which acts as the anchor for the throttle return springs. I think the servo may be a tad close too. Has anyone fitted twin HS2 carbs to a Minor and what inlet/exhaust manifolds did you use?