Morris Minor Owners Club

I need an abutment plate as I’m changing my carburettor to an HS4 (to match the Marina 1275 engine).

Would a plate for an HS4 carb from a mini be suitable, or would the throttle and choke cables be on the wrong side?

I have a Mini HS4 and abutment plate on my traveller. The throttle and choke cables are to the front of the engine, not sure if this is the same as a Marina

Thanks panky. My cables would be to the rear of the engine bay.

I had an interesting chat with a Minor specialist today, who implored me to leave the current set up alone. Currently I have Marina 1275 engine, HS2 carb, 1098 manifold, air filter and exhaust. I was told it should “pull like a train” on that set up and if I change to HS4 all I’ll do is ruin fuel economy.

The dizzy I haven’t actually checked, but I’m told it needs changed depending on which carb I’m running and that over-advancing is a particular problem on 1275 upgraded cars. It was suggested a slightly modified 45D is the best option.

I had been considering changing to a standard Marina 1275 manifold (which I was told today I’d also need to inlet water heat) corresponding exhaust, HS4 carb and K&N air filter. And after all that getting an SU tuning whizz to set it up. I thought keeping it all Marina made the most sense and would let the engine perform as intended. I was very much put off today though.

Very much back to the drawing board now. Not sure what to do??? I have most of the bits already (manifold, K&N & refurb HS4 carb), but I’m now thinking it might be a better idea just to have the SU guy tweak the current set up? Sell the current parts, or plough on…?

Sticking with the HS2 will not allow the engine to run to it's potential, in my opinion you need an 1 1/2" carb at least (HS4 or HIF 38) and a similar sized bore exhaust system. The point of fitting a 1275 is to increase the available engine power and to restrict it so seems a bit of a shame.
If you do decide to carry out the modifications I would ditch the K&N cone filter and fit a slightly modified (inlet tract cut off and a few holes drilled in the casing) Mini air box with a K&N element inside - the cone filter can be quite noisy and there's little benefit over the air box set up.

panky wrote: ↑Mon Dec 05, 2022 7:11 pm Sticking with the HS2 will not allow the engine to run to it's potential, in my opinion you need an 1 1/2" carb at least (HS4 or HIF 38) and a similar sized bore exhaust system. The point of fitting a 1275 is to increase the available engine power and to restrict it so seems a bit of a shame.

Yeah, that was the type of thinking going on in my head. Air filter wise I fancy the K&N cone filter for nostalgic reasons. I had one fitted on my 1275 mini (my first car). The air sucking noise doesn’t bother me, in fact I quite like it.

What I have assembled parts wise is: refurb Marina 1275 manifold (with vacuum take off for brake servo), refurb HS4 carb (from a Marina) and K&N cone filter. I have a friend that’s offered me a suitable good used exhaust, taken from one of his cars.

I was going to fit all the above (hadn’t planned water heating the manifold) and then get an SU tuning guy from the mini scene to profile a needle, set up the mixture etc. I hadn’t planned on changing on the dizzy, but now it seems that’s something I may need to do?

I’m interested to know if these plans are a sensible way forward? I just want a little more top end poke.

You can fit a water heated manifold (and they can be picked up pretty cheap) without connecting the water up but it's a simple job to re-rout the heater pipes to fit.
I'm a Mini man too and run a '91 Cooper. I grew a bit tired of the induction roar (getting old ) and re-fitted the original set up with the 'Cooper' embossed inlet tract. Goes just as well but a bit more sane.

This is the set up I have at the moment. !2G940 head on a 1098, HS4, alloy inlet manifold, Midget exhaust manifold into 1 1/2" system. But what you are planning sounds pretty good