23 replies to this topic

[samsfern]

I know 'Ivor' tried split Webers at one point - but not sure if it was at this time..... I'm sure he will be back to tell us! But yes - all this is for the very last couple of BHP and probably not all that important for anything other than out and out competition use.

we use split 45s on our lenham leman coupe (fibreglass backended mg midget) class b race car at work, never tried anything else yet, but produced 142bhp @ 8,200rpm. Look sexy though! And if you look into the carbs with the throttle open, you can see the valves,

Edited by samsfern, 22 October 2011 - 05:09 PM.

[Cooperman]

Hey Sam, that's a great set-up.

[samsfern]

thanks peter, we bought them from minisport, they were advertised as a split 45 dcoe setup, all we got were two still complete unmodified webers, 2 manifolds, and a throttle linkage, we had to cut and modify the webers our selves to make them "split", the throttle linkage minisport supplied was so cap we threw it in the bin and made our own linkage up, and the manifolds were rubbish, so needed tidying up.

[Cooperman]

If I could get hold of the original BMC drawings of the 'prototype' split Webers I wouldn't mind making some. I've seen lots of photos, but no engineering drawings.
How's the Rover coming on? We started working on the 214 this weekend.

[djmini92]

With a really hot cam and high revs, like over 6500 rpm, the twin HS6's would probably be good on a decent inlet manifold.
twin HS4's would also work well. The limitation is not so much the carbs as the horizontal inlet tracts. After all, there is no point in having a carb cross sectional area greater than the inlet tract area. If they are more or less the same the inlet charge velocity will be optimised. Measure the inlet tract area then decide.

I'm going to be installing a kent 286 rally cam in it. I also have an original cooper s head as well.

[Cooperman]

With a really hot cam and high revs, like over 6500 rpm, the twin HS6's would probably be good on a decent inlet manifold.
twin HS4's would also work well. The limitation is not so much the carbs as the horizontal inlet tracts. After all, there is no point in having a carb cross sectional area greater than the inlet tract area. If they are more or less the same the inlet charge velocity will be optimised. Measure the inlet tract area then decide.

I'm going to be installing a kent 286 rally cam in it. I also have an original cooper s head as well.

My Cooper 'S' has the 286 and a very well-modified big-valve head at 11.2:1 comp ratio. It runs twin H4's. BHP is well over 100 at 6400 rpm. If running a 286, to get the full use from the cam you'll need an engine which will rev safely to around 6700 rpm as peak power is not until 6400. In other words a strong bottom end, fully balanced with a centre main bearing strap is essential.

Edited by Cooperman, 22 October 2011 - 07:55 PM.

[AndyMiniMad.]

With a really hot cam and high revs, like over 6500 rpm, the twin HS6's would probably be good on a decent inlet manifold.
twin HS4's would also work well. The limitation is not so much the carbs as the horizontal inlet tracts. After all, there is no point in having a carb cross sectional area greater than the inlet tract area. If they are more or less the same the inlet charge velocity will be optimised. Measure the inlet tract area then decide.

I'm going to be installing a kent 286 rally cam in it. I also have an original cooper s head as well.

My Cooper 'S' has the 286 and a very well-modified big-valve head at 11.2:1 comp ratio. It runs twin H4's. BHP is well over 2100 at 6400 rpm. If running a 286, to get the full use from the cam you'll need an engine which will rev safely to around 6700 rpm as peak power is not until 6400. In other words a strong bottom end, fully balanced with a centre main bearing strap is essential.

Wow...Thats a lot of horses...typo maybe?

[Cooperman]

Typo corrected
It was measured at 117 bhp at 6400 rpm on H4 carbs. It really does have a lot done to it as it's a full-on 1310 cc historic rally car. In fact I do have a pair of HS6's which I might try to see it that makes any difference. I doubt it would though.

[AndyMiniMad.]

Sorry Cooperman. Ive been in the pub...Errr ....pubs...