alright guys, this is for the people who have used SU carbs, i know theyre not completely traditional but im sure some old hot rodders have used them at some point. im thinkin about building an intake for my 303 olds and i dont want to have something the guy 'down the street' would have. so im thinkin about some SU's, maybe some HS6's. my question is this...do they have to be run with the throats horizontal/close to, or can they be run vertical and still be completely functional. i think it would be cool to have four of them with those cool bowls all polished up with some tall stacks pokin up! or any other ideas for intakes? its gettin hard to find the 94's, 97's, and all those other single/double barrel commonly used but pricey carbs.
I am pretty sure that you need to run them near to the horizontal as the piston is gravity controlled.
anyone got any ideas?[/QUOTE] http://www.stoveboltengineco.com/acartpro/product.asp?productid=95 has Pinto carbs and a S&H air cleaner reasonable.
You can run them siihtly down hill say about 30 degrees if 0 is horrizontal. The jags and several of the other English cars ran them at a slight angle. But it still wouldn't accomplist your end result. That's not a bowl its a piston tower. The bowl is a tiny tiny thing that sits out on the side. A cross ram with SUs has been done in the remote past, looked pretty cool, carbs jutting out just past the rocker covers.
SU's can be made to work quite well and they still being made today for many applications. These are the real guys to talk to www.burlen.co.uk They own the rights to the SU name and can recommend the best carbs for whatever engine. The angle they sit depends on the float chamber and how the float operates inside it. Earlier carbs had an external float chamber that sat at the side of the oil filled dashpot (the bit with the piston in) and I've often modified them so that they sit at different angles to the rest of the carb. They need to be as horizontal as possible for the float to lift properly, but the rest of the carb can then sit at pretty much any angle, though I wouldn't go beyond 45 degrees myself. Later carbs (HIF) have a built in float chamber that can't be altered, so they have to sit at the angle they came from factory. Many of these seem to have the mounting face between 60 & 90 degrees. I'm running this pair of SU HS2's on my 100E four banger.
yeah im familiar with the SU's, i have two HS6's on my current project. i just didnt know what else to call the piston towers. theyre fun, but cantankerous little things. i was thinkin about doing a cross ram deal, which would be cool, i could just have stacks that bent at the carb face so they pointed up. those holley carbs are cool and look like a good deal, but im lookin for something thats a single barrel, or something really weird. ive thought about the weber DCOE style carbs, but those cost a ton. whats goin on with motorcycle carbs? would something along those lines work? or too small of CFM? use a bunch of them?
I have used SU's in all sorts of applications here in the UK. They are cheap (about 25 USD for a good one) and easily available. The float chamber must be horizontal or very close to it. Some SU's have a seperate float chamber that can be rotated. However, the better SUs are the HIF series (HIF 44 sans any sort of electric choke mechanism is the one you want). These can be kept horizontal by simply putting a bend in the inlet manifold. Remember that the longer that manifold is the more torquey the engine will be. SU's polish up beautifully and look very nice with a bellmouth (try Mini spe******ts). Avoid any carb with ******ed screw heads as it is likely to have had attention from a bodger
SU's for 25$? wow i might just have to go with some of those! shipping to over here wouldnt be all that nice, but it might still be very cost effective. it might look really cool to have four of them, cross ram style, placed slightly inward of the valve covers (gotta be able to see the rocket valve covers) with some stacks bent up vertical.
S&S used to make a carb they called the L series made to resemble a side float Linkert (M-74 I believe). They came in 40 mm and 44MM. probably pretty hard to come by these days. They were a monster carb. I used a 40MM to feed my stroker (96" or so inches). Don't know where you'd come by any but if you could come by say 4 or 6 it would make an awsom setup. real old timey lookin and a relatively modern carb. We used to run the little SUs on the our HAWGs but they had a tendency to starve out at highway speed (gravity feed) I figured out how to put 2 float bowls on 'em. Worked like a champ. The **** were using a carb that resembled an SU on the early Z cars. A solex. it was a good carb and I don't doubt they could be had cheap. It's been done a ton and I don't know how hard they are to come by but the side draft carbs from a GM Blue Streak are a pretty good carb, again a side draft, but there really isn't anything wrong with a side draft carb even on a V-8. Different is good right?
Here's an SU used on the 602cc flat twin in my trike - it was off a 1500cc 4 cylinder. The thing with SU's is that because they operate on the constant vacuum principle they just sort themselves out and work on anything.
Here's a 1 bbl for $80 http://www.stoveboltengineco.com/acartpro/category.asp?catcode=33 or pick up a copy of Country General's tractor catalog. Zenith, Marvel for under $200. I get carbs like that at my local fork lift JY a lot cheaper. I didn't see any side drafts, but a High School friend had a '53 Corvette and said it ran terrible until he got a tractor mechanic to work over the carbs. So I wonder if some tractors had the Carter side draft? Also front wheels in the catalog for $40. Wish I knew sizes and bolt patterns. Might be an alternative to Divco.
dang that 1bbl looks pretty cool, maybe get 3-4 of them. where could i find info on the CFM of these little carbs? are they like a 2 bbl cut in half? electric choke is nice too. im going to look into runnin 4 SU's maybe
I would think a pair over each cover with horizontal stacks would be slick looking. I would set them facing about 45* forward and staggered like
I know multi carbs cost so I went with his 2 bbls for $65 each. I put it in a 260Z and hopefully will test it in a month or so. E mail him and he will tell you CFM of the 1 bbl.
They did make down draught SU's in the 30's, i have a bunch of the things i was going to run on a flatty just to be different. All fairly small bore but very reliable carbs all the same. SU down draught model number is DA3, Burlen services list them in their book & still sell service parts, SU Midel in Australia have NOS bodies still in stock! Kev.
if I was going to use SU carbs would seach for the japanese versions off a 240Z. Case of the Japanese improving on good old British tractor technology. Would be incredible looking if you ran 4 of the on a scratch built crossram tube manifold.
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