Catigale wrote:We are probably the only two in America who dont think SU stands for Syracuse University...
spent most of today with my mechanic tuning the SUs on my 72 GT. The friggin HIF style just can't be tuned for the cold weather without backfiring..get them rich enough.. they idle like crap, and suck fuel faster than my Land Rover! Oppps sorry.. forgot this wasn't an MG forum! LOL
Sounds like time for a Weber! Got one on my shelf..ready to install \
Only here could we have a tangent from coffe makers to SU carbs!
KayakDan wrote:...but a Moggie +8 in BRG and Biscuit with Chrome Dunlop 60's still makes my heart race. I can't help it.
You should go visit the factory in Greater Malvern... I've been there twice... it's a hoot... like stepping back in time 100 years!
OK, experts... so how many of you know the reason why all of a sudden in the late 60's all of the non-British Motor Corporation (BMC) cars, like Triumph, Jaguar, Sunbeam, etc., dropped the S.U. brand and started using Stromberg’s (with their *horrible* diaphragm system)?
BL and BMC did very few things that made sense. Don't get me going about BL pushing Triumph tr7/8 instead of bringing over the MGB GT V8. MG owners are STILL steaming about that (among other things!)
Paul S wrote:spent most of today with my mechanic tuning the SUs on my 72 GT. The friggin HIF style just can't be tuned for the cold weather without backfiring..get them rich enough.. they idle like crap, and suck fuel faster than my Land Rover! Oppps sorry.. forgot this wasn't an MG forum! LOL
Sounds like time for a Weber! Got one on my shelf..ready to install \
Only here could we have a tangent from coffe makers to SU carbs!
Nahh... just change back to HS-series S.U.'s - get rid of the HIF ones. You'll never regret it. A Weber is nice, but don't think they are trouble free - they're a real pig to get tuned the first time, and because they are a progressive carburettor they have all the same problems with flat-spots, etc. S.U.'s, because of their constant vacuum progression don't have any flat-spotting with the right needle installed.
Paul S wrote:BL and BMC did very few things that made sense. Don't get me going about BL pushing Triumph tr7/8 instead of bringing over the MGB GT V8. MG owners are STILL steaming about that (among other things!)
Yeah, agree - instead they gave us the MGC with that heavy Austin 6 up front - what a pig. But although there were a lot of bad decisions, they sure did make some nifty little cars. Poor management and labor unrest ultimately killed the British motor industry... and it's killing ours too. Geez, ya think we'd learn from watching them, wouldn't you?
Paul S wrote:spent most of today with my mechanic tuning the SUs on my 72 GT. The friggin HIF style just can't be tuned for the cold weather without backfiring..get them rich enough.. they idle like crap, and suck fuel faster than my Land Rover! Oppps sorry.. forgot this wasn't an MG forum! LOL
Sounds like time for a Weber! Got one on my shelf..ready to install \
Only here could we have a tangent from coffe makers to SU carbs!
Nahh... just change back to HS-series S.U.'s - get rid of the HIF ones. .
It comes down to the weber is free (on my shelf), and the SUs are a grand or so for a new pair. Easy choice. Even so, I would still go with the weber. $3-400 for the setup, my mechanic has installed hundreds of them. Once the float is set right, the right jet installed. good to go. I would like HFs since they look better, but it is cost prohibitive at this point to go with HF SUs.
Here is a video of my weber powered B motor in a race http://www.youtube.com/watch?v=HI03fUZigCw. I think it is more than acceptable Having a mechanic that knows how to tune a weber to get rid of the 'flat spot' - priceless! Getting 33 mpg on the highway with the weber (compared to SUs 17-23) is not a bad thing either!
Catigale wrote:Ill bite Kevin....there was a lot of consolidation in the british motor scene in that period - did the SU supply chain get sold to a competitor??
Yep. BMC bought'em! So they cornered the market in those dead-reliable S.U.'s and that's why the MG's, Mini's, Healeys, Morrises and other BMC cars continued to use them. Meanwhile, the other non-BMC makes didn't have any S.U. supply and got stuck using the lousy Strombergs. Crafty devils at BMC.
Didnt Zenith and Stromberg get hooked up at some point too? Maybe that was a response to the BMC acquisition. I remember seeing some aftermarket Zenith Stromberg carbs for VWs in the 70s...when the Solex carbs started getting loaded with stuff for smog they really sucked - that PICT 34 carb in the 1971 on beetles was surpassed in horror only by the first VW foray into FIJ..
(Mod note - Ill clean up the car stuff out of Mods in a bit)
Catigale wrote:Ill bite Kevin....there was a lot of consolidation in the british motor scene in that period - did the SU supply chain get sold to a competitor??
Yep. BMC bought'em! So they cornered the market in those dead-reliable S.U.'s and that's why the MG's, Mini's, Healeys, Morrises and other BMC cars continued to use them. Meanwhile, the other non-BMC makes didn't have any S.U. supply and got stuck using the lousy Strombergs. Crafty devils at BMC.
Kevin, I had Kirks British Speed Shop in Iowa rebuild and polish our SU's for the 1970 MGB, humm are you fellows saying I should anticipate fiddling with them? Dang I really don't want to go thru that.... again.
I have been working a little at a time on the interior and I am looking for a Tan Dashboard Cover as ours ( the black one, was destroyed by sun and abuse )
Catigale wrote:Ill bite Kevin....there was a lot of consolidation in the british motor scene in that period - did the SU supply chain get sold to a competitor??
Yep. BMC bought'em! So they cornered the market in those dead-reliable S.U.'s and that's why the MG's, Mini's, Healeys, Morrises and other BMC cars continued to use them. Meanwhile, the other non-BMC makes didn't have any S.U. supply and got stuck using the lousy Strombergs. Crafty devils at BMC.
Kevin, I had Kirks British Speed Shop in Iowa rebuild and polish our SU's for the 1970 MGB, humm are you fellows saying I should anticipate fiddling with them? Dang I really don't want to go thru that.... again.
Quite the opposite - if you have S.U.'s you should almost *never* have to fiddle with them... set'em up properly once and leave'em alone for years and years - I use two ColorTune's and a Unisyn to get mine spot-on. Just every 5,000 miles or so drip a little oil on the moving bits and clean the vacuum chamber of any varnish - that's it.
As for Zenith-Stromberg, yes, they are joined... I always just call'em Strombergs, but they are one-and-the-same. Their carbs suck (pun intended) for two reasons - although both are 'constant depression' carburettors, instead of using S.U.'s patented (and beautifully machined) sliding-piston vacuum chamber, ZS carbs use a diaphragm which eventually perishes and your carbs suddenly and catastrophically lose their tuning - usually at the worst possible time... and second, they are nearly impossible to modify for special tuning.
Paul S wrote:There were ZS carbs standard on 75-80 MGB cars
True enough... towards the end of the company when money was short they had to cut costs - so instead of getting two different sets of carbs certified by the Fed's, they just went with the ones that were already certified and pretty much dropped using S.U.'s for anywhere that pollution standards were in effect.
You can just use some clean petrol, but better yet you can use some carburettor cleaner - Burkpile 2+2 works nicely. I have a parts washer in my workshop, so that's what I use, casing it up with a little 2+2 on a soft cloth to clear any varnish off.
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