Triple webers

Talk about the E-Type Series 2

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Bigcatfrankie
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#1 Triple webers

Post by Bigcatfrankie » Mon Apr 22, 2019 2:51 pm

I am thinking of replacing my twin Stromberg's with triple Weber's. Has anyone experience of this conversion and what do you consider is a decent price to pay for them?
Tim

1970 ex.U.S. Series 2, 2+2, in course of restoration
1965 Austin Healey 3000

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Heuer
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#2 Re: Triple webers

Post by Heuer » Mon Apr 22, 2019 4:35 pm

You would be better off with triple SU's unless you are intending to race the car. There is some good information in the Forum KB which will give you an insight into the issues you will face:

Weber Set up Guide 1: https://www.dropbox.com/s/h8983mm6qxa3s ... E.pdf?dl=1
Weber Set up Guide 2: https://www.dropbox.com/s/7zhzctlaawjvq ... m.pdf?dl=1
Tuning DCOE Carburettors by Kimble & Trindal: https://www.dropbox.com/s/4hj5d08yxoi0b ... r.pdf?dl=1

The price you will pay will be lots of sleepless nights, abject frustration and a constant headache from the petrol fumes!
David Jones
S1 OTS OSB; S1 FHC ODB
1997 Porsche 911 Guards Red

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mgcjag
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#3 Re: Triple webers

Post by mgcjag » Mon Apr 22, 2019 5:05 pm

Depending on what you aftet have you thought about throttle bodies and fuel injection....some on here have done it with great success. ....Steve
Steve
69 S2 2+2 (just sold) ..Realm C type replica, 1960 xk150fhc

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Tom W
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#4 Re: Triple webers

Post by Tom W » Mon Apr 22, 2019 6:45 pm

I have triple Webers. They were newly fitted by the previous owner of car when I bought it 6 years ago, so can’t comment on price. I don’t know how the performance compares to Strombergs, but the car feels plenty fast enough. It’s as quick as my friend’s 4 litre TVR Chimaera, and feels faster than a friend’s 3.8 FHC

To those who say Webers can’t be set up right and stink of fuel, this isn’t true. They can be set up to work perfectly well, though whether you will see any performance gain on an otherwise standard engine is debatable. I suspect the SUs on the standard setup aren’t the biggest restriction in the system. Webers are completely tuneable, as pretty much everything can be changed to suit your particular engine. It’s taken me some work to get there, but my car now runs smoothly and returned about 19mpg in my recent trip to Goodwood, including giving it some stick through the twisty bits.

The problem with Webers is there aren’t any standard “book” figures to spec all the internal components. There are recommendations that will get you close, but to really get everything dialled in, you’re best off with a session on a rolling road. You’ll also need to recurve the distributor, something that’s easily done if you have a 123. This, I think, is where most people go wrong, and assume the problems are with the carbs. The Webers respond much better with more advance at idle. It was only after increasing the idle advance (but leaving the top end where it is), that I lost the low speed stumble that I’d not been able to tune out of the carbs. I made my own manometer to help with balancing. Getting that right mae the engine much smoother at high RPM. The linkage is important too. Some of the ones you buy aren’t complete, and there’s some fabrication to do to get everything to run right.

They’re tricky to get right, but very rewarding when you do, and the noise under acceleration is very addictive!
Tom
1970 S2 FHC

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abowie
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#5 Re: Triple webers

Post by abowie » Tue Apr 23, 2019 12:07 am

The obvious advantage of going to triple Webers rather than triple SUs is that it costs about half as much for a set.

The downside is that you will need to find someone who is very experienced in setting them up. This is a complex process, requires a quality dyno and someone with a large selection of jets, tubes etc. There are many E type owners with unhappy stories about Webers in their past. I'm not saying that the Webers are useless; just that a lot of time and money will need to be spent to get them to run properly with your car.

On the other hand, cough up the dough and bolt on a new set of triple SUs and your car will run perfectly.
Andrew.
881824, 1E21538. 889457. 1961 4.3l Mk2. 1975 XJS. 1962 MGB
http://www.projectetype.com/index.php/the-blog.html
Adelaide, Australia

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#6 Re: Triple webers

Post by Tom W » Tue Apr 23, 2019 7:43 am

Buying Des Hammill’s books on both the XK engine, and side draft carburettors goes a long way towards de-mystifying Webers. These give some starting point specs to build the carbs to, and methods for determining what to change to get the best performance.
Tom
1970 S2 FHC

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#7 Re: Triple webers

Post by Heuer » Tue Apr 23, 2019 8:54 am

Bear in mind that back in the day the recommended Webers for the E-Type were 40DCOE's which I belive are no longer available hence people fit the 45DCOE's which could explain some of the issues with setup.
David Jones
S1 OTS OSB; S1 FHC ODB
1997 Porsche 911 Guards Red

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#8 Re: Triple webers

Post by Tom W » Tue Apr 23, 2019 9:21 am

40DCOEs are still available, though most kits intended for an E-type come with 45DCOEs. It’s DC03s (used on C-types and D-types) that are either unavailable, or ridiculously expensive, depending on size.

There’s a lot of crossover between 40s and 45s. Getting the choke size right is more important. As small as you can get away with without strangling the top end power (for your desired rev limit) will help to avoid problems lower down. If this means quite a small choke is appropriate, then that size is probably better fitted in a 40, rather than trying to choke down a 45.

If nothing else is done internally to improve the rev limit of the engine, or the flow of the cylinder head, then 45 Webers probably provide a lot more flow than the engine can actually use. Having said that, some racers fit 48s!
Tom
1970 S2 FHC

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Bigcatfrankie
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#9 Re: Triple webers

Post by Bigcatfrankie » Thu Apr 25, 2019 4:03 pm

Thanks one and all for all your comments.......for and against.........most useful.
Tim

1970 ex.U.S. Series 2, 2+2, in course of restoration
1965 Austin Healey 3000

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docdcc
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#10 Re: Triple webers

Post by docdcc » Thu Apr 25, 2019 6:21 pm

have triple webers on a series 2 with classic jag series 1 head with bigger valves . Had to fiddle with jet size but the weber suppliers have all sizes. As well the fuel pressure has to be much lower than the gas pump puts out so you will need a gas pressure regulator. I tuned them with a manometer and a heat sensor measuring the temp of each manifold so they were all about 325 deg at idle . Never have to use the choke , there is no stumbling and they give lots of power.
docdcc

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Bahamas
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#11 Re: Triple webers

Post by Bahamas » Mon Apr 29, 2019 7:59 pm

Why would you go through the expense of this modification if you were not going to make your engine a full race engine to maximize your horse power and not be very streetable? Doesn't seem to make sense to me. Triple SU's might be a better change for the money. Of course, all of this depends on what your goal is. maximum horsepower or a great driving street car.

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#12 Re: Triple webers

Post by Tom W » Mon Apr 29, 2019 8:17 pm

If you’re swapping from Strombergs, then converting to Webers is usually cheaper than converting to SUs. Webers are not purely for race engines and top end power, they can be tuned to work perfectly well on a road car. Plenty of other manufacturers successfully fitted Webers to road cars. I think the reason Webers are perceived as a race carb, is that they are necessary if you want to make maximum power, so they’re on nearly every race car. Then it’s assumed that they don’t work at lower states of tune. That’s not the case.
Tom
1970 S2 FHC

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Paul bow
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#13 Re: Triple webers

Post by Paul bow » Fri Sep 25, 2020 7:21 am

Hi. I replaced a pair of strombergs with triple 45 dcoe Webber’s, I used the newer 5 hole progressive type. They were bought from southern carburettors at a cost of about £2300 including linkage and jetting. They run like a dream, no smell no hesitation in pick up and sound fantastic, pop a bit on the over run through the Hayward Scott headers, personally delighted with them. The engine was completely rebuilt but kept standard except for uograding chains/con rods etc, made 210bhp on the dyno at the wheels, tbh was hoping for more but hey ho.. goes like the a rocket . Hope this helps :drinkingcheers:
Previously...S1 OTS E type (sold)
S1 2+2 manual. (Sold)
S2 rhd OTS full resto finished 8/23
S1 3.8 coupe (full restoration yet to start!)

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dal2.0litrefrogeye
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#14 Re: Triple webers

Post by dal2.0litrefrogeye » Thu Oct 08, 2020 8:45 pm

There's is a lot of BS written about webers . As has been said , they are a good carb for any state of tune engine , and as far as going for a rolling road session . I would be doing this if it was webers, SU ,or throttle boddies, how is 450 quid alot to spend for absolute tune up that makes the car a pleasure to drive on cars like ours with an average value between 50 ish K to 150 K ish
It doesn't make sence not to
Its a way of life not a hobby
Darren . 64 4.2 modded 69 4.2

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#15 Re: Triple webers

Post by Paul bow » Sun Jan 24, 2021 9:13 am

Couldn’t agree more with that last post..
Only hesitation is the rolling road.
I took mine to Atspeed in Rayleigh, they said the carbs (brand new and jetted to suit the 4.2 e type, by southern carbs, and various other recommendations) needed re jetting, long story short.. £840 !!!
I believe a simple finer fettling was all that was needed, in the end I played around myself put the timing where it should be (they had it a 5 deg BTDC) now it goes like a rocket .. horses for courses but at over £800 I was not overly impressed..
Just beware and get the right rolling road..
Previously...S1 OTS E type (sold)
S1 2+2 manual. (Sold)
S2 rhd OTS full resto finished 8/23
S1 3.8 coupe (full restoration yet to start!)

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