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-   -   Webcon weber carb conversion? (https://www.volvoforums.org.uk/showthread.php?t=315479)

Ross Slaughter Mar 26th, 2021 10:28

Webcon weber carb conversion?
 
Hi guys, decided this is the way forward for me now.
Does anyone here have pictures of a successful install in their 740? Also where fid you put the choke lever on the dash and do you have any pictures of that?

Thanks all.

Ross

volvo always Mar 26th, 2021 22:16

On my 1986 740 GLE with B230K engine.

The choke was fitted on the left hand side between the switches from memory on the angled black part of the trim.

No pictures as car scrapped/PX in 2007.

We had the weber kit fitted. Ran well for a few years, but jets used to block up even with 2 inline fuel filters. Blow them out and would then run fine. Eventually got worse after 5-6 years and stalling, running rough and eventually PX for a new Corolla in France, as needed a dependable car as lived in rural Normandy. Waited 2 weeks for new Corolla and in that time the 740, "Rodger" Ran perfect! Not sure what the issue was. D795 RJW. Vowed to not have another Carb Volvo. Had 240 GLT. Now 940LPT.

James.:thumbs_up:

ukvolvo Mar 28th, 2021 18:29

I have no experience on petrol volvo's but have fitted a couple of webers now. If there is another more efficient alternative i would go for it.

They are awful on fuel and the new Spanish made units are prone to leaks and poor machine work apparently. I had no leaks but despite using my gas analyzer and timing gun never got good results or smooth power curve. I tried and tried but gave up in the end. Compare that to say a su carb and there is alot better efficiency and power curves to be had.

Just my 2p

Mick

Ross Slaughter Apr 1st, 2021 21:09

The Webcon looks designed to be a factory style replacement for the Pierburg, I can not imagine a better alternative to be honest.

360beast Apr 3rd, 2021 07:10

It might be worth looking in to Dellorto DHLA carburettoes too, they offer a better range of jet sizes too IIRC. I was looking at them for my 360 before selling it and my mk2 golf about 6 years ago but money was tight so I went for a used weber and a service kit on that.

Laird Scooby Apr 3rd, 2021 10:05

Quote:

Originally Posted by 360beast (Post 2724931)
It might be worth looking in to Dellorto DHLA carburettoes too, they offer a better range of jet sizes too IIRC. I was looking at them for my 360 before selling it and my mk2 golf about 6 years ago but money was tight so I went for a used weber and a service kit on that.

I think he's looking for a standard conversion Luke, rather than a performance one. Likely to be a 32/36 DGV sequential twin-choke which should give good economy and low-end torque but also good performance once both barrels are opened up.

The Del'Lorto DHLA would be great if he was adding a wild cam and 4 branch exhaust and system but not much help on an othewise standard engine, ditto for the Weber DCOE which is very different to the Webcon conversion kit. That would be something like :

https://www.webcon.co.uk/products/83...and-pulse-air/

Difficult to tell exactly what carb is used but a basic twin-choke cooking carb from the look.

Ross Slaughter Apr 4th, 2021 11:19

You are dead right Laird Scooby, I just want it to work, nothing fancy as I am a stock guy.
I found a better picture of the kit on another companies site who sell the Webcon item.

https://i.ibb.co/H27YK4Q/7-F377-C72-...B538-F1224.jpg

qscgyjl Apr 4th, 2021 13:13

I think that carb is a 32/34DMTL, Land Rover and Fiesta OE if I remember correctly.

Laird Scooby Apr 4th, 2021 13:42

Quote:

Originally Posted by qscgyjl (Post 2725342)
I think that carb is a 32/34DMTL, Land Rover and Fiesta OE if I remember correctly.

It does look a bit DMTL ish, no knowing as the listings don't specify the type of carb they use. Don't recall any Land-Rovers using them, mostly Zenith-Strombergs or SU or Stromberg. I know in the late 80s/early 90s, some of the "performance" Fiestas/Escrots/Orions and maybe other Fords used 32/34DMTL, anything from about 2.0 up (including the 1.6 Ghia Mk5 Cortina) used 32/36DGAV, the 3.0 Capri used a 38DGAS and the Webcon conversion for Vauxhalls that had previously used a GM Varajet-II bucket used the 32/36DGEV but could be had as a 32/36DGV with a choke cable, sometimes referred to as a DGMV.

Strangely webcon.co.uk list the replacement carb for the Volvo Penta (2.3/2.5) as a 38 DGES which obviously gives more flow with sunchronous venturis and electric choke. Sadly they don't quote what the carb is for the normal 2.3 although i have found kits for the pushrod red block B18/20 that use the 32/36DGV on several platforms and the performance version using the 38DGxS.

As long as it works and is more reliable than the Pierbug, maybe the OP can let us know what it is when he gets the kit?

360beast Apr 4th, 2021 13:59

I belive they used them in the 2.25 land rover series engines, it is the same carb I ended up with on my 1.3 golf and when searching for ot I came across plenty that had come off of land rovers. I struck lucky though and found one that had come off a 1.1 mk1 golf, it must have been running a bit rich in that as it ran perfectly on my 1.3.

Ross Slaughter Apr 4th, 2021 14:09

Quote:

Originally Posted by Laird Scooby (Post 2725352)
It does look a bit DMTL ish, no knowing as the listings don't specify the type of carb they use. Don't recall any Land-Rovers using them, mostly Zenith-Strombergs or SU or Stromberg. I know in the late 80s/early 90s, some of the "performance" Fiestas/Escrots/Orions and maybe other Fords used 32/34DMTL, anything from about 2.0 up (including the 1.6 Ghia Mk5 Cortina) used 32/36DGAV, the 3.0 Capri used a 38DGAS and the Webcon conversion for Vauxhalls that had previously used a GM Varajet-II bucket used the 32/36DGEV but could be had as a 32/36DGV with a choke cable, sometimes referred to as a DGMV.

Strangely webcon.co.uk list the replacement carb for the Volvo Penta (2.3/2.5) as a 38 DGES which obviously gives more flow with sunchronous venturis and electric choke. Sadly they don't quote what the carb is for the normal 2.3 although i have found kits for the pushrod red block B18/20 that use the 32/36DGV on several platforms and the performance version using the 38DGxS.

As long as it works and is more reliable than the Pierbug, maybe the OP can let us know what it is when he gets the kit?

I will be ordering the kit this week so will post up some details.

Laird Scooby Apr 4th, 2021 14:09

Quote:

Originally Posted by 360beast (Post 2725359)
I belive they used them in the 2.25 land rover series engines, it is the same carb I ended up with on my 1.3 golf and when searching for ot I came across plenty that had come off of land rovers. I struck lucky though and found one that had come off a 1.1 mk1 golf, it must have been running a bit rich in that as it ran perfectly on my 1.3.

Probably a bit worn on the 1.1 and your 1.3 used the wear to get the right fueling. I know Ford used the same FoMoCo carb on early 1.1 and 1.3 Fiestas etc. so highly likely VW used the same carb and jetting for the 1.1 and 1.3 Golf but also bear in mind being a fixed venturi it would have the right mixture for a 1.1 at idle and all speeds above so would also have had the right mixture for a 1.3 drawing more volume for a given engine speed.

I remember being a young autoelectrician and they had a 1.1 Fiesta that would flood out as soon as you tried accelerating. None of the others could sort it or even get near the problem. I asked if i could have a try - "Huh! What would you know about it, you're just the sparky!?!?!"

Yeah, ok, have it your way, took it up the road, had a word with the Service Director (my immediate boss), told him my findings and asked if we had another carb i could try. "Borrowed" a carb off a 1.3 Escrot in for bodywork, took it for a spin and came back, gave the keys to the old boy that had scoffed and mocked me and simply said "Give that a try".

Came back 10 minutes later with a look of total disbelief on his wrinkled face. Even more disbelief when i told him the problem which meant all along him and everyone else in the workshop had been looking in the wrong area for the fault!

qscgyjl Apr 4th, 2021 15:02

I think the carb in the photo has the air filter adaptor fitted so it looks a bit different to a Fiesta carb. The 38DGAS can suffer with a flat spot from idle to progression when fitted on other engines than the Essex, I ran a couple on Opel engines and the progression drillings in the carb body were causing the problem. One I cured by using the 32/36 progressive linkage and the other by filing the butterflies to change the progression timing. The progressive 38 worked well but lost some low end torque and the other with filed butterflies nearly but not quite solved the problem. I moved to fuel injection so never really solved the flat spot completely on those combinations.

Laird Scooby Apr 4th, 2021 15:58

Quote:

Originally Posted by qscgyjl (Post 2725381)
I think the carb in the photo has the air filter adaptor fitted so it looks a bit different to a Fiesta carb. The 38DGAS can suffer with a flat spot from idle to progression when fitted on other engines than the Essex, I ran a couple on Opel engines and the progression drillings in the carb body were causing the problem. One I cured by using the 32/36 progressive linkage and the other by filing the butterflies to change the progression timing. The progressive 38 worked well but lost some low end torque and the other with filed butterflies nearly but not quite solved the problem. I moved to fuel injection so never really solved the flat spot completely on those combinations.

A point we're both missing is that Webcon may have used a generic photo and it might not even resemble the exact carb in the kit.

As for the 38DGAS, there was something wrong other than the carb, biggest cause of flat spots on the 2.0 CIH Opel engine was incorrect points dwell and also the 38DGAS needed a few degees more adavance at idle to make it run properly through the rev range.

Shouldn't have needed to use the progressive 2-stage lnkage from a 32/36 and as you discovered, you lost low-end torque as a result of having to open the first butterfly more.

I'm guessing you also had the 2.0 CIH lump, originally fitted with the GM Varajet-II bucket?

The idle bypass is the screw that should control idle speed on them but too many people touch the throttle stop screw, completely messing the vacuum advance up. If that was the case and you went to a Weber without first getting the timing right because of messed up vac advance, you would have had incurable flat spots.
If memory serves the ideal figure for the vacuum advance was 8" H20 @600rpm, to be set (very carefully) with a water manometer.
Needed careful tweaking of the dizzy followed by careful tweaking of the throttle stop screw to get it right, especially if some muppet had played with the throttle stop screw instead of the idle bypass screw.
Once the right amount of vacuum was on the advance line, the igniton timing could be reset to where it should be and the idle speed brought up with the idle bypass.

First time i did mine took me a couple of hours and several episodes of drying the water off the plugs but it was worth it. Then i went for the 32/36DGEV, followed a short time later by the 38 DGAS, converted to a 38 DGEV using the same electric choke element and OE feed to the electric choke on the Varajet.

No flat spots or progression problems, just power all the way to 7200rpm in all 4 gears. Fuel economy was also improved on the DGES over the DGEV, nudging 30mpg which for a hard-driven car was pretty good.

qscgyjl Apr 7th, 2021 05:14

Digging deep into the memories here! :D The engine was a 2ltr, the GM carb, inlet and head went in the bin and a fresh engine built with a 1.9 inlet, big valve head, new 38DGV and Piper cam. Ignition is hazy, there were a few combinations, most likely being Lumenition in a resprung 1.9 dizzy. A Holbay cam went in shortly after. The flat spot could be driven round easily, it was more of a hiccup. The progressive linkage was a trial that gave way to EFi then a V8. The other engine was a friends 2ltr with a Granada 38DGAS we filed the butterflies on to alter the progression timing. The joys of tuning on a budget!

Were you racing your CIH?

Laird Scooby Apr 7th, 2021 09:11

Quote:

Originally Posted by qscgyjl (Post 2726409)
Digging deep into the memories here! :D The engine was a 2ltr, the GM carb, inlet and head went in the bin and a fresh engine built with a 1.9 inlet, big valve head, new 38DGV and Piper cam. Ignition is hazy, there were a few combinations, most likely being Lumenition in a resprung 1.9 dizzy. A Holbay cam went in shortly after. The flat spot could be driven round easily, it was more of a hiccup. The progressive linkage was a trial that gave way to EFi then a V8. The other engine was a friends 2ltr with a Granada 38DGAS we filed the butterflies on to alter the progression timing. The joys of tuning on a budget!

Were you racing your CIH?

I kept the 2.0 inlet, removed the studs from where the GM Varajet went on, drilled and tapped the manifold to the Weber pattern and reused the original studs for the 32/36DGEV.

That started life as a 32/36DGAV but i converted it with a Weber electric choke, obtained the jettings for the standard conversion and the jets at cost from a mate who worked in a carb specialist/rolling road place as at that time my commute was fairly long and the unreliability of the Varajet and poor economy were painful on the wallet.

I didn't set out to intentionally tune it, it was more that when bits wore i replaced them with tuning bits and the cam went next so in went a Piper Magnum 285/2 cam with solid lifters and a stepped plug in the head to increase the residual oil level, meaning the cam always had oil wash lubrication.
The downpipe went next so a Jetex 2" downpipe went on merging into a 2.5" outlet then the rest of the system changed to a Janspeed 3" skidded system.

Then the 32/36 didn't give enough flow especially at the top end so the 38DGAS was sourced, rejetted and converted to electric choke.

Ignition was more or less standard but running at ~11deg BTDC instead of the standard 5deg BTDC. Get the ignition timing even half a degree out and it was flat as a fart and sounded like one as well. Get it spot on and changed into a snarling beast that happily left Manta 2.0 GT/Es standing and on one occasion, left a 3.0 CDi (12v) Senator floundering in the weeds. That was the closest i came to racing and the wrong car to do it with, underneath that solid blue paintwork lurked some disco lights! :rolleyes:

Never had it on the dyno but estimates from the guy i got my cam and other tuning bits from and my own experience suggested ~160-170bhp.

Can't remember the full spec, think there were a couple of other bits thrown into the mix but it was a very quick beast.

qscgyjl Apr 7th, 2021 18:19

1 Attachment(s)
Do you still smile if you see a Cavalier/Manta or Ascona? I had a strange find on my first car, a low mileage bog standard Cavalier 1.9GL with a 28/36 Weber fitted in place of the Zenith 35/40 INAT. At first I was disappointed to find out the carb was smaller but it went well, in fact better than the Opel Manta I replaced it with that had the INAT!

I had some fun with that engine in two cars, the Ascona B it came in and a GTE Coupe. The Ascona had the Holbay cam and big valve head and would keep with 2.8i Capri's to well over 100 then the V6 torque had the legs. RS2000's were fun as I could keep with them and had a 5 speed Getrag so they ran out of gears about 115. The fuel injection went on the Ascona effectively making a 2.0E not sold in this country, then the engine and box went in a stolen recovered Manta GT/E Coupe less the big valve head. The Ascona was more fun though.

I wasted a lot of money on CIH engines, a mild Rover V8 made a real nice road car with no weight gain and twice the Torque. I had the best of both cars with that one, a Mancona GT/E coupe. That was so much more fun.

Laird Scooby Apr 7th, 2021 19:21

The Weber was a standard fit on some Mantas - i'd lay bets it had over-riders on the bumpers from the factory? Usually they went hand-in-hand and were German built.

The Belgian built (mainly Asconas but some Mantas and Mk1 Cavaliers) usually didn't have the overriders but the 28/36 Weber gave better economy and performance than the horrible Solex thing, even if it had Zenith stamped on it!

Can't remember the last time i saw a Mk1 Cav/Manta/Asona on the road or anywhere else for that matter.

I remember having fun with 2.8i Capris, their faces in the rear view mirror said it all really! I'd previously had fun with them in a Mk3 Cortina, it was an N reg with the 1.6 box and back axle (slightly lower ratio than the 2.0) but ended up with a Capri 2.0 GT engine with a wild cam in it - not sure what cam it was but it went like stink, nicely helped by the back axle and lower ratio 1st and 2nd so Capri 2.8i's were eating my dust up to about 100 then mine ran out of legs and the Capri went past.
I also had a few standard Datsuns that would eat Capri 2.8i's on both acceleration and top end, that was fun! :thumbs_up:

PS - i like the Ascona fronted Manta, the reverse of what Vauxhall did to create the Cavalier! :thumbs_up:

Ross Slaughter Apr 8th, 2021 19:50

Oh man total thread highjack 🤣

Laird Scooby Apr 8th, 2021 21:00

Quote:

Originally Posted by Ross Slaughter (Post 2726988)
Oh man total thread highjack 🤣

Errrrrrrr, yeah, i was going to apologise for that! In fairness most of it was around Weber carbs but not neessarily Volvo ones! :tounge_smile:

Ross Slaughter Apr 9th, 2021 18:10

Quote:

Originally Posted by Laird Scooby (Post 2727016)
Errrrrrrr, yeah, i was going to apologise for that! In fairness most of it was around Weber carbs but not neessarily Volvo ones! :tounge_smile:

Still interesting all the same though.

I have just ordered the kit so will report back.

Ross Slaughter Apr 27th, 2021 20:54

https://i.ibb.co/VTY67tw/600238-D6-2...-ACB5590-C.jpg

Sneak peak of half-way through the conversion.


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