47-55.1 Triple Side Draft Webers

[Dongray]

I have an opportunity to purchase triple side draft webers for my 1950 1/2 ton and was wondering if there are any clearance issues under the hood. Currently my truck is stripped to the frame and the 292 engine I plan on installing is at the machine shop, so needless to say I cant test fit the carbs. There is so much room under the hood that I cant imagine there being an issue but there is the tension rod that runs from inner fender to firewall and the engine will be tight against the firewall which may cause interference.
I have always loved the look of the triples and would love to use them but would like to understand what type of mods if any would be needed to make them fit.

Thanks,
Dongray

[MARTINSR]

SAAAAWEET! The only clearance I could imagine is the brace rod on that side. I am going to be running a '53 Corvette three single barrel side draft.

Brian

[mongocanfly]

I would think room would be no issue...and a lot of trucks have the tension rods removed anyway...
I know 3 looks cool but tuning multiple carbs can be a enormous headache sometimes...

[mick53]

I love the trips. Mine are set up with progressive linkage.

[joedoh]

those are DCOE carbs, they are not progressive, they are synchronous. what that means is that all 6 barrels will open simultaneously, there is no primary and then secondary operation the way most 4 barrels or other progressive carbs work.

they also cannot be set up as progressive in that configuration, the throttle shafts between the barrels is solid and each carb is set up to feed two cylinders.

I have had a lot of sidedraft carbed cars and trucks, and some downdrafts on VWs which are the same operation except mounted vertically instead of horizontally. Tuning is not as big a problem as temperament, although the first set of duals I synced on a BMW 2 liter took a while to understand.

the temperament change though is that your pedal is now an on off switch more than a linear accelerator. it is very different than progressive operation that people can be used to, where you get a very tame and gentle acceleration until you open it past 50% and the secondaries open. cracking the throttle off idle is instantaneous, and urgent, because there is essentially 240mm (40mm x 6, although those could be 38s) of throttle opening and you have it tuned to run with that much air.

figure out what you want, I have put synchronous carbs on relatively tame motors that were originally sleepy little 4 cylinders, like a stock dual port bug or a 2 liter mazda truck, and they arent really sleepy any more.

[Dongray]

Originally Posted by MARTINSR

SAAAAWEET! The only clearance I could imagine is the brace rod on that side. I am going to be running a '53 Corvette three single barrel side draft.

Brian

Nice Martin! I wouldnt have moved to a 292 if I had that set up.

[Dongray]

Originally Posted by joedoh

those are DCOE carbs, they are not progressive, they are synchronous. what that means is that all 6 barrels will open simultaneously, there is no primary and then secondary operation the way most 4 barrels or other progressive carbs work.

they also cannot be set up as progressive in that configuration, the throttle shafts between the barrels is solid and each carb is set up to feed two cylinders.

I have had a lot of sidedraft carbed cars and trucks, and some downdrafts on VWs which are the same operation except mounted vertically instead of horizontally. Tuning is not as big a problem as temperament, although the first set of duals I synced on a BMW 2 liter took a while to understand.

the temperament change though is that your pedal is now an on off switch more than a linear accelerator. it is very different than progressive operation that people can be used to, where you get a very tame and gentle acceleration until you open it past 50% and the secondaries open. cracking the throttle off idle is instantaneous, and urgent, because there is essentially 240mm (40mm x 6, although those could be 38s) of throttle opening and you have it tuned to run with that much air.

figure out what you want, I have put synchronous carbs on relatively tame motors that were originally sleepy little 4 cylinders, like a stock dual port bug or a 2 liter mazda truck, and they arent really sleepy any more.

Originally Posted by mick53

I love the trips. Mine are set up with progressive linkage.

Originally Posted by mongocanfly

I would think room would be no issue...and a lot of trucks have the tension rods removed anyway...
I know 3 looks cool but tuning multiple carbs can be a enormous headache sometimes...

Hey Joedoh ,Thanks for the information. I honestly dont know much about carbss and although I have heard the terms synchronous and progress before it wasnt clear to me until your explanation. Thanks!
The truck is going to be a weekend driver and the occasional long trip so I dont mind having to tweak the carbs occasionally. Heck I have friends with Harleys and they are constantly tweaking them, hopefully it wont be that bad. I was wanting a unique look and the ability to get up and go when I want it to so I thought this might just fit the bill.

Mick53 I couldnt get the file to open but if that is the blown 292 that I have seen before that thing is over the top! You will have to post a video of it running some day I would love to hear it and see what it looks like installed.

Mongo, after I posted I was thinking exactly what you said and looked at pictures of the trucks with V8s and most of them are removed.

I think I will end up giving them a try and if I dont like them just sell them again. They seem to retain their value so that would help it be less painful.

[mick53]

Originally Posted by Dongray

Hey Joedoh ,Thanks for the information. I honestly dont know much about carbss and although I have heard the terms synchronous and progress before it wasnt clear to me until your explanation. Thanks!
The truck is going to be a weekend driver and the occasional long trip so I dont mind having to tweak the carbs occasionally. Heck I have friends with Harleys and they are constantly tweaking them, hopefully it wont be that bad. I was wanting a unique look and the ability to get up and go when I want it to so I thought this might just fit the bill.

Mick53 I couldnt get the file to open but if that is the blown 292 that I have seen before that thing is over the top! You will have to post a video of it running some day I would love to hear it and see what it looks like installed.

Mongo, after I posted I was thinking exactly what you said and looked at pictures of the trucks with V8s and most of them are removed.

I think I will end up giving them a try and if I dont like them just sell them again. They seem to retain their value so that would help it be less painful.

It's on hold right now. I'm waiting on a cross flow aluminum head out of New Zealand. Should be here soon.

[mr48chev]

Simpy put the manifold (more of a plate than manifold) you showed in post one is designed for each carb to feed one of the individual ports in the head that serve two cyliners each with no way to feed the end cylinders off the center carb hence you cannot run progressive linkage. On the other hand the early Corvette intake works off a common manifold that could be run progressive but may or may not work best when run progressive. That intake, carb and exhaust mainfold has a combined resale value that is higher than some guys have in their whole trucks but that value would be killed if the finish on the intake or exhaust was altered from original I've seen one polished six cylinder Corvette intake at a swap meet years ago that had a Corvette restorer throwing a fit as he would have paid a premium for it if it hadn't been all polished up.

There is plenty of info out there on tuning the Weber side drafts and there are some guys who are really good on them but who normally work on vintage exotic foreign sports cars. You may end up at Norwoods in Dallas before it is all said and done. Bob sold out a few years ago but I think the shop still works on Vintage Ferraris. They might be the link to someone who can tune those carbs. https://www.norwoodautoitalia.com/

I've got a 68 292 for mine going with an Aussie Speed 4 barrel intake and the cast headers that Tom Langdon used to sell (I bought them from him) but 12 Bolt Tom Lowe sells now. I haven't picked a cam or carb yet though.