kevinl1058
Well-known member
Anyone running a try power set up with (3) 38 mm dual synchronous downdrafts?
tri -power with triple weber 38mm down drafts
- Thread starter kevinl1058
- Start date
Hi Kevin, I haven’t been able to find the time lately to do the fabrication yet but my plan is to try to use either a pair or set of triples of the Weber Progressives on my 250 project or if can find a real good deal would go straight for set of 3 Weber 40 IDF's or DCOE Side Draft's. I think your idea would be great, as there would be much better fuel distribution. Have you seen the project head that Xtacey was working on using set of 3 2Vs that are also canted it might give you some more idea's? Good luck 
kevinl1058
Well-known member
Yeah I hear ya. I can use the Offy manifold as an template for length and width then port out and gasket match for the carb adapters. the argentina guys use the 40mm IDF's my thing is that I would want good low end power 1500-6500 range is the idea.
Its all doable.
There are some wikedly cool 40 mm Weber carbs, but some have no power valve, and are solely designed for port on port carburation. An example of that is the Weber 40 FI5 which certain V12 Ferraris used. Great carb, but it has no power valve and is no good except at wide open throttle. All 32/36 and 38 Webers run 3.6 power valves, the US Holley Webers in later years run 8.5 power valves, and are unsuitable unless you change them.
The limit to packaging with the Offy intake is the spring tower braces to rear carb interferance. I found if you turn them (slew them) to the angle of the Ford Six studs, the spring tower brackes, Offy linkage, and later passenger side Air Condidtiong could fit without the float bowel inerferance problems.
The 38 series DGES/DGAS or or the miriads of staged 32/36 DGAV or 52xx/62xx/65xx Holley Weber's will work fine on a common log.
There isn't anything of any concern except making sure you have a good igntion system , good linkage, and an understanding of what happens when each carb venturi feeds only one cylinder. If it becomes a port on port, independent runner system, the air speed drops, and the carbs then pluse tune, with the air fuel mix exhibiting a fuel standoff situation which requires the intake runners to be of a certain kind to allow th air cleaner lid to withold fuel stand off. Then, you don't need power valves, and you can tune the engine using the time honoured classic Weber venturi per cylinder graph. You then the emulsion tubes using the classic David Vizard method. Power valves beome useless becasue there is insufficent signal to trigger them.
In your case, non of this will be a problem with a log head. Pulse tuning creates a situation where venturi area becomes crtically very important, and its only then that the carbs have to be sized exactly right.
The Argentinians use whatever carbs they have, I think there was a non staged Solex 34 in the 107 hp 1990's 3.1 liter Falcon ME were later sold as a Chinese EMPI Weber 34. Its not a Weber designed carb though. When the Argentinians look for replacement carbs, they replicate the non staged kind, and they tend to duplicate them on the detachable intake Sprint 221 or ME 188 head.
There was an early Falcon VA 3000 engine, which was orginally planned, designed and concieved as an early Falcon Stott Brothers or Edelbrock/ Holman Moody style engine but with three cast in triple carb bosses for a triple carb 221 that just used three Holley 1908 style 1-bbls. It is not independent runner, so you can run smaller or bigger carb venturis without pulse tunning. Ford Argentina soon replaced that with the 2-bbl SP 221, becasue the Turismo Carretera (literaly, Road Touring) in line six 3.8 liter Torina, 225 Dart, 221 Falcon, 230 Chevy engines were manadated to one 2-bbl carb.
So there was little point in making the Renault Torino style 248 hp GR380 style triple 45 DCOE Weber carb engines. Renault became the only one, since the long stroke Kaiser based OHC couldn't handle the revs in a Turismo Carretera environment
The linkage is simultaneous, each barrel opens at the same time. Six barrels. A 34 Solex has 25 mm venturs, a 38 DGES/DGAS/DGEV has 27 or 29 mm venturis depending on source. Six 29 mm venturis on a port on port carb intake will make the power peak quite on a 200 engine quite low, about 3800 rpm. If three 38 DGES/DGAS/DGAV carbs dumps into a common log, it will handel more rpm without starvation. The Itallians with there V12's and V12 Cadiallac GM engineers in the late 60's and early 70's found that port on port induction worked fine if the carbs where huge, but when you went to non port on port, the engine rquired much more revs to make the same power. In certain situations, the pulses fromother cylinders rob air flow, and this is why in line isx and V12 carb and fuel injection intake manifold design has taken 100 years to be optimized.
Here's a welded on log head Argie engie with triple 38's.
There are some wikedly cool 40 mm Weber carbs, but some have no power valve, and are solely designed for port on port carburation. An example of that is the Weber 40 FI5 which certain V12 Ferraris used. Great carb, but it has no power valve and is no good except at wide open throttle. All 32/36 and 38 Webers run 3.6 power valves, the US Holley Webers in later years run 8.5 power valves, and are unsuitable unless you change them.
The limit to packaging with the Offy intake is the spring tower braces to rear carb interferance. I found if you turn them (slew them) to the angle of the Ford Six studs, the spring tower brackes, Offy linkage, and later passenger side Air Condidtiong could fit without the float bowel inerferance problems.
The 38 series DGES/DGAS or or the miriads of staged 32/36 DGAV or 52xx/62xx/65xx Holley Weber's will work fine on a common log.
There isn't anything of any concern except making sure you have a good igntion system , good linkage, and an understanding of what happens when each carb venturi feeds only one cylinder. If it becomes a port on port, independent runner system, the air speed drops, and the carbs then pluse tune, with the air fuel mix exhibiting a fuel standoff situation which requires the intake runners to be of a certain kind to allow th air cleaner lid to withold fuel stand off. Then, you don't need power valves, and you can tune the engine using the time honoured classic Weber venturi per cylinder graph. You then the emulsion tubes using the classic David Vizard method. Power valves beome useless becasue there is insufficent signal to trigger them.
In your case, non of this will be a problem with a log head. Pulse tuning creates a situation where venturi area becomes crtically very important, and its only then that the carbs have to be sized exactly right.
The Argentinians use whatever carbs they have, I think there was a non staged Solex 34 in the 107 hp 1990's 3.1 liter Falcon ME were later sold as a Chinese EMPI Weber 34. Its not a Weber designed carb though. When the Argentinians look for replacement carbs, they replicate the non staged kind, and they tend to duplicate them on the detachable intake Sprint 221 or ME 188 head.
There was an early Falcon VA 3000 engine, which was orginally planned, designed and concieved as an early Falcon Stott Brothers or Edelbrock/ Holman Moody style engine but with three cast in triple carb bosses for a triple carb 221 that just used three Holley 1908 style 1-bbls. It is not independent runner, so you can run smaller or bigger carb venturis without pulse tunning. Ford Argentina soon replaced that with the 2-bbl SP 221, becasue the Turismo Carretera (literaly, Road Touring) in line six 3.8 liter Torina, 225 Dart, 221 Falcon, 230 Chevy engines were manadated to one 2-bbl carb.
So there was little point in making the Renault Torino style 248 hp GR380 style triple 45 DCOE Weber carb engines. Renault became the only one, since the long stroke Kaiser based OHC couldn't handle the revs in a Turismo Carretera environment
The linkage is simultaneous, each barrel opens at the same time. Six barrels. A 34 Solex has 25 mm venturs, a 38 DGES/DGAS/DGEV has 27 or 29 mm venturis depending on source. Six 29 mm venturis on a port on port carb intake will make the power peak quite on a 200 engine quite low, about 3800 rpm. If three 38 DGES/DGAS/DGAV carbs dumps into a common log, it will handel more rpm without starvation. The Itallians with there V12's and V12 Cadiallac GM engineers in the late 60's and early 70's found that port on port induction worked fine if the carbs where huge, but when you went to non port on port, the engine rquired much more revs to make the same power. In certain situations, the pulses fromother cylinders rob air flow, and this is why in line isx and V12 carb and fuel injection intake manifold design has taken 100 years to be optimized.
Here's a welded on log head Argie engie with triple 38's.
bubba22349":3tod224r said:Hi Kevin, I haven’t been able to find the time lately to do the fabrication yet but my plan is to try to use either a pair or set of triples of the Weber Progressives on my 250 project or if can find a real good deal would go straight for set of 3 Weber 40 IDF's or DCOE Side Draft's. I think your idea would be great, as there would be much better fuel distribution. Have you seen the project head that Xtacey was working on using set of 3 2Vs that are also canted it might give you some more idea's? Good luck
The head that has the triple carbs on it is the flat top Aussie and Argentine log head. ARC9-6049.
In the XY 4X4 Pickup, and the Falcon SL Tripower, both Ford Australia and Argentina slanted the engine 5 degrees to clear either the front transfer case or the carb to spring tower brace gusset.
The idea of two 32/36 webers was always fascinating to me. Three would be impressive and if you were skilled enough you could get them all tuned correctly.
It's not the same as carbs but has anyone done a study on two or three tempo tbi's? That along with EDIS would be some high tech performance stuff.
But the sensation of having extra barrels kick in when you floor it would be tremendous fun.
I never knew that the aussies and argies had log manifolds. I thought they were all detachable.
It's not the same as carbs but has anyone done a study on two or three tempo tbi's? That along with EDIS would be some high tech performance stuff.
But the sensation of having extra barrels kick in when you floor it would be tremendous fun.
I never knew that the aussies and argies had log manifolds. I thought they were all detachable.
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