All Small Six Dual webers ?

[districtqc]

Hi , i have a 1975 250 head that i plan to bring to a machine shop and have it milled for a Weber 32/36. I see tri power setups and i think multiple carb is cool.

So what about closing the middle port on the log and Mill two openings on each Side for a dual 32/36 setup ?

Would that even work ? Am i thinking too Much? Is it worth it ? Is two carbs too Much carbs ?

 

[bubba22349]

Yes I think that that would work fairly good.

 

[aussie7mains]

IMO there is no reason this wont work well, there was a Mercedes 2.8litre inline six which had twin Zenith carbs very similar to the Webers. However the mercedes did have the intake split into two groups of three pots, and I would recommend you do this. You would be best leaving a small passage between the two groups to allow some pressure balance between the two groups. Bear in mind that if you fit two 32/36 carbs and do not divide the engine, every cylinder has access to two carbs, which might be a bit OTT. However when you divide the intake into two groups of 3 pot each cylinder has access to ONE carby but manifold losses are reduced. Not sure of the mechanics of dividing the LOG, but perhaps a 3mm slot could be cut across the log where the old carby flange was and a piece of 3mm sheet steel glued or welded in with a small hole for balance.

 

[Invectivus]

I talked to Jeff Jones about it about 7—10 years ago, he thought it was feasible.

 

[drag-200stang]

Take a carb gasket and lay it out , see if it looks like it would work.

 

[78_200_C4]

If any brazing or welding is involved make sure the machine shop has the ability to do it in a furnace so the log doesn't crack when cooling.
Not all large log heads are the same. The top of the log on the D7 head is flat. The D8 head is rounded.
One way the Weber 32/36 could be installed is by enlarging the large log throttle bore with a carbide bit in a HF elect die grinder then enlarging the 32/36 aluminum adapter with a 2 flute router bit in a HF trim router.
If i was going to install a weber I would try a 38/38 to have 2 idle mixture screws along with 2 part throttle air/fuel mixture plumes.

 

[districtqc]

If any brazing or welding is involved make sure the machine shop has the ability to do it in a furnace so the log doesn't crack when cooling.
Not all large log heads are the same. The top of the log on the D7 head is flat. The D8 head is rounded.
One way the Weber 32/36 could be installed is by enlarging the large log throttle bore with a carbide bit in a HF elect die grinder then enlarging the 32/36 aluminum adapter with a 2 flute router bit in a HF trim router.
If i was going to install a weber I would try a 38/38 to have 2 idle mixture screws along with 2 part throttle air/fuel mixture plumes.

I have a d5 head , also i already have one 32/36, thats why i'm thinking about that.

Good point there about the furnace! Ill make sure if this !