Hey yall, Im woodgassifing a chev 350 and it currently has a non functioning 4 barrel rochester quadrajet that has small primaries and large secondaries. It needs to be replaced. Which type of carb is best for wood gas?
Should i buy another quadrajet or a carb with equal size primaries and secondaries. Thanks…
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You can either make an intake plenum like I did that has a separate woodgas throttle, or you could go with something that has mechanical secondaries. The square bore carbs aren’t as good on fuel economy as something spread bore like a Quadrajet.
Personally I think it’s worth the effort to have two separate throttles because your gasoline carb won’t get carboned/sooted up. I run a super tiny Holley 94 clone 2bbl for gasoline. It’s like driving with just the primaries of a QJet. I could have made it use the Dualjet 2bbl and I may do that if I find power is lacking.
A lot of guys have ran square bore carbs with woodgas through it and had no real issues. You’ll need a way to cut off the gasoline flow like a cutoff solenoid or a valve. Shut it off on the line that goes to the carb and not the mechanical pump, so you don’t run the pump dry.
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Being that I have put down like 30,000 miles on my Toyota with wood and did destroy one Holley, I would recommend a plenum hookup for woodgas instead of through the carb
Just my 2 cents. You can see videos on my build thread what happens to a Holley long term with woodgas use. Or separate front and back barrels
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