Do I need one?

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SouthBay64

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Im swapping out to an Offenhauser 4 barrel and Dutra Duals. Ive been doing some reading, I keep reading and heat box and Plenum keep coming up.

Do I really need it/one if I live in Souther California? Not too many Cold Starts over here.

I am picking up a Mini starter to help with the Dutra Duals.

I am debating between Edelbrock 500 4bbl or Holley 500 2bbl.
Any suggestions on which one?

Thank you!
 
Probably not. It's all in the tune, really. If you tune it correctly without manifold heat, it should run fine.
 
Probably not. It's all in the tune, really. If you tune it correctly without manifold heat, it should run fine.
He's right.
One thing I will add is that even if it's 100 degrees out, a cold engine needs to be warmed up for at least a few minutes before driving if it doesn't have a choke or heat under the carb.......
 
Id run heated if at all possible. You can tell with an AF meter where you are heated and not. If you heat, you can really lean out your carb as the fuel is not sticking to the cold intake. Air cooled VW guys add heat to their long intakes, makes tuning a lot easier. The 1-2 HP you lose if you run a heated intake (debateable) wont be noticed but it will run more consistantly. Id run a hybrid dutra and modded heater side if it were me and I had the option.
dduals-set.jpg
 
Contrary to very common misunderstanding, manifold heat is not a cold-weather thing. If it is configured and working correctly, it's all benefit/zero drawback.
 
There's no special hardware required. The Offy intake will bolt to the cut-and-capped rear half of a stock exhaust manifold as shown by Pishta in post № 6. Before you go to the work of cutting/capping (or the expense of buying cut/capped), see to it that the manifold has a working heat valve.
 
There's no special hardware required. The Offy intake will bolt to the cut-and-capped rear half of a stock exhaust manifold as shown by Pishta in post № 6. Before you go to the work of cutting/capping (or the expense of buying cut/capped), see to it that the manifold has a working heat valve.
I have Dual Dutra Duals
 
IIRC you could cap the heat stove on the Offy and run a water inlet to the manifolds PCV port (or whatever that little screw is on the side) , but you'd have to plumb a return off the bottom of the stove cap, easy enough to redirect it as the new extended bypass from head to pump.
s-l225.jpg
 
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IIRC you could cap the heat stove on the Offy and run a water inlet to the manifolds PCV port (or whatever that little screw is on the side) , but you'd have to plumb a return off the bottom of the stove cap, easy enough to redirect it as the new extended bypass from head to pump.
View attachment 1715594178
That is the exact set up that I have on the slant in the 83 D150 with dual Dutra’s. I changed the egr cavity in the stock cast aluminum two bbl intake into a hot water hot spot.
 
heat keeps the A/F suspended, more fuel to the cylinders. Can jet down!
 
my all stock /6 in my D150 dont like being run cold here in nc 100 summer heat! heck ol truck runs better cold in winter at 30 degrees and motor cold and choke on! it needs the heat to run right in my opinion!
 
There you go, looks good! Didnt know the solenoid was in play with a rear Dutra, even with a mini starter?
IntakeManifoldHeater.jpg
 
For many many years, Ferd used a coolant heated carb base on it's engines. "I guess" they worked well. I've been around a few engines that needed carb heat. One was a Chev inline with headers, way WAY back in the mid 70's. "Some girl." I tried to help her out. We MADE a carb base water heater and added it to the what, Clifford? manifold? And took her stock filter and built and air intake stove---which the truck had factory, anyhow. It did help

And I remember a couple of 'vair powered sand rigs in San Diego. You could sit there on a hot summer day and generate FROST under the carb box on the aftermarket steel tube manifold.
 
There you go, looks good! Didnt know the solenoid was in play with a rear Dutra, even with a mini starter?
View attachment 1715594245

That solenoid and starter were used on '60-'66 Canadian-built Slant-6s, and Frank Raso (who makes that water box) is in Canada. The '60-'61 US cars used a similar starter/solenoid setup, but the '62-up US cars used the familiar gear reduction starter with integral solenoid (or whatever mini starter you choose to install).
 
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