C-1 manifold heat

[Lee Boyer]

I have a 327 with 2-4 setup Should i block off the heat passages on the intake manifold. Were they open or blocked off orig. How important is the shield under the manifold.

[Clem Z.]

Re: C-1 manifold heat

if you block the heat crossover passage the oil will not "coke" to the intake because the high temp exhaust heat is not there. i blocked a lot of aluminum intakes on corvettes and other chevys and never had anyone come back to have it reversed.only the L-88s and ZL-1s had the crossover passaged blocked from the factory.

[Rob Dame]

Re: C-1 manifold heat

If you do block it off be sure to wire the heat riser open Rob

[Roy B.]

Re: C-1 manifold heat

If you live in cold country , leave it open

[Bob Simard]

Re: C-1 manifold heat

FI cars did not have the heat riser either. If you block the manifold passage, use an FI spacer instead of the heat riser valve.

[Clem Z.]

just pop the spring loose

and the heat riser valve will stay opem

[Clem Z.]

Re: C-1 manifold heat

i live here in PA. and other than a little slower warm up no problem with it blocked. the engines with a divorced choke systems causes a problem because of no heat for the choke so you just wire it open. exhaust manifold heated choke were no problem. when my Z-28s set outside in the cold and snow and i had the cold air intake setups that took the air in thru the heater intake in front of the windshield and the carb would backfire and blow the snow off of the cowl would scare the hell out of some passengers.