What can I expect from an intake manifold that has the heat passges blocked off? I have a Blue Thunder medium riser competition manifold. The heat passages are blocked off on the manifold, besides taking a long time to warm up, what other things can I expect from it? By the way anyone know when Jay Brown's book is coming out, or did I miss it?

I do not think you will see any problems with this other than the one you mentioned. The bottom of the intake will stay cleaner and not have burned oil on it after you drive for a while like the factory ones do. Good luck, Keith

My F-100 was closed after the PI floor rotted out and it ran through Massachusetts winters and has remained that way forever, even plowing snow at times and running though very cold weather

They are a little fussy cold, but not really that bad, if you think of the time it takes for the exhaust to get hot and saturate the manifold all the way to the carb, it not like it immediately helps anyway.


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- 70 Fastback Mustang, 489 cid FE, TKO-600 5 speed, 3.70 9 inch
- 71 F100 shortbed 4x4, 397 cid FE, headers, Street Dominator, 280H, 5 lug Dana 60, 4 speed

Thanks again. Threw it on the 390FE, it feels pretty potent with FPA headers. Wish I had a dyno. Sounds unreal with the x pipe and flowmasters.

Id rather have the heat in the manifold, but not have the exhaust swapping across it between two cylinders.

What do you mean?

"I drilled one side "



68 Mustang F/B
67 Fairlane GT

it only gets exhaust from one side. Thus it's blocked from crossing over completely.

Not sure how much actual heat it gets since once it's pressurized from one side, how can it move around enough to actually heat it as exhaust gets warmer? Probably gets just as much heat just from contact with heads.

LarryK

1964 Galaxie 2dr 390/6-71/4spd
1964 Country Sedan Wagon 428/5spd
1969 F100 428/4spd
1967 F100 352/now a 4 spd!
1959 B Model Mack

The exhaust crossover really only works if you have exhaust manifolds with a functional heat riser valve. The idea is it quickly warm the intake manifold by directing all of the exhaust from one bank through the manifold to exit out the other side. Without the valve, the only exhaust going into the manifold would be from exhaust pulsing back and forth between one of the exhaust ports on each bank....certainly not functioning as intended. Most of the valves freeze up early in life anyway and don't provide the manifold heating anyway.

So, block the exhaust passage...edelbrock heads don't even have them as cast.

66 Fairlane GT Silver Blue "BRUTE" Genesis 496/C4
66 Fairlane GT Nightmist Blue 428/TKO600
66 F250 Camper Special Rangoon Red 428/4-speed
2000 Lincoln LS Sport 5-speed

Moisture/acid could really build up in the higher parts of a dead ended exhaust runner w/ big temp swings. You could puddle acid/corrosives and eat the manifold