4bbl manifold oddity
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Postmaster
Joined: Jul 2003
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From: Pittsburgh
4bbl manifold oddity
Allright, i just picked up another 390 and it has kind of an odd manifold on it. It's a factory 4bbl cast iron manifold with a C4SE casting prefix on it. There's a threaded fitting on the back on the manifold, looks like it would be about 3/4" pipe thread. Off of this fitting there's a tube that runs up to just under the rear of the carburetor (Autolite 4100) and into a 3/4" thick aluminum spacer which is between the manifold and the carb.
I have never seen this tube before and don't know what it would be for. Also I don't know if this spacer is a stock piece or an aftermarket. The only thing i can think of is with how it's setup it would create a vacuum in the block and act as a crankcase vent since it has non-vented valve covers (but has a vented oil fill cap in each cover)
Any pointers would be great.
Justin
I have never seen this tube before and don't know what it would be for. Also I don't know if this spacer is a stock piece or an aftermarket. The only thing i can think of is with how it's setup it would create a vacuum in the block and act as a crankcase vent since it has non-vented valve covers (but has a vented oil fill cap in each cover)
Any pointers would be great.
Justin
Post Fiend
Joined: Mar 2004
Posts: 6,056
Likes: 8
From: Union, Washington
The first PCV systems used the road draft tube opening in the back of the manifold and pulled air in thru the one valve cover. PCV works better when used valve cover to valve cover. The manifold is left over from the pre-PCV days is all.
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Postmaster
Joined: Jul 2003
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From: Pittsburgh
I figured it was just a centralized crank vent, but it just looked so odd I had to ask.
As for the heads, they're C8AE heads that have had hot seats installed. The guy said he built the motor for a 56 Ford pickup that his brother in law owned. Ran it for about 6 months and rolled the truck, brother in law put motor in his garage, he wanted motor gone, brother in law hesitated, i bought it.
::Supposedly:: it has a pretty decent cam in it and about 10:1 compression, runs just at 400HP. Has an autolite 4300D, DSII, and has the crossbolt bosses.
All of that doesn't really matter to me, for all I care it could be a 2 bbl truck 390 that someone threw a 4bbl manifold and carb on. For what I paid for it it was worth it because it would turn.
Justin
As for the heads, they're C8AE heads that have had hot seats installed. The guy said he built the motor for a 56 Ford pickup that his brother in law owned. Ran it for about 6 months and rolled the truck, brother in law put motor in his garage, he wanted motor gone, brother in law hesitated, i bought it.
::Supposedly:: it has a pretty decent cam in it and about 10:1 compression, runs just at 400HP. Has an autolite 4300D, DSII, and has the crossbolt bosses.
All of that doesn't really matter to me, for all I care it could be a 2 bbl truck 390 that someone threw a 4bbl manifold and carb on. For what I paid for it it was worth it because it would turn.
Justin
