New 427 SB Almost Done.....
Thread Starter
Safety Car
Joined: Oct 2004
Posts: 3,926
Likes: 739
From: Youngstown Ohio
New 427 SB Almost Done.....
.....And now I am deciding how to feed my vacuum accessories. I have a World Motown manifold which does not have the vacuum port hole for the plug needed to supply my power brakes, auto trans, and headlights/wipers.
I think there was a thread showing a pic of access drilled in the rear of the manifold plenum(?). I am considering this, but has anyone just used the large access from the carb?.....any problems? I'm using a Quick Fuel (Holley) 950.
Thanks for replies.
I think there was a thread showing a pic of access drilled in the rear of the manifold plenum(?). I am considering this, but has anyone just used the large access from the carb?.....any problems? I'm using a Quick Fuel (Holley) 950.
Thanks for replies.
Thread Starter
Safety Car
Joined: Oct 2004
Posts: 3,926
Likes: 739
From: Youngstown Ohio
[QUOTE=MotorHead;1564426331]My Race Demon does not have a port in baseplate so I drilled the manifold, if your Holley has a port you can use that 
Thanks for the pic; my carb has the large vacuum port, so I'll use that.
Post info when your 427 sb is done
Thanks for the pic; my carb has the large vacuum port, so I'll use that.
Post info when your 427 sb is done
Team Owner
Joined: Nov 2004
Posts: 20,715
Likes: 25
From: Sorrento Italy
Pls educate me (and sorry if it seems a small hijack
): i have two tapped vacuum outlets in my 850 mighty demon, and the vacuum outlet on the distr is tap as well...
Would these vacuum connections be any good in a 570hp SB driven with no spare? The engine came from the builder as it is (all holes tapped)...
): i have two tapped vacuum outlets in my 850 mighty demon, and the vacuum outlet on the distr is tap as well...Would these vacuum connections be any good in a 570hp SB driven with no spare? The engine came from the builder as it is (all holes tapped)...
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Panic, Your carb manual should indicate which carb port is "ported" and "unported"
Vacuum advance should be on ported vacuum. So it doesn't see much vacuum at idle. It should only see the vacuum at cruise with the throttle blades cracked open.
Vacuum to the brakes, head lights, interior controls....... All need full unported manifold vacuum
C3 stroker I'm using the Motown intake on my motor also. It is about the tallest manifold made.
I had to go down to a 2 inch K&n with a big dropped base and open element top just to clear my hood.
Vacuum advance should be on ported vacuum. So it doesn't see much vacuum at idle. It should only see the vacuum at cruise with the throttle blades cracked open.
Vacuum to the brakes, head lights, interior controls....... All need full unported manifold vacuum
C3 stroker I'm using the Motown intake on my motor also. It is about the tallest manifold made.
I had to go down to a 2 inch K&n with a big dropped base and open element top just to clear my hood.
Thread Starter
Safety Car
Joined: Oct 2004
Posts: 3,926
Likes: 739
From: Youngstown Ohio
The Motown is rather tall.....I previously ran an RPM Air Gap which is also tall, but I no longer have it so I can't compare. With the L-88 hood and 1" spacer, I had 1/4" hood clearance with a 3" air cleaner. I'm hoping for the best.
