Vacuum Advance Timing Question

Engine, ignition, fuel, cooling, exhaust

Moderators: Ranchero50, DuckRyder

User avatar
Montana71-F100
Preferred User
Preferred User
Posts: 483
Joined: Sun Aug 02, 2009 5:56 pm
Location: Montana
Contact:

Re: Vacuum Advance Timing Question

Post by Montana71-F100 »

BobbyFord wrote:Use a ported vacuum point, not manifold vacuum.
According to this, manifold vacuum is the way to go:
http://chevellestuff.net/tech/articles/vacuum
User avatar
colnago
100% FORDified!
100% FORDified!
Posts: 1882
Joined: Tue Jun 14, 2011 8:48 pm
Location: Ridgecrest, CA

Re: Vacuum Advance Timing Question

Post by colnago »

Montana71-F100 wrote:
BobbyFord wrote:Use a ported vacuum point, not manifold vacuum.
According to this, manifold vacuum is the way to go:
http://chevellestuff.net/tech/articles/vacuum
Uh-oh, the gauntlet has been thrown down. Ported vs manifold (or Ford vs Chevy, since the link is to a Chevelle site). This oughta be better than an oil thread!

Joseph
"Sugar", my 1967 Ford F250 2WD Camper Special, 352FE, Ford iron "T" Intake with 1405 Edelbrock, Duraspark II Ignition, C6 transmission, front disc brake conversion.
Cal2121
New Member
New Member
Posts: 117
Joined: Mon Nov 23, 2015 6:36 pm

Re: Vacuum Advance Timing Question

Post by Cal2121 »

I'm definitely open to input on whether to use ported versus manifold vacuum. My engine builder did not give me a bright line, but said to see what seems to make it run best. Right now, I'm at 10 degrees initial timing and 35 total timing. It seems to run a bit better (idle, throttle response, etc) on the manifold vacuum. I also did some research online and found many threads discussing this topic, and none really focused on the brand of engine. It seemed that most people recommended manifold vacuum. Given that and the fact that the engine seems to like manifold vacuum better, I went with that. But as I said, I'm open to hearing all input.

Thanks again.
Post Reply