full manifold or ported
Post Fiend
Joined: Mar 2004
Posts: 6,056
Likes: 8
From: Union, Washington
I have always just deleted the PVS and used the ported vacuum dtraight to the advance unit. Then again I don't do any extended idling with my truck engines, and have always put the biggest radiator I can find in for towing.
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Post Fiend
Joined: Dec 2003
Posts: 6,658
Likes: 4
From: "Islander"
The crazy thing about a ported / manifold vacuum dual signal dizzy years ago is if you left the lines on as factory installed but they didn't function you would still pass a smog test. The visual was harder than the tailpipe sniff.
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Posting Guru
Joined: Aug 2000
Posts: 1,984
Likes: 2
A while back I accidently broke a port off my yellow (160*) PVS, and changed it for a green (128*) unit. This allows the fast idle to drop down a couple minutes sooner; not sure if it makes much difference, just thought I'd try something new.....? Since the weather's warmed up, I won't be able to tell much about the really cold start-ups until next winter.
My 78 351M came stock with a yellow PVS, and I'm curious, what colors are yours?
My 78 351M came stock with a yellow PVS, and I'm curious, what colors are yours?
Cargo Master
Joined: Apr 2004
Posts: 2,574
Likes: 4
From: Golden, CO
Originally Posted by Bear 45/70
When throttle plates open the ported vacuum ports sees manifold vacuum as long as the throttle plates are open......
At WOT and while accelerating the vacuum advance is static and does not advance the timing. The vacuum port is below the venturi and just above the throttle plate so does not sense the increased vacuum in the venturi.
At WOT and while accelerating the vacuum advance is static and does not advance the timing. The vacuum port is below the venturi and just above the throttle plate so does not sense the increased vacuum in the venturi.
Originally Posted by albcasummit
when I have the engine hooked up to ported and hit the gas hard aor going up a hill I get a gringing noise. when its hooked up to full manifold I don't.
Freshman User
Joined: Jun 2005
Posts: 29
Likes: 0
From: BC, Canada
[QUOTE=thelonerangerxlt]
... (On a 3 port PVS, center port goes to dist, #1 to manifold vacuum, #2 to carb timed vacuum) ...
...The yellow PVS is 160*, blue-green is 125*. There's many other colors and temps, but those are the main temps used for vacuum advance.
awesome, i'm almost there, but which one is #1 and which one is #2 ? top or bottom? i'm trying to hook this all up right so my truck can idle for long periods of time if need be and pass emissions. (BC, Canada) i'm running a motorcraft 2150 on a 400/auto. i have 2 three port switches on my water elbow, one is yellow, what color does the brown pvs kick off at? and i have 2 small vacuum ports on my carb, one on the passenger side and one on the rear, which one is which? any help would be greatly appreciated, thanks.
... (On a 3 port PVS, center port goes to dist, #1 to manifold vacuum, #2 to carb timed vacuum) ...
...The yellow PVS is 160*, blue-green is 125*. There's many other colors and temps, but those are the main temps used for vacuum advance.
awesome, i'm almost there, but which one is #1 and which one is #2 ? top or bottom? i'm trying to hook this all up right so my truck can idle for long periods of time if need be and pass emissions. (BC, Canada) i'm running a motorcraft 2150 on a 400/auto. i have 2 three port switches on my water elbow, one is yellow, what color does the brown pvs kick off at? and i have 2 small vacuum ports on my carb, one on the passenger side and one on the rear, which one is which? any help would be greatly appreciated, thanks.
Posting Guru
Joined: Aug 2000
Posts: 1,984
Likes: 2
Hi sunnyb. The number 1 port on the PVS is the one farthest from the threaded portion of the PVS, on the extreme end. The number 2 port is the one nearest the threads. The center port is the "D" port (for distributor). These ports are marked on the PVS, but you'll need a flashlight and maybe a magnifying glass to see them while they're installed on the truck.
If the PVS's are stock Ford, then the 3-port BROWN temp range is 92*-98*.
The 3-port YELLOW is 157*-163*.
The 3-port BLUE, GREEN, or AQUA is 125*-131*, (that's the one I'm using).
The carb timed vacuum is the port on the passenger side of the 2150, under the choke housing. Route it to the #2 port on the PVS.
There's a vacuum port on the manifold directly under the carb. That's what I use for manifold vacuum, and it's routed to the #1 PVS port.
The center PVS port is marked "D", and of course routes to the distributor vacuum advance canister.
This system really helped my cold start-up drivability. It is just about perfect now with no stalling, and has a steady idle throughout warmup. Hope this helps and good luck. Let us know how it works out. Anything else I can help with let me know.
TLR
If the PVS's are stock Ford, then the 3-port BROWN temp range is 92*-98*.
The 3-port YELLOW is 157*-163*.
The 3-port BLUE, GREEN, or AQUA is 125*-131*, (that's the one I'm using).
The carb timed vacuum is the port on the passenger side of the 2150, under the choke housing. Route it to the #2 port on the PVS.
There's a vacuum port on the manifold directly under the carb. That's what I use for manifold vacuum, and it's routed to the #1 PVS port.
The center PVS port is marked "D", and of course routes to the distributor vacuum advance canister.
This system really helped my cold start-up drivability. It is just about perfect now with no stalling, and has a steady idle throughout warmup. Hope this helps and good luck. Let us know how it works out. Anything else I can help with let me know.
TLR
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Post Fiend
Joined: Dec 2003
Posts: 6,658
Likes: 4
From: "Islander"
What year, vehicle and motor have the brown 3-port switch? Sounds like a good addition to feed the warm air vacuum motor as I get carb ice in the winter then switch ducting to ram air.
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Freshman User
Joined: Jun 2005
Posts: 29
Likes: 0
From: BC, Canada
Originally Posted by Beemer Nut
What year, vehicle and motor have the brown 3-port switch? Sounds like a good addition to feed the warm air vacuum motor as I get carb ice in the winter then switch ducting to ram air.
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i also have a 74 f250 4wd/np435manual, that has a '69 390 in it (i swapped the original 360 for the 390). it has one 3-port switch in it. (i can't tell what color it is, it's blackish grey now, could be just worn off.) it works awesome - kicks the rpm up a little when it gets too hot and cools it down, great for idling long periods of time.
FTE Leadership Emeritus
Joined: Jul 2002
Posts: 42,561
Likes: 423
From: Long Island USA
Is that switch in the '74 F250 from the original 360, or the '69 390?
My '74 highboy didn't have anything between the carb and the dizzy, and I'm pretty sure that was stock. (my brother had it since new, and he wasn't a "non-stock" kinda guy).
My '74 highboy didn't have anything between the carb and the dizzy, and I'm pretty sure that was stock. (my brother had it since new, and he wasn't a "non-stock" kinda guy).
Freshman User
Joined: Jun 2005
Posts: 29
Likes: 0
From: BC, Canada
i looked back at my old 360 intake at the water elbow, it's missing a pvs at that location and there's no plug in it, so it must belong to the 360. sorry to mislead you - the guy before me actually did the 360/390 swap, but i rebuilt the 390 to stock specs after i bought it - so when i got it, it had the pvs switch in the water elbow - i took it from there not changing anything. seems to work great - my highboy purrs without major emissions equipment - just the one pvs switch to keep it cool. and it passes emissions like a champ, when it goes for testing they test it to 360 specs (should be less emissions than 390) but it passes with flying colors everytime. you'd think it would fail as it's larger and should put out more pollutants, but it doesn't, and i even get great comments from the test people, "she's running great..." etc. etc. i must have done something right?
i still have the old 360 in the shed... what can i do with this boat anchor?
i still have the old 360 in the shed... what can i do with this boat anchor?
Last edited by sunnyb; Sep 26, 2006 at 12:29 AM. Reason: adding info
FTE Leadership Emeritus
Joined: Jul 2002
Posts: 42,561
Likes: 423
From: Long Island USA
Actually, that 390 probably puts out LESS emissions than a stock 360... When they measure emissions, it's PPM (parts per million). It's not an overall "how much total" but "how much crap in a certain amount of exhaust".
Keep the old 360 - the block and heads are usable for a 390
Keep the old 360 - the block and heads are usable for a 390
Post Fiend
Joined: Dec 2003
Posts: 6,658
Likes: 4
From: "Islander"
Back in 86 I installed a 414 we still had smog testing in Cali, I always called it a 360 as is was the dirty motor of the FE family. Even then the idle was held at 900 to pass the idle HC limits running a CJ cam.
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