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I added a big block tri power to my 72. I don’t have the ability with the tri powers to hook it up to the canister so I was going to cap the line and add a vented cap.
But where should I cap it? The nipple coming off the tank going to the separator?
What would you cap it with? I was thing a carb vacuum port cap.
From: At my Bar drinking and wrenching in Lafayette Colorado
You can hook up the vapor canister to the Tripower by hooking it up the same way as it's done with the Q-Jet: You simply "T" the canister purge line into the PCV hose between the PCV and the intake manifold. The difference is that the PCV hose on the Tripower is on the passenger side instead of on the driver's side, so the canister purge hose becomes a little longer.
You can hook up the vapor canister to the Tripower by hooking it up the same way as it's done with the Q-Jet: You simply "T" the canister purge line into the PCV hose between the PCV and the intake manifold. The difference is that the PCV hose on the Tripower is on the passenger side instead of on the driver's side, so the canister purge hose becomes a little longer.
Lars
Thanks Lars.
what about the small hose that went to the carb from the canister too?
From: At my Bar drinking and wrenching in Lafayette Colorado
The small hose from the canister purge valve going to the base of the Q-Jet carb is for ported vacuum signal to trigger the vapor canister purge valve. There is no flow through the canister at idle, since this would basically be a big vacuum leak at idle. So the purge valve allows a light purge (vacuum leak) only when the carb's throttle is open far enough to produce vacuum at the ported vacuum port (indicating that the car is at cruise speed, and can "afford" a slight vacuum leak.
On the Tripower, the vacuum fitting on the passenger side throttle plate of the center carb is ported vacuum for vacuum advance (to reduce emissions). Don't hook up your vacuum advance to this port. Rather, "T" your vacuum advance into the manifold vacuum fitting just behind the rear carb so you get full manifold vacuum to the distributor. Then, hook up your canister purge valve signal line to the ported nipple on the center carb. This will make your entire purge system work right, and will greatly reduce gasoline fumes coming off your car.
The small hose from the canister purge valve going to the base of the Q-Jet carb is for ported vacuum signal to trigger the vapor canister purge valve. There is no flow through the canister at idle, since this would basically be a big vacuum leak at idle. So the purge valve allows a light purge (vacuum leak) only when the carb's throttle is open far enough to produce vacuum at the ported vacuum port (indicating that the car is at cruise speed, and can "afford" a slight vacuum leak.
On the Tripower, the vacuum fitting on the passenger side throttle plate of the center carb is ported vacuum for vacuum advance (to reduce emissions). Don't hook up your vacuum advance to this port. Rather, "T" your vacuum advance into the manifold vacuum fitting just behind the rear carb so you get full manifold vacuum to the distributor. Then, hook up your canister purge valve signal line to the ported nipple on the center carb. This will make your entire purge system work right, and will greatly reduce gasoline fumes coming off your car.
Lars
You don’t want to T off the center carb nipple to the vacuum advance and to canister?
Right now I have the vacuum advance hooked to there and car is running great. I want manifold vacuum instead for the distributor? I just want to make sure I am understanding.
The vapor canister "signal" line needs to come from a 'ported' or 'timed' vacuum fitting on the center carb. This type port has ZERO vacuum at idle, so it will NOT trigger the canister to purge during idle. Once the throttle plates open a bit, that port goes to full manifold vacuum so that the canister will purge when the vehicle is in motion.
The distributor vacuum advance can should be connected to a 'manifold' vacuum line (or carb base fitting) on the center carb so that timing stays advanced at idle, improving idle quality and lowering combustion chamber temps while idling.
Last edited by 7T1vette; Feb 22, 2020 at 05:07 PM.
From: At my Bar drinking and wrenching in Lafayette Colorado
Originally Posted by Joe79Vette
You don’t want to T off the center carb nipple to the vacuum advance and to canister?
Right now I have the vacuum advance hooked to there and car is running great. I want manifold vacuum instead for the distributor? I just want to make sure I am understanding.
Thanks
Joey
If you are very concerned about the environment, if you need to pass an emissions test, and you enjoy a hot-running engine that does not idle well, use the ported vacuum port for vacuum advance. If you want a snappy, responsive engine that runs cools and efficiently, use manifold vacuum for the vacuum advance - not that ported vacuum source. Read my vacuum advanced paper - e-mail me if you need a copy.
From: At my Bar drinking and wrenching in Lafayette Colorado
Originally Posted by 7T1vette
The distributor vacuum advance can should be connected to a 'manifold' vacuum line (or carb base fitting) on the center carb so that timing stays advanced at idle, improving idle quality and lowering combustion chamber temps while idling.
The Tripower does not have a manifold vacuum source in the carb base on the center carb - the center carb base fitting is actually a ported vacuum source. The only way to get manifold vacuum on a Tripower is to tap into the vacuum fitting in the manifold located just behind the rear carb.
The Tripower does not have a manifold vacuum source in the carb base on the center carb - the center carb base fitting is actually a ported vacuum source. The only way to get manifold vacuum on a Tripower is to tap into the vacuum fitting in the manifold located just behind the rear carb.
Thanks Lars
I got it plumbed and took it out. Runs and idles great. Never tried manifold vacuum before for the vacuum advance. Thank you again.
I got it plumbed and took it out. Runs and idles great. Never tried manifold vacuum before for the vacuum advance. Thank you again.
Joey
Hello Joey, I am also adding tripower to my 74 454.....and also have the same concerns that you do......glad you started the thread and that Lars explained everything needed to be done to make the system work correctly. Can you post up pics of how you routed the hoses? I think I understand everything, but just want to make sure that I hook up everything correctly as you have. Thanks and appreciated......Tom
Hello Joey, I am also adding tripower to my 74 454.....and also have the same concerns that you do......glad you started the thread and that Lars explained everything needed to be done to make the system work correctly. Can you post up pics of how you routed the hoses? I think I understand everything, but just want to make sure that I hook up everything correctly as you have. Thanks and appreciated......Tom
Tom
I had to fly out early this morning. I will get pictures when I get back home.
Here are some picture. You Pm me if you want more or talk about what I did. I still need to clean it up etc. I wanted to try it first. 1st picture is tying into manifold vacuum. 2nd is tying into PCV and 3rd is hose ran to canister with ported vacuum.
Capping Vapor return line
