Need help with line routing
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Senior User
Joined: Mar 2001
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From: Maryland
Need help with line routing
Please help! I have a 1979 351m with a 1973 C6 trans. The 351m has an Edelbrock Proformer 400 with a 650 Edelbrock (1406) I need help with the lines from carb to vac advance. The Carb has 3 vac lines if you look at the front of the carb there is a large vac port in the center. (is this the PVC hookup?). My 351m does not have a PVC, Do I need one or should I just hook this to the valve cover breather?.I have Chrome Ford Motorsport valve covers. There are 2 small vac lines one on the drivers side and one on the pass side.There is a vac port in the back pass side of the Proformer 400. This is were I think the C6 Vac will hook up. Please help. Thanks Art
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From: Virginia
Need help with line routing
Get it running with the ports capped off, and with the engine at idle, pull each of the small vacuum port caps off till you find one with no vacuum. With this cap off, rev the engine a little and vacuum should appear when rpm is high, and no vacuum at idle. This is the port you need to hook to the distributor.
You need a PCV system. It keeps sludge from building up in the engine. Stick a PCV valve in one of the valve covers, and then run a hose from the PCV valve to the large port on the carb. Put one of those fancy chrome breathers in the other valve cover, or stick a fitting in it and run a hose up to the aircleaner. This is where the air goes into the engine.
You need a PCV system. It keeps sludge from building up in the engine. Stick a PCV valve in one of the valve covers, and then run a hose from the PCV valve to the large port on the carb. Put one of those fancy chrome breathers in the other valve cover, or stick a fitting in it and run a hose up to the aircleaner. This is where the air goes into the engine.
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On the Edelbrock 1405, 1406, etc. The center big port is the PCV valve port. The one to the right of the PCV is a full time vacuum port, and the one to the left of the PCV port is the "ported" vacuum port - meaning it has no vacuum at idle, and provides vacuum at RPM.
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From: Houston/Hope BC
Re: PVC system, non-valve side
At low blow-by states fresh air is draw in, breather caps do not offer adequate filtration, so the hose to the cleaner is much better.
At high blow-by states, more gas is produced than the PVC valve can accomodate (high load, low manifold vacuum) so flow reverses and this should be piped to the air cleaner for combustion rather than vented to atmoshpere.
At low blow-by states fresh air is draw in, breather caps do not offer adequate filtration, so the hose to the cleaner is much better.
At high blow-by states, more gas is produced than the PVC valve can accomodate (high load, low manifold vacuum) so flow reverses and this should be piped to the air cleaner for combustion rather than vented to atmoshpere.
