I know it has been covered many times but I can't find the right answer for my setup. I have a 1962 327 sbc with the crank case vent breather (road draft) and a 3x2 Offenhauser, intake, Holley ECGs carbs and vented oil fill tube. 1- First where do I connect the rear crank case vent breather? I don't want oil to go all over the car. Do I need to install an inline pcv? If so where do I plug it if I have no holes at carburator base or on the intake carb base? There is two ports on one side of the intake shown on picture #2, left one goes in the intake and the front one straight through the valley under the intake. Can I use the first hole to connect the pcv line if not, where??? 2- Second question is where do I take my distributor vac. advance for fully electronic distributor? There is no place on carb and no place on intake if I use one of the port for the pcv? PLEASE help me out ! I'm not familiar with tri power setup, after figuring out these two things I'm ready to start up the engine after 3 and half years of building process. if you have a similar setup please post some pictures.
The port you have would probably be best for the vacuum advance as the PCV may lean that runner out. This could be done to the center carb to allow for an inline PCV.http://www.eatonbalancing.com/blog/...ey-94-two-barrel-for-late-model-distributors/
Btt. Lots of info on here, used to be under dreddybears listing, holley 94s but seems that with new forum it can't be accessed. I have same carbs on edlebrock manifold, been a headache but good learning at the same time. I vented my valve covers with a breather as rear road draft tube was blocked with frost plug. Don't know if this was the best solution though.
My 67 Chevy C10 has the same pcv as the one you show in the back of the engine, mine has a hose that runs up to the back of the carburetor and there is a pcv valve threaded into the carb base.
Just a guess. I think you would have to drill and tap into the area between the center and rear carb to place a fitting for your pcv line. It appears there is a raised area for that. P.S. If your engine is in good shape you will have little oil out your draft tube.
Yes it can be accessed and I've searched through it,there is plenty of informations but there is not much on sbc tri power setup and I would prefer not to drill the valve covers if possible...
GM used a hollow carb stud in the 60's for vacuum, easy to get from suppliers. PCV in line on the draft tube will require a forward breather somewhere on the engine to complete the loop.
Your engine is already set up for a PCV valve system. The rear outlet you refer to goes to a "tomato can" baffle beneath the intake which prevents oil vapor from being drawn out of the engine. Connect this outlet to a PCV valve connected to a vacuum source beneath the butterflies of the center carb. If there's room you can drill and tap the intake and use a screw-in-type PCV valve. You could also drill and tap the intake for a male fitting and use an in-line-style PCV valve. A third option would be to find/fabricate a plate to go between the center carburetor and the intake, the plate being drilled and tapped for the PCV valve/male fitting. Your open front breather serves as the fresh air inlet source just as it is. Your vacuum source for the dizzy should come from a "manifold vacuum" source and NOT from a "ported vacuum" source. The fitting you've already installed in your manifold should do just fine for this purpose. Hope this helps.
You are setup now for a road draft tube, it runs under the car and should not puke oil all over the car unless your engine is toast or someone had removed the baffle in your lifter valley. If you want run a PCV remove the plumbing for the road draft tube (the actual tube is missing by the way). throw a grommet in the hole and stuff a PCV in it. Then take your fill tube out and replace it with a later model fill tube with a screw on cap and out your breather in one of your valve covers. If you want to stay old school you will need to put a tube on that little stub you got sticking out and run it under the car.
Should work. Another option, not cheap but easy. http://cgfordparts.com/wwwsectionfiles/cg_cat1_rear_axle_columbia.html#Columbia Carburetor Plate
The Columbia Carburetor Plate as linked by landseaandair is the perfect part for you. It gives you a male hose fitting at exactly the right spot and is designed to be used with an in-line-style PCV valve. You DO NOT have to plug your filler pipe/vent as has been mentioned, nor should you. That is where the clean air enters your engine as it must for the PCV loop to operate properly. You also DO NOT have to cut any holes in your valve covers, nor should you. Clean air in through the fill pipe, dirty air out through the rear fitting arrangement you already have with no modifications except to run a flexible hose with an inline PCV valve installed to the vacuum source provided by the Columbia Carburetor Plate.
The reason I say to block off the fill tube ( like GM did when they went to PCV) if because if you don't you are basically just pulling air from the front of the lifter valley to the rear of the lifter valley. It will still work but it will be marginal.
Something to consider, before you drill any holes in your intake, I don't have a similar Offy intake to check; but I'm pretty sure it is a dual plane intake. If you drill and install the PCV valve in the intake, it will only feed one plane of the intake and "unbalance" the mixture to half the engine. Don't know if that would be a "killer" problem; but I wouldn't do it. Originally the PCV valve was in the base of the carb and fed both planes of the manifold equally. Problem is the 94's and 97's for that matter don't have a similar port. You could probably install a spacer made to accommodate the PCV valve under the center carb and plumb it to the adapter you already have in the road draft tube boss. Might be a little obtrusive to the look of simplicity of the early style carbs have. Simpler still, you could just replace the adapter with an original road draft tube. If the engine is in good shape, you shouldn't have much problem with oil blow-by. In either case, you should check to see that the "beer can" baffle is in place, it really helps keep the oil in the engine where it belongs. Lucky you have an early engine that still has the rear vent provision in the block, make the whole deal easier. Vacuum for the distributor is easy, just hook it up to the brass fitting in the one picture.
Exactly. That's how the PCV system works. It simply changes the air inside the engine with a gentle vacuum, allowing clean air to enter to displace the contaminated air sucked out. Look again at the early GM systems, like the one on my stone-stock '64 El Camino with a 283, for example. It's got exactly the same system as the OP - exactly - the only difference being that the OP's PCV loop is not yet completed. When he adds the hose from the rear vent to a PCV valve and then to a vacuum source beneath the carburetor it will be completed. When GM closed the filler tube they provided an alternate source of clean air, sometimes through a tube from the air cleaner and sometimes through a valve cover breather, but always from somewhere. If you plug the fresh air source the greatly increased vacuum inside the engine will cause high oil consumption because it will pull vaporized oil out along with the airborn combustion byproducts which includes blowby (burnt combustion gasses) and, most importantly, water vapor. The function of the "tomato can" baffle is to keep the vaporized oil from leaving the engine by providing a means of separating it from the combustion byproducts in an efficient yet passive way. The PCV system is a hot rodder's friend. It keeps the inside of the engine sparkling clean while costing no horsepower to operate. Compare two high mileage engines, one with a vent tube and another with a PCV system, and the difference in sludge buildup is like night and day.
The engine hass been rebuild recently and has 0 mile on it so I'll do that for now to try it and I'll figure out something for a pcv system with all the suggestions you guys gave me. thank you very much!
The Jalopy Journal
