Hey I'm tacking off 1 edelbrock and putting on 4 stromberg 97's on my SBC. What do I do with the PCV?
Hook it to a manifold vacuum source, or vent it to the header collector. Do a search, been covered a bit...
only problem i see with intake vacuum source is each separate carb supplies two cylinders so wont i be putting oil just to where I hook it up and fouling those plugs? I cant find anything on header collector? Do you mean put a plug into the exhaust right where it comes out of the motor? Sorry i'm so dumb I'm new to car motors.
Or you could just throw it as far as you can and put another breather in it's place. I also checked out your album and you look a little like Ron Perlman from Sons of Anarchy in that picture.
Scripps, I'm currently doing the same thing. I'm using an offy manifold with 4 97's. Based on what I read, you must have a man a fre to have 1 carb for 2 cylinders. I agree with Landseaair, use a breather off your valve covers
Here is what I did on a dual 97 intake. My PCV valve is in the valley pan. I drilled and tapped my carb adapters for the vacuum source that you see running down between intake runners to the PCV valve. I replace a road draft tube and did not want to pull and drill the intake. That balances out the extra air that the PCV valve adds to the air fuel mixture after it leaves the carb. Doing that 4 times may not be practical but if you study your intake you will find smaller runners that connect all 4 carbs in the intake manifold as seen above. Sort of a balance tube. You might not be able to see them from the top of the intake but they are there and will have the same vacuum signal as anywhere in the intake system below the ****erflies. My Man-a-free balance tubes were not vissible from the top. I'd look for a spot somewhere near the center and tap into that balance tube for your vacuum source. If you can find a central spot that you can drill and tap from the top down into that balance tube then you have a good centrally located source of vacuum. The big barbed fitting above was use for power brakes on this intake. You will have to get a new inline PCV valve. Just make sure you test the direction of flow. (I put it in my mouth and blow! very scientific) Unles your engine has excessive blow by, I wouldn't worry about the oil fumes fouling plugs. I do worry about leaning out a cylinder if the vacuum source comes from only one or two cylinders. As far as breathers go...just keep what ever you were using with the 4 bbl. If you do want to change them then do a search because that is the other end of the system and there are a lot of options.
Hooking a road draft tube or PCV valve works in town, but on the highway backpressure will build up & get into the crankcase with the road draft tube & would prevent a PCV valve from ****ing anything out of the engine. Don't ask me how I know. Unless you aren't using mufflers!
Yah - exhaust be be very low backpressure or it stops working. That balances out the extra air that the PCV valve adds to the air fuel mixture after it leaves the carb Excellent point - with small carbs that matters quite a bit.
Maybe I didn't understand the original question but I thought he had a perfectly fine factory PCV system but wanted to change intakes and need to know where to get the vacuum from on his new intake.
If you note the quote, it was suggested that he could run the PVC hose to the exhaust collector & let exhaust flow **** out the fumes instead of running it to the carb. I was saying that won't work if you have mufflers in your system & using a road draft tube, & I suspect there wouldn't be enough suction for operating a PCV valve even w/o mufflers. Just saying in case someone thught that tying into the ex system was a good idea.
Man this board is great! thanks for all the ideas. I only run 1/2 a cherry bomb on each side for mufflers. There is no smog check where i live and no sound restrictions, great for all my bikes I run with straight pipes.....I'll post a couple a pictures of what I'm getting. I cant tell you weather the intake has presure balancing tubes till it gets here in a few days. but it might not look that bad to make a PCV log that splits the line two four small tubes and run 4 small lines to tapped holes in the intake. 4 red fuel lines on 1 side 4 red PCV lines on the other. I suppose its not that bad to butcher up my intake, Or is it?
OK, what about this: I'm going to tap a small hole in all 4 risers. Then split the PCV line to all 4. might look good and I only butchered up the risers.....thoughts?
Bets on weather my HEI Dist is going to fit? I'm thinking it just might. I seem to get lucky allot. But that ****er looked huge when I was looking at it today.
It sure looks like that tapped hole right above the cast logo in the center is the hole that you want to use for the PCV valve. That appears to be the balance tube between the front and rear carbs. Check it out closely but it looks like you won't need to build a vacuum manifold. That is where I'd hook it up if I'm right. Be grateful that your HEI won't fit. They work great but are ugly as sin. It just won't look right with this set up.
Good idea - if the port is pretty central, the dilution to each carb will be pretty close - no harm, no foul.
What he said. Looks like they all share a common plenum to me. If you really want to run one of those inlet charge contaminating pieces of...
What should I run instead of the HEI? I look at the stuff in Speedway and it just looks like real expensive **** you see on cars that show up on trailers. I'll start looking on ebay for alternatives
oh yeah i'll look at that pluged up hole but I think that may be where a water temp sensor goes. I'll know for sure next week when i get it.
What I've done is use a Crane Cams electronic ignition conversion ( p.n. 750-1710?) in a points dist w/an MSD coil. You can get them from Jegs. It even has a built in rev limiter and only costs $65.00. Just make sure you follow the wiring instructions. Pertronix also makes them but I've never used one and can't say how well they work. Regardless I would still carry the parts and tools with me to change it back to points on road trips if need be. Also water has no business being anywhere near that part of the intake.
This is where on my 3x2 set up i teed off to go to the distributor and to the vacuum modulator for the ******. if you go there for the pcv, what will you do for the dizzy and ****** if it is an automatic? I came across this thread looking for where to plumb in my pcv fumes, they are rising out the oil fill tube and blowing all over the firewall. Any thoughts beyond the florida co that does the spacers?
That's the same Weiand I have. It's a dual plane design and all the carbs are interconnected through the runners. Look in the ports and you can see out the other side. That plug in the center is a common vacuum that will work for your pcv. I'd run a cetrifugal advance only distributor. You won't have much vacuum with those 4 carbs, especially if you have a decent cam. Tom
you can run the inlet to the pcv through one of those compressor airline traps first, then to the valve in the manifold, the oil condenses out in the trap, pcv is much better for your engine then road draft,not from an emissions standpoint,but in keeping the oil clean, they also make oil seperator boxes for this application,keeps the oil out of the intake,still gets the junk out of the crankcase
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