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Expert 5K+
Posts: 8953
     
Location: WHEELING,WV.>>>HOME OF WWVA | is there any real differences-say between one for a 61-318 and a 65-426---any and all help welcome---later---chuck lowe  |
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Wise Old Village Idiot
Posts: 3591
Location: Dellslow, West ("By God") Virginia ! | Yep! I put the wrong one in the old F-250 (who cares, a PVC is a PVC right?,,,,,,WRONG!) and blowed out part of the rear main seal!
Guy at owrk had a 350 chevy pick-em-up, put the wrong PVC valve in, and started smoking real bad!
Whether using a differnt suction rate PVC in a MoPar motor has adverse effects, like on Ford (mine had 400 and some thousand miles on it at the time) and Chevy motors,,,,,,,????????????
Would be interisting to know which Mopar PVC valve is being used in the early Hemi/poly(s)/B block conversions?
But, after mine, and the guy where I used to work, bad experiences, I'll put in what is called for, and by that manifacture. Not some aftermarket. Especially Allied-Signal. Untill they get out of receivership and get their production quality (shit) in one bucket,,,,,,,? |
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Expert 5K+
Posts: 8953
Location: WHEELING,WV.>>>HOME OF WWVA | ok-canman-i'll go along with that !---let me ask this---on your engine-did you have a hose on the pcv and one on the other valve cover breather to the air cleaner?-------------what i'm thinking is !---if you have the pcv hooked up on one valve cover and have a breather on the other valve cover-open to the atmosphere(letting air in)not to air cleaner-it really doesn't matter what the suction rate is-as long as it's working properly and it is matched to 6cyl. or 8 cyl.---later |
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Wise Old Village Idiot
Posts: 3591
Location: Dellslow, West ("By God") Virginia ! | OK. First. Where's the little picture of you up there in the corner? Prying eyes want to 'see' if you're as ugly as Einstine out there! LOL
Here is how I had the old F-250 PVC hose routing.
PVC valve, hose to the thick spacer 'neath the carb, on one valve cover. The other VC, HAD (notice the 'HAD') the oil filler/breather cap 3/4" dia hose to a little filter instide the air cleaner. As soon as the truck turned 400K the air cleaner started filling with blow-by oil. I mean there would be a quart or two of blow by muckey gunk. It would soon soak the filter and choke the motor off.
A guy told me to put in a 4 cly PVC vlave, it would 'suck' more, and eliminate the air cleaner filling with oil. Well THAT didn't work because the motor built up so much pressure it shoved the dip stick out of the tube, spude milkey oil all over the firewall, and blowed out part of the rear main seal.
I then put in a Motorcraft, 400 Ford, PVC valve, and routed the 3/4" breather cap hose down inside the frame. Then, a hose over the dipstick tube, then over into a sealed glass jar. (when the jar filled up with oil I dumped it back into the motor.) That set up almost eleminated the rear seal blow-by.
The last 100K miles I was running straight 50W year round. Winter time, I had a block (big diesel) heater and strung out a extention cord wherever I went.
I kept driving the truck because it still ran good, and my butt fit the seat real good. Plus I din't have the expence $$ of Ins/tax/payments of a new/newer truck. (secretly I wanted to try and get into the Guinnes Book Of Records)
I don't mean drving short trips either. I will be willing to bet, I have proof, (it's in the bacground picture of '93 Mopar Carlisle) that ole F-250 has been to more MoPar shows than most Mopars!
Right now at 509K miles the ORGINAL dist went bad inside, so I'm not driving it,,,,yet. Simple you think. They sell a reman dist for $48. at Advance, but the problem,,,,,the OM dist is gualded to the block. I can't budge it. I've heated, beat, used a entire can of WD-40, even used a pipe wrench, trying to twist it. Won't budge. Every week, I go out now and squrt some P-B Blaster, hoping by spring (gotta haul firewood) it will break loose.
Anyway.
Bryon's Chevy truck, I don't know how the OM PVC sys was routed. All I know, he put in the wrong PVC vlave and his truck 100 some K miles started smoking real bad. After a month he put back in his OLD valve and the truck, slowely diminished smoking. I see him every now and then, I figure he is pushing 200K now, and it's not smoking.
Someone else told/mentioned, a couple of decades ago, about not changing differnt PVC vlaves, something would go wrong (don't remember), but they must be right. (?)
I figure as soon as Fearless opens the flood gates tomorrow, you will get a good awnser. I'm just realting what experience I'VE had, to you and you can react on that suggestion. |
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Expert 5K+
Posts: 8953
Location: WHEELING,WV.>>>HOME OF WWVA | well you already know the answer to the first part of your reply---unless there is a computer wizard that can help-no photo yet!what you did for your problem is pretty much what i said------the hose running down to the side of the frame is open to the air------flood gates-thats what i'm thinking to------thanks------later |
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Wise Old Village Idiot
Posts: 3591
Location: Dellslow, West ("By God") Virginia ! | I'm going to try and show you 'this' picture Chuckey.
Me and a buddy loaded up 9 cases of beer, (that was when I drank beer all the time) two bottle of moonshine, and headed off the Arizona, and came back with all that stuff there.
The old Ford 'only' had around 280K miles on it then.
For some reason just as we crossed the WV line on the 470 bypass, it quit running. We were still on the end of the bridge at 3 AM drinkin' beer.
After about an hour it fired right up and we went on home. I had pull that hill and the one out of Tridalphia in first gear. |
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Wise Old Village Idiot
Posts: 3591
Location: Dellslow, West ("By God") Virginia ! | I'm going to try and show you 'this' picture Chuckey.
Me and a buddy loaded up 9 cases of beer, (that was when I drank beer all the time) two bottle of moonshine, and headed off the Arizona, and came back with all that stuff there.
The old Ford 'only' had around 280K miles on it then.
For some reason just as we crossed the WV line on the 470 bypass, it quit running. We were still on the end of the bridge at 3 AM drinkin' beer.
After about an hour it fired right up and we went on home. I had pull that hill and the one out of Tridalphia in first gear.
OK I'm having trouble getting this scanned picture to take.
So I'll describe. My Pick up w/ a campertop, fully loaded with parts. The trailer has a '41'46 HD 1 1/2 ton Chevy truck, and a complete rear half of a '70 Fury. We were wighed in AZ, something like 17K total,,, |
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Wise Old Village Idiot
Posts: 3591
Location: Dellslow, West ("By God") Virginia ! | I'm going to try and show you 'this' picture Chuckey.
Me and a buddy loaded up 9 cases of beer, (that was when I drank beer all the time) two bottle of moonshine, and headed off the Arizona, and came back with all that stuff there.
The old Ford 'only' had around 280K miles on it then.
For some reason just as we crossed the WV line on the 470 bypass, it quit running. We were still on the end of the bridge at 3 AM drinkin' beer.
After about an hour it fired right up and we went on home. I had pull that hill and the one out of Tridalphia in first gear.
OK I'm having trouble getting this scanned picture to take.
So I'll describe. My Pick up w/ a campertop, fully loaded with parts. The trailer has a '41'46 HD 1 1/2 ton Chevy truck, and a complete rear half of a '70 Fury. We were wighed in AZ, something like 17K total,,, |
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Expert 5K+
Posts: 8953
Location: WHEELING,WV.>>>HOME OF WWVA | from the end of that bridge-if you look down the holla-south-you can almost see where we live---scanned photos!---i got mine down to size-less than 65kb---but the whole file uploads---private stuff and all---i had two trucks do that---one was fuel filter-tank was full of rust and the other computer melt down---later---chuck |
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Member
Posts: 26
Location: Long Island, NY | PCV is (normally) connected directly to the intake manifold or carburetor base flange, and affects intake manifold vacuum at all times. The PCV valve’s function is determined by three main factors:
1. high vacuum (small) orifice size, for idle, deceleration and light throttle cruising
2. low vacuum (large) orifice size, for open throttle
3. restrictor cone spring tension - this is what balances the large orifice against high vacuum, pulls the cone back and gradually opens the large orifice when vacuum drops.
During idle (high vacuum, up to 20” Hg), a tapered cone inside the PCV valve is held against the small orifice by high engine vacuum, leaving only a small opening for crankcase vapor to be drawn into the motor. The small orifice size is a function of engine size and idle vacuum. This has some effect on idle mixture, and will speed up the motor slightly and (proba-bly) lean it out somewhat. A motor with a big cam should use a PCV with a small high-vacuum orifice and low spring tension to be sure that the cone is fully retracted at idle.
During part throttle (moderate vacuum) conditions, the spring tension partially overcomes the reduced vacuum and pulls the cone away from the small opening, and allows crankcase va-por to be drawn into the motor more of the larger aperture.
During open throttle (very low vacuum, as low as 1” Hg) conditions, the spring tension over-comes the lower vacuum and pulls the cone away from the small opening, and allows crankcase vapor to be drawn into the motor through the larger aperture. This larger size is a function of engine size.
The PCV doesn't have only 2 discrete settings (small aperture @ high vacuum and big opening @ low vacuum). At intermediate vacuum levels (like part throttle acceleration, idle tip-in, etc.) there is a spring-loaded cone that gradually transitions from small to big opening as the vacuum drops, so to tune this you also need to be able to shape the taper of the cone, and the spring rate and pre-load.
Anyone have any good drawings or illustrations of the internal guts?
Here's one I color-coded, but I don't think it's accurate; notice how the spring is "hanging", and doesn't stop against the small end?:
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pcv valves
