Sucking Oil
#1
Sucking Oil
I'm new to the forum, and need some advice. I have a 352 with the draft tube out the back of the intake. Stock rebuild 500 miles ago, 4-V carb, runs great. I recently wanted to get rid of the draft tube set-up and turn it into a PCV system. Got a carb spacer with the PCV port, made a fitting for the crankcase vent port on back of the intake, put a EV1 PCV valve in line in a hose from this fitting to the port on the carb spacer. Replaced the stock oil filler cap with one that has the hose fitting and ran a hose from that to a fitting on the air filter.
Still with me? Started right up, ran fine. Took it out on the road. Every thing still OK. Got it up to speed a few times, came back home, checked inside both newly installed vent hoses and they were wet with oil. The PCV valve was oil-logged. Should I scrap this set-up and get valve covers that allow for PCV fittings? What have I done wrong?
Thanks.
Still with me? Started right up, ran fine. Took it out on the road. Every thing still OK. Got it up to speed a few times, came back home, checked inside both newly installed vent hoses and they were wet with oil. The PCV valve was oil-logged. Should I scrap this set-up and get valve covers that allow for PCV fittings? What have I done wrong?
Thanks.
#2
#3
just a thought, but installing the pvc in the rear of the intake it has no baffle to prevent it from sucking in the oil from the lifter valley, I use an early intake like this but plug that hole and use a later type valve cover...changing to a later type valve cover with a baffle for the pvc might help alot and would be cheap to try
#5
Seems to me that there is an oil separator on the bottom of the intake. Made of fluffed up metal (very coarse 'shavings') and held in place by a piece of sheetmetal and 4 pushed in pins. If that is plugged and coked, as most are after almost 50 years, it will allow the oil to get sucked into the PCV and thence the intake instead of blowby vapors.
If you have oil in both hoses you are not getting air flow thru the crankcase. I'd check that the crankcase will go into negative pressure by holding my finger over the 'in' side while running the engine at a decent rpm. Should build a slight vacuum over time, and not really that long a time. If the separator is clogged, you will get slight vacuum, but not as quickly. Do you have a PCV for a later model FE, to get the right volume?
tom
If you have oil in both hoses you are not getting air flow thru the crankcase. I'd check that the crankcase will go into negative pressure by holding my finger over the 'in' side while running the engine at a decent rpm. Should build a slight vacuum over time, and not really that long a time. If the separator is clogged, you will get slight vacuum, but not as quickly. Do you have a PCV for a later model FE, to get the right volume?
tom
#6
Well, I can't really account for the condition of that oil separator, or even if it's in place, but it does seem to be free-flowing. Yes, I do get a slight vacuum on the "in" side fairly quickly. The PCV valve I'm using is supposed to be correct, but I will certainly double-check on that.
What do you think about the valve cover idea and no longer using the current crankcase vent?
What do you think about the valve cover idea and no longer using the current crankcase vent?
#7
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#9
I agree, the road draft tube that went into the rear of the manifold only created enough vacuum to draw out the fumes, your pvc connected to the intake creates a lot more..I think the covers changed in 1965, so anything later then that would work..maybe get some cheap used ones at a junkyard to try..I think that will cure your problem...
#11
#12
Well I switched to vented baffled valve covers and hooked up the PCV system, and plugged the old draft tube vent. Seems to be working great so far. I've only driven about 100 miles, but all is well. No more oil sucked in, plus no more oil drippage from that old road draft tube.
Thanks to all for your $0.02!
Thanks to all for your $0.02!
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