Try it without the PCV, and yoru vented valve cover. I hope that you have a vented front cover with the air'/oil separator.
Two vents should work, but I would add another vent to the crankcase at the fuel pump boss if you have not already.
Those pistons are flying around in there, pumping quie a bit of air in and out, so high crank case pressure is not an unusual thing if you are running it on the road at 4000 RPM all day long. The engine needs an extra breather or two, especially up top, and in the middle, and below...
Do you have oil leaking out the front cover main seal?
Engine Breathing
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jonclancy
- Posts: 943
- Joined: Tue Nov 01, 2011 9:30 pm
Re: Engine Breathing
Hi Jan,
Yes, I do have the separator can on the front timing cover. I replaced the old, corroded and contaminated filling with a stainless scouring pad. And yes, there is a small leak from the front. Most of the oil is coming out of the back, though.
I'll re-plumb as soon as I can get my rocker cover (re)modified. The spigot in the back was fouling the rocker shaft. Needs to be between a rocker set...
As I understand it, the fuel pump boss vent would have to be drilled while the block is bare. I'd do that if I had to get it rebored. Hoping this is a ventilation issue! Luckily, my driveway is crap. It's oily and crap now!
Yes, I do have the separator can on the front timing cover. I replaced the old, corroded and contaminated filling with a stainless scouring pad. And yes, there is a small leak from the front. Most of the oil is coming out of the back, though.
I'll re-plumb as soon as I can get my rocker cover (re)modified. The spigot in the back was fouling the rocker shaft. Needs to be between a rocker set...
As I understand it, the fuel pump boss vent would have to be drilled while the block is bare. I'd do that if I had to get it rebored. Hoping this is a ventilation issue! Luckily, my driveway is crap. It's oily and crap now!
Last edited by jonclancy on Thu Jun 09, 2016 10:39 pm, edited 1 time in total.
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Westfield 129
- Posts: 867
- Joined: Sat Jun 04, 2011 4:20 am
Re: Engine Breathing
I brazed a hose barb to the side of the cover, (near the top) with a small sheet metal baffle (about 1") across the opening spot welded in place (open top and bottom). No clearance problems with the 1.5 roller rockers.
Just did a 250 mile trip at 3800 RPM. Nothing in the catch tanks at all. No excessive oil blow by at the scroll or main seal.
Just did a 250 mile trip at 3800 RPM. Nothing in the catch tanks at all. No excessive oil blow by at the scroll or main seal.
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jonclancy
- Posts: 943
- Joined: Tue Nov 01, 2011 9:30 pm
Re: Engine Breathing
Well, I am hoping this is almost cracked! 
I have installed my vented rocker cover. The hose from which joins a Y with the timing cover hose to the catch tank. Catch tank via PCV to carb.
I now get an odd oil drip, but not Torrey Canyon style oil pollution.
I think I'll try one more configuration and omit the PCV to increase the vacuum... As long as the smoke levels remain low.
Next question will be whether I'll get enough running in miles on to get a rolling road tune before LMC!!
I have installed my vented rocker cover. The hose from which joins a Y with the timing cover hose to the catch tank. Catch tank via PCV to carb.
I now get an odd oil drip, but not Torrey Canyon style oil pollution.
I think I'll try one more configuration and omit the PCV to increase the vacuum... As long as the smoke levels remain low.
Next question will be whether I'll get enough running in miles on to get a rolling road tune before LMC!!
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erictharg
- Posts: 680
- Joined: Thu Jan 29, 2009 7:50 pm
Re: Engine Breathing
As long as your bores / rings are working OK that should be fine. I ran my old A Series with a breather each from the timing cover and the rocker cover for 7 years into a catch tank with no significant oil carry over.
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jonclancy
- Posts: 943
- Joined: Tue Nov 01, 2011 9:30 pm
Re: Engine Breathing
With my unvented cap, and PCV removed, there was little or no oil dripping from the engine, and the catch tank was empty after a 58 mile run a couple of days ago.
Shakedown run of exactly 100 miles went well, too! Nearly at the stage for a service and retune on the rolling road.
Oh, and I am working on a secret plan... All will be revealed in due course. But it does involve a coil pack and modded, cut off dizzy with another barb welded to it. That should get some nice negative crankcase pressure going!
Thanks to all for their help. Especially Ken, who helped me yank out the engine twice!
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Westfield 129
- Posts: 867
- Joined: Sat Jun 04, 2011 4:20 am
Re: Engine Breathing
So you are going to a crank fired ignition with coil on plug? I have had mixed results with that setup. The main advantage I have found is that the cold side of the engine is cleaned up nicely, especially if you eliminate the oil pipe by installing an oil cooler. Another advantage is the simple crank trigger, and no mechanical advancer with the attendent slop in the mechanism, and the ability to have a vacuum advance using a MAP sensor.
Disadvantage: Setting up the advance curve, and the vacuum advance.
While the results can be impressive, there is the queston as to whether it is worth the trouble. One guy that had one here was impressed that his used "reliable Ford ignition parts", about the time that Ford was having the largest recall in history for defective ignition parts (the ones used in his crank fired ignition system). I am impressed as to how a properly done installation can simplify the engine installation, but not by much else.
No need to cut off the dizzy. You can buy a cap for the distributor drive hole, or have your machinist make one easily enough.
123 Ignition has a distributor with multiple advance curves if that is what you are looking for. Easy plug and play. The mechanical advance is eliminated from the distributor, and an electronic system is substituted.
As for getting a negative pressure in the crank case, you can pull a few inches of vacuum with a pulse valve in your exhaust, just south of the collector. This is called an "Evacu-Sump" by Moroso. Vizzard even had pages in his BMC A book devoted to the installation of such a system.
However, while this really works well, you do need to completely seal the crankcase from pan to rocker cover, install an air oil separator to keep from looking like a Red Bull air racer after "Smoke On" is called. I don't know anyone still running this setup. Of course, there might be some advantage to this if you live in an area where mosquitos are found.
You can eliminate the smoke problem by using a vacuum pump in place of the pulse valve, and an air/oil separator with a drain back to the pan. but you do have to find a way to drive the pump.
If you have minimal leakage, no oil in your catch/breather tank, you have the problem solved. No need to add another mechanical system to correct a problem that doesn't exist.
Disadvantage: Setting up the advance curve, and the vacuum advance.
While the results can be impressive, there is the queston as to whether it is worth the trouble. One guy that had one here was impressed that his used "reliable Ford ignition parts", about the time that Ford was having the largest recall in history for defective ignition parts (the ones used in his crank fired ignition system). I am impressed as to how a properly done installation can simplify the engine installation, but not by much else.
No need to cut off the dizzy. You can buy a cap for the distributor drive hole, or have your machinist make one easily enough.
123 Ignition has a distributor with multiple advance curves if that is what you are looking for. Easy plug and play. The mechanical advance is eliminated from the distributor, and an electronic system is substituted.
As for getting a negative pressure in the crank case, you can pull a few inches of vacuum with a pulse valve in your exhaust, just south of the collector. This is called an "Evacu-Sump" by Moroso. Vizzard even had pages in his BMC A book devoted to the installation of such a system.
However, while this really works well, you do need to completely seal the crankcase from pan to rocker cover, install an air oil separator to keep from looking like a Red Bull air racer after "Smoke On" is called. I don't know anyone still running this setup. Of course, there might be some advantage to this if you live in an area where mosquitos are found.
You can eliminate the smoke problem by using a vacuum pump in place of the pulse valve, and an air/oil separator with a drain back to the pan. but you do have to find a way to drive the pump.
If you have minimal leakage, no oil in your catch/breather tank, you have the problem solved. No need to add another mechanical system to correct a problem that doesn't exist.