Technical Flathead crankcase vent/PCV thoughts

So, you guys are in the cheap seats. Here, lemme say it louder...

THAT'S AN 8BA! I'M RUNNING A 59A! THEY'RE DIFFERENT! LIKE AN EARLY SBC VS A LATER VORTEC SBC!

Did you hear that this time? 8BA has a front oil fill too, I have one that shares the pump stand. In my best Jack Nicholson, "ARE WE CLEAR?"

Thanks my friends, see ya tommario...

 

Yeah, thanks. I will document the whole gig, and if I can I might make 2 or 3 at the same time. If it works on the V-12 it should be ok for a V-8. We just did a manifold swap on that 12 and I gotta say that old motor was less gummy than what I expected inside, and it isn't a fresh rebuild either, good ol original. Hopeful...

 

If you liked the oil pan, you’ll surely like my block:

 

Well,have not played that way with any Flathead V8. But I did with one of my Ford-Y..
I custom made a replacement,using the road draft tube hole in the Vally cover. Used a PVC fitting from 5.0/302.
Run it into the intake runner/along the back of intake.
It did cut back on smoke out the fill tube,but when I first did it,old baby had a lot of blow-by. We'll see when I get the new ring job done ? May not help,other then just the idea!

 

They made an aluminum intake for the Canadian 59As (CIIA-6520-C2) with a front oil fill and an additional tapped port below the carb base. Gives many more options for fitting a PCV setup. This one is missing the oil fill tube, but you can see where it bolts on https://www.ebay.com/itm/284727448021

 

Can you say “side show”?

 

Bro you make a good one. Fun stuff, funny as fuck...!

 

This discussion moved this plan in a right direction. Thanks, and yes even for the sarcasm at times. Love that shit.

As we make improvements the less invasive the better, yes? I didn't consider the vent cup on the pan, but that plays. Upon closer examination of the Zephyr here and it's stuff it seems that after 91,000 miles there's little to no detriment of just venting the case vapors right back into the engine. AND it is a vacuum source albeit at the carb airhorn vs full manifold vacuum and tempered by incoming air as well. This is the inside of the Zephyr air cleaner after all those years:

The inlet for the vent pipe (shined a light in):

My stock air cleaner inlet, which I plan to run for a whole season just to shake the car down:


Again, I won't have full manifold vacuum but more than enough to help positively vent the case, especially at speed. The adventure continues and if this goes well and easy, yes as stated before my get up will also take a full on PCV gig but I'm not sure a stock flatty really needs much more than mild positive evacuation. Peak RPM is under 4,000 and highway cruise is 2600. How bad can it be? Why this direction; most non invasive add-on approach. No manifold removal or drilling, simple air cleaner mod and well, you gotta wait for the rest.

 

I did mine like Hillbilly Werewolf suggested. I welded the hole in the pan rail closed then drilled a hole straight thru both the vent bottom and the plate I welded in the pan, then soldered a 3/8 tube in to attach a hose that will connect to the pcv then to the carb riser under the front carb on my Edmund's intake. I can't say it is going to work yet the motor is still on the engine stand. It has to be better than having oil and dirt down the right side of the motor like it was before!

 

I've fitted a pcv valve a couple of times and it is completely undetectable from outside the engine. This was used with a French block. I used a 59A pan and welded up where the road draft tube is.

 

@theHIGHLANDER anything you do will be an improvement. I ran mine without one for a while and the oil leaks and that smell of hot oil was overwhelming.
Plumbed up a PCV in lieu of my draft tube (8BA) and there are no leaks or odors. Probably runs better having the crankcase sucked out but not that I have noticed.

 

Nice Mart. Just curious though, does a pcv valve need to be vertical or near it to work properly? I’ve never cut one open to see what’s inside but it always sounded like a check ball or something similar was in there. I may have to sacrifice one tomorrow when I get to the shop just to see.

 

My instance is this, how can I do this without the angst of pulling the pan or the intake? I was caught unawares not considering the vent at the rt front of the pan. My engine is done, almost fully dressed and in the car. Had that dadgum Zephyr not showed up I probably would have just "let it eat" like Henry did. I whipped up a cover with additional volume by making a quicky posterboard template, rolled up some sheetmetal, and cut some ½" aluminum for an overall shape. I'm fortunate in that I have good 59A laying about, was able to sit right there and sort it all out. Just got a case of the ass about 4:30 and went for it. So far...


Next I'll cap it, tube it, find a molded hose then make a nice subtle tube going into the air cleaner. I was in the zone shaping and fitting and didn't get pics of the aluminum shape gauge. It will get a mounting tab to attach to that oil pan bolt, and I notched for the pan rail support bar. Next time...

 

Curious; does that valve go into the lower plenum of the intake or is that intake open?

 

Here's how I vented the crankcase fumes. No chance of the oil mist pooling in the air cleaner and making a mess. Note this is a vent, not a PCV valve connection.

 

Had an off topic 1200cc engine that would periodically James Bond smoke screen it’s self after enough oil fumes accumulated into an oil pool due to how the factory created a pee trap shaped tube to the air cleaner.

 

Ron I had the valve vertical but it made a gentle shuffling rattle when idling. I put the 90 degree bend in and it stopped the rattle. I think I can hear it when driving at speed now, not sure. It could be something else.

Rich. I carefully drilled and tapped directly in line with the dividing wall between the two runners. I then opened the hole out into both runners. I used this particular manifold because both runners are at the bottom of the casting. Many manifolds have an exhaust crossover that would make this job difficult.

Note this is a certain type of pcv that flows towards the threaded end. Standard V100.

I showed it in a couple of my videos.

Fitting the pcv:
Fixing the noise:

 

Some PCV's have a spring in them and are made to work horizontally. Others have a disc or ball and no spring and must run vertically.

 

For all the 59A flatheads out there, is the right side of your engines constantly covered in oil? The actual vacuum available on this get up is constant and light. Not full manifold vacuum so I'm thinking Henry's oil separator arrangement will be fine. All I want to accomplish here is add some additional extraction to the case. If I was building from scratch and trying to create full case depression (not necessary) I'd approach this differently. What I hope to achieve is cleaner combustion, reduced oil film underhood, and less harmful crankcase byproducts which lead to undue sludge and varnish buildup. It is a fresh engine so give it a fresh start. I don't see how it can ever pull oil. Also with the oil fill cap being filtered I'm not dragging dust and dirt in either. I figure there's at best and inch or so of vacuum at all times, more at speed. I mean this ain't 14:1 7,000 RPM science needed here, right?

 

That's real purdy!

 

If I'm reading you right, the way you're describing plumbing this up would be the same as the way a closed pcv system works at periods of low vacuum. A closed system runs the air inlet side of the pcv system from the air cleaner housing; the air is drawn into the engine from the pcv and the connection at the air cleaner housing provides a source of clean air for that. But during periods of low vacuum level, i.e. accelerating, and when the crankcase pressure exceed the level of vacuum, the air inlet side of the system serves as an outlet, and the fumes are drawn into the air cleaner housing and then into the engine, so the system is closed. You wouldn't be using a pcv, just allowing the air to move through the engine into the air cleaner. There is very little to no vacuum at the air cleaner (only what is provided due to restriction of the element), but there is air movement, which is what you want. If you plumb it correctly, the air moving past the tube you install will cause a venturi effect and draw air from the tube into the carburetor and mixed with the air/fuel mixture. So I think this is a plausible ventilation system that should work. The size of the hose or tube from the engine to the air cleaner has to be pretty substantial though, I'm thinking something like 1/2" id at least; because there is no vacuum, so the hose needs to be large enough to not cause any restriction to air movement. Placing the hose/tube on the inside of the element will provide the slightest amount of vacuum to help pull the fumes up from the crankcase; and would prevent any oil soaking of the element.

Or you could reverse the flow of the system, use the original outlet as an inlet and fabircate some kind of filter down there, and then place the same style of pcv that was used on Corvett's that installed in the oil fill tube, but you'd have to cap off the oil fill to make it draw through the engine.

 

If your heads still have the umbrella seals install positive style when your doing the rings.
Many don’t like your vacuum connection; they say the vapors from the engine end up contaminating the rear cylinders and under the carb at the front barrel are best…but who really knows.

 

I use the same PVC valve horizontal just like ALL the SBC’s did from 62 up until the closed off the rear breather. The threaded send goes to the vacuum. A V100 valve. Is there a oil deflector?

 

This does take care of about 90% of the stink after pulling in the garage. It needs to be larger from my experience.

 

Much better to pull dirty crankcase fumes directly into the intake vs down through the carb.

 

Lotsa good discussion here.

 

We are on the same page. If you look at the air cleaner pics I posted there's a chamber sort of isolated from the regular filtered inlet, but it does produce a low amount of full time vacuum. I can only believe there's even more at speed. Preliminary "hillbilly" testing, I stuck a small shop vac in the carb inlet of the Zephyr air cleaner. While I can't draw enough to get a scientific reading it is absolutely pulling. Early next week we test fire the Zephyr and I'll stick a vacuum gauge on that pipe nipple. I expect 1 to 2" and more when revved higher. Yes, I'm using ½" tubing for volume. Yes, I'm sealing the original oil pan vent with my new part and it will be my source for case vapors. The flatheads have enough infrastructure to keep oil separate from what they were doing. Full time negative pressure is an improvement along with better quality oils today as well. If and when I add the dual carbs I'll also have a source for actual PCV. Inlet air is filtered at the oil cap. Win/win I think...

 

So the pick up is done. I was in the zone and didn't shoot the whole deal, gotta settle for done, sorry.
I capped it, welded the tube on, whipped up a mounting tab and made adjustments to able to fit a socket and nut it down. I'll replace the bolt with a stud and nut it. Sadly I have to jack the motor up to install it. Better now than later. I welded the tube to the body then drilled through. Yeah, I'm lazy like that. Actually I tacked n checked. Predrilled is a commitment. Anyways, step 1 done, step 2 is the air cleaner (easy, silver braze). Last I'll build a tube from the pickup to the air cleaner and get some hose to hook it all up. I might have enough steel, if not I might just make the tube outta ½" copper coil and I want it gloss black either way. Forward motion...

 

That looks pretty good. Paint it the same color as the pan and it will fool most people into thinking it's factory.

 

I actually try to make things look close to OEM, (or WWHD?). My pan is black so the pickup will be too. Air cleaner gets 2 tone black/wrinkle black and like said above black tubes. Seamless...