Crankcase ventilation

F

Flat32

Member
Hi, I'm new to posting here, but have been lurking and studying since being aquired by a 1931 Model A roadster with a B engine. Half of one rod babbit destructed 110 miles into the 750 mile trip needed to get to my home from Pocatello, Idaho where I found it. My driver is a 1932 3 window coupe flathead powered and hot rodded a fair amount so no stranger to engine work. B engine is apart and I'm starting reassembly. Oil pan and dipper tray had substantial brazing repair of rust pits so I got a better one. New one had a couple small rust pits inside at the bottom that I chose to repair with silver solder.

Prepping the pits was interesting as they extended under the surface well beyond the initial open pits. I'm guessing they were caused by condensation water with acidic content. Seems like the only crancase ventilation is via the oil fill tube.

Camshaft and lifters were so rust pitted I bought new ones. Crankshaft main journals also are rust pitted, but I'll use the crank since the main babbit is decent. Crank timing gear is rusted so both gears are getting replaced.

I can't help but believe some decent crankcase ventilation is needed for my engine which will be driven around town mostly.

What are the best methods being used, if any, on Model A engines?

Thanks,

Ray
 
Ray I think you are basically correct, ....to a certain extent, however maybe it had a little too much ventilation!! Compression gasses are very corrosive as you well know which is a great reason why each time our beloved automobile is driven, the engine needs to come up to full operating temps to help rid (evaporate) the crankcase and/or oil of any condensation or these gasses. Also, it is crucial to drain and refill the crankcase with fresh oil at least annually.

To answer your question specifically, if there was a PCV system in place, the engine still needs to come up to operating temps so that gas can be drawn out. If the current system is like most Model A/B engines, there is just enough blow-by to help pressurize the crankcase which will let the gasses escape out the oil fill tube. This is just another example of why it is bad to just let one set and not be driven. ;)

BTW, welcome to Fordbarn!!

.
 
Why does everybody try to re-invent what's worked for 80+ years??
No telling where your b engine has been, or what it's been subjected to in the past. Maybe it sat outside and got rained on/in and that's what caused the corrosion. Ford, in fact did increase the size of the oil fill (breather) tube for the B, over the one on the A.
Paul in CT
 
Flat 32 , I had the same problem on a 28 sport coup a couple of years ago. What we did was Bore .040 turn rod bearngs and had mains polished, reground cam new valves Snyder head ect.. The engine turned out to be a real good runner and so far the owner is happy. Bubby Sharp in KY
 
My B engine has the A size oil fill tube. Apparently my effort to improve crankcase ventilation isn't needed however I will braze a 3/8 pipe thread boss on the upper rear corner of the side cover so I'll have provision. My Flathead V8 had a road draft system probably to help keep oil fumes out of the engine bay more than anything else.

Did any later version of the A design engine whether it be foreign, industrial or agricultural use have anything other than the fill tube breather?

Another question regarding the pan; the original B dipper tray has the four drain holes while the replacement one I got doesn't even though it is also a B pan. Should I put the four holes in??

I fully intend to drive long enough trips to get the oil hot, but how often will depend on how it drives, handles and stops. Twice a month maybe.


Ray
 
Later 32-34 B,s had the larger oil filler tube.B,s also used the dipper tray with the 4 holes & the shield between block & pump.Your spare pan likely has an A dipper tray.Install a T-stat & give it regular oil changes & you shouldnt have to worry about condensation.
 
Just noticed the Fumaze post and found the earlier threads. My needs for crankcase ventilation information are met nicely. Search of this forum for "crankcase ventilation" didn't find Fumaze, but Googling Fumaze lead me to the threads.

Ray
 
Hi Ray, I just thought I'd throw this out for whatever its worth. I've installed a breather tube between the valve galley and the carburetor intake (using a short collar) to ventilate the engine internals while running. I had to go to the top of the side cover to avoid picking up any oil, and the rubber tubing hides very nicely behind the intake manifold so that you would have to be looking for it in order to see it. The overall effect is not of the PCV type, but of the marine flame arrestor, with its open evacuation of crankcase fumes. Benefits include: NO burping of oil up though the filler tube, evacuation of all moisture related condensation, no oil mist in the engine bay, and combustion of unburned crankcase gases. I recommend it to any Model A driver.
Happy Motoring!
 
Can you post a picture of your set up? I'm very interested. I started the Fumaze thread and am curious as to what your set up looks like.
 
On my '30 coupe I sold, I drilled & tapped a hole in the upper rear of the side cover, installed a PCV valve from an early small block Chev, drilled & tapped for a nipple on the bottom of my Weber intake manifold, connected them with a short hose, put the available small foam filter in the oil cap so grit wouldn't be drawn in, and it was done!:D That was a loooong sentence.:eek:
With no crankcase pressure, THAT DUDE DIDN'T LEAK OIL! Sorry, I don't have pics. Bill W.
 
Same here with a 31 pickup, drilled the side cover near the top, threaded it and ran the hose thru a PCV to the manifold. Put an old style PCV tester on the oil tube and it sucked the little ball around just the way it should.

Welcome to the barn.
 
Milton said:
Same here with a 31 pickup, drilled the side cover near the top, threaded it and ran the hose thru a PCV to the manifold. Put an old style PCV tester on the oil tube and it sucked the little ball around just the way it should.

Welcome to the barn.
Click to expand...

Way to go Milton,
I don't why more owners don't consider this. It ain't Rocket Science. Especially good for cars that aren't driven much to help get the condensation problem under control. An engine is expensive, why not protect it the best way, even when it's "not proper?" Bill W.
 
I doubt I'll ever install a pcv valve, but the relatively passive system mentioned by Chris is quite reasonable and would only require putting a tube in the air cleaner elbow aimed directly at the carburetor inlet. Being an old phart that loves to tinker I'm going to put an evac tube in the exhaust down pipe to see if it would generate a stronger vacuum than the carburetor inlet version.

Although this engine is a B it has An A intake, carburetor and distributor. Would it be more proper to have all B components?

Thanks for the responses.

Ray
 
Actually, it would be more proper to have an A engine.:D
But to maximize the B engine you should have the B carb and intake.
 
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