59A/B intake Pcv valve conversion

[SkylarknMerc]

Hey guys, I'm looking for info on a pcv valve conversion for a 59A/B intake.
I tried to do a search but came up empty.

I have a 255 8CM Mercury, and currently running the PCV valve where the old down draft was before.
Earlier this year I came across a deal I couldn't pass up on, a pair of Offenhauser #400 heads and a 4 barrel Holley 390 cfm and Offenhauser intake to match.

Doing some research I found out both heads and intake will fit on my 8CM, the heads I have to plug a hole on the block (?) And the intake will fit too, but won't have the downdraft tube hole , and the oil fill tube in the intake manifold that came on the 8CM motor.
Since I'll be running an electric fuel pump, the original mechanical fuel pump mount will be blocked off. I was thinking of installing the PCV valve on the blank plate by drilling a hole in it for the valve.
Has anyone done that or will this not work out?

Thank you in advance for taking the time.

[tubman]

It is a known fact that the crankcase ventilation is totally different between the later 8BA type flatheads and their earlier brethren. Here are a couple of diagrams showing each type. Keep these in mind when considering this project.

I believe a couple of guys on here have done it by mounting the PCV valve in the valley under the intake and running some plumbing. I have no idea how effective it is.

[Newc]

Problem is with a 59 A/B type-oil pan breather. . I weld that closed and with a pipe coupling there use that for the PVC source. Newc

[SkylarknMerc]

Originally Posted by tubman

It is a known fact that the crankcase ventilation is totally different between the later 8BA type flatheads and their earlier brethren. Here are a couple of diagrams showing each type. Keep these in mind when considering this project.

Thank you for the response

I believe a couple of guys on here have done it by mounting the PCV valve in the valley under the intake and running some plumbing. I have no idea how effective it is.

Looking at the first illustration, won't the direction of the TEAL arrows go the opposite way, as the Vacuum at the carburetor base be going In/Down the intake into the cylinders?

[glennpm]

THIS WILL WORK ONLY ON THE 59AB BLOCKS.
For an 8BA, 1949-1953, tap into the "road draft tube"

I have a PCV on my 268CI 59A. I used a MOPAR valve that I found referenced in an old article which used a MOPAR PCV. I also add a piece of open cell foam into the oil pan vent.

[petehoovie]

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Originally Posted by glennpm

I have a PCV on my 268CI 59A. I used a MOPAR valve that I found referenced in an old article which used a MOPAR PCV. I also add a piece of open cell foam into the oil pan vent.

[SkylarknMerc]

Originally Posted by glennpm

I have a PCV on my 268CI 59A. I used a MOPAR valve that I found referenced in an old article which used a MOPAR PCV. I also add a piece of open cell foam into the oil pan vent.

Thank you for your input!
I guess I could follow the first steps, drilling and installing the PCV valve up front, and connecting it the carburetor base where there is currently a vacuum connection.

[petehoovie]

Originally Posted by SkylarknMerc

Thank you for your input!
I guess I could follow the first steps, drilling and installing the PCV valve up front, and connecting it the carburetor base where there is currently a vacuum connection.

[glennpm]

Yes, that's correct.

Regarding the PCV valve, the one I used, referenced in the article is for a 3L or 183CI engine.; 1/8" MNPT X 5/16" hose barb. It works great for me with no excess oil film on the firewall or oil pan.

There is another PCV that also works in the horizontal position that is a little larger and made for SBC among others, in the 300CI range.; NAPA 2-9255 AND Standard SIV100. These have a 1/4 MNPT X 1/2" hose barb. Note the flow direction. These two flow toward the threaded end. The MOPAR flows toward the hose barb end of the PCV.

[SkylarknMerc]

Kool! Thank you.

[rich b]

Looks like that intake could be an 8BA intake by drilling the road draft tube boss to mount your PCV valve and boring the breather boss to fit your push-in tube & breather cap.

[SkylarknMerc]

Originally Posted by rich b

Looks like that intake could be an 8BA intake by drilling the road draft tube boss to mount your PCV valve and boring the breather boss to fit your push-in tube & breather cap.

I thought of that, just drilling a hole to put the PCV valve there only, and using the current oil fill tube in the back and leave the breather cap there and let it flow from back to front then vacuum in the manifold.

[Zeke3]

Attached is a link to a discussion on this topic that may help you from our late friend V8Coopman.

https://www.fordbarn.com/forum/showt...e+ventilationK

[rich b]

Originally Posted by SkylarknMerc

I thought of that, just drilling a hole to put the PCV valve there only, and using the current oil fill tube in the back and leave the breather cap there and let it flow from back to front then vacuum in the manifold.

Looking at Tubman's picture of 8BA internal air flow it appears drawing air in thru a rear mounted breather may "short circuit" flow thru the lifter valley; whether that would amount to anything is anybody's guess.

[glennpm]

Originally Posted by rich b

Looking at Tubman's picture of 8BA internal air flow it appears drawing air in thru a rear mounted breather may "short circuit" flow thru the lifter valley; whether that would amount to anything is anybody's guess.

The way "Mr 42" handled it was very good in my opinion. Regarding his design, I would do it a little differently with a 59A intake manifold on the 8BA. I would fix a short section on heater hose or similar, pushing the hose into the top of the block that the draft tube would slip into. Trim the hose such that it butts up against the bottom of the intake. Once trimmed, fix the hose in place. A hose clamp or a couple of zip ties just above the block to hose junction would work. You are just want to keep the hose from being pushed down further into the block. Tap the intake just above the this hose for hose connections for the suction side of the PCV. Connect the outlet of the PCV to manifold vacuum beneath the carb.

Note that the hose to block to underside of the manifold doesn't have to be super tight. The suction will be sufficient to draw from the crankcase and little to nothing from the fresh air inlet at the back of the 59A intake manifold.

https://www.fordbarn.com/forum/showp...38&postcount=6

[glennpm]

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