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38 Flathead Engine Question - Breather Assembly

Started by rismt, November 09, 2010, 08:53:22 AM

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rismt

I am considering rebuilding a 1938 346 Flathead that I have bought that came from a Series 60S. It is going into my 39 Series 61 as it has a damaged block.

I believe the 38 motor is missing the breather parts that connect to the top of the valve covers. I haven't been able to find a clear picture, drawing, or manual reference to help me determine what parts are missing and how it connects to the motor. I do know that the 38 breather system is very different then my 39 motor.

Would appreciate any input and help you can provide. Also, please let me know if you know of anyone with the parts I need.

Thanks,
Bob Schwartz
CLC Member # 25646
Bob Schwartz
CLC Member #25646
Spokane, WA
1939 Cadillac Series 61 Sedan

Chris Bryant #19358

Begging your pardon, but a flathead V8 doesn't have valve covers but it does have cylinder heads. Why can't you use the 39 Air Breather assembly. Only wishing to help, not get in your face.

Cheers,

Chris Bryant

Brad Ipsen CLC #737

The 38 has a positive crankcase ventilation system that didn't work out to well at the time.  The 39 and up had a road draft type system and no PCV system.  The trouble is the vertical down portion of the road draft tube is cast into the block so it is very difficult if not impossible to install this system on a 38 block.  On the 39 and up engine the valley covers had an outlet at  the top of each that joined into a horizontal tube that connected to the vertical down pipe cast into the block.  The oil pan had the final section of the road draft tube so that is different from the 38 also.
Brad Ipsen
1940 Cadillac 60S
1938 Cadillac 9039
1940 Cadillac 6267
1940 LaSalle 5227
1949 Cadillac 6237X
1940 Cadillac 60S Limo

rismt

Thanks Brad for the information. I understand the 39 system as my old engine is complete. Do you have any thoughts on where I can find literature or pictures to show me what the 38 PCV system or parts look like so I can try and find them for the 38 I want to rebuild? On the other hand would you recommend that I scrap the idea of rebuilding the 38 and try and find a decent 39 or later motor to rebuild? Appreciate your time and input.

Bob Schwartz
CLC #25646
Bob Schwartz
CLC Member #25646
Spokane, WA
1939 Cadillac Series 61 Sedan

Chris Bryant #19358

Thanks, Brad!

Your information helped me out too!

Chris

buicksplus

I have 37 and 40 engines which I believe are similar to the 38 and 39 engines respectively.

My 37 forward valve cover  has a hole in it.  This is connected to a tube that attaches to the bottom side of the intake manifold, see the two pictures attached.  I think if you have this 38 manifold with all that tubing, this would work OK.   This tube supposedly sucks out crankcase gasses into the intake, the only other crankcase vent is through the dipstick filter.

I agree with the other posters that converting the earlier engines to the open ventillation system used 1939 and later is not that simple, you would need to fabricate some sort of road draft tube to the sheet metal collector that sits on top of the valve covers.

I'm not sure why Cadillac scrapped the closed pvc type ventillation system that was really ahead of its time.  I suppose it was because it didn't work properly.  But I have not heard of any pre-39 flathead folks complaining about it.
Bill Sullivan CLC# 12700

rismt

Bill ... my many thanks for the information and pictures. It has cleared up the questions in my mind.

Sincerely,
Bob Schwartz
CLC # 25646
Bob Schwartz
CLC Member #25646
Spokane, WA
1939 Cadillac Series 61 Sedan

harry s

The rear valve or valley cover has a vent tube that goes up to the back of the air cleaner and attaches with a small clamp (at least on the '37, not sure about the '38). This set up does seem to be better than the later models
Harry Scott 4195
1941 6733
1948 6267X
2011 DTS Platinum

John Washburn CLC 1067 Sadly deceased.

Folks,

If you want a picture of the tube from the valve cover that goes to the air cleaner I can send one. This was used in 37 & 38 (as Brad said, positive air flow system) and I have the engine out of the 38 so can show how it connects.

The Johnny
John Washburn
CLC #1067
1937 LaSalle Coupe
1938 6519F Series Imperial Sedan
1949 62 Series 4 Door
1949 60 Special Fleetwood
1953 Coupe DeVille
1956 Coupe DeVille
1992 Eldorado Touring Coupe America Cup Series

rismt

Johnny .... a picture would be great help and much appreciated.

Many thanks,
Bob Schwartz
CLC #25646
Bob Schwartz
CLC Member #25646
Spokane, WA
1939 Cadillac Series 61 Sedan

rismt

Harry ... my thanks to you also for your information.

Bob Schwartz
CLC #25646
Bob Schwartz
CLC Member #25646
Spokane, WA
1939 Cadillac Series 61 Sedan

John Washburn CLC 1067 Sadly deceased.

Bob,

Sent 3 pictures to your e-mail. So check you e-mail. Hope they help.

the johnny
John Washburn
CLC #1067
1937 LaSalle Coupe
1938 6519F Series Imperial Sedan
1949 62 Series 4 Door
1949 60 Special Fleetwood
1953 Coupe DeVille
1956 Coupe DeVille
1992 Eldorado Touring Coupe America Cup Series