Air compressor for number 6 cylinder?

[JaberJaw]

I just received my head back from Cosgrove's Racing and discovered an interesting feature on my 1939 P8 Deluxe 4-Door with the 201. After consulting with Ken Senior, we were surprised to find what looks like a wormhole from the back number 6 cylinder and it leads to a plug where apparently after jogging Seniors Memory they used it as an Air Compressor and to possibly find TDC on number 6 because it's straight down.

When an engine builder says "I've never seen that before" and we both get educated from an Older Gentleman that has been Rebuilding Engines for Decades you throw that in the back of your Mechanical Memory Bank.

Extremely interesting and would love more input if anybody has more information about it ✌️??

Edited July 22, 2023 by JaberJaw

[Jerry Roberts]

It has often been said here that that hole is for finding T D C as the number six piston moves the same as the number one piston . I have never heard of the hole being used for an air compressor .

[TodFitch]

1 hour ago, JaberJaw said:

. . . When an engine builder says "I've never seen that before" . . .

Then you know you are dealing with an engine builder who has never worked on a Chrysler product L-6 engine from the 1930s, 40s, 50s, or on industrial engines into the early 1970s.

[Plymouthy Adams]

while a person could in an emergency connect with a well built check valve in place to use for compressed air, it is not a safe nor clean manner to get air due to the compressed fuel on combustion.  I would not want a tire inflated with fuel laden air.  The hole's sole purpose by design is to check TDC.  Many engines in the past have been made to run on half the cylinders and compress with the other half...but fuel induction and spark was never part of the setup.   Find a better liars bench..

[JaberJaw]

Senior mentioned it could have been used as an air compressor and that's when I rolled my eyes because of the fuel mixed with the air and it would be running on 5 which is totally illogical. But when he mentioned about TDC that's when it made sense to me. Not that I would ever use it for air but it's nice to know the ins and outs of my engine. I appreciate the clarification ✌️?? 

[Sniper]

What disturbed me is that you don't have a service manual.  The function of that plug is discussed in it.

 

 

[JaberJaw]

I do have a service manual. I actually have two of them. I now notice where it is but I didn't look into it at the time or after because I was in a hurry to get the head off and into the machine shop and not setting up the timing. Cosgrove's Racing is where I took it and he's more familiar with engines from the 60s and on but I'm glad that Senior knew what it was. I'm learning everyday and that's the joy of having a pre-war classic ✌️??

[vintage6t]

Obviously the answer is as stated above. This thread did remind me of an interesting Hagerty article I read a few months back on the history of Ford model A based air compressor conversions. 

 

https://www.hagerty.com/media/automotive-history/when-america-reinvented-a-ford-to-get-stuff-done/

[JaberJaw]

Extremely interesting article. Maybe senior is only going half senile.. he said it could be used to compress air and used to get TDC... I just wanted to dispel his myth that's why I posted here where the most knowledge is. I appreciate all the information ✌️??

[Plymouthy Adams]

as stated, one could, one should not...but that is my opinion based on inability to shut the fuel to the cylinder...we can unplug the spark plug.  The check valve would have to be very well built...why compressor use reed valves to that end.....not worth the effort.  

[desoto1939]

As stated by speedster that tiny plug was taken out and the factory miller timing light was put on and there was a rod that went down to the piston and when the piston came back up it would corollate to having the lining on the harmonic balancer at TDC and also for timing the engine.

 

To set the timing on these cars it is suggested to use number 6 sparkplug wire and not number one, but either can be used. Everyone that has a service manual should read through their specific car model manual. You will be surprised at what you will learn about your car.

 

Chrysler was very innovative about their engines.

 

Rich Hartung