jerrdanjohn
Active member
- Joined
- Oct 16, 2014
- Messages
- 39
Wanted to do a little post on my Quincy A-4 air compressor that I made into an engine. You see this kind of thing a lot at shows, but most, if not, all are hit and miss engines and I have never seen one actually power anything, so this is what I built and how I built it.
First you must understand that the piston in a compressor comes all the way to the top, so there is no place for a actual combustion chamber where the fuel mixture is fired, also you have to have a spark plug, intake and exhaust valves and a cam to time the valves themselves. When building something like this, I like to break it up into systems fuel, fire, valves, valve timing, cam, it just takes one thing at a time and eventually you run out of things to do.
I am big on saving money on a project, if your just going to buy a bunch of stuff, I see no point in building it myself, I watch these shows on TV and they do these (build on a budget) shows. I am not quite sure where they grew up, but I am from a holler in West Virginia and when their budget build reaches in the thousands and sometimes tens of thousands of dollars, I just assume they grew up with a well to do family, the only well to do family I knew had a pitcher pump in their kitchen and we had to get water from the well. I later learned they were as poor as us. Ok, sorry for the rant, the point I was getting to was my budget includes friends that have junk like me and don't mind throwing a plate of steel or a old hydraulic pump your way when you need it. It also includes making what I have work.
So here is what I used to build the engine,
1950,s Quincy A-4 Compressor.
Early 1920,s Ford Model T valves, valve springs, and lifters.
1940,s John Deere B rocker arms, shaft, and stands.
1950,s Oliver 77 6 cylinder cam shaft.
1950,s Case DC magneto mount housing.
1950's Case SC push rods.
1950's Shrebler Carb. (mail order through Popular Mechanics in 1954 $8.00)
two 11 tooth #25 sprockets for the crank
tow 22 tooth #25 sprockets for the mag and cam
Magneto is a Wico that was on an Allis Chalmers WC flange mount, I used the parts from a base mount Wisconsin 1 cyl. the convert it.
Here is a photo of the combustion chamber I made. This is about 1/2" this and is aluminum.
As you can see it had to be much larger then the bore inside and I also clearance for the valves. Head gaskets were made from .060 thick Graphite. It does compress to well under .060. The ports for intake and exhaust also was machined is because the intake and exhaust mounts to the block, not the head.
Below is a photo of the completed head with the model T valves. No seat were added, run a lead additive in the fuel and it will be fine. Valve guides were made of bronze. This was all done on my vertical mill. If you think ahead and mount your part ones without having to remount it all bores will line up fine.
Also remember that I am NOT a machinist, I do have an antique machine shop as my hobby shop, if any of you real machinist think I am doing something wrong, your probably right!
Below is the cam, I did a little grinding on it to remove some of the valve overlap for easy starting. The lift was left the same.
The cam was shortened to make it a single cylinder and turned on the lathe to accept 1991 Chevrolet outer wheel bearings and a 3" piece of pipe was used for the cam tube. I made caps for each end and made shims to I could adjust end play.
As you can see in the photo above I had one chain running both the cam and mag. I didn't like the erratic chain you get from the cam because my magneto is set up to be able to turn after starting to advance the timing, so no kick backs when starting. So I went to two chains.
I also wanted to use the big old 7/8" thread spark plug, but with no room, I had to go with the 14mm in the head. Timing is not hard on these neither, just find the sweet spot between the lobes on the cam and set it with the piston on top you will be one turn out or 180 degrees out on the cam (half a turn) Then set your mag timing just before TDC and go from there. After you dial it in using the set screws to hold the sprockets, then when your 100% happy, mark them and cut your keyway.
My carburetor had a 1/2" venturi and it was causing some idle issues, so I turned out a new one 3/8"
Below you can also see the first combustion chamber I built for this engine. The compression was to low, so I used this one on a hit and miss engine built from another quincy A-4
I didn't take a lot of pictures during the build. I know this post don't cover the entire build, but I will be glad to help all I can if anyone decides to build one. Below is a link to a video of the engine running.
I was running it of a buzz coil because my Wico coil went out.
If you would like to see what I am using the engine to power here is another video of that.
All the machine work was done with my 1936 Gorton 9j vertical mill, my 1914 Leblond 14" lathe and my 1903 Brown and Sharp #3 horizontal mill, all saved from the scrap yard, just remember, laziness is a disease we all have to a certain extent we just have to fight it and just because you don't have money, it don't mean you can't build cool stuff!!
First you must understand that the piston in a compressor comes all the way to the top, so there is no place for a actual combustion chamber where the fuel mixture is fired, also you have to have a spark plug, intake and exhaust valves and a cam to time the valves themselves. When building something like this, I like to break it up into systems fuel, fire, valves, valve timing, cam, it just takes one thing at a time and eventually you run out of things to do.
I am big on saving money on a project, if your just going to buy a bunch of stuff, I see no point in building it myself, I watch these shows on TV and they do these (build on a budget) shows. I am not quite sure where they grew up, but I am from a holler in West Virginia and when their budget build reaches in the thousands and sometimes tens of thousands of dollars, I just assume they grew up with a well to do family, the only well to do family I knew had a pitcher pump in their kitchen and we had to get water from the well. I later learned they were as poor as us. Ok, sorry for the rant, the point I was getting to was my budget includes friends that have junk like me and don't mind throwing a plate of steel or a old hydraulic pump your way when you need it. It also includes making what I have work.
So here is what I used to build the engine,
1950,s Quincy A-4 Compressor.
Early 1920,s Ford Model T valves, valve springs, and lifters.
1940,s John Deere B rocker arms, shaft, and stands.
1950,s Oliver 77 6 cylinder cam shaft.
1950,s Case DC magneto mount housing.
1950's Case SC push rods.
1950's Shrebler Carb. (mail order through Popular Mechanics in 1954 $8.00)
two 11 tooth #25 sprockets for the crank
tow 22 tooth #25 sprockets for the mag and cam
Magneto is a Wico that was on an Allis Chalmers WC flange mount, I used the parts from a base mount Wisconsin 1 cyl. the convert it.
Here is a photo of the combustion chamber I made. This is about 1/2" this and is aluminum.
As you can see it had to be much larger then the bore inside and I also clearance for the valves. Head gaskets were made from .060 thick Graphite. It does compress to well under .060. The ports for intake and exhaust also was machined is because the intake and exhaust mounts to the block, not the head.
Below is a photo of the completed head with the model T valves. No seat were added, run a lead additive in the fuel and it will be fine. Valve guides were made of bronze. This was all done on my vertical mill. If you think ahead and mount your part ones without having to remount it all bores will line up fine.
Also remember that I am NOT a machinist, I do have an antique machine shop as my hobby shop, if any of you real machinist think I am doing something wrong, your probably right!
Below is the cam, I did a little grinding on it to remove some of the valve overlap for easy starting. The lift was left the same.
The cam was shortened to make it a single cylinder and turned on the lathe to accept 1991 Chevrolet outer wheel bearings and a 3" piece of pipe was used for the cam tube. I made caps for each end and made shims to I could adjust end play.
As you can see in the photo above I had one chain running both the cam and mag. I didn't like the erratic chain you get from the cam because my magneto is set up to be able to turn after starting to advance the timing, so no kick backs when starting. So I went to two chains.
I also wanted to use the big old 7/8" thread spark plug, but with no room, I had to go with the 14mm in the head. Timing is not hard on these neither, just find the sweet spot between the lobes on the cam and set it with the piston on top you will be one turn out or 180 degrees out on the cam (half a turn) Then set your mag timing just before TDC and go from there. After you dial it in using the set screws to hold the sprockets, then when your 100% happy, mark them and cut your keyway.
My carburetor had a 1/2" venturi and it was causing some idle issues, so I turned out a new one 3/8"
Below you can also see the first combustion chamber I built for this engine. The compression was to low, so I used this one on a hit and miss engine built from another quincy A-4
I didn't take a lot of pictures during the build. I know this post don't cover the entire build, but I will be glad to help all I can if anyone decides to build one. Below is a link to a video of the engine running.
If you would like to see what I am using the engine to power here is another video of that.
All the machine work was done with my 1936 Gorton 9j vertical mill, my 1914 Leblond 14" lathe and my 1903 Brown and Sharp #3 horizontal mill, all saved from the scrap yard, just remember, laziness is a disease we all have to a certain extent we just have to fight it and just because you don't have money, it don't mean you can't build cool stuff!!
