I have a 40 to 50 year old White 4 cyl gas engine that I am going to convert to a half and half engine compressor.
the Hp arrangement on it was 64 BHP governed to 1800 RPM 226 CI displacement
I bought the engine at an auction a couple of years back whit this in mind or to scrap it out for parts
it was locked up when I bought it so I managed to get it for $30.00. At the time it would have scrapped for weight for more than that.
This build will be as a time and budget allows so it may take awhile I thought that I'd tear into it just to see if the configuration was even reasonably feasible it turns out that #1 & 4 and 2 & 3 are the matted pair configuration which makes the conversion more reasonable instead of a 1 & 3 2 & 4 arrangement
I can either go with the 1 & 4 cylinders as the engine or the 2 & 3 cylinders either way has its good and bad points.
the combustion chambers are in the pistons leaving the cylinder side of the head flat with only the valves protruding this makes it and even more reasonable build to allow me to reduce the compressor head area. All I will have to do is either make new pistons or make flat crowns to attach to the existing pistons.
For the head I will remove the valve springs from the intake and exhaust valves in the 2 cylinders which will become the compressor and replace them with very low tension springs and stop collars making both the intake and exhaust valves become the intake valves so the valves can be pulled open by the vacuum of the pistons on the down stroke. the rockers and push rods will also be deleted this will allow the compressor to compress air on every up stroke.
I will also drill out the spark plug holes to as large as I can to accept a larger nipple for the poppet or exhaust valves that will hold the compressed air from returning to the cylinders
for the engine part I haven't decided if I will make a new single carb intake manifold that will only serve which ever 2 cylinders I deside will be the engine or in the case I might decide to use #1 & #4 as the engine I may use 2 small engine carbs like those found on the 24 HP V twin engines.
Experience shows me that in the past I could expect a 40 to 50 % efficiency sometimes as much as 60% from a compressor such as this or 47 to 54 CFM @ 100 PSI possibly 70 CFM and 33 to 36 CFM @ 150 PSi I have seen the Ford 289 ci engines develop as much as 100 CFM @ 150 PSI more if they are revved up higher
but I'll be satisfied with 45 @100 PSI
I could add a turbocharger to the exhaust of the engine to feed the compressor to up the output of the compressor if I wanted to I have a nice little one off of a 4 cyl Volvo engine