The engine is the compressor.

[HoosierBuddy]

Guys,

Thought a few of you might be interested in this old gasoline powered air compressor. It’s not exactly correct to call these old Grimmer-Schmidt compressors “engine driven” because the engine is part of the compressor and they share the same crankshaft.

Basically this is a Ford 302 engine that runs on 4 cylinders and the remaining 4 cylinders pump air. The ingenious bit, in my opinion, is the automatic throttle control that revs up the engine as the air pressure in the air tank is pulled down by attached equipment such as a jackhammer, sandblaster, etc.

 

[Firebrick43]

I have a customer with a propane powered 302 compressor

I have seen VW flat four with 2 cylinders running and 2 pumping

 

[OccupantRJ]

Here is a monoblock compressor thread that I started when I had one.

The Monoblock Air Compressor Resource Thread

This thread will be similar in function to my Abrasive Blasting thread in the sense that it will be a repository for information on a specific tool, the monoblock air compressor. For the uninitiated, a monoblock compressor is made from a standard automobile engine, usually a flathead or...

www.garagejournal.com

 

[finn]

There were flathead Ford based air compressors like that in the thirties, and four cylinder Model A engine air compressors before that.

Schram, or something like that comes to mind.

460 Fords were used well into the nineties.

 

[Wrench97]

Many years ago when I was in high school I worked for a company in West Chester Pa that repaired Schramm air compressors the early ones had flat head Ford V8's converted, 6 cylinder OHV Fords and IH 6 Cylinders converted to 3 running 3 compressing. They basically used what ever they could get cheapest, there were some with their own 4 cylinder gas engines driving a 4 cylinder compressor to Wisconsin air cooled conversion, any industrial engine could have been used. Schramm in the 70's started moving toward drill rigs and by the mid 80's divested themselves of tow behind and stationary compressor rigs.

 

[c39er]

And Chevy 348/409 engines also used as compressors.

 

[TurnipTruck]

I found this awhile back when researching something else and saved the screenshot.

 

[larry4406]

....I have seen VW flat four with 2 cylinders running and 2 pumping

Volksair by Dunn Right Not sure if the company is still around or not, I could not find its website.

 

[OccupantRJ]

One issue with the monoblock is the extra heat in the output air from both compressing the air and the heat from the running portion of the engine.

 

[Ultradog MN]

Guys,

Thought a few of you might be interested in this old gasoline powered air compressor. It’s not exactly correct to call these old Grimmer-Schmidt compressors “engine driven” because the engine is part of the compressor and they share the same crankshaft.

Basically this is a Ford 302 engine that runs on 4 cylinders and the remaining 4 cylinders pump air. The ingenious bit, in my opinion, is the automatic throttle control that revs up the engine as the air pressure in the air tank is pulled down by attached equipment such as a jackhammer, sandblaster, etc.

I saw a similar set up years ago. I want to say It was a Pontiac or Olds engine - can't remember now. Pretty clever, and cool.

 

[HoosierBuddy]

One issue with the monoblock is the extra heat in the output air from both compressing the air and the heat from the running portion of the engine.

We’ve had this one at my work for over 25 years. It doesn’t get used a lot but is a good machine. Parts at this point for the compressor side are unobtainable. The biggest issue we ran into many years ago was using it to run a sandblaster where a hose was supplied to the helmet of the guy blasting to keep him cool and prevent fogging. Can’t do that! He was breathing engine exhaust.

 

[930dreamer]

I bought a Grimmer Schimdt for $250 with very low hours. I sat on it for a few years and sold it for I think around $3300. The buyer was surprised when I asked if he wanted to hear it run. I'm not sure what he thought he was buying, it ran perfect.

 

[finn]

One issue with the monoblock is the extra heat in the output air from both compressing the air and the heat from the running portion of the engine.

Heat released by combustion of fuel is far greater than the heat generated by compressing air with no combustion.

Your premise is incorrect.

 

[nadogail]

Many years ago when I was in high school I worked for a company in West Chester Pa that repaired Schramm air compressors the early ones had flat head Ford V8's converted, 6 cylinder OHV Fords and IH 6 Cylinders converted to 3 running 3 compressing. They basically used what ever they could get cheapest, there were some with their own 4 cylinder gas engines driving a 4 cylinder compressor to Wisconsin air cooled conversion, any industrial engine could have been used. Schramm in the 70's started moving toward drill rigs and by the mid 80's divested themselves of tow behind and stationary compressor rigs.

The US Navy had some tractors with Schram comressors, I drove one to a jobsite in 1971.

 

[Sumboodie]

One of the shops at work has 454 vac pumps on huge vac trailers. Deere powered hydraulic system that turns a Chev 454 with special heads.

They send the blocks out to some race shop for rebuild. Surprising there aren't a ton of engine machine shops around anymore, and less that are well versed on BBCs.

I forget the brand now. We recently switched them to Delo 100 40wt, as Delo 400 15w40 XLE was causing fairly low life cycles.