underhood compressor

[Danco]

im wondering if anyones ever bought or built one?

[Franz]

I've put them on a few Chevys, a Ford or 2 and a 1952 Dodge M-37 military, and a Lincoln pipeliner, although I had to expand the side pannel on that machine to do it.
What do you want to do, in terms of compressed air delivery, and usage?
It's definitely not efficient to run a truck engine to make compressed air, unless you are using a PTO driven compressor to deliver a lot of volume.

[Danco]

well......i'd like to be able to gouge. thats about 20 cfm which is quite a bit. what model was it? any idea of the price? i have a gmc 3500 with a 350v8 engine....some extra room but not a whole lot. a friend of mine has a 5 ton ford (older) and he put a belt from his engine to an old comp pump and replumbed it. works well, but i dont have the space he does.

[Franz]

[email protected]# from under the hood is going to be brutal to acheive.
That kind of capacity would be a lot easier to do with a constant run type compressor that is PTO driven.
Look around for an old furnace cleaning truck that had an air driven beater worm and huge vacuum cleaner, and get the compressor off the truck. I've picked up a couple of those, cause they set up real nice for driving off a tractor PTO.
I don't think even an air brake compressor could deliver 20cfm, but you might check the Bendix site.

[bluesman2a]

This is actually pretty common in the offroad world.

20CFM will be tough to do. If you need THAT much, you may need 2 compressors. The popular choice for others doing this is the York Compressor.

For more info, see here:

http://www.onboardair.com

http://www.mobileairsystems.com

[Danco]

check this out! http://www.throttlecommander.com/und...w_products.htm 140 cfm and 175 psi probably costs an arm and a leg AND a few fingers

[grahambl]

and probobly some toe's to boot

[Franz]

Now, I might have been around the block a few too many times, and I've seen one **** of a lot of air compressors, including both piston and screw typs, but I'm gonna make a statement right here and now. Any time you use an air conditioning compressor for an air compressor, you will have 2 problems, oily air, and the need for a spare compressor. I've installed more than a few of them, and unless you have a midget riding under the hood with an oil can, you cannot keep sufficient oil in either a York or a Mark 4 air conditioning compressor to keep the rod from breaking.
If you want something of that size, find yourself a Bendix 7 1/4, and you have a compressor that will deliver 7.25cfm of 100# air all day every day. It will also eat 9 horsepower off the engine, but it is built to run constantly. It's also a self lubricated compressor.
Once you get beyond that capacity of air compressor, they all tend to be lubricated by the engine oil system, and are a pain to mount up to anything other than the engine they were built to go on.
I don't think Midland ever built a self lubriacted compressor, so there ain't much point to looking for one.
As far as that 200+ pound "screw compressor", I have some serious doubt. Unless things have changed recently, GardnerDenver owns all the patents for screw compressor technology, and has refined that thing to the max. Screw machines generally aren't built below 20hp, because it just isn't cost effective. Throttlecommander definitely has an interesting looking web site, but, I can't see any way in **** a screw compressor can be driven by a single serpentine belt, and deliver the cfm they are claiming.
The air compressor industry has learned a lot about sleazy marketing in the last few years, and is employing everything they have learned to sell junk to suckers. One manufacturer has even designed a fake 2 stage that is being sold in the box stores, that even has a phoney intercooler on it.
If a guy wants a compressor on his off road vehicle to blow a tire back up, you can find a Mark 4 compressor in most junk yards, and put it on the engine, along with a receiver and a pressore switch and have a fairly decent system. It will even last a long time, if you keep the crankcase filled. Unless you put a large receiver on it, it definitely won't keep a 1/2" impact going long. The actual delivery at a nominal 100psi is about 1cf per 2 miles at 1800 engine rpm. That system could be put together for about $100- and would probably be all that most people needed.

[chadl]

I got a york type on my jeep, but there is no way it would handle arc gouging

It will run a cheap 1/2" impact if my wife holds the rpms around 2300

Chad

[Danco]

a heavy duty mechanic i worked with 5 yrs ago had an underhood compressor that put out i believe 30 cfm continously. hes no longer there, and i cant reach him. ill find out what i can about throttle commander and post it here.

[bjdenommee]

Franz
Where do you find those midgets with oil cans?

[Franz]

If you can't find a midget, a small child will work.
I've blown a couple rods myself trying out various AC compressors as air compressors.
Frankly, AC compressors are terribly inefficient as air compressors, and air brake compressors are huge horsepower eaters.

[Danco]

well......i emailed throttle commander...gave them the specs of my truck (gmc 3500) and said i needed 20 [email protected] psi. they emailed me next day that they dont have units that small, but gave me a link to this site http://www.extremeoutback.com/catalog.htm

[Franz]

Well, I went and looked at that site, and it reminded me Aussies are still crazy, just like the ones I knew back in 68 when we played together.
The belt driven model only delivers 8cfm unless I'm completely blind, and looks an awful lot like a modified Chrysler wobble plate compressor that has been modified.
The field tire breaker sure looks interesting though, not too difficult to build elther, now where did I put that square sign post material?

[Franz]

Check out the VR 70 on this site

http://www.triindustries.com/underhood_air_compressors.htm

It appears to be the compressor Telecomander pretends to be.