PERKINS 354 AIR COMPRESSOR

[uglydukwling]

I'm installing an air compressor (I believe it's an SC4) on a Perkins 6-354 (naturally aspirated). This is the style of compressor that bolts to the left side of the engine block. The manual doesn't cover the plumbing for the compressor.

There's a small-diameter tube fitting on the crankcase end-plate (of the compressor, not the engine). Is this the oil feed to the compressor? Where does the oil feed come from on the engine? Should there be a restrictor in the oil feed line? The oil appears to drain back to the engine crankcase through the base of the compressor.

There's another small tube fitting on the compressor cylinder head, apparently the air-pressure sensor for the compressor governor. Should this tube be taken to the air reservoir or is there another place it should be connected? Does the compressor have its own air cleaner, or is the intake drawn from inside the engine air cleaner? Is there any external valving on either the inlet or outlet air line?

 

[used red MN]

So this is a compressor for air brakes or some similar
application? Is there a brand name on the compressor
is it a single or twin cylinder? I assume this is not going
in a truck that originally had air brakes and an engine
with a compressor? You have 5 post should be able to
post pictures now. That would definitely be helpful.

 

[Destroked 450]

I m not familiar with that combination but have messed with engine mounted compressors for several years
A photo if you can post one would help
Need to know if the compressor you have is air cooled or water cooled
As far as the oil supply you can tee in a fitting at the oil sender port or there could be another oil port on the engine
Without see the compressor I don t know if it has a provision to direct mount a air governor that would plumb into a air tank of if a remote governor is needed
Some compressors have a small air filter on the side of the head and others have the air intake plumbed into the engines air intake

Again without photos it s difficult to say what you need to do

 

[caterpillar guy]

From all the truck compressors I've had over the years. IS this a bendix compressor? If so the line at the end ofthe compressor crank is oil to the oil galley on the block. You can tee into the oil sender or use a closer oil plug on the galley line. Then the small line on the head. How small. If about and 1/4-18 inch then it is probably a pressure line to the governor. If larger like 1/2 inch or so then might be a coolant line to the engine coolant port. Is this a water or air cooled compressor? Makes a difference. Usually if it has a larger line at each end of the head then it is water cooled if not then might be missing or air cooled with fins. The small line would need to go to the air tank to sense pressure for the governor. Usually the oil drains back to the engine with a return line from the bottom of the compressor crank case to the side of the engine. The govenror can be mounted on the compressor with a couple 1/4 inch size bolts or remotely mounted like on the firewall or frame in the case of a tractor. there will be about 3 lines from the governor then.

 

[uglydukwling]

The compressor is single-cylinder, air-cooled. There is nothing on it to identify the manufacturer. It looks like the S.C 4 compressor covered in the manual. The manual doesn't say who made it either, so it may be Perkins' own manufacture.

I think I have most of it figured out. I went back for another look at the engine it came off, and there's a tapped hole in the oil gallery within reach of the piece of tubing that came with the compressor, so that must be where the oil feed comes from. No sign of any restrictor other than the small-bore tubing. It looks pretty obvious that the oil drains back into the engine through a passage in the base of the compressor.

Re-reading the manual (why didn't I do that before asking?), it does have some information on the air plumbing. I guess I missed it the first time because there was no diagram. It says that "the compressor draws air from the engine induction system", so no separate air cleaner. It also says "the compressor unloader mechanism is built into the compressor and is operated by reservoir pressure fed back to the compressor governor through a small-bore pipe", so the only other small- bore pipe on the compressor has to be the pressure feed-back. I didn't get the reservoir with the compressor, but it shouldn't be too hard to improvise the connections to the reservoir I do have.

 

[Destroked 450]

Sounds like you have it all figured out except possibly the air governor
Is it mounted onto the compressor or not, should look like the one in the photo, mounts to the side of the compressor head with two bolts