After rebuilding the compressor and fabricating a mount for it, I have installed the Midland Air Brake Compressor on my 455 Olds engine. This is so I can keep my trucks power brakes (they are AIR over HYDRAULIC).

The compressor must have pressurized oil and coolant from the 455 to operate correctly. Coolant is easy, I will get that from the intake where the heater core used to be.

Oil is a different story. I thought about putting a T fitting on the oil pressure sender, would this work? I also need to know if running this compressor will potentially use enough of the engines oil supply up that the cam or other parts may be starved of oil? The 455 was not designed from the factory to supply another small motor with oil. Is this a non issue? Can I just measure how much it will use and then add extra oil to the 455's pan to make up the difference?

For the oil return I was going to put a fitting on the pan when I have it off.
I don't seem to be getting many answers over the internet, perhaps I should contact a local engine builder?

 

The proof of the pudding is in the tasting.

The key question here is how much oil flow does the compressor take, and how much resistance does it offer to that flow? You will get a certain volume of pressurized oil from that oil pressure fitting before pressure starts to drop. How much? I'd say you'll have to check. I'd fab up a temporary line, with a valve and a pressure gauge in it, and run the engine for a minute and watch. Worst oil flow is at idle, best is at high RPM, so I'd say watching it at idle, hot, should give you an idea. I'd also try to figure out a second location to check your pressure (maybe at the filter adapter) to see whether you're starving any other areas when you tap off that port. If you find pressure drops anywhere to a level you're not comfortable with (and going from 40psi at idle to 30 psi at idle is probably fine, so long as it picks up at higher revs), then you might consider a high volume oil pump (if you don't have one already). As for return, probably not critical, but point it in a direction that's unlikely to create flow problems in the pan at high RPMs.

That's one man's opinion...

- Eric

 

It seems to me that the diesel Olds had an external oil cooler (in front of the rad) that was piped from ports cast into the oil filter housing...so what you might do, is find an oil filter housing for a diesel Olds...and feed your compressor and add oil to cover pump capacity and hoses.

 

All good info, thank you! That's over 3 people who have suggested tapping into the right side of the block for the compressors oil supply. I guess the pressure is highest in this area. I believe what I need is a "sandwich adapter" which are normally used for external oil coolers. It's probably the same part that Olds used on their 350 diesels.

http://www.flex-a-lite.com/auto/html...-adapters.html

I think the best way to go about this will be using this adapter and filling the crankcase with enough extra oil to make up for whatever the compressor and compressor lines will be filling up with. Foaming in the crankcase should not be an issue as the extra oil would almost immediately begin circulating throughout the compressor an lines.

 

You might also think about adding a power steering pump in the stock location and use it as an oil pump to supply oil to the compressor. No reason why this wouldn't work with an adjustable pressure valve and a relief bypass line so you don't over pressure the compressor. just add a second pressure switch. you could also do this with a 12 volt oil pump similar to a fuel pump.

Just a couple of thoughts. I would not tap into the engine oil system for this as a broken line or a failed compressor could cause damage to your engine

 

international trucks use that type of air compressor in the early 90s,it had a pully on front about 10 inchs in diameter.Maybe go to your local dealer they should have the info you need,talk to 1 of theolder tech.

 

You also could pick up one of the older compressors which did not use engine oil, they had their own reservoir, used the old splash method. There is also an air cooled version out there if you did not want to tap into the coolant system. Many of the 345, 394 IH engines had compressors, the 361 370, and 429 Ford also had compressors. They tapped into the oil galley with a #4 fitting and there was no noticable pressure loss. The compressor needs very little oil so if you do notice a drop you could install a metering valve to cut the oil down to the compressor with no ill afect to the compressor. Just one other thought is a high volume oil pump. Dave

 

I have already put a lot of work into this compressor. Tearing it apart for a cleaning, reassembly and making the mount for this particular compressor. And I really don't feel up to making a whole new mount for a whole new compressor again. It's a big boy at about 55lbs and is built solid as a brick so I should never have any problems with it. I would agree, it should not use up that much oil and I will be sure to watch my gauge. I suppose I could even put a 2nd pressure gauge at the oil inlet on the compressor to see if that registers differently than the engines oil pressure. This motor will never see anything above 3500 RPM's and it is in no way a performance motor anymore, nor will I be making it a true performer. Beats the heck out of the old GM 302 that the truck was originally built with.

 

Tapping off the oil pressure gauge port is common for feeding add-on turbochargers, for example. Yes, you'll need to ensure that the oil level in the pan is correct even after filling the compressor. Also, be wary of a pressure drop due to the additional oil "leak path" in the add-on compressor. A drain-back fitting in the pan is fine. You may want to consider a high volume pump.

 

Thanks, that's the 3rd recommendation for a high volume pump, since I have to take the pan off anyway for dent removal and adding that return port I will also put a high volume pump in there. It has the original factory pump in there anyway so a new one would be a good idea. The oil drain back holes in the heads don't look too bad, I still need to put a timing chain and gear set in there too and I'd imagine it has the factory set still in it. Will be interesting to see how badly the nylon has crumbled on the teeth.
Still need to do valve seals and a new water pump as well. Then it will be about finished.