Picked this up recently, got it to pop off today but it's not getting fuel, gotta pull and clean the carb. Most of the photos I've found of these are just the engine/pump, this ones on its cart with tank and all.
Pat, I would suggest pulling whatever mufflers the engine has and probe the piston rings with a scribe. I would not run that engine if it has stuck rings. Several folks on here have commented about the poor metallurgy of those engines in the past. Andrew Mackey will likely chime in. Some penetrating oil goes a long way with these old engines. If the rings are all free, a good heavy mix of oil, perhaps 8:1 would be good to run for a while before switching to the recommended fuel mix. It looks like your complete 3R36 was built out of two units, so perhaps all of the hard work is already done. Definitely hold onto those spare parts. When you get tired of them strap them to a pallet and send them off to New York
80 psi, so most likely single stage. Have seen three cylinder compressors where all cylinders are the same, but two are working as first stage into the third as the second stage. Would add an extra layer to the coolness factor.
Do you have the manual, if not, please PM me your email address and I can send PDF to you.
In Australia, they were used by Railway gangs for track maintenance and construction, they were known as Spot Air.
Removing mufflers (they don't have any) would not help viewing the rings as these are four cycle engines. The compressors are single stage and have the odd Ingersoll-Rand channel valves not the more common disc valves. The compressors do not have an unloader as built although who knows this one with a separate receiver may just do. You are supposed to finagle the engine speed so that the compressor output matches the load requirement, a tricky procedure at best and only valid with loads that are at least somewhat constant. Still these are some of the most interesting and unique little compressors out there, or so say I.
According to the book (Dated March, 1966),
"….A discharge line unloader is provided as optional equipment when specified on order. Compressors shipped after February 1, 1962 were equipped with the Type UL-94B Discharge Line Unloader, Figure 11. Compressors shipped prior to February 1, 1962 were equipped with the Type UL-94A Discharge Line Unloader, Figure 12. The two unloaders are completely interchangeable, but their parts are not.
Both unloaders operate in the same manner and are used to unload the compressor when the desired discharge pressure is reached. Unloading is accomplished by exhausting the discharge air to atmosphere. At the same time, the compressor is slowed down to minimum speed by means of the Type UL-70A Speed Controller. A check valve, included in the unloader, prevents the back flow of receiver air pressure when the compressor is unloading...…"
I have one of these with a few issues. Water froze in one engine cylinder and broke the top of the cylinder completely off where it bolts to the head. Head has crack damage too. Piston did not fare well either.
My 3 R-36 operates at 120 PSI. Production date unknown, contacts with I_R have been unfruitful. I do have a partial owners manual. Some highlights - ONLY use SAE 20 oil! Sae 30 is too thick for use in these units. USE HIGH TEST gas. It does not degrade as fast, nor have the excess alky that crap E-10 has in it. THE UNIT MUST BE LEVEL WHEN RUN! it cannot be run off level on that cart as in the photos. I would pull the jugs and free the rings as noted. There are several vendors that are sponsors here on the Stak that can get replacements, if you need them. Check the head gaskets! They used minimal cooling on the heads, and the head gaskets tend to blow if torque is not kept up on the head mount nuts. Be careful with the rockers and push rods, they ate thin and can be broken easily. I run mine at shows, and it sure draws a crowd!
The original exhaust is a 6" piece of 3/4 tubing, squashed 1/2 flat at the ends. It is LOUD and does not have much back pressure. On my 3 R-36, the exhaust 'stacks' were rusted out. I tapped the 90 degree ells with an NPT pipe tap and installed B&S 5 HP engine mufflers. Now nice and quiet exhaust and not much back pressure. If you rebuild the carb, be careful of the gasket. DO NOT overtighten the top mount screws, the carb will warp.
If you still have the parts pile, I would be interested in the starter pulley and shaft, as the one on my unit is broken. Please contact me if you want to sell it.