The one from Sears is like the one you are talking about it lasted about 4 years the only thing I used it for was airing up tires. Those pancake ones are used all day long in construction and have lasted longer.

mines a 30 year old Monkey Wards belt drive...

It goes....

Pucka, Pucka, Pucka, Pucka, Pucka, Pucka, ....

Oldfeller--FSO wrote on 01/16/10 at 12:50:37:


ain't none of us, what we used to be....

   
Hard data time ....      (remember, this thing is the size of a 5 gallon gas can)

==============   this is what the data covers  ==============



http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=95498

===========================================

Time to pump up to full pressure (115 psi) from Zero (0) pressure == 60 seconds

Time to pump up from low pressure cut in to high pressure cut out == 16 seconds

Time for an old style (unrestricted) air blow gun to trigger the low pressure cut in == 4 seconds

Time for unending air blow gun use to drain the tank == it never happens, after cut in the pressure dropping slows considerably as the input from the 2 hp unit is an appreciable fraction of the outflow of the air gun.  As tank pressure slowly drops the drain volume through the air blow gun decreases until equilibrium between 2 hp unit and blow gun drain rate is reached.  So, the air blow gun volume/pressure slowly drops to around half speed/volume then it just goes on endlessly blowing at the same rate the 2 hp unit provides.  

A modern restricted pressure/flow blow gun would hit this equilibrium point much quicker (and at a higher pressure) than my antique "full tilt" blow gun would do.

How hot does it get?  Motor stays pretty cool, crankcase gets warm, iron barrel gets hot, but the aluminum head gets Savage head fins scalding HOT.  That protective shroud is there for a reason !!  

I'd go along with the current internet "Bobistheoilguy" info on high rpm air compressor lubes and go with a synthetic compressor oil for this small tightly packed powerhouse unit.  There is evidence of oil frothing (it is a high rpm splash lube system after all) so be sure to get an anti-froth package in your chosen synthetic oil.

I would not use a standard non-detergent straight 30 weight dino compressor oil as was sold for the old style low rpm belt driven pucka pucka units sold in years past -- get you a specialty "synthetic" compressor oil.

Bobistheoilguy posts say that Mobil 1 is commonly subbed into these units by cheapskates not wishing to spend $15 for 16 ounces of synthetic compressor oil.   Mobil 1 is also apparently used my many industrial maintenance departments and has a decade of good performance data on high speed compressor uses.

Weight of synthetic oil is a matter for debate.  If you store your unit in the winter cold, get a multi-weight oil to keep the cold cranking amp draw from tripping your breaker (noted as an issue at Bob's).  These high rpm compressors get as hot as an air cooled bike engine does, so the same multi-weight thoughts do really apply here.

Same new oil technology that gets your car to last 300,000 miles will help your high rpm compressor to last a long time.  Hey, I know nobody does it, but actually changing your compressor oil every 2-3 years would likely be a smart thing too.

Yep, the frothing is natural, but turning your oil into a finely divided smoothie that stays that way can help promote oxidation and oil breakdown into varnish/sludge products should you use some "standard" 30w non-detergent compressor oil in a high speed direct drive compressor.  

Most auto oils have anti-froth additives of some sort which could be helpful in this case and remember the direct high speed type compressors really do get pretty hot too.

Compressors can have issues with varnish build up on the flutter valves gumming up the works and causing low performance or slow pressure build up.  I will use some carb cleaner on my old pucka pucka machine to see if I can get it to do a little better now that I can take it out of service for a while to work on it.

I tend to follow the logic of the BITOG people who are using the Mobile 1 full synthetic for $7 a quart, you got no wet clutch to worry about so even having an energy star on the bottle would be helpful, not hurtful for this particular application.

Heck, I might even go one past the Mobile 1 idea and pick me something that is known to run good in them really big 8 to 10 cylinder 6,000 max rpm 20:1 style air compressors, something with anti-foam and ZDDP and all those other known "good stuffs" in it ...