corax
02-09-2009, 01:46 PM
Today's cheap project is to port a cheap air compressor cylinder head.
I'm pretty sure this isn't anything new, but it's so simple and does make a difference. Total time spent was ~ 30 minutes including the time it took for me to walk out to the truck.
This is our patient - a Harbor Freight cheapie air compressor, it's lasted nearly 1.5 years so far and has some good design features such as: big motor, no separate cylinder sleeve (better heat disipation) and cheap . . . did I mention that already? I think I paid $20 for it on sale
http://i280.photobucket.com/albums/kk171/batardsalamano/100_2829.jpg
I took the head off, which was just 4 allen bolts (no pics 'cause it was simple) - the "head gasket" is just a recessed o-ring (cylinder has a ridge which goes into the recess to sandwich everything) and was reused. Here's the inlet side of the cylinder head - the air gets pulled through dual reed valves on the piston and pushed through the reed valve in the cylinder head. BTW, the gunk you see on it is dried up anti-seize.
From the cylinder, air has to pass though this 1/8" hole
http://i280.photobucket.com/albums/kk171/batardsalamano/100_2823.jpg
here's the actual reed valve (covered by measuring tape) where air comes into the chamber on top of the head before going to the air fitting, note the little ring seal - the reed valve side of the air hole is 3/16"
http://i280.photobucket.com/albums/kk171/batardsalamano/100_2825.jpg
here's the Dremel bit I used
http://i280.photobucket.com/albums/kk171/batardsalamano/100_2826.jpg
cylinder side of the head plate after opening it up - about 1/4" diameter in 30 seconds - I also tried to "radius" the hole a bit so the air wouldn't have to flow past a sharp edge (think of the air horns on ITB's or side draft carbs)
http://i280.photobucket.com/albums/kk171/batardsalamano/100_2827.jpg
discharge side of the head - just under 1/4" diameter - I didn't want to get too close to the reed vavle seal and as passage diameter decreases the air velocity will increase, so it shouldn't matter anyway
http://i280.photobucket.com/albums/kk171/batardsalamano/100_2828.jpg
I didn't bother timing how long it took to fill a tire from x psi before and after this mod, but I can tell it's moving a higher volume of air now - and with the easier flow should come lower operating temps.
I'm pretty sure this isn't anything new, but it's so simple and does make a difference. Total time spent was ~ 30 minutes including the time it took for me to walk out to the truck.
This is our patient - a Harbor Freight cheapie air compressor, it's lasted nearly 1.5 years so far and has some good design features such as: big motor, no separate cylinder sleeve (better heat disipation) and cheap . . . did I mention that already? I think I paid $20 for it on sale
http://i280.photobucket.com/albums/kk171/batardsalamano/100_2829.jpg
I took the head off, which was just 4 allen bolts (no pics 'cause it was simple) - the "head gasket" is just a recessed o-ring (cylinder has a ridge which goes into the recess to sandwich everything) and was reused. Here's the inlet side of the cylinder head - the air gets pulled through dual reed valves on the piston and pushed through the reed valve in the cylinder head. BTW, the gunk you see on it is dried up anti-seize.
From the cylinder, air has to pass though this 1/8" hole
http://i280.photobucket.com/albums/kk171/batardsalamano/100_2823.jpg
here's the actual reed valve (covered by measuring tape) where air comes into the chamber on top of the head before going to the air fitting, note the little ring seal - the reed valve side of the air hole is 3/16"
http://i280.photobucket.com/albums/kk171/batardsalamano/100_2825.jpg
here's the Dremel bit I used
http://i280.photobucket.com/albums/kk171/batardsalamano/100_2826.jpg
cylinder side of the head plate after opening it up - about 1/4" diameter in 30 seconds - I also tried to "radius" the hole a bit so the air wouldn't have to flow past a sharp edge (think of the air horns on ITB's or side draft carbs)
http://i280.photobucket.com/albums/kk171/batardsalamano/100_2827.jpg
discharge side of the head - just under 1/4" diameter - I didn't want to get too close to the reed vavle seal and as passage diameter decreases the air velocity will increase, so it shouldn't matter anyway
http://i280.photobucket.com/albums/kk171/batardsalamano/100_2828.jpg
I didn't bother timing how long it took to fill a tire from x psi before and after this mod, but I can tell it's moving a higher volume of air now - and with the easier flow should come lower operating temps.