replacing air compressor

TU FLO 550 and a 750 are interchangeable... I was told that by my local Pete dealer. Not sure how quicker a 750 than a 550 one but couple hundred bucks more expensive

 

just a little inside info on the 550 and 750. there is no way to determine one from the other with out tearing it down. The only difference is the wrist pin location in the piston, allowing for a longer stroke and producing more air. simply remove the tag and tell them its a 750 and boom, no upcharge.

 

that is not the difference between a Tf-550 and TF-750. The TF-750 is a stroked 550 so it has a longer throw on the crankshaft and the piston are different. so cosmetically the 2 are identical and directly interchange.
Also a 550 is 13.2CFM at 1250rpm and a 750 is 16.5CFM at 1250rpm

 

Yes, its the same exact case with slightly bigger pistons/ stroke.

 

really wabco and knorr single cylinder compressors are used on semis, so I belive if compresor is OK, it must build pressure!

but sometimes tube from compressor to air driyer is clogged with oil deposits, so I'd start checking this tube

 

I have always wanted to replace my 550 with a 750. I don't remember what the core charge was going to be, but it was high enough that I didn't do it.

 

bendix, that's exaactky what the other guy said, stroked motors usually have a shorter stroke to increase cubic inches. like the 383 chevy is a stroked 350, the throw is shorter creating more cubic inches. and changing the location of the wristpin can do exactly that. if the pin is moved closer to top of piston, it wont go an high in the cylinder creating more cubic inches. the advantage of this is the same rod and crank can be used , the piston would be the interchangeable part.

 

Longer stroke makes more cubic inches, 3.75 for a 383 vs 3.48 for a 350. Moving the piston pin does nothing for the volume of the air being moved, it just changes the compression ratio. For a compressor it's not as important as for an engine, but the more dead space in the cylinder the less efficient the compressor will be.
First replace the compressor line with a larger diameter, all the air passes through there and the less restriction the better. Also the line should be replaced when there is more than 1/16" of carbon buildup. If you pull the line off the compressor head and see black crusties, it probably needs a new line.