I've been chasing this R4 vibration FOREVER. It used to do it only around 800rpm idle, so I upped my idle to 1000..but now its back with a vengeance, worse than ever at my 1000 rpm idle. Its seems to be a harmonic. I really do NOT wanna start a huge discussion about how*****py the R4s are. I do read a lot of threads with people chasing vibrations with R4s. So lets get to it. QUESTION: If I adapt in a Sanden compressor, do I stand a reasonable chance of solving this issue?
I chased a York compressor vibration on a 289 once. New compressor, the factory clutch wrapped out after a year so we put a new Murray****y on it. It was different than OEM in appearance but lined up nice. The original had a pretty heavy damper ring behind the belt groove. This would vibrate like crazy at idle, worse off idle. I could not find a correct clutch anywhere. I ended up putting a Sanden on it.... best thing I could have done! Dead smooth, took less effort from the motor to turn, it would freeze you out!
This is the second R4 doing the same thing.. I am done with R4s, if for no other reason than to try something, HELL, anything different.
Believe it or not, a lot of science/engineering goes into compressor mounting bracket design to ensure they don’t resonate with the natural frequencies of the compressor. Not saying this is the cause of your issue, but something to consider. A modern swash plate design compressor will outperform the tech in the R4 and will be quieter and more efficient. We only used Sanden compressors in all of our construction, and forestry equipment.
True. I admit I had to delete a support brace or two when I swapped out the factory intake due to no place to bolt to. I also read a link saying GM retrofitted some cars with additional bracing for R4 vibration issues.
When I worked for WH Thomas in Waco in the 70's we replaced a couple of R 4 compressors a week with the older A 6 style units. I went to college in the mornings and got to Tommy's at about 12 and swapped a lot of them out and put the vacuum pump on them. I'd have to agree with changing to a Sanden compressor these days though.
Hello, When we bought the 327 powered 1940 Ford Sedan Delivery for our next car, it was drivable, but a giant project. It was not completely finished and needed lots of care and planning, as well as repair and replacement of parts. It was a major project that took several months of work and replacements to make it road worthy and safe. The 327 had a York compressor and at the time, the newer rotary compressors were around and that was our goal. The York compressor was what came with most A/C systems as they were readily available at the GM parts departments and junk yards. Ours was a working unit, it was cold, but, it did create problems. The hoses were all replaced and the York was completely gone through by a refrigeration expert. It was now ready and worked well for a couple of years. Just looking at a York, versus a low tubular cylinder type makes one wonder why more Yorks did not have problems in balancing and functioning. But, because they came first on most GM cars and did not create one massive problem on factory cars, it continued. A few months before we sold it, the new rotary units were taking over the installations on most hot rod motors. They had less problems and ran smoothly. Plus, the small tubular factor was good for less*****ola in the motor spaces. Some, even placed them lower into any opening that could run the belt. Jnaki “The York is a rarity these days, but can be identified by its large square shape. The York compressor is much like a lawn mower engine, being a two cylinder, reciprocating pump. The reciprocating motion causes it to vibrate more than modern Sanden compressors. The York also has higher torque requirements for peak pumping, and they don’t like higher RPM operating speeds." York was old school, but at the time, it was the only game in town… YRMV Note: The old York compressor being the only game in town back then was instrumental in my wife enjoying driving our 327 powered Sedan Delivery anywhere and at any time. A/C power is cool … Pun intended. Visiting friends when pulling up in their driveway was something, but arriving “cool” was done in more ways than one… So, if care is taken and continuous upkeep is necessary to have a cool drive anywhere. Work with what you have, but otherwise a rotary unit has a much better design and can be placed just about anywhere a belt will fit.
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