GM R4 Compressor - New Scroll Design. Better than Piston Type ?

[waid1017]

How many times are you going to post a like to the product?

Nothing do with weather I like it or not. I don't know too much about AC Compressor. Just trying to find out if anyone has actually use these alternative scroll from professionals since everyone claim that R4 are junk. I found another company called GDP who also makes scroll type R4. I don't think its same one that is on eBay.

According to RockAuto, Scroll Replacement For 7511351 R4; 6 Groove;

Waid

[Tim]

How many times are you going to post a like to the product?

Nothing do with weather I like it or not. Just trying to find out if anyone has actually use these alternative scroll since everyone claim that R4 are junk.

Waid

You have a topic going for discussion. No reason to repost the link to the product again and again, unless you're spamming our forum. I'll let the post continue. But if you repost the link again! I'll kill the thread altogether.

[waid1017]

Ok. My bad. I will not post any link.

Waid

[Tim]

PS: I spoke with my compressor guy this morning. This scroll is not all that much better than the piston R4. Bottom line it's a R4.

[bohica2xo]

Scroll compressors have poor low speed performance.

I struggled with an Explorer that had a scroll - it was worthless under 45mph here in Las Vegas. I finally swapped the gear sets in both axles to 4:56 because I got tired of driving in low gear to keep the scroll pumping.

The Trailblazer scroll issue was mentioned in the other thread about this "new" R4 scroll.

What we are trying to tell you is that "Chinese innovation" revolves around repurposing available stuff. To make this hybrid they grabbed the guts from an existing scroll & made a new outer shell to center it in an R4 can. The depth of an R4 limits what scroll will fit.

The "1 inch shorter belt" means the pulley is slightly smaller - not the 60% smaller it would need to be to make things right.

The guy that wrote the book about A/C in hot rods visits this site. He had a had in the development of your under dash unit. Perhaps he will chime in.

Many people have put small blocks in Falcons. The factory did it. They even got the York compressor under the hood. There are plenty of pictures, brackets etc. already out there. A different compressor might be a better choice. If you do press ahead with the scroll keep us posted.

[waid1017]

Most vintage Falcon's and Mustang's have the monster York compressor that hides the motor. See pic below. I am trying to be little bit different and make it look little nicer so when you open the hood, you see the nice shiny motor and not the accessories. We have all you can carry day for $50 at our local pic-a-part and brought home tons of stuff including AC Compressor from 2015 Chevrolet Sonic and Spark but they are still too long.

I may pull an R4 from my local pic-a-part and re-seal it my self. As long as the compressor move freely and hear the compression strokes - suction and exhaust, it should be fine. Correct?

Speaking of being different, I dumped the power steering pump as well to make my engine bay nicer. I am the first one as far as I know, to take a Toyota Prius Electric Steering and adopted to my Falcon for less than $100 and works great. Search up "DIY Electric Steering" on YouTube!

Waid

[bohica2xo]

There are probably only a half million Ford small blocks in junkyards with factory installed FS6 compressors with serpentine drives.

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[71403]

I may pull an R4 from my local pic-a-part and re-seal it my self. As long as the compressor move freely and hear the compression strokes - suction and exhaust, it should be fine. Correct?

Nope - won't know how noisy/rattly it is until it's under load. The greasiest, nastiest, bottom of core barrel unit might be quiet while the new reman might sound like rocks in a blender. Unless you dealt with R4's when they were common in daily drivers 15+ years ago you don't appreciate what a headache they were.

The pics you have show a condenser with high side accumulator, so I assume the underdash is a TVX? Every R4 system (disclaimer: that I have worked on) was a cycling clutch / orifice tube with an accumulator that fed the compressor an oil mist on the suction side. No internal oil reservoir in a piston R4 so they don't tolerate low charge or no oil for very long.

If it's not a daily driver maybe longevity isn't a concern. The R4 that came on my DD went in the scrap pile in favor of a non-cycling V5. Wasn't even noisy by R4 standards. Sanden would have been easier but V5 was worth the effort.

[waid1017]

I may pull an R4 from my local pic-a-part and re-seal it my self. As long as the compressor move freely and hear the compression strokes - suction and exhaust, it should be fine. Correct?

Nope - won't know how noisy/rattly it is until it's under load. The greasiest, nastiest, bottom of core barrel unit might be quiet while the new reman might sound like rocks in a blender. Unless you dealt with R4's when they were common in daily drivers 15+ years ago you don't appreciate what a headache they were.

The pics you have show a condenser with high side accumulator, so I assume the underdash is a TVX? Every R4 system (disclaimer: that I have worked on) was a cycling clutch / orifice tube with an accumulator that fed the compressor an oil mist on the suction side. No internal oil reservoir in a piston R4 so they don't tolerate low charge or no oil for very long.

If it's not a daily driver maybe longevity isn't a concern. The R4 that came on my DD went in the scrap pile in favor of a non-cycling V5. Wasn't even noisy by R4 standards. Sanden would have been easier but V5 was worth the effort.

Great Info. This is a big learning curve for me! My head is starting to spin.

Correct. The Condenser comes with FLU101 AC Receiver Drier Universal for high side. The Under Dash AC Evaporator has the TVX. See picture below.

It appears that Mercedes in late 70's and 80's did used the R4 with TVX. It used Four Seasons #33396 Receiver and Drier on high side. Don't know if there was anything special about it. See the link below.

http://dieselgiant.com/repairyourac.htm



Thanks

Waid

[waid1017]

There are probably only a half million Ford small blocks in junkyards with factory installed FS6 compressors with serpentine drives.

.

I have complete serpentine system from the Explorer and and Mustang (including the compressor) but does not fit the Falcon Engine Bay. The Falcon Engine Bay is actaully tigher than 1965 Mustang. Compressor hits the drivers side sock tower.

Waid