Hello Experts I am considering replacing the York compressor in my Mondial QV with a Sanden SD508 in a bid to resolve the recurring Polyflex belt breakage issue. The Sanden compressors seem to put much lower stresses on the belt due to its higher efficiency and 5-piston wobbly plate layout vs the York's 2-piston on a crankshaft construction. I plan to use one of the readily available conversion plates but will be obliged to reuse the Polyflex belt due to the crankshaft pulley section. The new compressors come with clutches, but of course for regular V-belts as far as I can determine. So, here my question: Does my York compressor clutch (with Polyflex section) fit onto the Sanden output shaft? By the way, has anyone done a similar conversion on a Ferrari? Thanks for your insights! Urs
The Sanden compressors have some advantages for sure. The Sanden compressor is a great compressor that is used on many large trucks, farm tractors, and industrial equipment. They can be easily found on eBay. The Sanden Corp. web site also has some super engineering/specification information. I think there are several threads on Fchat regarding this conversion and the issues involved. Try searching the words: "york sanden" in this section, or the 308 and Mondial sections. It will be hard to find a single grove v-belt pulley for the Sanden compressor that matches the Ferrari belt width. There are a lot of single grove pulleys that would fit the Sanden compressor, but the belt grove will be larger/wider. However, a wider v-belt compressor would probably work. You will likely have to use the narrower/smaller Ferrari belt size because the engine drive pulley will still be the narrower Ferrari width. I am not aware of anybody making a wider Ferrari v-belt engine pulley. Luckily, Sanden SD pulleys, clutches, and clutch coils are very interchangeable. Just make sure you use a 12v clutch coil.
Thanks Jerry for your insights. From their doc, it seems that the Sanden 5-piston versions are for R-12 and the 7-piston variety for R-134. I was looking for sections of the output shafts and found that the York has a tapered shaft, where the Sanden's is a parallel shaft. So no easy way to adapt my Polyflex-style York pulley to the Sanden compressor. I searched the forum for the conversion threads and have found quite a bit of information - except the pulley question - so far. I only know that the Sanden compressor on early 2-belt cars was in fact driven by a Polyflex belt - I have a picture of a crankshaft damper for the Sanden compressor and it clearly shows the 60° groove. So Sanden clutches for Polyflex belts existed.
It may be hard to find a single v-belt pulley for the Sanden compressor, especially, the same belt width as the Ferrari. I never had a problem with the poly-flex belt, other than belt noise, but on the Ferrari they are certainly small for work they do. I am sure there are several that have been removed from the early Ferraris, just lost or thrown away. A wanted ad on F-Chat may help. You could get really lucky and find the Ferrari Sanden compressor mounts, too. York automotive compressors were actually very good compressors. I tested a few in a research lab for use on a solar powered air-conditioning system in the 1970's for a NASA/DOE contract. But, Sanden has become the standard for automotive use and replacement today. There are York type compressors that are in current production. I might strongly consider using a replacement York type compressor to solve some of the conversion fitment issues. Best regards, Jerry
Hi Jerry. Hard, and potentially dear. Eurospares sells them for the price of a second hand car here in HK. Lucky you. The alternator/wp belt on mine is fine. The a/c keeps busting. I guess the heat load here in HK is just too much for it. When it goes, it usually takes off the other belt in the process and leaves me stranded. 2 per summer average. All is OEM, lined up, idler free, new rubber bushings, the compressor in very good shape. I cannot solve this on my car without a change somewhere in the system. That is what I am trying to find. Good idea. I was on ebay so far. I don't think the York compressor is the issue here. Is its adaptation to our specific application. It seems to be more efficient so putting less strain on the belt, and with more pistons probably reducing the impacts on it too. My car was fitted with one of those incl. a new clutch a few years ago when the original one seized. Straight swap - but the same belt snapping problems continued. So I am looking into my options and appreciate advice from people more knowledgable than I am. Best Urs
Do you know what the discharge pressure (aka: high pressure side or head pressure) is when the motor is at about 3000 RPM? This just a thought. You might try to find a wider non poly-flex belt that would be a little stronger. It would run a bit higher in the belt groove, but shouldn't make a big difference once you get it on the pulleys. The old GM Delco a/c compressors were also wobble plate type compressor. It was a good design, too. I think you are right about the stresses to drive the York vs. Sanden. I have not looked at the measurements of a two v-belt pulley for the Sanden. There are a lot of two v-belt pulleys available, although, probably for a larger belt than the Ferrari. It may be possible to remove one of the groves with a lathe, if there is not enough room to mount the compressor with the two v-belt pulley. Just a thought. I bought a Sanden single belt compressor on eBay, it was for a Peterbilt truck. It was also 24v. I put the Ferrari 12v clutch and pulley on it. This web site may also have some information. Ferrari A/C Compressor Upgrades | RetroAir, Inc. Best regards, Jerry
One car i know that uses a sanden compressor and a relatively small single v-belt is a Lancia Thema 8.32. It's a sanden sd510 and is driven by a avx10 belt. i'll might have 2 clutches and v-belt pully's lying around just in case.
I machined out the inside of my York pulley, and pressed it onto a machined Sanden pulley. I straightened it in the lathe and then tack welded it.
Here is another conversion. The picture looks like a single pulley. Jeep York Sanden A C Compressor Upgrade New USA Made Compressor | eBay Single pulley source http://www.ebay.com/itm/132mm-SANDEN-SD5-5H14-STYLE-CLUTCH-ASSEMBLY-1-GROOVE-12-VOLT-1-A-BELT-GROOVE-/311292528259?hash=item487a7b0683&vxp=mtr Jerry
The OEM Ferrari clutch, for the York, is a Ferrari only part. thru a tragedy, I lost my original York, clutch and all, so I had to reassemble all the bits. As you post, a single groove AC clutch is a rare thing anyway, probably a tractor application! I have no idea on what to do to match up to the v groove angle, reading about "cutting and welding" may well be it! FWIW the poly belt on the OEM clutch is about twice the size of the alternator/water pump belt, I never had trouble with it. Of course if the component fails and seizes, any belt out there is going to give up.
Jerry, I don't - but the mechanic who replaced the compressor 5 years ago with a new "Climate Control ER210R" told me that the max. pressure is achieved at about 3'500 engine rpm. As the crank pulley is much smaller than the compressor's there must be quite an rpm drop, probably close to 3'000. As we switched from R12 to R134a at the same time (with a new dryer and system flush) the system was charged to about 80% of the previous' if I remember right. Also, the min/max pressure switch got replaced and limits the pressure to 24 bars now. This works as the compressor does get cut when in a traffic jam in summer and airflow through the condenser is limited. The yellow a/c warning light then comes on in the console. Below 2 bars, the system would be cut too but that never happened. Also, the HVAC ecu does cycle the compressor normally from what I can tell, so the overpressure cut out only happens in "extreme" cases (traffic jam, reversing!) Tried, unsuccessfully... The Mondial also seems to have the biggest (210 model = 2cyl. 10cu.in.) York-style compressor fitted, which increases stresses on the belt too. I would go for a smaller displacement Sanden. Mondials came with an Sanden SD-508 (5 cyl. 8 cu in). May my larger compressor be the issue? I think those are just two regular V-belt grooves in parallel. Unfortunately, due to the reverse mounting on the Ferrari, we cannot fit 2 parallel belts. I am thinking of machining a 60° groove clutch pulley from scratch. I just would have to know what exact material is being used for it. I am in contact with Rock at Retroair. He sells the regular V-belt in his kit and says it he hadn't have any belt failure reports. Best Urs
Stefan, that is interesting information. Would you mind checking up on what clutch/pulleys you have? (Diameter, groove angle, key or splined shaft mounting) Thanks! Regards Urs
Jerry, I looked at that ans I am pretty sure it's a double pulley in the first one - and the second one has the wrong (as in: not my silly 60°) sheave angle... Regards Urs
Big Tex, my York-Climate Control compressor has recent a 60° double groove pulley, see attachment. The black dust is what is left of the regular 40° Gates belt I tried to run. Would you know the material type required? Lucky you! 7mm vs 11mm Not the case on my car. Image Unavailable, Please Login
Outside diameter of the pulley is 135mm I think as far as i can remember that it had a straight shaft with a key. Groove angle is sadly 40degrees..... I also have a harmonic balancer from this engine but i have no clue if the other belts are the same as 308. Chances are that the balancers itself are interchangable since the engine is more or less the same but it depends offcourse on the other belts. Image Unavailable, Please Login Image Unavailable, Please Login
Somehow I think everyone is over thinking this issue. I did the conversion on my 77 and used the conversion bracket where it eliminated the adjustment tensioner. I also got an oversized V belt (don't know angle and didn't care) and cut it until I got the correct length. Then went and got a belt a size smaller and a size larger and installed it. After all was said and done the belt fit fairly tight at the lowest adjustment and when final adjustment and run in was done it was in the middle of the adjustment range. It was not a polyflex belt but just an off the shelf Gates belt. It was on the car and working for 4-6 years and still on when I sold the car. Just my thoughts here.
Thanks for your experience report and opinion, Steve. I get your point... just trying to solve the "under-engineering" problem I have on my car
