[rpol78]

Those with an SD7 A/C compressor how well does it work? Some time ago I communicated with Vintage Air and my understanding was the small SD7 compressor may have a hard time keeping up when the car is idling. Given this I've been a little reluctant to go down that path. I'm running into a clearance issue with my current build and am considering one instead of notching the frame for a GM compressor.

 

[123pugsy]

Mine keeps up fine when idling. Probably not as hot, but it does get quite hot up here in the summer.

 

[LeoP]

What engine fan are you using??

 

[swampy 6x6]

hi
If running an automatic trans compressor speed needs to be the same D or N. This is done by throttle actuator either push /pull vacuum or electric operated . Power comes from compressor wire . Engine needs 900 rpm .
Vehicles from the mid 80`s had this .
If your A/c has a thermostat [system cycle on/off ] ""idle up"" will also work .

Excessive high pressure readings eg over 200psi with engine at idle and either fast idle /1500rpm will reduce cooling . How do u reduce high side pressure ?? Answer = fit bigger high quality elec fans and larger parallel flow condenser . eg Spal 20 amp 12--14 inch
Last issues concern charging is it overcharged =high vent temps // undercharged not enough refrigerant .

Who charged the system and how do they no its properly charged ??
--indicators of fully charged
all test done at idle and 1500rpm any issueswill show
low side should cycle 20--40 psi
a good system high should be below 200psi an avg upto 250psi
txv should be around 10f subcool
accumulator should be 5-10 super heat
no flooding of suction /compressor
just clear sight glass
strong pull down of temp
recirculate selected
heater off

 

[Hotwire]

Vintage air systems use an orifice valve so it should keep the low side pressure pretty stable? Older GM vehicles used a fixed orifice tube that would suffer during idling since the compressor wasn't pushing freon in high volume. As swampy states the band aid for that was idling the engine up to get enough freon flow through the orifice tube to keep the low side happy.

You can add a fast idle solenoid to your system if you notice the a/c warming up when at low idle.

 

[rpol78]

What engine fan are you using??

I'm doing an LSA swap and using a C&R aluminum radiator with dual electric fans. Given this I also have a heat exchanger in the radiator stack for the intercooler. I had to move the engine back to get enough clearance for the cold air intake. I want to mount the A/C compressor low on the passenger side but with moving the engine back I need to either notch the engine cross member to clear the CTSV compressor or use the SD7. The A/C is a Vintage Air system.

Also it's a manual transmission so changing the idle shouldn't be an issue.

This is a pic of the earlier mock up before I had to move the engine back. With the engine forward I had clearance for a CTSV A/C compressor.

With the LSA setup I had to move the engine back to get clearance for the cold air intake tube.

 

[Hotwire]

I've heard people having problems using the LS style compressors as they're designed for larger systems than the vintage air condenser/evap core. There's also fixed or variable output compressors.. I talked to vintage tech support a while back when I had the spare coin for their system as I wanted to use the low mount a/c option on my ls swap as well.

Might benefit from giving them a call to see if anything's changed, especially since they've come out w/ the next gen system. They may have an option that works better for you than hanging a ugly compressor high off the engine.

 

[rpol78]

I've heard people having problems using the LS style compressors as they're designed for larger systems than the vintage air condenser/evap core. There's also fixed or variable output compressors.. I talked to vintage tech support a while back when I had the spare coin for their system as I wanted to use the low mount a/c option on my ls swap as well.

Might benefit from giving them a call to see if anything's changed, especially since they've come out w/ the next gen system. They may have an option that works better for you than hanging a ugly compressor high off the engine.

I spoke with Vintage Air when I was first going through this and that's when I got the comment on the SD7 not being as good at idle as the larger Sanden compressors. I know their systems is designed around a fixed displacement compressor and variable displacement compressors don't work well with their system.

The CTS-V compressor I have is an earlier fixed displacement compressor. When I spoke with them I was planning on using the GM truck compressor which is also a fixed displacement compressor and the tech said it would work fine. The CTS-V compressor I have is basically the same compressor as the truck compressor but it has different end caps to allow it to align with the LSA balancer pulley. I know GM made two sizes of compressors for the trucks. The smaller one has a similar displacement to the Sandens Vintage Air uses. The CTS-V compressor has the same displacement as the smaller truck compressor. I'd have to look back to see what the displacements are.

 

[rpol78]

From Vintage Air - Displacements
SD7-B10 - 6.1 CI
SD508 - 8.4 CI
SD709 - 9.5 CI

GM truck or CTSV - Displacement
Denso 10S17F/10S20F - 10.8 CI (I can't find the difference between the 10S17F and 10S20F, somewhere I have a spec sheet on the two. The 10S20F is slightly longer and used on Suburbans and Tahoes that had dual A/C vs the 10S17F was used on trucks so I'm not sure if the 10.8 CI is for the 10S17F or the 10S20F)

The SD7 has a higher RPM limit (9000 vs 6000) so I assume it could be overdriven if you could find proper pulleys. Also FWIW others have said the Denso worked fine with Vintage Air in their swaps.

 

[Hotwire]

Great info!

I lost out on purchasing a vintage setup before the stupid covid tax kicked in. Was looking at using a single cab silverado fixed displacement compressor as I've got truck spacing, was hoping it would work itself out.

 

[swampy 6x6]

hi
match up
1st evaporators are for the heat load with matching TXV/orifice to feed the correct amount of refrigerant when needed at max load
2nd Compressors are matched to evaporator core size . They have to suck on the evap core and keep it at a specified pressure window txv 20-40psi
3rd condensers are matched to compressor size

SD7 B10 = 99 cc per revolution 6cuin
Very Very common SD7H15 155cc per revolution 9.4cuin

either there using small evap core sizes or there using a to small of a compressor size for the job

 

[rpol78]

hi
match up
1st evaporators are for the heat load with matching TXV/orifice to feed the correct amount of refrigerant when needed at max load
2nd Compressors are matched to evaporator core size . They have to suck on the evap core and keep it at a specified pressure window txv 20-40psi
3rd condensers are matched to compressor size

SD7 B10 = 99 cc per revolution 6cuin
Very Very common SD7H15 155cc per revolution 9.4cuin

either there using small evap core sizes or there using a to small of a compressor size for the job

So far I haven't found anyone that sells a bracket kit for the SD7H15. It looks like there's tons of different models of it but so far I haven't found one that looks similar to the SD7B10. I was thinking that potentially it was just a slightly longer body like the 10S20F is. It would be nice if they made an SD7B15 so the outlets and mounting would be similar. If that was the case you could use spacers or something to potentially use the mounting systems that are available.

I was looking at it again last night and my space is really limited so it looks like an SD7B10 may be in my future.

 

[swampy 6x6]

hi
Rpol78

1st SD7H15 is a direct replacement fo old school SD508 SD509 SD510
SD7H15 is an ear mount

The Sd7 B10 has thru/side bolt mount
hose connections probably different posi
available clutch diameter
clutch multi groove count

phone Sanden USA for there possible substitute