Jeremys720z Posted September 21 Report Posted September 21 Hey guys, Working on a 720 with the Z20 2.0L inline four that’s been sitting dead under a tarp in my mom’s dad’s yard for about 13 years. Unsurprisingly, the original A/C compressor is completely locked up solid from sitting in the elements. I’m trying to get the cold air working again, but finding a direct-fit replacement for the Z20 is turning into a headache. A few questions for the Ratsun hive mind: Direct Replacements: Does anyone have a part number or brand (Four Seasons, UAC, etc.) for a compressor that bolts straight up to the Z20 bracket without weird offset issues? Interchange / Cross-Fit: Do the compressors off the Z22 or Z24 engines match the Z20 mounting points? Hardbody / D21 Swap: I’ve heard rumors of guys adapting D21 Hardbody compressors or running custom line fittings to convert to R134a. Is that worth the effort, or is there an easier bolt-on solution out there? If anyone has a known good compressor lying around, a link to one on RockAuto/Ebay that actually fits, or advice on custom line fittings, let me know! Thanks in advance. Quote
datzenmike Posted September 21 Report Posted September 21 Sitting 13 years and you’re worried about the AC???? Begs the question… what was wrong with it that it was parked??????! Does it even run??? Engine blowing blue smoke??? Blown transmission???? Brakes are almost certainly non functional sitting that long. does it hold coolant or over heat??? Get it running first. Fix what’s needed to make it safe and reliable. AC should be last. Quote
Jeremys720z Posted September 21 Author Report Posted September 21 `I have been fixing it and been driving it Quote
Jeremys720z Posted September 21 Author Report Posted September 21 I need a ac compressor and i don’t know which one to get if its cheap or good but expensive Quote
iceman510 Posted September 21 Report Posted September 21 I have a compressor from an 81 Z22. Now of course it would originally been an R12 system, but you are welcome to it very cheaply if interested. I could verify it spins (pretty sure it is fine, just haven't touched it lately). Quote
iceman510 Posted September 21 Report Posted September 21 Someone must have backdated your engine? Was a Z20 still available in that model in '84? Quote
datzenmike Posted September 22 Report Posted September 22 You already have a post about your AC. Make use of it rather than starting another. If things change you can alter the title to match. Quote
datzenmike Posted September 22 Report Posted September 22 On 9/21/2026 at 5:25 AM, Jeremys720z said: `I have been fixing it and been driving it Good to know. 22 hours ago, iceman510 said: Someone must have backdated your engine? Was a Z20 still available in that model in '84? The Z20 was a Mileage option from '83 on and will have the W04 head ID on front near distributor otherwise it may just be a garden variety Z20 from a car. The Mileage option had over 9 compression, only came with manual transmission and 240mm clutch, had a 3.3 ratio differential and needed a knock sensor on the passenger side top of the block with electronics for ignition retarding. Quote
iceman510 Posted September 22 Report Posted September 22 Hmmm, good to know. I didn't really know but figured they followed the Z20/22/24 progression on engine size over the years. Quote
Jeremys720z Posted September 23 Author Report Posted September 23 I have an inline 4 and the compressor is locked up from being in the woods how much could you do for it Quote
slateferry95 Posted October 3 Report Posted October 3 Jeremys720z said: I have an inline 4 and the compressor is locked up from being in the woods how much could you do for it If it's been sitting exposed, I'd treat it as a core unless it turns by hand. The cheap Z22 unit sounds worth checking before hunting down a reman. Quote
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