1990-1995 ZR-1 AC Condensers

[XfireZ51]

Does anyone know if there is a difference between AC condensers for 1990-93 v 94/95 condensers? Some places show same part # while others do not.
Picked one up from AZ and hose alignments are off and oil cooler mounting is missing.

[WVZR-1]

Does anyone know if there is a difference between AC condensers for 1990-93 v 94/95 condensers? Some places show same part # while others do not.
Picked one up from AZ and hose alignments are off and oil cooler mounting is missing.

very different - thread specifications would verify maybe what you received.

Brand and part #?

Best of recollection maybe R12 fittings remained SAE thread spec and R134 was the first GM Metric thread spec. A quick check would be if a '94 or '95 owner checked the 'nut' to condenser and see if it has a 'notch' on the hex. That would indicate Metric. I'm quite sure earlier didn't have the notch.

I have the thread specs I'm quite sure in a document not on this computer. A note in this link hints I could be correct.

https://coldhose.com/fittings/metric.html

*** If I'm correct a 'screw pitch gauge' would confirm what's in your hand.

[XfireZ51]

The AZ condenser is part# 7-4306. It says it fits a 92 C4 ZR-1 as well as a C4 and the brand is Spectra.
The 94 part# is 7-4557. Same here for both ZR-1 and C4.
Pictures show mounting holes for oil cooler but the part came without any of that.

https://www.autozone.com/cooling-heating-and-climate-control/a-c-condenser/spectra-premium-a-c-condenser/52697_0_0

[WVZR-1]

The AZ condenser is part# 7-4306. It says it fits a 92 C4 ZR-1 as well as a C4 and the brand is Spectra.
The 94 part# is 7-4557. Same here for both ZR-1 and C4.
Pictures show mounting holes for oil cooler but the part came without any of that.

https://www.autozone.com/cooling-heating-and-climate-control/a-c-condenser/spectra-premium-a-c-condenser/52697_0_0

I use some different ID information and I don't see the 7-4306 having the bracketry for the cooler. AZ might use some random/older images and 'maybe' years ago the condenser did have the bracketry. A side by side and screw pitch gauge I'd think wise for confirmation.

[XfireZ51]

I use some different ID information and I don't see the 7-4306 having the bracketry for the cooler. AZ might use some random/older images and 'maybe' years ago the condenser did have the bracketry. A side by side and screw pitch gauge I'd think wise for confirmation.

Side by side, the OEM v the Spectra are different. The hose connections are at differing angles as a start along with no provision for cooler mounting.

[-=Jeff=-]

Maybe they sent you an 89-older version by mistake, that would explain the differences..
post a pic of the 2?

[XfireZ51]

Maybe they sent you an 89-older version by mistake, that would explain the differences..
post a pic of the 2?

The AZ condenser is physically somewhat smaller than the OEM. The hose connections are lower and the bottom connection goes off at the wrong angle.
The top connection can work, but the bottom one will not without bending the tube somehow. I have Jason at V2V looking for a good condenser.

[-=Jeff=-]

what is the AZ PN.. I bet that is an 89 part

[XfireZ51]

Jeff,

Look at my #3 post.

[-=Jeff=-]

Which AZ PN did you use:

7-4306 or 7-4020?

Ecklers shows it:

https://www.ecklerscorvette.com/corvette-air-conditioning-condenser-1990-1993.html

[XfireZ51]

7-4306

[-=Jeff=-]

7-4306

got it.. is the PN stamped on it anywhere?

[XfireZ51]

got it.. is the PN stamped on it anywhere?

Its on a tag attached to the bracket that holds the hose ends in place. The box also says 4306.

[-=Jeff=-]

this does not help you, but this is the part I bought
P32603P I got it at autoparts warehouse and no longer shows on their website

a link to one
http://autopartsvalley.com/autopartsvalley/a-c-condenser-chevrolet-corvette-1990-1991-1992-1993-p32603p-52456459

[XfireZ51]

All the online catalogs show the OHV and DOHC condensers as the same part# which end w ..306. The pics used appear to show the correct part, but the one I got from AZ doesn't look like that. Taking it back for refund.

[-=Jeff=-]

Can you get me a picture of the other end of both of them?

Is ti the same width? I see the core height is less but the frame 'end' structure looks the same height. How far off are the fittings? inches? 10ths of inches? 100ths of inches?

I seem to remember mine being a pain and did not quite line up..

[WVZR-1]

this does not help you, but this is the part I bought
P32603P I got it at autoparts warehouse and no longer shows on their website

a link to one
http://autopartsvalley.com/autopartsvalley/a-c-condenser-chevrolet-corvette-1990-1991-1992-1993-p32603p-52456459

Industry interchange says your ref# and the one he was sold are same applications. It can't be an '89 as the '89 stood straight up and the fitting were 'parallel' with the floor.

[-=Jeff=-]

yeah, thanks.. I seem to recall having to 'adjust mine a bit' to work. 8 years no leaks

[XfireZ51]

Got a refund from AZ. Very straightforward. Picking up a used condenser from Vette2Vette today. Jason said he has several 90-93 units in good condition that hold pressure. New compressor and tensioner are in.

[-=Jeff=-]

I should add that the Parallel Flow condenser while it may need a bit of tweaking, being parallel flow is suited more for a R134a system.

As some know on a typical R12 to R134a conversion the R134a tends to run a bit higher head pressure than R12. the Parallel flow will help alleviate that. in fact my R12 system with the parallel flow compressor I barely notice the added load on the motor due to the nature of the parallel flow vs the OEM Tube and Fin

While I understand some want the OEM fit and drop in, this will help others when looking to fix there systems

Happy Cooling

[XfireZ51]

Thanks Jeff. I went ahead and picked up a used condenser from Jason at V2V yesterday. Perhaps u could try to recall what mods were required in order to make the // condenser fit. The one I bought had no provision for the oil cooler mounting as an example. I could handle that but the connector lengths and angles were just not going to work.

[-=Jeff=-]

Dom,

What year is the condenser out of? would you mind posting pictures of the ends? looking at your old one, it might be Parallel flow. I know the 90 OEM was Tube and fin and not sure what year they fully switched the corvette to R134a.. the Parallel flow is why some of the 'newer"/ cars that are converted are a bit more efficient

[XfireZ51]

Jeff,

Here is a pic of what the condenser that I just pciked up from V2V. Jason said this is a 90-93 condenser but not certain which of those years

[-=Jeff=-]

looking at it on both ends, I would say it is parallel flow, so a later version

[XfireZ51]

looking at it on both ends, I would say it is parallel flow, so a later version

Is that anything like the cross flow rads they started using in the LT1/4 motors?
I'll see if I can get a part# off it or my old one to better ID it.

[-=Jeff=-]

Is that anything like the cross flow rads they started using in the LT1/4 motors?
I'll see if I can get a part# off it or my old one to better ID it.

not sure I remember how the cross flow radiator worked

[XfireZ51]

Here’s why a 94 AC condenser is different than 90-93.

1. Its thicker and appears to be made of aluminum, likely due to reduced effciency of 134a
2. The oil cooler does not mount onto it as it does 90-93 condenser (see pic)

NOTE on condensers. Altho they may have same part # as any other 90-93 condenser, some have a smaller diameter low side connection. My Low side AC line would NOT work with one of the condensers I picked up from V2V.
I returned that one and Jason and I looked into the rest of his inventory. And we found what Jason thought were 90-93 condensers but nearly half of them had the smaller diameter orifice for the low side. Pic is below. Note the smaller orifice on the condenser behind the Autozone condenser.

[WVZR-1]

Here’s why a 94 AC condenser is different than 90-93.

1. Its thicker and appears to be made of aluminum, likely due to reduced effciency of 134a
2. The oil cooler does not mount onto it as it does 90-93 condenser (see pic)

NOTE on condensers. Altho they may have same part # as any other 90-93 condenser, some have a smaller diameter low side connection. My Low side AC line would NOT work with one of the condensers I picked up from V2V.
I returned that one and Jason and I looked into the rest of his inventory. And we found what Jason thought were 90-93 condensers but nearly half of them had the smaller diameter orifice for the low side. Pic is below. Note the smaller orifice on the condenser behind the Autozone condenser.

So the snapshot in #23 is of the "1st bad guess" by Jason?

I've no idea what Jason had in his inventory to sort but '90 - '93 condensers all share the same threaded specifications. Jason was 'guessing' as to his inventory applications - half of his pile just weren't '90 - '93 condensers. There was an SPO part # change very early in '92 but without having the 2 side by side I don't believe you could speculate physical differences differences. Inlet and outlet ports would have shared the same thread specifications.

You're correct that the oil coolers are different on '94 & '95 cars but that's 'by design'.

The 'reason why' '94 is different is because of the 134a changeover by design. An 'engineering' thing.

I've never been concerned enough to see if there's actually stamped ID on a condenser but it's reasonable to assume there likely is.

[XfireZ51]

WV,

When I posted this, I was hoping u would provide some further insight. We checked the condensers including the one I removed from my ZR. No part# appears to be stamped on it. I’m including a compare pic of my original condenser alongside the AutoZone sourced one. U can see the difference in the angles of the connections.

[WVZR-1]

WV,

When I posted this, I was hoping u would provide some further insight. We checked the condensers including the one I removed from my ZR. No part# appears to be stamped on it. I’m including a compare pic of my original condenser alongside the AutoZone sourced one. U can see the difference in the angles of the connections.


That's not a very effective way to attempt comparisons. You've got them 'front to back' stacked. You can't effectively compare the profiles. You would need to lay them on their 'face' and with measuring devices do comparisons. I don't doubt that there's likely a difference but is it a 'tolerance ' that can be accommodated? I'd think so. Could I be wrong? FOR SURE!

I had buyers guide (paper) at one time that I relied heavily upon for some stuff. I don't have them still and the only definitive difference that one vendor notes in there guide is that their last offering for the applications was '90 - '93 6mm serpentine, '94+ is parallel and I believe that nearly all (if not all) GM 134a productions were parallel.

I do believe that if a '94+ was checked there would be 'notches' in the HEX to the condenser and assorted AC components. That would ID them as being Metric vs an SAE thread spec which I'm quite sure yours is.

I serviced a very large fleet that used all OEM - the GM offering didn't fit and required a considerable 'force fit' and they weren't happy. I bought after-market that fit and after that it was the only source I used for that condenser application. That was the only thing that fleet bought that wasn't OEM if available. Filters aside.

[-=Jeff=-]

I would have tweaked the tubes as needed on the new condenser, Which I believe I had to do when I fixed my AC 8 years ago

[Locobob]

So did anyone ever find a good source for the correct early style condenser? mine has sprung a leak.

[XfireZ51]

Bob,

The condensers from AZ and the like do not have provision for the oil cooler mounting that ZR-1s had. Those condensers are built for base C4s. I had asked Haibeck who they used for a source on condensers. Sounded like they have used Spectra condensers which are the AZ ones. I think Ecklers and CC may have ZR specific condensers but we are looking at $3-400.
The 94-5 condensers are 134a specific and won’t fit the 90-93 oil cooler.

[jss06c6]

Hey Dominic,

Do you think there's a way to modify the '94-95 condenser to accept the '91 oil cooler?

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[jss06c6]

Alternative might be to build new oil cooler lines and install two coolers on fabricated bracket(s) in a new location?

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[XfireZ51]

Hey Dominic,

Do you think there's a way to modify the '94-95 condenser to accept the '91 oil cooler?

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Steve,

The 94 condenser is wider and a bit thicker than the 90-93 condenser. I am sure there would be a way to fab some small brackets which could make up for the difference in width. The oil cooler will bolt on to one side of the condenser. Not sure if oil cooler on 94-95 cars is wider or perhaps there is an adapter for the oil cooler to the condenser for those years. Not sure how that affects the shroud again given that the 94 condenser is also thicker cross section, undoubtedly to make up for lower efficiency of 134a.
I got fortunate and found a 90 condenser that held vacuum.

[WVZR-1]

Hey Dominic,

Do you think there's a way to modify the '94-95 condenser to accept the '91 oil cooler?




I believe it's more important to understand the difference in the '94+ METRIC inlet threads vs the earlier condenser.

[jss06c6]

I believe it's more important to understand the difference in the '94+ METRIC inlet threads vs the earlier condenser.
Understood. My son is a master fabricator.. I may have have a go at some mods to see if I can use the '94-95 condenser with my '91..

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[Locobob]

Bob,

The condensers from AZ and the like do not have provision for the oil cooler mounting that ZR-1s had. Those condensers are built for base C4s. I had asked Haibeck who they used for a source on condensers. Sounded like they have used Spectra condensers which are the AZ ones. I think Ecklers and CC may have ZR specific condensers but we are looking at $3-400.
The 94-5 condensers are 134a specific and won’t fit the 90-93 oil cooler.



I haven't pulled the shroud off to look yet but I would think rigging up something to attach to the oil cooler wouldn't be too hard.

[Locobob]

Alternative might be to build new oil cooler lines and install two coolers on fabricated bracket(s) in a new location?

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I was actually kicking around relocating the oil cooler to the rear of the car using an aftermarket unit. This would move some weight rearward and also free up some radiator clutter for better air flow. I was thinking it could mount to the rear crossmember and utilize under car airflow. The downsides I see to this are: a lot of extra hose to route, how that extra distance might effect pressure, managing heat from the hoses and cooler itself.

[XfireZ51]

I haven't pulled the shroud off to look yet but I would think rigging up something to attach to the oil cooler wouldn't be too hard.

Bob,

U can drill the side bars on the radiator to fit the cooler but the screw came too close for comfort to the cooling fins. And then, the cooler lines on the AZ unit were at off angle from the ones in the engine bay.

[jss06c6]

I was actually kicking around relocating the oil cooler to the rear of the car using an aftermarket unit. This would move some weight rearward and also free up some radiator clutter for better air flow. I was thinking it could mount to the rear crossmember and utilize under car airflow. The downsides I see to this are: a lot of extra hose to route, how that extra distance might effect pressure, managing heat from the hoses and cooler itself.I am looking at the real estate in the wells under the headlights to mount two high efficiency coolers.. while I've got mine "apart", I'll see what I can come up with..

Rear is an option too!

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[jss06c6]

Ok, resurrecting Dom's thread..

I've got mine pulled down. I have a stamped part number on the drivers side header flange.. 1909902BL.

Looking at both AZ and Ecklers, the condensers in the photos are a bit confusing. Both Ecklers and the AZ R-134 condenser appear to have similar inlet/outlet geometries. The AZ picture of a '90-93 condenser shows the inlet/outlet connections straight and near the center of the condenser. This would never work on my '91.

I believe Marc indicated that the R-12 condenser would work fine with an R-134 setup. If someone has the dimensions of the '94-95 condenser, that would help me decide how much Fab is needed.

I can make a set of 134 hoses if needed to mate to the 134 compressor. What I'm not sure of is, specifically how much wider is the unit. This would affect how it sits in the mounting well at the bottom of the front air intake.

Fyi, my radiator, while not leaking and no issues with cooling, appears to have been "cut" with a saw blade on the top! What the heck is this from, prior repair job?

Some photos attached.. condenser looks like a mess and likely has small leak in a tube as evidenced by the refrigerant oil covering about 1/4 of the surface area..[ATTACH][ATTACH][ATTACH][ATTACH]

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[jss06c6]

Metal shavings in the filter!!8107

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[jss06c6]

One last note regarding AC Condenser replacement. I installed the Auto Zone condenser (Spectra 7-4306). I shortened the screws, placed the oil cooler and marked the holes to be drilled. Slipped on the screw clips and installed the oil cooler.

I test fit the unit to see how much I needed to tweak the hard line connections. Not too much and aluminum is easy to bend.

This is a parallel flow condenser with the same number of tubes as the OEM that I removed. The core appears slightly shorter, but the number of tubes is the same.[ATTACH][ATTACH][ATTACH]

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