Any stock AC experts?

[JohnC]

I am gathering parts for my 67 and part of the plan is to use the stock AC.

Is it still best to plan for 134a conversion? I know you can get R12 but it’s pricy and dont want to limit myself in the future should it
become more unavailable.

I’ve heard that one should get the biggest parallel flow condenser available. Asking on the OCS there were many recommendations on this. I suspect the physical limitations of size is the opening in the core support and the recess in front of the core support that the condenser sits in. I’ll have to measure those when I get home from work but with the car completely blown apart I don’t want to buy a big condenser and later on find out it interferes with a bracket or do-hickey and now it’s too late to return it.

Anyone who has a 67 with factory air, can you measure approximately how much wider and taller one could go with the condenser? This might be something I put on the back burner until the car is more put together. I know Orignal Air has a condenser that fits without
Modification but not sure how much of an upgrade it is size wise.

Likewise I’m going to hold off on a compressor but I think I saved my A6 unit. Is there any reason to keep this thing? I’m not going for a nut and bolt restoration.

 

[kmakar]

I asked the same questions regarding my 67 (haven't even started the car yet), but the biggest recommendation I was given was the condenser must be flat tube to work well with 134a.

The reasoning I was told behind it was 134a doesn't cool the same way as 12 and needed more exposure on the condenser to drop the temp. Made sense to me. That's all I can offer.

 

[1971Chevelle]

If you are going to convert to R134a, you better stock up on it now. They are already making noises about phasing it out.

 

[Nashville Cat]

If you are going to convert to R134a, you better stock up on it now. They are already making noises about phasing it out.

Wow, thanks for the tip. I have two vintage air units to install

 

[Nashville Cat]

Check Facebook Marketplace for refrigerant. There are good deals on there.

 

[Chevelle_Nut]

Classic Auto Air in Tampa can convert the POA from R12 to R134A, they do great work.

 

[JohnC]

Does anyone know what the next flavor of the month refrigerant will be?
How much 134 is needed? I have about 5-6 of the little cans somewhere in the garage.

Just a quick search shows Horrible Fright to have 12 oz cans for about $7. Might be time to stock up before the price gouging starts.

 

[1971Chevelle]

Does anyone know what the next flavor of the month refrigerant will be?
How much 134 is needed? I have about 5-6 of the little cans somewhere in the garage.

Just a quick search shows Horrible Fright to have 12 oz cans for about $7. Might be time to stock up before the price gouging starts.

My understanding is that it takes about 80% of the R12 amount when you switch to R134a. However, you should just charge it with gauges hooked up, then you will know when
you are at the correct fill. As far as buying, go to Walmart - it is like $5 or $6 per can. I will be purchasing a 30 pound can from a local parts store, as they had them for $105 (may
have gone up some since I was in there last).

 

[Robinls5]

I have two 70s with factory A/C. My driver is a 70 Wgn ( it a fake / Fraud SS with a 468) I did a 100% conversion to R-134. As of today I get 39--42 degrees out of the center vent. I like to play with factory A/C. First item,, REPLACE the evaporator unit, ( it is full of dirt & junk from 50 some years of service, you lose about 30/40 % airflow with your old unit) TWO.. send your POA valve to an A/C shop and have it set for R-134. ( I used Florida) Three,. Buy ALL new hoses ( R-134 molecules are smaller and will bleed through R-12 hoses) Four.. Get a new dryer that is R-134 compatible. Five.. Get the biggest P. Flow that will fit, Keep it about an inch or two away from the Rad. SIX.. I was using the old style A-6 compressor, AND I would charge it every year. ( R-134 will leak out of the A-6 front seal ) So I went to a 10 cyl DIRECT REPLACEMENT of the A/6, The Florida replacement uses ALL the FACTORY brackets, its a direct bolt on. It a new style designed ( all ALUM. ) for R-134. A 1970 Harrison system holds 60 oz. of R-12...... I charged mine with 48 oz of R-134 ...... NO more and NO less, I tried 46/47 oz. not good.... I tried 49 & 50 oz. of R134 no good. my one owner 70 A/C is 100% org. with R-12. This is fact not fiction..... A G.M. Harrision unit with R-12 is the best unit ever built. NO AFTERMARKET A/C unit will ever come close to a G.M. unit. So do your homework. Trivia: The florida place has a direct replacement P. Flow condenser fo 70-72 Chevelles. I helped the fla. guys get this one done. If I can help just ask.
P.S. I forgot to mention, use 80% rule for the correct charge. Also R-134 runs much hotter than R-12 .. SO you need more SURFACE AREA to cool it down. HERE is a big " IF " you can use your stock Tube & Fin condenser, ( I have done this) The " BUT " is...... If you can maintain 35 or 40 M.P.H. the tube & fin condenser is fine,, BUT when you slow down or are in traffic, Guess what,, You will get hot air???? like I said R-134 runs hotter so you need WAY MORE surface area to cool it down. Dont even ask how I know some of this stuff, A lot of trial and a hell of a lot of errors.
If I can help just ask.................... Bob
P.S. Being KOOL is expensive, You need around $1300.00 to do this correct.

 

[Alan F]

I have two 70s with factory A/C. My driver is a 70 Wgn ( it a fake / Fraud SS with a 468) I did a 100% conversion to R-134. As of today I get 39--42 degrees out of the center vent. I like to play with factory A/C. First item,, REPLACE the evaporator unit, ( it is full of dirt & junk from 50 some years of service, you lose about 30/40 % airflow with your old unit) TWO.. send your POA valve to an A/C shop and have it set for R-134. ( I used Florida) Three,. Buy ALL new hoses ( R-134 molecules are smaller and will bleed through R-12 hoses) Four.. Get a new dryer that is R-134 compatible. Five.. Get the biggest P. Flow that will fit, Keep it about an inch or two away from the Rad. SIX.. I was using the old style A-6 compressor, AND I would charge it every year. ( R-134 will leak out of the A-6 front seal ) So I went to a 10 cyl DIRECT REPLACEMENT of the A/6, The Florida replacement uses ALL the FACTORY brackets, its a direct bolt on. It a new style designed ( all ALUM. ) for R-134. A 1970 Harrison system holds 60 oz. of R-12...... I charged mine with 48 oz of R-134 ...... NO more and NO less, I tried 46/47 oz. not good.... I tried 49 & 50 oz. of R134 no good. my one owner 70 A/C is 100% org. with R-12. This is fact not fiction..... A G.M. Harrision unit with R-12 is the best unit ever built. NO AFTERMARKET A/C unit will ever come close to a G.M. unit. So do your homework. Trivia: The florida place has a direct replacement P. Flow condenser fo 70-72 Chevelles. I helped the fla. guys get this one done. If I can help just ask.
P.S. I forgot to mention, use 80% rule for the correct charge. Also R-134 runs much hotter than R-12 .. SO you need more SURFACE AREA to cool it down. HERE is a big " IF " you can use your stock Tube & Fin condenser, ( I have done this) The " BUT " is...... If you can maintain 35 or 40 M.P.H. the tube & fin condenser is fine,, BUT when you slow down or are in traffic, Guess what,, You will get hot air???? like I said R-134 runs hotter so you need WAY MORE surface area to cool it down. Dont even ask how I know some of this stuff, A lot of trial and a hell of a lot of errors.
If I can help just ask.................... Bob
P.S. Being KOOL is expensive, You need around $1300.00 to do this correct.

Welcome Bob.

 

[JohnC]

Thanks for the write up. By your spelling of the word “Kool” I feel like your contributions on the other site convinced me that the factory set up was the best. Thanks for sharing your knowledge with us.