Adding AC

[bluebanshee]

Couldn't find much about adding AC on trucks or old Mopar in general. Ordered the Old Air CAP-300 under dash complete kit which should be shipping this week. 

 

I'll be switching out my 12 volt generator with a 140 amp alternator. This will future proof if I need to add an electric fan later. Since my L6 did not come with a fan shroud I do not know if I will have the air flow through the condenser. It sure does have some pull on the front of the rad (55-59 K series 3 row). I'll try one of the universal fan shrouds before I go electric. I did request the trinary switch just in case I want to do a relay driven pusher fan later.

 

I have a two groove alt pulley if I need to drive the compressor off the alt.

When it gets into the upper 80s it simply isn't enjoyable to drive this truck, looking to change that. 

 

Edited July 28, 2021 by bluebanshee
Ingo

[bkahler]

I'm looking forward to updates on your progress.  Here in Richmond Kentucky driving a non airconditioned vehicle is just miserable in the summer.  

 

A couple of questions:

 

Do you have a double groove crank pulley?  

 

How and where are you going to mount the compressor?

 

Brad

 

[bluebanshee]

Brad, I have a single groove crank pulley. I may drive the compressor off the 2nd grove on the alternator pulley. I don't see why this would be an issue. It would also allow me to cut/remove the AC belt if I had a pump issue on the road. I plan to mount the compressor directly above the current generator position. I did see another member on here did something similar.

 

I'll have to figure out what to do with the ammeter and plan to re-wire a bit.

[kencombs]

33 minutes ago, bluebanshee said:

Brad, I have a single groove crank pulley. I may drive the compressor off the 2nd grove on the alternator pulley. I don't see why this would be an issue. It would also allow me to cut/remove the AC belt if I had a pump issue on the road. I plan to mount the compressor directly above the current generator position. I did see another member on here did something similar.

 

I'll have to figure out what to do with the ammeter and plan to re-wire a bit.

I'd like AC on my '56 pickup also.  Seems two groove crank pulleys are sort of rare things, and the front motor mount would make routing a second belt difficult.  So, I was considering a similar method but came to the conclusion that Driving the compressor from the alternator may not work.  The alternator pulley is so small with little belt contact area that driving the compressor may not work.  So, when I get to that point I think I'll put the compressor down low, driven directly by the crank pulley.  The alternator will be above the compressor and driven from the second sheave of its pulley.

Edited July 28, 2021 by kencombs

[bluebanshee]

Yeah, I will not know until I have the parts in hand to see how they fit. The alternator and AC compressor will require 3-4hp to run at full output so it should not take too much. With a small belt on the alts 2nd grove you'd have about 2/3 contact. 

 

Not much room with the engine mount for a belt.

[kencombs]

18 minutes ago, bluebanshee said:

Yeah, I will not know until I have the parts in hand to see how they fit. The alternator and AC compressor will require 3-4hp to run at full output so it should not take too much. With a small belt on the alts 2nd grove you'd have about 2/3 contact. 

 

Not much room with the engine mount for a belt.

 

My concern is that 2/3 contact on a 2-2.5" pulley is very few square inches of area compared to the contact of a 6" or  so crank and compressor pulley. I know from experience with electric motors on compressors that a 2-3HP motor with a small pulley will slip under load.  That's why most small compressors now use a multi-rib belt.   that is what I'd really like, a modern serpentine single belt running everything.  But, I'm not up to designing one of those right now.  too time consuming to layout, mock up, build brackets and search out parts.

[bluebanshee]

59 minutes ago, kencombs said:

 

My concern is that 2/3 contact on a 2-2.5" pulley is very few square inches of area compared to the contact of a 6" or  so crank and compressor pulley. I know from experience with electric motors on compressors that a 2-3HP motor with a small pulley will slip under load.  That's why most small compressors now use a multi-rib belt.   that is what I'd really like, a modern serpentine single belt running everything.  But, I'm not up to designing one of those right now.  too time consuming to layout, mock up, build brackets and search out parts.

I couldn't find the post where someone mounted the compressor to run off the alternator. It will be my second choice if all else fails, only cost to try it is time and possibly a belt. I did see where someone on here tried it off their modified water pump with two groves and it did slip.

[bluebanshee]

Got the kit today and figuring out how I'll be mounting it. I have the universal mounts for the compressor that I could weld to to the lower generator bracket. This would give me the ability to tension the main belt with the single mounting point and not using the bar off the water pump. I will still need to make some plates or something for the small ~22" belt from the compressor inner groove to the alternator.

 

Hose kit is uncrimped on one end.

 

It will be very similar to this post:

 

 

 

[bluebanshee]

Comp bracket is done. Have to make a tab to hold the alternator. It will utilize the 4 ears on the compressor and stock adjustment bar for tension. 

[bluebanshee]

Brackets are done, just need correctly bolted up. 

 

Condenser brackets and wiring are next.

[kencombs]

Nice looking work.   How were the brackets cut, water jet, plasma or ?  they really look like clean cuts.  Mine will be flame, bandsaw or abrasive I'm afraid.

[bluebanshee]

I got universal brackets for the compressor but the alternator brackets are from stainless plate I had cut with a wafer wheel. It's not perfect because I eye balled most of it and didn't have a marker lol.

[bluebanshee]

Hoses are done and partial vacuum applied. Still have all the related wiring to do plus for the alternator. If no leaks I may get it charged up tomorrow.

[Lingle]

keep up the work!  I'm contemplating a vintage air system myself, I was unaware of the company you are using until now.  Did Old Air help spec the system for you(compressor size, condenser size, etc.) or was it a pre-matched kit offered?

 

[bluebanshee]

Just now, Lingle said:

keep up the work!  I'm contemplating a vintage air system myself, I was unaware of the company you are using until now.  Did Old Air help spec the system for you(compressor size, condenser size, etc.) or was it a pre-matched kit offered?

 

I didn't contact them but that's the generic universal kit that came up on their site. 

 

You can pick which compressor and condenser size you want. I got a trinary pressure switch if I need to add an electric fan later. I think the condenser is 21 wide by 16 tall and fits pretty well. 

 

Evap, condenser and pump all came either under vacuum or pressure, I couldn't tell. Overall kit seems good but did buy a $150 crimper for the lines and the ends are not complete.

[bluebanshee]

Have cold air blowing but alt isn't charging. Need to try a power wire to see if it excites.

 

Need to clean up wiring, add support bracket to the blower and the drain lines. Seems to blow pretty cold. I don't think electric fans are needed. I didn't get over 200psi sitting idle in the garage for 20 mins. 

 

At 900rpm idle it will drop to about 650-700 RPM when pump kicks on.

 

I do like a higher idle that spec's to help on all the hills here. 

Edited August 10, 2021 by bluebanshee

[bluebanshee]

Replaced my 12si with a local 10si one wire for $52 +$33 core charge so I got to take it for a test run. As a side note I have 14.5v at idle without having to rev at all to excite the alternator. Lights don't dim a bit at idle when fan is kicked on high. 

 

Low 70s sitting idle in the garage for 20 minutes the AC comes out at 50. 30mph 1/4 mile loop the air coming out was in the low 40s. Won't know til it gets 85+ how things work.

 

Temp gauge was near the upper end of normal. The needle was parallel with the right side of the A in HEAT. head temp was about 185 via IR temp gun. This is a bit hotter than it normally runs but my rad was about 3" low too. I'll do a Dawn soap flush and add some water wetter and see if there is an improvement.

 

Still need to add the drain tube on the evap. It produces a significant amount of water.

Edited August 11, 2021 by bluebanshee

[bluebanshee]

90 out today and on the highway temp gauge is in the middle and the air coming out of the evap is mid 40s. Ended up ordering a 16 electric fan which will be on both a pressure switch and toggle via a relay. 

 

Added 5/16 closed cell insulation to the floor and ceiling so that should help a good bit. Might not freeze you out like a new car but is nice and comfortable when it's 90 out.

[bluebanshee]

Added 16" fan on manual and AC high pressure switch off its own relay. I consider the AC project done. It will now hold 44F idling in the garage at 70 ambient.

 

Water pump is seeping so that's a project for Thursday.