I'm getting ready to install a new AC Compressor on my 77' and I don't know if I should go with a rebuilt VIR from a vendor. Or go with a VIR eliminator kit. Are they easy install, is it plug and play.

 

I also have a 77. Others have used the VIR eliminator successfully. I found it to be a bundle of snakes and finally replaced the entire HVAC system with one from Vintage Air (there is no kit, and I made my own - see my write up on CF. If you are going this way, PM me - there is much new info and it is now much easier)

 

Bump

 

I guess you are aware that the 1977's had two different types of A/C systems...one was the VIR and the later system is CCOT. Which is what is used from then on.

SO...I have installed the VIR Eliminator and it was not that bad BUT I did have to evaporator core case housing off the firewall due to replacing the evaporator core and that allowed me to get the VIR eliminator fitted up really well and secured in a manner that I liked.

I know that doing it with the evaporator core case still in place can be a bit of fun and can test your patience. HECK...replacing the VIR will do the same thing..it is a tight spot with very little ability of movement.

DUB

 

Are you sure it has the VIR system. My 77 is the late 77 and has the CCOT as Dub stated.

 

The system will cool better in varying conditions with the VIR in place.

Neal

 

Yep, the early 77's had a VIR system

 

I do not know about this statement being entirely correct.

I know the 1974 that I installed the VIR Eliminator...the owner can drive in the hottest summer days here in the Charlotte area and can sell ice cream out of his car....HIS WORDS..NOT MINE.

If anyone doubts me on this...PM him. http://www.corvetteforum.com/forums/...ettejimcr.html

DUB

 

The CCOT system has a fixed orifice which will not compensate for varing compressor speeds, idle to cruise. The EEVIR has a TXV and POA that will maintain correct coil pressure for most all conditions producing better temps in different conditions.

Neal

 

I have had the same experience as well with my ccot system. It runs very cold, never an issue with heat. Is the vir eliminated system a ccot conversion?
Other cars that I have had with an expansion valve type system do not run as cold. All of my Fords use ccot and all run really cold as well. I think it is related to the office size used. Use the right size and it works really well.

 

I can not dispute this...and will talk with the guy I know in the next few days so I can better educate myself on this.

I am ...by NO MEANS an expert on A/C systems...but I have been around the guy I know who is and I pay attention to what he says and other guys I know that can get an a A/C system to throw ice cubes at you.

I do know from the earlier systems that a sticking valve/switch or whatever can cause for the system to not work correctly. I have had to deal with that on some customers cars.

Also I was told that the sensing tube that gets sealed up with the black sealant tape on the top pipe of the evaporator core can be put in a different areas and get the system to respond differently. I know the guy I use wants me to leave that alone so he can put it where he needs it to go ....and then I let him apply the thick back tape on it.

I know using different colored orifice tubes can change the aspects of the system. Blue, white, black..do different things...or at least those are the three colors I remember seeing them use.

I also know the amount of air begin pulled across the condenser is important because I have seen the HIGH side pressures (on the gauges) INCREASE like crazy when one of the two electric cooling fans was not used....while sitting still at idle.

All I know is what I have seen and felt...and that is the CCOT systems seem to perform better....and that seems to be the system of choice now-a-days.

I know just enough to be dangerous....which is why I leave it up to him.

DUB

 

They now make a variable orifice to replace the fixed orifice that are used,

I haven't tried one but plan to soon,

Like you mentioned care had to be taken when servicing systems with TXV's as they were prone to issues if not kept very clean. The automotive industry moved to the CCOT system as there are fewer problems and less cost for a system that will perform acceptable in most situations but you do give up some cooling efficiency in certain conditions.

Chrysler kept the TXV around longer than most but had many issues as they used steel line sets that would eventually rust internal and plug the TXV inlet causing havoc. Once serviced incorrectly air would be allowed in the system and soon to follow the mixture of freon, oil and moisture would turn acidic and attack the steel line sets.

With the use of more efficient condensers and a more efficient refrigerant (r134a) the new systems in service today do a really good job.

I am no expert on AC systems for sure,

Neal