[FrankieT/A]

Originally Posted by gillyiowa

Frankie Ta,is the bolt that holds the manifold to the compressor anything special? What size is it?

It's usually metric

[tharkun8]

Frank,

It just so happens that there was an 81 Grand prix with a 301 in the local u pull it.
(dang that 301 looks like a toy engine)

I just took a look at it and there was nothing attached to the pass side
head.. on the driver side there was a pump attached to the P/S Pump just
above it but on the back I read AS... presuming thats a smog pump or something
and not the AC compressor.. correct ?

thanks
John

EDIT - Actually now that i looked it up .. in 81 the 301 wasnt offered. so it
was prob the Buick v6 that year. Makes sense.. never saw a pontiac with
the Dist in the front.. didnt think the 301 did but dont know much about it.
Glad i didnt waste time or money buying anything off of it.
The hunt for 301 A/C brackets goes on....

[tharkun8]

Hey Frank..

tried to send you a PM but your mailbox is full..

Think i found the 301 AC brackets.. will the ones in
this thread work ? They look like they will but I want
to be sure before I buy em..

http://forums.maxperformanceinc.com/...d.php?t=740942

thanks

John

[Ollie]

Also, inquire at 301garage.com
Someone there might have some.

[tharkun8]

Originally Posted by Ollie

Also, inquire at 301garage.com
Someone there might have some.

thanks.. I did try that.. Ive had a WTB ad over there for a few months
now and as far as i can tell no ones ever even looked at it.

I located what i need.. now its just down to the price...

John

[tharkun8]

Frank..

Ok so I found a set of the 301 brackets .. and I re-examined the pics of your setup in
the first few posts.. but I would just like to make sure i get it all straight.. I studied
your setup as well as the diagrams in the 66 AC service manual to get a better idea
of how the old setup and presumably your new setup works...

so..

Starting at the compressor on your R4 setup.. it looks like the flow is as follows..

1. Lower A/C compressor connection to top of condenser using hose with lined rubber.( presume this is the high pressure side )

2. From lower condenser connection ( still pressure) - hard line to lower connection of AC box/ Evaporater ( pressure release point) .

3. From Upper AC Box / evaporater connection (low press) to top middle connection of dryer/accumulator using long smooth rubber hose(clean and dry-low press)

4. Bottom connection of dryer/accumulator (low press) back to compressor upper connection using short smooth rubber hose.


I think that that is correct - but I still have a few questions..

1. what is the electrical connection on the upper right connection of the Accumulator ?

2. For the hard line from the condenser to the lower AC box.. was that off the shelf or fab'd up ( size of line/connections) ?

3. For the flex hoses.. same question -- custom or off the shelf ?

4. Do both evaporater connections connect directly to the evaporater or is there a expansion valve of some kind
on the lower connection ? ( where the pressure is presumably released ?)


Thanks a lot for your time. I'm actually enjoying trying to figure this out.
The compressor and dryer/accumulator look like easy off the shelf components..
I just have to get the dimensions of my old evap so I can find a newer replacement
that fits in the same spot in my AC box.. ( likely looks like a c-10 evap at this point)


John

[Ollie]

1. The electrical plug is the pressure switch that starts and stops the compressor.
The compressor does not run all the time. The pressure builds up to the high limit
then the compressor shuts off until the pressure drops to the low setting.

2. The hard lines are off the shelf.

3. The flex hoses can be replace by any local Automotive AC shop. The hoses
should be replaced with modern barrier hose. The metal fittings can be reused, as
long as they are not damaged.

[tharkun8]

Originally Posted by Ollie

1. The electrical plug is the pressure switch that starts and stops the compressor.
The compressor does not run all the time. The pressure builds up to the high limit
then the compressor shuts off until the pressure drops to the low setting.

Thanks

So I take it that is a separate sensor that has to be purchased.. does that sensor
only connect to the R4 with a 12v source coming off of the comp ? how does it hook up ?

Thanks
John

[tharkun8]

So Im looking at new R4 compressors at Summit..

they show 2 from 4 Seasons cooling.. 58221 and 58231..
Summit didnt list the difference but from looking at the 4 Seasons site
it looks like there is a switch Difference..

58221 is listed as Non-switched
58231 is listed as High Pressure switch ?

the setup in the first post shows a cycling switch attached to the
accummulator.. so does that mean the comp I need would be non-switched ?
or do I need the switched that would then plug into the accumulator ?

Thanks

John

[Ollie]

The early AC systems such as your 64 Bville were Non-switched,
I don't know the exact year of the change over. Photo 2 in post 1 is a
switched accumulator. The plug on the right is the pressure switch that engages and dis-engages the compressor clutch.
It is my understanding the early systems can be converted.

[FrankieT/A]

The switch located in the compressor is called a super heat switch. It turns off the compressor off in case head pressure rises above acceptable levels. The switch that cycles the compressor in the later models is called a low pressure switch. When the evaporator gets too cold the low side pressure drops and causes the compressor to turn off so the evaporator doesn't freeze. Real late models have a low pressure switch, a high pressure switch, a wide open throttle switch(usually controlled by the vehicle computer) and a switch located in the high pressure power steering hose(it cuts compressor for parking lot maneuvers). If the compressor has the switch or not will not effect the function of the compressor. If your wiring does not have provisions for the super heat switch then it just wouldn't be hooked up. If you don't have the wiring for it then just get the compressor without the switch for a cleaner looking install.

[tharkun8]

Frank..
thanks for the explanation of the comps..
Im going to be redoing my elec harnesses so I could prob add
all that switch stuff if I wanted to.. I only recall 1 wire connecting
to the actual compressor but ill figure out all the wiring when
I get there.. so now all thats left is looking at evaps until i find
one that fits snug in the AC box.


Ollie thanks for your input as well.. my 64 Bonn has no AC so
this setup is for my 66 sedan..

[FrankieT/A]

The only switch you really need or should I say would be useful is the low pressure switch and that you just wire in series with the compressor. The LPS attaches to the accumulator.

[tharkun8]

I did want that low pressure switch... was
going to see if it came with the R4 when i bought
it or if i was going to have to get it separately.

also frank.. when you can if you can post a pic of the
rear side of the compressor to show how that is mounted
that would help as well.

Thanks

John

[FrankieT/A]

The LPS does not come with any compressor. The pig tail is part of the vehicles wiring harness. I just picked one up from the junkyard(switch and pigtail). It comes out of any late seventies or eighties GM car. Again just wired in series with compressor power wire.

[Ollie]

Originally Posted by tharkun8

also frank.. when you can if you can post a pic of the
rear side of the compressor to show how that is mounted
that would help as well.

Thanks

John

This link shows photos of the back side of the R4 compressor page 3 post 56.
http://forums.maxperformanceinc.com/...=690512&page=3