Let's discuss adding A/C to my 1st gen V8 truck that never had it to begin with..

[Uncle Gump]

When I did my V8 swap... my truck was a non A/C vehicle. I just had to cut a small corner off the heater box.

The picture of the the hole you had to open in the evap housing is substantial. Maybe even wrap the header tube to help with heat issues.

 

[Bird76Mojo]

I had cut that hole before my V8 swap and just cut it larger than necessary to make sure it would go in easily and fit. Fiberglassing them up is easy to do, no matter the size of the hole, and I already have a kit for that. I won't wrap headers, because I won't have them rusting out. Even though mine are already coated inside and out with high temp coating from a shop in Indy. The rest of my exhaust is stainless, mandrel bent tubing because I hate dealing with exhaust issues down the road.

The fiberglass, self-adhesive reflective mat I already have works extremely well. I figured it would peel away easily if the adhesive softened up, but it's been flawless so far. I'm not worried about heat affecting the plenum. The headers aren't very close to it anyway. I'll just use the reflective mat I have already and call it a day.

It's actually a good thing I cut that hole so large, because it requires a hole that large to slide everything in to place. I placed my engine as far back as possible for better weight distribution, and this is the end result of that.

My heater-only plenum isn't butchered that badly. It required far less cutting.

 

[Uncle Gump]

My experience with headers on a daily driver is that there are two kinds...

One that is rotted out and the other is one that's about to rot out.

Edit... Maybe it's just the picture but it looks like the header tube is about on the box.

 

[Bird76Mojo]

Mine has been driven nearly every day for over two years (in everything but snow as I won't drive it on salted roads) with no rust on the headers at all. A $150 paint job on the headers, I expect they better not rust too quickly.

The header does look close, but it's not that close. The reflective fiberglass mat I have should do ok. Time will tell. The fiberglass will do much better near the heat than the plastic part of the box would, and the glass will overlap the plastic a bit.

I should probably use a remote mount accumulator to make changing plugs and other maintenance easier, but the factory unit looks like it will fit fine, and it's cheap. (I'm mocking up with all used parts)

 

[Bird76Mojo]

Ron Francis has some really good customer service in my opinion. I called them a few minutes ago to ask about their MG-70 harness in my truck, and how to go about letting the A9P Mustang ECM know that the A/C had been turned on. The ECM increases the idle speed whenever the A/C is kicked on from what I've read. But in the MG-70 instructions, they only mention the following:

"NOTE: The short orange and pink wires with the gray connector running out of the computer connector is for the wide open throttle air conditioning compressor clutch disengagement connection. This is not used in an aftermarket application."

The tech wasn't 100% sure on how this was supposed to be wired in, but he assumed the same thing as I have. That these two wires are hooked up in series to a ground for the A/C clutch relay. When the ECM knows you've gone WOT it then opens this circuit, removing the ground from the relay which deactivates the A/C compressor clutch.

He mentioned that they expect the IAC valve to control idle speed when it senses the load from the A/C clutch being activated, but I told him that Ford designed a circuit in the A9P ECM to increase the idle speed when the A/C clutch was activated for a reason. Ford obviously didn't want to rely on the IAC only.

He said he'd have to do some testing on one of their harnesses and ECU's and get back to me. He took my name and phone number.

 

[Bird76Mojo]

Got my compressor bracket finish welded, trimmed down for clearances and appearance, cleaned up and primed/painted yesterday.

Today I got a couple of these fittings ground down to add more clearance, and I plan to have the local machine shop TIG them on to my compressor manifold block. Things will still be EXTREMELY tight behind the compressor. I may have to find a way to grind down or cut off the forward edge of my engine plates without removing the engine. About 1/8" to 1/4" would make a world of difference. The steering components being in the way make getting to it to trim or cut a nightmare.

After having the machine shop TIG the fittings and checking for fitment, I need to pull the truck over to my shed and cut off the lower radiator mounts again, modify them, and re-weld them back in the truck. I may make entire new brackets that still use the factory lower radiator mounting rubber bushings. I can make nicer looking and stronger brackets than the OEM ones..

The A/C plenum is fiberglassed up, painted, and fits in to place with the evaporator installed, but just barely. Once slid past the SN95 valve covers there is plenty of room though.

I made some better bushings today to space the compressor away from my flat plate bracket, so the body of it didn't hit the plate.. I was using 5/8" nuts as temporary spacers for mock-up.

No pics for now, but progress just the same.

 

[Bird76Mojo]

@Uncle Gump have you abandoned me? lol

 

[Uncle Gump]

Nope... still around.

What happened to silver soldering the 90's to the manifold block?

I think I already expressed the use of fittings as you're doing now as a better way to go... at least in my humble opinion.

 

[Bird76Mojo]

I did some thinking on it and even though I'm sure I could silver solder those 90's with the hoses already crimped, I'd have to do it all over again if I ever damaged a hose. Plus I was concerned with the hose crimps longevity after soldering it. Even if I kept the heat out of the crimped portion of the connector, it may end up reducing the reliability of the crimp and giving me trouble in the future, and I want this system to be "one and done" for as long as the truck is alive. I've invested so much time in it now..

So I thought I'd try these MIO fittings and low profile 90 degree fittings instead. I think I can make them fit in the extremely tight area I'm working with, but it will still be very tight. I had a new idea last night to give myself some more room. I plan to remove about a 1/16" to an 1/8" off of one part of the face on the manifold block, which after the (shortened by me) MIO fitting is TIG'd on, will create more clearance for me.

Just to kill some time, I ran some tests using some scrap steel and the silver solder I already had on hand. I was happy with it's strength as far as trying to twist the soldered joint apart, but when I tapped it from the side, the joint was a little too weak for my liking. So I went and priced some 15% silver brazing rod and a smaller amount of 15% silver solder, as either of these would produce a very strong joint. Stronger than a traditional weld in some cases. Both were too expensive for my taste. So I plan to have the local machine shop TIG them for me. It'll probably be around $20 in labor. Again, budgetary issues rule the roost here. I just hate to have someone else do it for me because I like to do 100% of my own work when I can. I just can't afford a TIG machine right now. I will have one in the near future though.

 

[Uncle Gump]

I honestly think those fittings are the right choice...

Now for removing material from the face of the manifold block... What if you counter bored the inlet and outlet holes in the manifold to recess the fitting down into the manifold before tig welding them on... allowing enough room that the line fitting would thread on fully and seal? Would that gain you the clearance you were hoping to achieve?

 

[Bird76Mojo]

That would require turning down the MIO fittings on a lathe, and also counter-boring the manifold block. Which would be expensive at the machine shop. The same thing can be accomplished by removing material from the bottom (hex end) of the MIO fittings (which I've already done) and then removing a little material from the manifold block on one face. Not the entire face though. Just one end, of one face. It's plenty thick enough to have some material removed. Plus it's a modification that I can do at home for free.

 

[Uncle Gump]

I was kinda thinking a small end mill in a drill press and boring it to the OD of the hex... kinda redneck machine shop stuff.

Moot point being you put a grinder to the fittings.

Have you took into consideration any engine movement (that will surely be there) that is allowed by the motor mounts? Or are you solid engine mounts?

 

[Bird76Mojo]

If I bored a hole that was equal to the OD of the hex, it would be larger than the manifold block's width. A guy would have to turn down the hex portion of the fittings.

As for grinding on the fittings, I only removed half the thickness of the hex. Just to gain that tiny bit of additional room fore/aft..

I've thought about engine movement and so far I don't have any concerns about movement. That's kind of why I'm fighting for as much clearance as I can get between the back of the compressor/manifold block and the engine mount plate. I'd like to shorten up the front of the engine mount plate because it sticks out farther than necessary, but as of right now I'm not sure I can even get a cutting or grinding tool in there. I should have trimmed down the front of that plate before installing the engine, but at that time I didn't think I'd ever be able to add A/C so it wasn't a concern.



On the not so bright side, I caught this big boy today, but the metal (snap type) stringer I put him on, he managed to unclip and get away. I'm still pissed about it. I've been trying like hell to add more fish to the freezer this summer, and I'm limited on the number of good fishing holes I have available to me.

Just shy of 3.5lbs

 

[Bird76Mojo]

I removed 1/16" from the manifold block on the suction end, to make the fitting lay closer to the body of the compressor, and dropped off the fittings/block to be TIG welded at the local machine shop.

Hopefully he'll have it done by tomorrow around 3 or 4pm. He told me around $20 would cover it.

Pics incoming..

 

[Uncle Gump]

Nice fish BTW... He will be catchable again soon.

With the evap housing in place... compressor bracket done... condenser hung and the manifold back tomorrow... it's about time to make some lines. You're about make a cool breeze. You have the controls in and wired?