SBF V-Belt to Serpentine Drive Swap - Questions

Gentlemen,

I'm contemplating swapping in a serpentine belt drive system on my 1984 302, and this has brought up some questions in my mind that I need to sort out before I even think about doing it. I dropped by the junkyard this morning and found two Bricknose trucks with 302's and complete serpentine systems still intact. So, I know this would necessitate changing out the water pump and timing cover, and I'm OK with that. It would probably be a good opportunity to do a 3G alternator swap. Since the water pump is reverse rotation, I guess that means I'd also have to get the radiator fan and thermal clutch as well? What about the AC compressor...can I buy/order a Bricknose era AC compressor and install it with the 1986 AC lines and everything I have set aside now? I assume I could simply delete the smog pump and use a shorter serpentine belt? Would I want to grab the alternator wiring harness and connections from this truck, or should I buy new (if available).

The back story here is that I'm thinking about aftermarket EFI, and that got me thinking that maybe my original 40amp alternator would have to go...which got me thinking of doing a serpentine swap...lol, so I'm just trying to make sense of it all. They are all topics that I have largely ignored, so I'm as green as grass on all of the above.

I'll start a separate thread on the potential EFI swap as I feel that is an entirely different topic and is independent of the serpentine swap.

None of the AC lines will connect from Bull to Brick. If you are seriously considering the update, the underhood HVAC case openings and attachment points did not change from 1980-1996/7 so a later underhood portion will fit, vacuum line routing and wiring is different in that the wiring is moved to the top of the housing next to the blower. 1994 up trucks had R134a as a factory charge, if you can get an entire AC system from one of those, everything will fit, but the condenser mountings will have to be adapted.

I can give you more information as needed. The inside duct work on the firewall will also swap and eliminate the plastic "hinge" in favor of a pivoted door. Vacuum functions are the same.

85lebaront2 wrote

None of the AC lines will connect from Bull to Brick. If you are seriously considering the update, the underhood HVAC case openings and attachment points did not change from 1980-1996/7 so a later underhood portion will fit, vacuum line routing and wiring is different in that the wiring is moved to the top of the housing next to the blower. 1994 up trucks had R134a as a factory charge, if you can get an entire AC system from one of those, everything will fit, but the condenser mountings will have to be adapted.

I can give you more information as needed. The inside duct work on the firewall will also swap and eliminate the plastic "hinge" in favor of a pivoted door. Vacuum functions are the same.

Thank you sir. These issues may very well put the brakes on this idea...we will see. Finding an 80-96 truck around here with AC is not easy. Of the 10 or so trucks I looked at this morning, only 2 had AC, and both were Bricknose trucks, an 88 and a 90 (I think). I don't know how easy it would be to remove the necessary parts from these trucks, and I already have all of the Bullnose stuff purchased already (last year).

If you go forward I have a fan and clutch from my '89 302 that you can have for cost of shipping  and the fan is already painted up pretty, lol.

It is no harder than removing it from your truck, all the attaching points are the same. If you get the inside distribution housing you will have all the improvements.

85lebaront2 wrote

It is no harder than removing it from your truck, all the attaching points are the same. If you get the inside distribution housing you will have all the improvements.

The same attachment points, yes...I get that part, it's just that it's much harder to work on trucks at the junkyard as many of them are parked too close together, and access is not always the best on both sides...and then everything is rusted into oblivion...

However...

So if I got the outside AC housing (I mean the whole section on the engine side of the firewall) from a 1988 or 1990 truck, would it bolt up and work with my 1980-1986 internal parts (inside the cab)?

I'm going out to get a better look at these trucks this morning, and was just curious if I did want to swap over to that serpentine system, and thus swap in the serpentine drive AC compressor, could I then use some of the engine side AC housing to work with it?

I'll keep my eyes open for a later system, but so far this is all I have access to.

Oh, and what year trucks would have a 3G alternator? I'd need a harness to go with one I assume. I'll check those today as well.

I put a 1990 A/C system in Big Blue, but used the '85 system in the cab.  And it bolted right in with a minor exception - the vacuum lines run slightly differently in the two systems, but that's an easy fix.  And you use the later blower motor.

You can read about it in Big Blue's Transformation thread starting about here.

Ok, next question...

I assume the answer is yes, but can you have custom AC lines made up?

What if I went with a system like this one below with the "Sanden style" AC compressor, could I have lines made up to work with the 1986 evaporator and condenser?

https://www.cvfracing.com/ford-289-302-351w-serpentine-conversion-kit-alternator-power-steering-a-c/

The "1 wire Ford alternator", I assume is a 3G?

I know the system is expensive, but it would kill a few birds with one stone, and allow me to keep my stock rotation water pump.

Thoughts, good or bad?

Yes, Murray used to sell hoses and fittings to make them up. Some shops that do hydraulic work can make custom hoses. Another source a friend used on his custom 1956 Dodge truck was: https://www.vintageair.com/ They make some very nice pieces. He used a heater/AC combination unit that we put where the glove box would have gone. Door was left for appearance and access for servicing, Had floor, defrost, and AC vents. No fresh air provision.

Lines were sold as a measure of diameter and length and there were lots of fitting options. We used a penetration plate where the lines screwed on on each side so there was no chance of chaffing.

You have to change the water pump, but not the timing cover. Fan and clutch need to be from reverse rotation vehicle as well.

I used all of the left side components from a bricknose when I converted my '81 to serpentine, including the a/c compressor and hoses. The fuel pump is a tight fit, and I had to relieve the p/s bracket a bit to clear it. If you have electric fuel pump this isn't a worry. My 3G alternator bracket is from my '94 roller donor. Everything plays well together.

myrl883 wrote

You have to change the water pump, but not the timing cover. Fan and clutch need to be from reverse rotation vehicle as well.

I used all of the left side components from a bricknose when I converted my '81 to serpentine, including the a/c compressor and hoses. The fuel pump is a tight fit, and I had to relieve the p/s bracket a bit to clear it. If you have electric fuel pump this isn't a worry. My 3G alternator bracket is from my '94 roller donor. Everything plays well together.

Thanks Myrl883,

You answered some questions that I had!

So I had some plans this morning that got screwed up, so I marched straight out to the junkyard as there were two Bricknoses there, both with 5.0's and factory AC. The one 1990 was bone stock original and still perfectly intact under the hood...the belt was even still on ot. The other, a 1988 had had the AC disabled at some point and a delete pulley/bracket was installed in place of the AC compressor.

Anyway, I was able to remove it all fairly quickly...I think it maybe took me 45 mins by the time I got it all loaded into my trusty wheelbarrow. The one major snag I ran into was the long 7/16" pivot bolt for the alternator was seized in the alternator and in the bracket, and badly too. I got it removed when I got home, and drilled the broken bolt out, but it was extremely unfun.

I grabbed the whole works, and will be returning some parts tomorrow.



So I grabbed the whole system off a 1990 Bricknose. One the way out, I grabbed the AC delete bracket/pulley from the 1988, only to find out when I got home that it wouldn't work on the 1990 assembly...they were different, buggers. Not a big deal really, I'm planning on installing AC anyway.



I was wondering how I was going to piece together several different years worth of AC parts to make the whole system work, and with the little bit of studying I have been doing, it looks like this isn't too bad.

Correct me if I am wrong, but I should be able to run a 1990 AC compressor, and the 1pc line that is available for it, along with my Bullnose era AC system. It looks like everything should play well together.

According to the aftermarket, the accumulators were the same from 1983-1993, and the condensers the same from 1980-1993, so the 1pc line for the 1990 AC compressor should work just fine. I'll just order a Bullnose evaporator and liquid hose (I have one now, removed from a 1986).

I should also be able to run a shorter serpentine belt since I have no smog pump? Do you know what size is required?

I'm going to get my parts all sand blasted and painted, and get ready to do this swap.

I can't answer all those questions, but Big Blue is sporting a 1990 underhood system, inc condenser, evaporator, compressor, receiver/dryer, and plenum.  Bolted right up to the 1985 firewall with the '85 system inside the cab.

As previously said, the only issue was that the vacuum lines run slightly differently so I had to make a minor mod there.  No biggee at all.

So, why not get the evaporator and condenser from the truck where you got the other parts?  If the system was all together they should be fine if you flush them.  That's exactly what I did and it works nicely.

Gary Lewis wrote

So, why not get the evaporator and condenser from the truck where you got the other parts?  If the system was all together they should be fine if you flush them.  That's exactly what I did and it works nicely.

Well, only because I already have everything from a 1986 truck, and if everything work together, then I'm good to go. According to everything I'm looking at, they will all plug in together, so I think I'm set.

Oh, Gary...one more thing. This system had a 2G alternator (with the 7" bolt spacing) so all I need to do now is order a 3G and harness, and it will fit right in place where the 2G was, correct? I know I need to make the wiring changes, etc...but a 2G and 3G are physically the same size, correct?

The 2G and the 95A 3G are about the same 135mm diameter.
The 130A 3G has a 148(?)mm diameter.

If you are using the 5.0l serpentine setup with the alternator on top you need the 7" C-C mount used on the 3.0l V-6.
And will have to cut away some of the bracket to allow the larger 130A alternator to fit. (Or use the 95A version)
I'm pretty sure Gary has those pics in the upgrades tutorial.

Yep.  From our page at Documentation/Electrical/3G Conversion:

Right Gary.
But these are both 148mm diameter 130A 3G's.  (Two holes in the front ribs)
If Cory wants a 130A 3G he will need to clearance the polygroove Windsor top mounting bracket with a die or angle grinder.
You have this illustration:



The 7" mount 95A (four hole) 135mm alternator will fit without modification.



With this he will still have the advantage of better charge at idle and half again as much max output over the ~65A 2G design that is prone to melting the charge plug.

ArdWrknTrk wrote

The 2G and the 95A 3G are about the same 135mm diameter.
The 130A 3G has a 148(?)mm diameter.

If you are using the 5.0l serpentine setup with the alternator on top you need the 7" C-C mount used on the 3.0l V-6.
And will have to cut away some of the bracket to allow the larger 130A alternator to fit. (Or use the 95A version)
I'm pretty sure Gary has those pics in the upgrades tutorial.

Thanks for this Jim. Now that I go back and read up on the details I see that there are small and large case designs both with the 7" bolt spacing. A 95amp should be more than enough for me. Adding EFI, electric cruise control, and factory AC won't be adding very much load to the system. My factory 40amp alternator works quite well as it is. I'll look at both options regardless, and see which one is more readily available. I don't mind grinding the bracket a little bit if I have to.

If so the 3G for a '96-'97 7.5l f- series or a '92-'94 3.0l Aerostar is the one you want.
Ford # F1SU-10300-BA, Lester # 7749-3

These are small body (95A), 7" mount alternators that come with a 59mm polygroove belt pulley

https://www.dbelectrical.com/products/alternator-3-0-aerostar-92-93-94-7-5-f150-f250-f350-pickup-96-97.html#new-description-overview