Serpentine setups..info please

[Pyrotechnic]

That looks awesome. Is the Firebird serpentine setup the same as a truck setup?

I got some questions about the A/C setup.

What did you do about the A/C condenser? With the compressor on the drivers side on my 78, the lines to the condenser were on the drivers side as well. What did you do to correct this ?

I know these setups come on the 88-91 Blazer/Suburban/CrewCab. Did you just use those hoses ?

[DirtyLarry]

Originally Posted by Pyrotechnic

That looks awesome. Is the Firebird serpentine setup the same as a truck setup?

I got some questions about the A/C setup.

What did you do about the A/C condenser? With the compressor on the drivers side on my 78, the lines to the condenser were on the drivers side as well. What did you do to correct this ?

I know these setups come on the 88-91 Blazer/Suburban/CrewCab. Did you just use those hoses ?

This is how the A/C was hooked up when I had Zoomad’s engine with the '92 – ’95 aluminum brackets. The local Napa store custom made my A/C hoses.

The second picture is how my 4fidy4 is A/C plumbed.

[Pyrotechnic]

Sorry to shift the topic of the thread, but I got an A/C compressor question.

On my 78, it had this HUGE log style compressor. It was very long and the brackets made it impossible to use use tall valve covers. I also hated the way the hoses crossed over the engine.

Is the newer style short and fat compressor found on the earlier serpentine setups more reliable than the old log style one ? How about the newer Delphi ?

Basically what I'd like to achieve is a clean serpentine setup, no hoses crossing over the engine, and the ability to run tall valve covers, and ice cold a/c for the hot Texas summer.

Whats my best bet? Should I just keep the old log compressor? I swear that thing takes 50 HP to turn...well not that much but you get the idea.

[DirtyLarry]

Originally Posted by Pyrotechnic

Sorry to shift the topic of the thread, but I got an A/C compressor question.

On my 78, it had this HUGE log style compressor. It was very long and the brackets made it impossible to use use tall valve covers. I also hated the way the hoses crossed over the engine.

Is the newer style short and fat compressor found on the earlier serpentine setups more reliable than the old log style one ? How about the newer Delphi ?

Basically what I'd like to achieve is a clean serpentine setup, no hoses crossing over the engine, and the ability to run tall valve covers, and ice cold a/c for the hot Texas summer.

Whats my best bet? Should I just keep the old log compressor? I swear that thing takes 50 HP to turn...well not that much but you get the idea.

Brackets, A/C question…what’s the difference...they all go together. After all it is that time of year to start thinking of A/C.

The log style that you are talking about the is old Harrison A6 compressor. That is a very good piece. Big, heavy, intrusive, and not very efficient describe it best although it is very reliable running on R12 refrigerant, which the R12 refrigerant is expensive and hard to find. Those dogs do not like new R134A refrigerant at all. Every one that I have ever converted to R134A leak like crazy…R4 compressors as well. Even the newly remanufactured compressors that were supposed to be R134A ready still leaked. You can plan on adding refrigerant a couple times a year once you convert it to R134A refrigerant.

I have run all the GM compressors on different vehicles and actually all on 1 specific truck…..My ’78 K10. I would say the R4 is the worst of the bunch. I have yet to figure out why so many members here use them other than they are dirt cheap. The R4 is noisy, vibrates like crazy and is not very reliable. The good news is you can buy replacement R4’s dirt cheap. I guess, the Chinese are getting pretty good at remanufacturing them and manufacturing counterfeit knockoffs. Heck, many dime store part stores like VhatoZone do not even require a core on them anymore.

Actually, the R4 A/C compressor gave the serpentine belt system a bad rap back in the early serpentine days because the compressor had a habit if locking up and burning the serpentine belt off while leave you on the side of the road.

Delphi is one screwed up automotive supplier right now but my preference is the late model pad mount Delphi A4 like I am running on my ’78 K10, as it is quite and is hardly noticeable when the clutch is engaged (the same compressor is also called the H4, HT6 and a few other names…not sure why all the names are commonly used for the same compressor…could be the clutch options or pad mounts). It is also a much better compressor than the common Sanden compressor that comes with most aftermarket A/C kits and brackets that the street rod crowd loves... Streetroders like carburators too

I also have that same basic compressor with different pad mounting and clutch assemblies on my 2004 Tahoe, 2001 Silverado and 2006 Poncho GTP. I am a field service rep for a truck manufacturer and we use only the Delphi. It is a good piece with very little warranty exposure. A bit pricy to acquire but a good piece of equipment. There were some bad compressors that landed on a lot of GM trucks in 2002/2003 that suffered from main shaft failures right out of the box but other than that….good stuff. If you chose to go that route you will need the ’96 – ’04 small block serpentine brackets to mount it. You will also need to go with the later model Delphi alternator of that vintage to fit the brackets as well. Again, pricy but at least you will also get a 145 Amp alternator too boot!

Once you change over to whatever serpentine setup you chose the A/C hose routing us totally up to you and your hose fabricator. You can route them as hidden as you like or middle of the road like I did. The R134A hoses do not need to be as big as the old R12 hoses as you can see by my pictures. Finding an A/C manifold to connect the hoses to the compressor for the late model Delphi's are pretty easy as pretty much all GM products in the last 10 years have used them.

This is the shizzle right here…..


POS R4


Old Harrison A6

[Pyrotechnic]

Thanks for the info, I'm learning a lot here. So it looks like if I upgrade, the only worthwhile way to go is the new serpentine setup with the Delphi and 145 amp alternator. I really like the hose routing you did on the 454. I never considered having hoses custom fabricated, is it reasonable as far as cost goes ? Does the Delphi compressor running R134A run as cold as the old R12 setup on these trucks ?

One last question. Where on the head does a hole have to be drilled and tapped, and is there anyway to get around it such as adding a support brace at another location, etc ? The heads I have are Dart Iron Eagle made in the late 80's, so I'm not sure if these will have the hole already or not.