Fan shroud for my engine

[SCANTRON]

I have a 1963 gmc 1/2 ton with a 396 BBC I have an after market aluminum radiator. My question is about how the shroud and baffles are assembled/installed. If any one has pictures or can walk me through it I would appreciate it

[POWERSTROKE]

I had a '78 F150 with stock 300-6 that over-heated in summer because of no fan shroud. I made one, just a 3-4 inch wide piece of galvanized roof flashing backed up with 1/8" x 1" aluminum strip bent into a circle around the outside of the fan and attached to the sides of the radiator. It just needs to be wide enough to reach the tips of the fan blades. I didn't even cover up the corners of the radiator, it improved air flow thru the radiator enough to stop over-heating on hot days. My next problem was how to get it warmed up running 65 mph in below Zero temps.

If you have a salvage yard or You Pull A-Part yard nearby you might be able to find a shroud there that will fit.

My old '96 F250 diesel was running warm, hot actually the last couple years in summer when towing in hills. SON put gauges in it, coolant temp, boost, egt, and oil psi. He can get all 16 psi boost, 1100-1200 degrees EGT, but when coolant hit 220 and was gaining fast he started working on cooling system. New water pump, fan clutch, thermostat, coolant flush & refill, a new fan belt, belt tensioner, after-market all aluminum radiator, and running into a 20-30 mph headwind on 80 degree day 80 mph, 12 psi boost 1100 egt, running 195 degree coolant temp with 194 degree thermostat, I think he Fixed it. The stock fan shroud fits the Mishimoto radiator.

[AZKen]

Don't understand what you need? How to assemble or how to build a shroud? Do you have one already?
Also, are you overheating? What is the problem?

Basics: The shroud should cover the whole radiator and the fan should fit about half in and half out of shroud. Fan should be in center of rad. Be sure you have proper thermostat. About 1" fan to shroud clearance all around the diameter. Shrouds do no good after 40MPH. In extreme cases of overheat, electric fans are used by some folks.
With no shroud, space fan to 1 1/4" from rad.

That's a good looking, well done BBC install. Is your alternator belt way off line?

[SCANTRON]

What my question was is if the shroud is one piece how do I install it do I pull off the water pump slip the should over and re install the pump. I don't have a shroud yet I found one in a catalog but the dimensions are off.

[AZKen]

If you ignore my questions, I can't help you. ARE YOU OVERHEATING? What is the temp reading? What thermostat do you have? Is it working for sure? Have you tested it? Do you care if you really need a shroud or just want one? I realize you just want to know how to install but I am not sure if you have thought it all out. From what I see and new aluminum radiator, I am suspicious. It should not need a shroud. But I don't know the history and what is happening.

To just answer the question:
First, buy one that meets the requirements I mentioned, and fits the radiator, as close as possible. Then you will have a better idea. We can help, but right now you are asking a hypothetical question. You don't have an install problem until you have an install problem.

You said you don't have a shroud yet, so what is that in the picture? Does "found one in a catalog" mean you bought one? Are you looking at a picture in a catalog and the dimensions?

[James]

Originally Posted by SCANTRON

I have a 1963 gmc 1/2 ton with a 396 BBC I have an after market aluminum radiator. My question is about how the shroud and baffles are assembled/installed. If any one has pictures or can walk me through it I would appreciate it

You can pull the water pump off and see if that permit enough room to fit a one piece shroud (once you find the right one). Or you can pull the radiator slip the shroud in over the fan/water pump then place the radiator back in.

[WE7X]

I am not able to see much detail, so this may not be possible; but can you pull the new radiator and get the shroud down around the fan and water pump? This is fairly commonly done on a lot of vehicles to replace the water pump.

Pull radiator, pull fan shroud, R&R water pump (when that is the task at hand), then re-install in reverse order. Add coolant, bleed air from system, bandage skinned knuckles. and hope you have no leaks.
YMMV; particularly with non-stock parts and a non-stock motor in that classic GMC chassis.
Rod Johnson
Issaquah WA.

1970 RM7500 401M

[David R Leifheit]

I think AZKen already gave you the best answer possible.

<Quote>
Basics: The shroud should cover the whole radiator and the fan should fit about half in and half out of shroud. Fan should be in center of rad. Be sure you have proper thermostat. About 1" fan to shroud clearance all around the diameter. Shrouds do no good after 40MPH. In extreme cases of overheat, electric fans are used by some folks.
With no shroud, space fan to 1 1/4" from rad.
<End Quote>

The only other answer is "do you actually need one?". You have a custom setup, there is no way someone can give you a specific answer when what you have is a semi-unique setup.

[LEWISMATKIN]

You will have to custom make a shroud for your truck. If it had the 305E in it that came in it, a shroud from a '62-4 Full size Pontiac will bolt in (you have to install it in upside-down from how it is installed in the car). The original replacement # for the 305-V6 yrs 1963-66 is Modine 284 (a 3 row core).