Fan shroud differences? BBC-SBC - The 1947 - Present Chevrolet & GMC Truck Message Board Network

67_SS396 · 02-13-2003, 08:23 PM

What are the differences between BB and SB fan shrouds? I installed a 16" electric fan and now need a shroud. I have a BB in the truck with later model engine mounts. If the SB will fit, then I'll go with that, they tend to be easier to find around here.

JimKshortstep4x4 · 02-13-2003, 08:48 PM

You should be able to make the small block work. They both bolt up to the radiator support the same, both have the fan openings in the same location. The big block shroud has a fan opening of 21 1/2" and the small block opening is 19 1/2".

Probably the dimension that may have to be altered is the front to rear dimension. The big block is 4 1/2 " and the small block is 6".

Jim

Blue68 · 02-13-2003, 09:23 PM

Not sure what a shroud is going to do for you with an electric fan unless the fan is mounted in the fan opening on the shroud. If the fan is on the radiator, it would seem running without any shroud would allow better ram cooling at speed. The shroud allows the fan to pull air from the entire core.

Jackal2k9 · 02-13-2003, 09:25 PM

exactly. i got a trick fro cheap electric fans too. Find a nissan early ninties maxiam or altima thefan are perfect dimensions dual fan setup for these trucks AND they are desinged and manufactured in the USA our of TN or GA cant remeber.

67_SS396 · 02-13-2003, 09:57 PM

It cools fine at speed with the fan off, it's at idle and slow speeds that I'm concerned about. I go on alot of cruises and plan on making the Hot Rod Power Tour this summer so I want to have all my ducks in a row before the season starts up again. With the shroud and the single fan, it should help direct the air through the radiator therefore, offer better cooling. That's my thoughts anyways. The fan I have is a 16" Perma-Cool that flows 2950 cfm of air. I would think and hope that will do the trick. Thanks for the advice and information.

02-13-2003, 08:23 PM	#1
67_SS396 Registered User Join Date: Mar 2000 Location: Blue Ridge, Tx Posts: 1,172	Fan shroud differences? BBC-SBC What are the differences between BB and SB fan shrouds? I installed a 16" electric fan and now need a shroud. I have a BB in the truck with later model engine mounts. If the SB will fit, then I'll go with that, they tend to be easier to find around here. __________________ Fawker Fab three seater rock crawler buggy 498 BBC/SM465/203/205 doubler, propane, 5.13's, 42" PB Rockers '66 C10 - The new hot rod '77 3+3 Dually - 12 valve 4wd conversion tow rig project '28 Ford 2 door sedan street rod RevLimit Offroad "Hang on beer, we can do this."

02-13-2003, 09:23 PM	#3
Blue68 Registered User Join Date: Apr 2000 Location: Frisco, Tx, USA Posts: 606	Not sure what a shroud is going to do for you with an electric fan unless the fan is mounted in the fan opening on the shroud. If the fan is on the radiator, it would seem running without any shroud would allow better ram cooling at speed. The shroud allows the fan to pull air from the entire core. __________________ http://home.comcast.net/~r.landrum/w...tos.html-.html '68 C-10 LWB, '98 Z-71 350 w/accessories (Serpentine), Edelbrock Performer, Edelbrock 1405 (600cfm) carb, GM HEI, CompCam Extreme 4x4 roller cam, Thorley Headers, Carter Electric Fuel Pump, Vintage Air, 700r4, 3.73, disc brakes and power steering upgrades.

02-13-2003, 09:25 PM	#4
Jackal2k9 Registered User Join Date: Apr 2002 Location: Katy, Texas Posts: 171	exactly. i got a trick fro cheap electric fans too. Find a nissan early ninties maxiam or altima thefan are perfect dimensions dual fan setup for these trucks AND they are desinged and manufactured in the USA our of TN or GA cant remeber. Attached Images

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02-13-2003, 08:48 PM	#2
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	You should be able to make the small block work. They both bolt up to the radiator support the same, both have the fan openings in the same location. The big block shroud has a fan opening of 21 1/2" and the small block opening is 19 1/2". Probably the dimension that may have to be altered is the front to rear dimension. The big block is 4 1/2 " and the small block is 6". Jim

02-13-2003, 09:57 PM	#5
67_SS396 Registered User Join Date: Mar 2000 Location: Blue Ridge, Tx Posts: 1,172	It cools fine at speed with the fan off, it's at idle and slow speeds that I'm concerned about. I go on alot of cruises and plan on making the Hot Rod Power Tour this summer so I want to have all my ducks in a row before the season starts up again. With the shroud and the single fan, it should help direct the air through the radiator therefore, offer better cooling. That's my thoughts anyways. The fan I have is a 16" Perma-Cool that flows 2950 cfm of air. I would think and hope that will do the trick. Thanks for the advice and information.



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