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Lee B. · 07-09-2017, 01:18 PM

I've got a '65 Chevy 4x4 truck I put big block in about 20 yrs ago. Set it up originally with 3 electric fans in a shroud. I've always had running hot issues with it during Phoenix summers. Temps would go over 230 deg and I would shut it off, leaving the fans on. I've done everything possible to correct it : Ron Davis direct fit aluminum radiator (2- 1" rows), heavy duty hoses, changed timing, carb tune, t-stats, coolant ratios... The best I've ever had it was after reducing the crank pulley to 1:1 from the overdrive pulley that's stock on the 454 ci motors of the late '70s and '80s. As I was mostly having trouble at rpms 2500 and up, no matter the speed this seemed the way to go and helped, at least it didn't go over 220 deg. It was recommended I try a performance water pump. This again made it go over 230 deg. (pushing coolant too fast?). I've gone back to a stock water pump and am trying a 19-1/2" clutch fan with heavy duty clutch. Now it runs at any rpm and any speed staying around 210 deg. but gets hot in stop and go traffic. I haven't yet put a shroud on it but I think I'll have to build one. The only one I can find on the internet is for a small block and I hate to spend $150 for a plastic piece just to look at it.
Does anyone have a suggestion for me?

07-09-2017, 01:18 PM	#1
Lee B. Registered User Join Date: May 2013 Location: Vernon, Az Posts: 4	Fan shroud for '65 4x4 Big Block I've got a '65 Chevy 4x4 truck I put big block in about 20 yrs ago. Set it up originally with 3 electric fans in a shroud. I've always had running hot issues with it during Phoenix summers. Temps would go over 230 deg and I would shut it off, leaving the fans on. I've done everything possible to correct it : Ron Davis direct fit aluminum radiator (2- 1" rows), heavy duty hoses, changed timing, carb tune, t-stats, coolant ratios... The best I've ever had it was after reducing the crank pulley to 1:1 from the overdrive pulley that's stock on the 454 ci motors of the late '70s and '80s. As I was mostly having trouble at rpms 2500 and up, no matter the speed this seemed the way to go and helped, at least it didn't go over 220 deg. It was recommended I try a performance water pump. This again made it go over 230 deg. (pushing coolant too fast?). I've gone back to a stock water pump and am trying a 19-1/2" clutch fan with heavy duty clutch. Now it runs at any rpm and any speed staying around 210 deg. but gets hot in stop and go traffic. I haven't yet put a shroud on it but I think I'll have to build one. The only one I can find on the internet is for a small block and I hate to spend $150 for a plastic piece just to look at it. Does anyone have a suggestion for me?