The Stovebolt Site Forums The Parking Lot '60-'66 Trucks what to do about my overheating issues?

Hi everyone, So i have been having overheating issues with my build. i put a 1986 305 V8 into my 1962 chevy C10 with the three core radiator from Classic Parts of America. i have narrowed it down to the fan is just way to far from my radiator. What i was hoping to find out from anyone who has put a V8 into the 60-66 C10's was did Chevy move the radiator closer to the engine for the V8s or did they just leave it in the same spot as the L6? if so did they just extend the fan the 12in gap? if there are any pictures of builds that anyone has done i would love to see them so that i could get an idea of what to do about my build. I have been looking at having a shroud made for my truck then i found this: [url=http://www.chevychevy.com/images/59_63_Shroud.jpg]Shroud[/url] I have also looked into going to an electric fan but i would really like to stay with the mechanical fan because i already have the parts for that. Any help or info would be very very very appreciated. -Andrew

http://www.chevychevy.com/images/59_63_Shroud.jpg

The first link didn't work. sorry.

A shroud will do wonders for cooling, esp at slow speeds/idling.

i am positive about the shroud fixing the problem but i would also like to know about why there is such a large distance between the radiator and the V8 where the L6 was so close. Thank you for your response.

the difference between the V8 and L6 is the engine length - cheaper to use a shroud than to move the V8 forward and change the rear mounts and driveshaft

Bill

I have a '62 converted to 383 FI v8. This FI engine is smog compliant and normally runs a little hot. Used the original front engine mount. You do not need electric fans.

First, you need a good radiator. I put a Griffin aluminum in mine (expensive), but as long as you have a large capacity radiator, then OK. You also have to add an overflow tank, which I got from an 85 Eldorado. You do not have to move the engine, but I put a 3" extension on the fan (local speed shop has that) to move the fan closer to the radiator (use a light plastic 18" FAN with this 3" extension), and then got a steel fan shroud from a '63-'64 Impala. That shroud is 7" from up against the radiator and just covers the fan. Not too much modification is needed. Even on 100 deg. days, idling for as long as you want, I never go above 195 deg. I normally run 180 deg. E-mail me for more details.

Tim hit a subject which many miss, fan & shroud.
The location on the fan in the shroud has a huge effect on air flow thru the radiator.

Thank you everyone so much for the information. i would really be lost without the help i get from this website.

Was the 305 a serpitine type and was it changed to V-Belt, if so your water pump might be reversed. Check the thermostat, even new ones can be defective, pull it put in a pan of water and put it on the stove. Use a therometer to see when it opens. 180 is plenty on a carb engine, maybe 160 out in Cali. These old trucks had a fan shroud for the V-8.

Also verify that is actually running hot...temp gauges can read wrong,
Scott

I actually thought that was the case but I checked the specifications for the part and it is spinning the right way, plus there is good coolant flow in the radiator. I checked it with a thermometer and the coolant slowly raises over 180*f at idle on a cool morning. It will keep getting hotter if I don't shut it off. And I did the boiling coolent test and it opened just under 180*f. I am trying to get a fan shroud from Chevychevy.com for my year but I can't get ahold of the guy. Maybe I need to make a post on this site to see if anyone has a shroud they would like to sell me. Thanks again.

12" is pretty far away without a shroud. It does kind of sound like you may have another problem because it heats up on cool morning? . After you get a 3" extension (if that's what you do), you will have 9" to radiator. The shroud should be attached tight at radiator and just cover about half the fan. Be sure your water pump is working full flow, no collapsed hose and timing is correct.

TOG - the shroud you picture is a good repro of the factory original for the 60's cars and trucks - I found one from a car at a wrecking yard, as seen here on my '58, and added a spacer behind the fan to get it in the 'sweet spot' right at the opening of the shroud ... the fan has to be less than an inch from the rad in order to cool properly without a shroud

Bill

A blown head gasket will cause it to overheat also.

I had a mechanic friend of mine check the head gasket and that was not the issue either. my issue was the distance from the radiator. i am nowhere near the radiator and i have two 4" extenders. i will begin looking for a shroud. i am certain that this will fix my issues. once again thank you all for the help.

It's not a crime to move the radiator back. I will support you %95.

haha i have considered this but i don't think it will look that great seeing that my fan is still around 5" away from the radiator. i would prefer the shroud. i found out that ChevyChevy.com doesn't make that shroud anymore so it looks like i am going to have to find one somewhere else.

I just assumed that you knew that there is a Chevy long neck water pump available. That pump would also get you closer to the radiator, but you will have to fool around with all of your other pulleys to get them re-aligned with the longer pump.

I have the long neck water pump and 8 inches of extenders on it to get me close to the radiator. But It only gets me about 4-5 inches away from the radiator.

hey, this is my first time on here, your questions and problems may have already been solved but for good measures i figured id give you my input. i have a 1961 apache 20 and it was originally equipped with a 283 v-8 and i in fact just recently did an early 80's camaro 305 swap. the gap has always been about a foot, yes even with the factory v-8, and all i can say is that it came original with quite a large shroud. -Ray

I've got a 290horse 350 in my '61.
Here's what I did:

I installed an aftermarket 4-row 3/4-ton radiator. It bolts right in.
I don't remember what radiator cap I have, but a radiator cap WILL make a difference.
I also run a 160-degree thermostat in the summer, and 180 in the winter (which reminds me, I need to change my thermostat!)
My feeling is that in the summer, the 160-degree t-stat opens sooner, so the system is able to stay on top of things easier, rather than playing catch-up.
But the really big thing I did was added the largest-diameter reproduction clutch fan I could. I went with a 7-blade unit that is originally for Mopar big blocks with A/C. It's about 1/4-inch larger in diameter than BB chevy A/C fans.
I attached it with a repro fan clutch. The Mopar and Chevy fan mounting patterns are the same, so it'll bolt right up to your Chevy.
The clutch acts as a spacer, but there's still a ton of space between the fan and the radiator--close to a foot.
But at idle, that fan moves enough air that it'll suck a piece of paper tight to the front of the radiator.

I drive the truck every day, including Atlanta summers, and rarely have cooling issues. It gets a little dicey if I'm stuck in traffic, but I try to avoid that.

I have a factory shroud, but I haven't installed it yet--it's been about three or four years since putting the system together, I've just never made installing the shroud a priority.

I also need to install an overflow bottle.

Finally, for an additional edge, you can install Water Wetter... it really does work.

-Brad

Put in a shroud . You should have your fan blade 1" from the rad and 1" from sides of your shroud. I have a 425 hp 350 running with a 3 core factory rad and never go over 180 degrees in my 65.

The picture of the fan shroud is different than the truck one and looks like a car shroud of the same vintage. Also there are two mounts for the radiator. If you look in the lower frame crossmemember you can see them. You do need an original shroud or try to make one if you are handy. Also the location of the fan in relationship to the edge of the fan is critical. Usually just inside the edge. Without a shroud you just have a swirl effect with nothing really going anywhere. Someone mentioned a multiblade fan with more blades which is also a good idea. If everything is right you should run just a little over the thermostat you are running. Provided you don't have a caked up engine and some casting sand where it should not be . Kind doubt that and lean more toward the shroud/fan. Good luck.