how close should fan be to radiator ?

[1983shorty]

after replacing my 6 cyl. with a 350 , my fan is not close enough to the radiator to pull the air through well. i know i need a spacer but just how far from the radiator SHOULD the fan be ? i also need to make an extension for the shroud . started the freshly rebuilt 350 for the first time today. temp got close to 210 so i had to shut er down and let it cool.

[bigblock73]

The fan should be roughly halfway in the shroud, and halfway out.

[qksilver]

Did you replace the rad with a bigger one? You might need to upgrade and get the spacer. I rather use a fan clutch type that has a thermostat as an inexpensive solution

[1983shorty]

Originally Posted by qksilver

Did you replace the rad with a bigger one? You might need to upgrade and get the spacer. I rather use a fan clutch type that has a thermostat as an inexpensive solution

i actually ordrered a new 3 core radiator from napa but it was 2 inches taller. i would not be able to use it with the fan shroud in the truck. i put the old radiator back in for now. i am going to take it in to a radiator shop to see if they can recore it to a 3 core. right now the blades of the fan are about 6 inches from the radiator.

[beaterC10]

I am in the process of replacing the 4.3 in my 86 with an 350, and can get some measurements later today. Did you go from a v6 or L6? You should be able to use everything from the front of the V6 on the front of the smallblock and get the fan close to where it needs to be.

The 3 core radiator would require a different shroud, upper radiator mounts, lower radiator cushions, and different trans cooler lines.

[84slopwaggin]

So you saying I will need a different shroud as well as upper rad brackets in order to use the four core I upgraded to. It was originally a two core. I'm already experiecing problems locating the upper brackets. LMC stop selling them, so looks like I'll have to looking in the junkyards. Now the fan shroud will not work as well. What do you guys suggest for the upper brackets? I can still buy shroud from LMC. I see LMC lists a one piece shroud for the 454 package. Is this the one I need for in order to use my four core radiator? LMC stated that I would have to change upper brackets and support pads, but they didn't state anything about the fan shroud.

[speed]

I replaced my 18" 2 core with a factory style aluminum/plastic 3 core. Cools alot better than the original. Took the old rad in the parts store and matched them up, only mod I had to do was remove the upper insulators and replace with a couple pieces of inner tube.

[beaterC10]

My reply was in reference to changing the radiator from the v6 to the v8.

I don't know about the four core radiator.

When I swapped my two core v8 radiator to a 3 core radiator I had to replace the upper shroud, radiator mounts, and rubber insulators. All that was available from the dealer. If the four core is the one used on big blocks it would at least require a different shroud.

[84slopwaggin]

Ok so the upper radiator bracket is available from the dealer. Cool Thanks

[HOGDADDY]

Originally Posted by 84slopwaggin

Ok so the upper radiator bracket is available from the dealer. Cool Thanks

I bought one today only $10 but BB shroud is discontinued.

I have an 86 and my stock 3-core radiator is 28 1/4 x 19.xx and its the same size as the BB radiator but the 4 row is 5/8" wider/deeper.

I wonder if I can modify existing shroud to work with the 4row rad??

[benoit454]

On my 76 my old 2 core rad or 1 core? was 31x19 inches. I swapped from a straight 6 to a very mild 350. I reused that radiator, put on a 6 blade flex fan, and no shroud, it ran great, never got too hot.

I put the same motor and radiator in my monte carlo, ALL it done was OVERHEAT!!!!!!

Someone told me the clutch fans were better then a flex fan, BS!!!!!

I ran a flex fan, and only in teaffic stopped in the summer would it raise, once moving, cooled great, harder you ran faster and better it cooled it.

I put on a clutch fan, that thing heated up to over 280 twice, blew a radiator hose, and burnt up my valve seals. I had to tear it down do a valve job and new head gaskets. NEVER and I mean NEVER will I ever run a clutch fan again NEVER!!!!!! lol just because of that.

Now with that said, I changed to a 3 core radiator, bought another flex fan this time a big 7 blade, shoot I don't get past 190 in triple digit temps. with aweful humidity, setting in traffic.

Now I put the small 6 blade fan on our 86 4x4, and it had a 3 core radiator, never got past 190 either.

A fan shroud makes a big difference while setting in traffic, big a 3 core radiator made a huge difference for me, of course a monte carlo ss has a very small opening for air, and like a foot of room before the radiator to the grille.

If it's a new engine gotta make sure it's in time and not out of time or it'll run hot, and make sure it aint running lean on the air/fuel mix or it'll run hot.

One WILL get hotter setting, evving up then it does driving since the only air flow is from the fan.

I say try another fan, flex fan IMO, or clutch fan with the thermo clutch if you want, and try to get a shroud on it, and if that doesn't work, 3 core radiator.

You could make your own bracket possibly out of some scrap or something.