distance between a clutch fan and the radiator

ok, im going to have to use the 4 row copper brass radiator I have.along with the factory fan shroud. im going to my local pull a part to try and find a clutch fan (I will be getting a new fan clutch)...... what kind of cars/trucks to get one from?..... and now for the critical question... how much distance should there be between the clutch fan and the radiator??.... im also going to fab up some aluminum pieces to try and block off any air flow that would otherwise by pass the radiator. both top and bottom. also going to a 160 deg thermo and trying "water wetter". any ideas?

Watter wetter-dont - no need- get a thermostatic controlled   clutch fan-temp controlled-NOT a cheap one!! Try rock auto.com best prices anywhere! Now when the clutch fan is all installed- the blades -AFT!!- area should be at least =even with aft edge of SHROUD! or they can be inside the shroud  max 1" =what u do not want -is the blades MIXING up the air  within shroud (too deep inside)  you want  the fan to PULL the air  out from the shroud!! I personally have all mine  just at the end blades @ end of shroud! Spend the $$ on a high Quality clutch! and if you can get one for an air conditioned model !! best!

Now =?? Is the radiator new?? Why not get a new alunimum raidiator? Disipates heat faster!!

Twinpilot001 wrote:Watter wetter-dont - no need- get a thermostatic controlled   clutch fan-temp controlled-NOT a cheap one!! Try rock auto.com best prices anywhere! Now when the clutch fan is all installed- the blades -AFT!!- area should be at least =even with aft edge of SHROUD! or they can be inside the shroud  max 1" =what u do not want -is the blades MIXING up the air  within shroud (too deep inside)  you want  the fan to PULL the air  out from the shroud!! I personally have all mine  just at the end blades @ end of shroud! Spend the $$ on a high Quality clutch! and if you can get one for an air conditioned model !! best!

Now =?? Is the radiator new??  Why not get a new alunimum raidiator? Disipates heat faster!!

my 4 core is not new, but it is clean as I can get it. why I don't pony up the $600 for a new radiator? out of reach ,financially. thanks for the reply .in a few days I will be going shopping for a clutch fan. and while rock auto may be the best on prices. my local oreilleys will have to do.

donivan65 wrote:I would say you need about 4" of space between the waterpump shaft and the radiator for a fan clutch to fit,,,,,

my set up is ;I have a 1970 340 but I used all the pulleys and bracketry off a 1966 273 A-100 to put it in. including the cast iron water pump.which is shorter than the more modern aluminum one.i may have to fab a spacer to position the fan blades just right

How about a using push/pull electric fan system on each side of the radiator and not use the convenital fan at all?

fan spacers are !! available from summitt & jegs!! Ill also say - look @ rock auto.com &  ive bought (recently) a new one (fan clutch) for my 67 vette big block from NAPA!! But i get a deep disc. there too. Seems napa has a better quality  thermostat clutch!!

Ill also say I do promote the use of an electric pusher fan in front of the raidiator! hooked to an off / on switch or have it thermostacially controlled -if ever needed =mainly in stop / go traffic!!

If you use the cast iron 273/318 water pump it is shorter than the aluminum water pump. So you will have more room between the fan and radiator .....BUT you MAY ALSO have to change your drive PULLEYS

rustytoolss wrote:If you use the cast iron 273/318 water pump it is shorter than the aluminum water pump. So you will have more room between the fan and radiator .....BUT you MAY ALSO have to change your drive PULLEYS

look man , if I have to trash everything on the front of the engine, well so be it. but WTF!. all im wanting is to DRIVE my van WITHOUT fuel percolation issues. and WITHOUT buying a $600 dollar aluminum radiator. all this is so out of reach. that after 20 something years it seems all I have is a collection of un wanted headaches/ parts. rant over, you may proceed.

dodge A-108 wrote:

rustytoolss wrote:If you use the cast iron 273/318 water pump it is shorter than the aluminum water pump. So you will have more room between the fan and radiator .....BUT you MAY ALSO have to change your drive PULLEYS

look man , if I have to trash everything on the front of the engine, well so be it. but WTF!. all im wanting is to DRIVE my van WITHOUT fuel percolation issues. and WITHOUT buying a $600 dollar aluminum radiator. all this is so out of reach. that after 20 something years it seems all I have is a collection of un wanted headaches/ parts. rant over, you may proceed.

Fuel Perc you say? Now you have my attention.

I went through a lot of the same fuel perc issues with my van when I first got it. I discovered that it wasn't engine temp that was causing it as much as it was a combination of other things (fuel line routing, carb problems, poor air flow in the engine box etc)

. i.e. the carb would still percolate even if engine water temps were under 200 degrees.

What fixed the problem for me, or at least made it manageable during the summer time was the following:
1) I went to a high flow mechanical fan blade to pull more air through the radiator.

2) I added an electrical fan to the front of the radiator as well to "push" air through when I'm sitting in traffic. I only run it when I'm sitting still or going slow, it draws a lot of power and the old wiring/charging systems struggle with the load.

3) I added a cooling spacer under the carb and ditched the gigantic factory air cleaner that was smothering the carb and holding heat. My OEM 2BBL carter carb is an "old rochester" bolt pattern, they don't make a heat riser/phenolic plate for that pattern so I made one. I went to the local cabinet shop and got a scrap of cabinet grade maple (dense with a tight grain) and using a gasket as a template, cut a 1/2" riser to insulate the carb. I run it with gaskets on both sides obviously.

4) I re routed the fuel line from the OEM location (right beside the exhaust header on the passenger side frame rail) to the firewall. I added a heat sleeve to the line inside the engine box and also went to an electric fuel pump so there's no fuel getting preheated before it hits the carb.

some pictures:

OEM fuel line location:



re-routed fuel line (it's all metal until it gets underneath the van):



High flow fan from summit:



carb heat/spacer:





Doing all that didn't cost much and it fixed about 80% of my percing issues, as much as can be expected in GA I guess.

Hey-SLOW!! nice choices on doing all that = If i may suggest= adding an 1/8--3/16 thick alunimum plate below the spacer!! large enough to prevent that chrysler intake/exhaust area from heat soaking the carb area. GM used to make some plates for their HI - Po cars available @ parts counters. never for a 2 bbl setup. heres one on ebat & a few others??= http://www.ebay.com/itm/Oem-Gm-Holley-Carb-Heat-Shield-3969835-/291311592283?pt=Motors_Car_Truck_Parts_Accessories&hash=item43d386235b&vxp=mtr

http://www.ebay.com/itm/ROCHESTER-2-BARREL-HEAT-ISOLATOR-PLATE-PARTIAL-CHOKE-KIT-GM-CARB-/231103137038?pt=Vintage_Car_Truck_Parts_Accessories&hash=item35ced2050e&vxp=mtr

http://www.ebay.com/itm/NOS-1974-1975-Chevrolet-Luv-Truck-carb-to-manifold-heat-shield-94023280-RARE-GM-/121494464896?pt=Vintage_Car_Truck_Parts_Accessories&hash=item1c49a26980&vxp=mtr You get the idea!!

Twinpilot001 wrote:Hey-SLOW!! nice choices on doing all that = If i may suggest= adding an 1/8--3/16 thick alunimum plate below the spacer!! large enough to prevent that  chrysler  intake/exhaust area   from heat soaking the carb area. GM   used to make some  plates for  their HI - Po cars available  @ parts counters. never for a 2 bbl setup. heres one on ebat & a few others??=    http://www.ebay.com/itm/Oem-Gm-Holley-Carb-Heat-Shield-3969835-/291311592283?pt=Motors_Car_Truck_Parts_Accessories&hash=item43d386235b&vxp=mtr

http://www.ebay.com/itm/ROCHESTER-2-BARREL-HEAT-ISOLATOR-PLATE-PARTIAL-CHOKE-KIT-GM-CARB-/231103137038?pt=Vintage_Car_Truck_Parts_Accessories&hash=item35ced2050e&vxp=mtr

http://www.ebay.com/itm/NOS-1974-1975-Chevrolet-Luv-Truck-carb-to-manifold-heat-shield-94023280-RARE-GM-/121494464896?pt=Vintage_Car_Truck_Parts_Accessories&hash=item1c49a26980&vxp=mtr    You get the idea!!

Hey I appreciate those links, I'm going to mothball this engine anyway in favor of a mild street rod 318 so I'll be able to get riser plats etc for it.

slowflapper wrote:

dodge A-108 wrote:

rustytoolss wrote:If you use the cast iron 273/318 water pump it is shorter than the aluminum water pump. So you will have more room between the fan and radiator .....BUT you MAY ALSO have to change your drive PULLEYS

look man , if I have to trash everything on the front of the engine, well so be it. but WTF!. all im wanting is to DRIVE my van WITHOUT fuel percolation issues. and WITHOUT buying a $600 dollar aluminum radiator. all this is so out of reach. that after 20 something years it seems all I have is a collection of un wanted headaches/ parts. rant over, you may proceed.

Fuel Perc you say? Now you have my attention.

I went through a lot of the same fuel perc issues with my van when I first got it. I discovered that it wasn't engine temp that was causing it as much as it was a combination of other things (fuel line routing, carb problems, poor air flow in the engine box etc)

. i.e. the carb would still percolate even if engine water temps were under 200 degrees.

What fixed the problem for me, or at least made it manageable during the summer time was the following:
1) I went to a high flow mechanical fan blade to pull more air through the radiator.

2) I added an electrical fan to the front of the radiator as well to "push" air through when I'm sitting in traffic. I only run it when I'm sitting still or going slow, it draws a lot of power and the old wiring/charging systems struggle with the load.

3) I added a cooling spacer under the carb and ditched the gigantic factory air cleaner that was smothering the carb and holding heat. My OEM 2BBL carter carb is an "old rochester" bolt pattern, they don't make a heat riser/phenolic plate for that pattern so I made one. I went to the local cabinet shop and got a scrap of cabinet grade maple (dense with a tight grain) and using a gasket as a template, cut a 1/2" riser to insulate the carb. I run it with gaskets on both sides obviously.

4) I re routed the fuel line from the OEM location (right beside the exhaust header on the passenger side frame rail) to the firewall. I added a heat sleeve to the line inside the engine box and also went to an electric fuel pump so there's no fuel getting preheated before it hits the carb.

some pictures:

OEM fuel line location:



re-routed fuel line (it's all metal until it gets underneath the van):



High flow fan from summit:



carb heat/spacer:





Doing all that didn't cost much and it fixed about 80% of my percing issues, as much as can be expected in GA I guess.

hey thanks for that. I will do all these mods and let you know how it goes

dodge A-108 wrote:

Twinpilot001 wrote:Watter wetter-dont - no need- get a thermostatic controlled   clutch fan-temp controlled-NOT a cheap one!! Try rock auto.com best prices anywhere! Now when the clutch fan is all installed- the blades -AFT!!- area should be at least =even with aft edge of SHROUD! or they can be inside the shroud  max 1" =what u do not want -is the blades MIXING up the air  within shroud (too deep inside)  you want  the fan to PULL the air  out from the shroud!! I personally have all mine  just at the end blades @ end of shroud! Spend the $$ on a high Quality clutch! and if you can get one for an air conditioned model !! best!

Now =?? Is the radiator new??  Why not get a new alunimum raidiator? Disipates heat faster!!

my 4 core is not new, but it is clean as I can get it. why I don't pony up the $600 for a new radiator? out of reach ,financially. thanks for the reply .in a few days I will be going shopping for a clutch fan. and while rock auto may be the best on prices. my local oreilleys will have to do.

well, time for an update. when I removed my custom built 4 core radiator , it fell apart. nothing but a green corroded mess. SO I must buy a aluminum one in order to drive it again.looking for an AFFORDABLE radiator and im installing a new cast iron water pump while I have it apart

DodgeA108,
The Dodge A100 Service Manual says the "clearance between the fan blades and the radiator is from 5/8 to 1 1/4 inches". Hopes this helps.
Sweetvan