Inliners International Forums General Discussion Engines 261 > 55 1st truck cooling.

So this will be my first post in this forum i hope someone could help me to some answers.

I am currently rebuilding a 55 1st series 3100,
when i bought this truck it came whith a 235 from '53 but it probably frozen up in the boat.
there was a mayor crack in te side of the engine (big dissapointment). Altough it ran, i did had to find an other engine which are very expensive here in the Netherlands. so i ended up whith an '56 Canadian 261 wich probably came out of a Pontiac. I checked the numbers whith Patrick's before i ordered parts. I finaly rebuild the 261 whith evrything new exept the cranckshaft, the block and the head evrything else moving has been replaced. i did put it in the truck with a short shaft pump on it but i still have only a 2 inch gap between the ballancer and the new radiator. The fan is just missing the balancer but is hitting the radiator bottom, plus the fan is only partialy behind the bottom and will have little effect i think.
I am not comefortable with this setup so i am looking for an electric fan that pushes the air trouhg the radiator. but what kind of fan should i use? how much cfm? and how much current will it draw? and will my 12 volt generator have enough amps to drive the whole electric system and the fan to?. Where should i place such a fan? at the top or in the middle of the radiator.

Anyone with good experiances please help??

Dennis.

Dear Dennis;

In/for that application the "short shaft" pump is not needed.

Use the stock pump & pully and your "all set"!!!

Good luck, John M...

First series '55 is the same as a '54, so the short pump would be needed if everything else is stock.

The problem you are describing shouldn't be there. What are you using for a fan blade? are you using a spacer between the blade and pulley?
When installing the later engines into these trucks, the centerline of the pump is lower than original, so having the fan blade overlap the lower tank is typical. It shouldn't present a real cooling problem if everything is good shape.
Moving the radiator forward and trimming the shrouds is another option. Keep in mind that if you get too far away from the radiator, the fan isn't going to do much good without adding a fan shroud. Moving the radiator forward would allow you to use the stock late '55-62 water pump and pulley setup. Thats what I have in my '53.

As for adding an electric fan, I believe a 16" will just fit on the radiator, but how much clearance you will have between the pump and radiator I can't say for sure. It may be necessary to mount it a little high so the fan motor can clear the water pump. It is definitely preferable to use a puller rather than a pusher.
I believe they typically draw between 20-30 amps, so I doubt your generator will be able to keep up in a worst case situation. Switching to a one wire 55 amp or higher altenator would be advisable, in my opinion. Any vendor that sells electric fans should be able to give you proper specs and dimensions of their fans.

I have seen a plate adapter available to use the 53-54 style water pump on the newer engines, but I have no direct experience with this, but it would get your alignment issues back closer to the original first series '55 specs. Try Ebay for this plate.

Thanks John and gearhead.

I believe i found the problem when i read your reply's. with the short shaft pump i am using and the spacer, the fan does clear the balancer only 1/4 inch but it hits the lower tank of the radiator. Since i did put in a new radiator i looked at the old one and noticed that the lower tank is 1/2 an inch wider than the old one. I think i am going to adapt the support so that i can put the radiator inside it instead of the back. I think i wil gain 1/2 an inch of space with it. But how much space should there be max between the radiator and the fan? I believe that the fan i am using is an 55-62. if this wil provide enough cooling i won't put in an electric fan. i can always do that afterwards and the altenator to. First i wouldt like to get my truck on the road again.

BTW it is the first time i completely rebuild an engine myself last weekend i tried to fire it up and like a mirracle it did after only two turns.
i put the radiator an inch forward on an wooden plate because my fenders were not on the truck.
The gasoline was coming out of the carb evrywhere but it ran and gave good oilpressure, that gave me new hope for the rest of my project.
First things to do: adapt my radiator support and rebuild the carb.

Thanks again

Dennis.

Dear Dennis;

Sounds like you did a good job all around.

I would check the float assembly before you try to start it again. Last thing you need is a fire. It's pssible you just have a speck of dirt between the needle/seat.

You might consider switching the lower tanks. A radiator shop could do that cheap.

Good luck, John M....

Sounds like you have it worked out. As for fan clearance, you need enough to be able to get the bolts in, otherwise I would try to be around 2" away. Like you said, give it a try, you can always go to an electric fan later on if you prefer.

I am running a 261 in my '50. I found that I couldn't get a fan to fit to my satisfaction, so I used a 2400 CFM electric 17" on the street side of the radiator. I am running a short waterpump with a Ford pulley. I am running a GM 10si alternator instead of a generator, though. The fan draws 15 amps. I have a thermostat on it so it only kicks in when the radiator gets hot. It works in 100 degree weather just fine.

The alternate way is to get the adaptor plate that lets you use the old 216 water pump. It moves the mounting point up high on the block and lets you use a mechanical fan. A friend of mine has that setup and it is what I would use if I did it again.