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[bmorgil]

TJ, if you have a BIG fan or two, set them in front and give it a little help. Lets see if this is a simple airflow issue. If it will cool down with airflow, some shrouding and higher CFM fan/fans will help with the low speed/idle driving. The radiator I have isn't high capacity by any means. There is very little room. Probably just enough capacity to dissipate the heat from a 60HP motor! I didn't think the one you ended up with was much larger. I don't think they hold much water.

Try more air. If it will cool down then you know its not just running away. 225 is hot enough. I would keep adding air to keep it under 220. It is a new motor. They might run a little warmer for a few minutes but, I wouldn't expect it to run but a few degrees warmer while the rings break in. That should be well on its way from the dyno. It should be fairly broke in.

[gmwillys]

I concur with Bmorgil on the air flow. Your engine should be past the point of worrying about the rings seating in, so your temperature should hold steady as Bmorgil said. In dirt track racing, it was always a struggle to have just enough radiator to cool without adding a whole bunch of weight. With the small blocks being punched out to the minimum cylinder wall thickness, high operating temps were the norm. Adding fan and radiator shrouds, adding holes to the nose, and using different pitch fans to increase airflow. Even with all this, temperatures would still run high. We even tried chemical additives to put in with the coolant to reduce the overall temperature. With all this, we still had fire extinguishers filled with cool water to spray down the radiator to cool it down some when pulling off the track, before shutting down.

[TJones]

Here is the fan I got yesterday, and today I picked up some spacers to ge it close to the radiator.
My next move will be to build a shroud if it doesn’t cool down a little.

DCC5436C-8793-4839-A2F4-5FAAAC574289.jpg

[bmorgil]

It is hard to beat a 6 blade steel flex fan with a good sealed up shroud. The shroud is the key. Tight to the blades and sealed to the radiator.

[TJones]

I’m going to try it with the 160 thermostat tomorrow and the spacers I got today and if that doesn’t get the Ole girl from having hot flashes I’ll call Champion and have them send me a shroud.
I’m sure they have one for mine.

[bmorgil]

I am thinking we are going to see your skills once again TJ. I think you are going to have to make that shroud. Thin gauge aluminum is the way to go if you do fab one. Your favorite neighborhood Racing store has a good start. I have used the one from Speedway. They may be a bit large. It is Stock Car size. They can be used a s a good start. There are a few other choices. You are not alone on this one. Everyone who tried to push extra HP through a stock radiator learns the need for a perfect fitting sealed up shroud.

https://www.summitracing.com/parts/s...xoCsOgQAvD_BwE

https://www.speedwaymotors.com/Alumi...xoC360QAvD_BwE

[gmwillys]

The SBC in our wagon runs the inline 6 radiator, so it is 18" or so from the front of the fan. There was a home made shroud that worked fairly well mounted in front of the radiator. The fan was a suicide fiber blade variable pitch fans..... Knew a guy that raced dirt track that was killed by one of those fans losing a blade while he was setting the timing on a Ford. Hit him in the neck and jobbed through the jugular.

[TJones]

I told the guy from Champion what I was building and he said they put an extra core in mine and said it should work good.
GM that is exactly why I bought the stainless fan, remember your story somewhere and I think it was in my earlier days of my post about the fiberglass blade fan grenading and taking the ole boy out.
Thanks bmorgil for the reference from Summit, if she doesn’t cool after today I’ll get some measurements and build one.
I’m kinda nervous about leaving it open anyways, the fan I have will take a hand or arm off in one clean swipe if your not careful.

[bmorgil]

I’m kinda nervous about leaving it open anyways, the fan I have will take a hand or arm off in one clean swipe if your not careful.

The exact reason I make sure the shroud is on everything with an exposed fan. Trust me there are lots of stories about what can go wrong in and around the buzz saw. In reality it is the shroud that makes it work efficiently. Without it the fan pulls air from everywhere. It actually pulls very little directly in front of it without a shroud. On small engines with relatively large HP to Cooling capacity ratio, that's OK. Not so on the radiator size you have and the HP you have.

[LarrBeard]

If I remember correctly, on the ’48 the shroud was a two-piece shroud and part of it had gone away over the years. The radiator we found at the Jeep yard over in Toledo was a bottom mount radiator, but almost nothing else was right. The top tank was different; hose locations were a bit different so we had to build a custom shroud. We used part of the old shroud, so it has some originality.