I have a new build of a 522 stoker motor in a 71 challenger. 850 quick fuel carb. 16 degrees intial timing and 32 all in. 10:1 compression, aluminum heads, very mild cam. Idles very smooth, be cool radiator and fans. March pulley system, Temps at 190 to 195 when you keep it under 2000 rpms does fine. Punch it or take it up to 3000 rpms crusing and temps start rising. Mechanic is saying I am going to have to run race fuel or octane booster to get this thing to run. It idles for a hour with the ac on in Florida and not overheating just under higher rpms. Mechanic thinks we need to retard the timing and put bigger jets in the carb and a high flow theromstat. Any ideas?

 

What type of water pump and housing do you have?
How restrictive are the radiator fan shrouds, do they allow air to pass at speed?
What is the bore size of your 522?
Have you tried 34° total?

 

Miildon high flow water pump. Aftermarket aluminum housing.
It's a be cool setup with 2 fans. But the shrouds look like it covers the whole thing. They say they sell them for motors up to 700hp
It's supposed to 30 over on the bore.
Havent tired 34 degrees. advancing further would help with cooling. I thought it would need to be retarded?

 

Late timing will make it run hot but your probably close.
What aftermarket pump housing, 440 source?

 

[QUOTE=Iowan;150772]What type of water pump and housing do you have?
How restrictive are the radiator fan shrouds, do they allow air to pass at speed?
What is the bore size of your 522?
Have you tried 34° total?[/QUOTE

Certainly go with the 34 and bring it in before 2500 rpm. If that shows signs of improvement add 1 degree at a time up to 36 to see if it makes further improvements. You WILL need some 93<94 octane pump gas.

 

Kevin -

Hate to say this, but since it's a new motor, it just may need some time to "break in".
Definitely try the timing, and I assume you're already using 93 octane.
Try a 165 thermostat, and do NOT use a Mr. Gasket, high flow, a lot of us have been burned by them.
The std Stant ones are fine.

Archer

 

running 93 octane. Put octane booster in and it dropped it 5 degrees. The mechanic ordered a high flow thermostat and I will check on the brand but I am pretty sure it's not a Mr Gasket.. I will get with the mechanic on the timing.
Thanks for the advise.

 

I Agree with the timing.... I think the carb needs to be a 950XP, I think it's running lean at speed, Check it if you can.. I would stay with the 180* themostat, and stay with the Stant product, that my preferance....
Double check the coolant flow and for restrictions with the flow at speed and make sure you didnt miss anything... I'm with Archer, New tight motors take a little time to loosen up and get rite of the friction.
One think I like to ask folks to try when this issue comes up it Water Wetter.... Give it a try and see if it helps..>>>> https://www.extremeterrain.com/auto-...u-install.html

Good Luck and keep us posted.... Welcome to the site...

 

The wetter water is a good product, I had a Kubota tractor that ran hot since new so I used it, dropped operating temperature 10 to 15 degrees.
I agree with the carb choice also it is on my 500" 440 although it is a race carb it works but for the cost its a short trip to FI.

 

One other item came to mind... Make sure you have a good 16LBS radiator cap... Hope it's not leaking,,, But just thought i would throw it out at you...

 

What's the progres on this?