Overheating during cam break in

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While I agree that a guy might want to have a box fan running during cam break-in, if you need it as a matter of course idling in your driveway, your cooling system is not up to the task.Specifically, there is not enough heat being sucked out of the rad; be it the (crappy IMO) flex-fan, or the lack of a shroud, or a failing viscous coupling,a poor pulley ratio,insufficient size and number of fan-blades, a low-performance water-pump, or a restrictive rad,etc;I cannot say.
A properly working system won't skip a beat; easily handing that situation, even with a 205*stat. If you have a wheelbarrow full of cash in the engine, a couple or few hundreds in the cooling system is nothing but cheap insurance. .
I know what works.
On the street;Trying to save a few horsepower with a marginal system is NOT the way to go;especially with a BB. I know you said you had that fan laying around, but now it's time for a situation-review.
And you gotta put the stat back in! It's job is to set the minimum operating temperature. For a street-car this is important for a couple of reasons; help in detonation control,long oil-life, long engine-life, fuel economy, even heater operation.And they say that the hotter you can run your engine without destroying it, the more power it will make;witness today's tiny engines propelling 3000plus pound cars, running 220* plus, and getting 30plus mpgs.They are on to something. I've always run a 205* in my 400plus hp 367; since 1999.That was the hottest stat I could find at the time, or I woulda run hotter.My 3650# race-weight car goes 93 in the eighth with that 205. I wonder how much faster it would be with a 210, or 220............:)
Oh yeah she's turned on well over 100,000 miles and counting...........
 
a box fan helps, cuz breaking in a cam is NOT idling, and an initial fire up can have - the cooling system not full - the timing not perfect - the jetting not perfect etc. you want an assistant to check the timing at 2500 rpm, and to add coolant. and for initial fire up you want a hole in the therm. or no therm. and if a therm. is used always test it for opening in a pot of boiling water for opening. I have an old thin fiberglass "flex" fan that does not flex, a small lower pulley, no shroud-(shrouds add aerodynamic drag) and she is very slow (like 20 minutes) to get to 180*
 
AJ/FormS said:
If you have a wheelbarrow full of cash in the engine, a couple or few hundred in the cooling system is nothing but cheap insurance. .
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Click to expand...

I've always said, this is why I have my engines broke in and tuned on a dyno. It's worth the money and piece of mind. Drop it in the car and go.
 
I always install a restrictor plate in the stat-house, and a direct-drive fan.
And when it fires up on fast idle, I check the oil-pressure gauge while tugging on the dizzy to maximize the rpm. Adjust the rpm.Check for leaks.Relax a bit.
Check the O/P,Check for leaks,Check the temp.,Relax.
Repeat
At 2500 there should be massive flow through the rad with the direct drive fan.
That's what I do.
But yeah, I keep the box-fans handy, and running water, and a fire-extinguisher, too.And I fire-up outside; I may be brave, but I'm not foolish.............I learned some stuff along the way.
All it takes is a bit of a fuel leak and an errant spark to ruin your car,your garage, or your life. You know, we take gasoline so totally for-granted in our everyday lives, it's surprising we don't hear about more tragedies than we do. That stuff is just looking for any excuse to burn or explode.And when it goes,look out!
Yeah, I have done some stupid stuff..................But I made it to age 63 now...................and my buildings are still standing.
 
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