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Discussion Starter #1
I now have a 68 camaro with a 327 t350 trans with A/C
Long term I would like to go with a 383 stroker crate motor.
Will my current radiator and fan keep the new motor cool. It is all stock And i would like to keep the A/C
 

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You should have no problems keeping your new motor cool with the stock setup. I've seen 383's using the stock radiator, fan and shroud run comfortably at 180 degrees.
 

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I concur. had a 430hp motor ran fine with stock rad. but just in case installed a $50 dollar elec fan from Kragen's. rarely it ever came on....
 

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When building a new engine, good practice is replace oil pump..ALSO water pump and get the header tanks removed and radiator manually flushed....
Considering the cost of a re build, these items are not expensive, but can and often do, over heat a big pile of money....
Its not worth penny pinching for
Stock radiators where way over designed...so much so, the flow is so great from the stock water pump and thru the radiator, running with no restriction (thermostat) can cause over heating, running hot...
Even Smokey Yunick refers to this in his early books.
 

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It would seem to be a conflict to have the radiator flushed out to increase the flow then preach that too much flow will cause overheating.

Smokey Yunick has the following to say about coolant flow:

I believe the standard coolant flow in a smallblock Chevy is simply not adequate for an engine that develops more than 500 horsepower...a coolant flow of at least 100 gallons per minute is required to maintain a suitable thermodynamic balance in the engine.
I don't think it is possible to gain these flow levels with a stock water pump and a conventional flow pattern...I have never tested any stock or specialty Chevrolet water pump that can push more than 68 gpm through the stock block and heads! And I don't care what you do to the pump, it's not going to get any better with a stock flow system. The biggest trouble, of course, is air cavitation...when the shaft speed exceeds the point where the stock-type pump puts out about 68 gpm through the system, the pump starts pushing air into the engine along with coolant, and this greatly reduces the heat carrying capacity of the coolant.
Running an engine at 180° will drop the overall horsepower by 2-3%. For max power the coolant should be at least 200°, and you should have at least 25 pounds of pressure in the system. Actually a racing engine like the smallblock Chevy will produce more horsepower as the operating temperature is increased, all the way to a maximum limit of about 220°.


Smokey Yunick's Power Secrets - Page 118-120
 

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Cleaning the radiator is not as much of a flow issue (though it is to a degree) as it is getting coolant as close to the oustside world as possible. The crud is like insulation and doesn't allow the core to dissipate the heat.
 

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Smokey is talking about a 500hp TRACK car...where it is running full power over very long periods...
The same engine as most of us use doesnt produce this HP for such long periods...
 

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When is Smokey not talking about track cars? Did he put out a book on daily drivers? There's no difference in cooling a track car or an ordinary street car. You basically need sufficient coolant flow through the engine to pick up the heat, a radiator with enough area to dissipate the heat, and air flow sufficient to carry the heat away.
 

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The amount of heat to disapate is directly relative to the amount of fuel burnt to produce the required HP at the time....
A 500hp engine cruising down the highway maybe using only 40 or 50 hp..not 500hp... therefore follows that as there is far less energy being used there is far less heat to be disapated....
The other parameter is the total heat over a given time...
A car on a track racing hard out for say 20 miles will need to disapate a total heat far greater than if on a 1/4 mile....
 

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Discussion Starter #12
And at 50+ miles an hour is a hole different then a a long light in stop and go traffic.
 

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Yep...and how many have problems becuase they havnt done this
When building a new engine, good practice is replace oil pump..ALSO water pump and get the header tanks removed and radiator manually flushed....
You would be amazed at the bits of hose spings, gasket , and crud that collects and partly blocks a few cores...these are not removed by a good flush thru cause they are jammed in...sure a flow test may show you have enough, but a few more of those little bits of gasket goo etc from the new engine that break fee, then get caught up.....
Bottom line...the cost of removing radiator headers relative to the overall cost of and engine rebuild is insignificate, and the risk of damaging an engine.
 
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