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Old 08-13-2012, 03:34 PM
the82elco the82elco is offline
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Originally Posted by oldbogie View Post
If youre using a flow restrictor and have an adaquatly sized radiator what you are are seeing is typical.

Is this a race only or street driven, I see a small carb compared to the 350 inches and a fairly big cam. Kind of an odd combo.

The 600 CFM will not be lean if it's metered correctly i.e. jet, metering rod sizes and metering piston springs versus manifold vacumm which is probably rather low with the 280 cam.

I'm not a fan of running without a thermostat unless this is a competition only engine. The point of flow restrictor instead of a thermostat is simply the simplifaction of a device that can cause a problem by its failure. Getting enough flow is not the issue. The problem with arestritor is the messing around to find the size that works in the desired temperature range by the methods of coping other people's efforts or the messy process of cut and try.

For a street engine low operating temps really kill life expectancy. When the engine isn't hot enough the clearances are too wide, the oil doesn't get hot enough to boil off the water that gets into it, fuel condenses on the upper cylinder walls wiping out the top end lubrication of rings to wall. Just a long list of problems that reduce engine life. A thermostat gets the engine warmed up and holds a tight temperature range so clearances remain very steady across a wide operating range. The oil needs to run about 200 degrees to drive water from it, this is constantly renewed by the blow by which is about 50% waters of combustion, the rest unburnt fuel that needs to be evaporated out, and oxides of carbon and nitrogen. Unburnt fuel that condenses on the upper cylinder walls and in the ring lands wipes out what thin lube is on the upper wall as it is causing mico-welding between the upper ring and cylinder wall which erodes both. What works for a race engine that sees at least yearly teardowns and fixes if not more frequently is not conducive to long engine life on the street.

its a street driven car. so i should get rid of the restrictor an run a 180-190F thermostat?
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