fe pulleys whats best

[wrench87]

Well right now i have a 7.5 crank pulley and a 6 inch waterpump pulley so I am overdriving the pump?. Does any one know what size the Kirkham pulleys are?.

[patrickt]

Originally Posted by wrench87

Well right now i have a 7.5 crank pulley and a 6 inch waterpump pulley so I am overdriving the pump?. Does any one know what size the Kirkham pulleys are?.

For every revolution of your crank you will turn your water pump pulley 1.25 times, if I did my math correctly. So, yes, you are overdriving it. If you drive your car on the highway, on a hot day, and then you get stuck in stop and go traffic for 10 minutes or so, does your temperature continue to climb or does it level off at 100-105 and hold there? That's a little high, but not terribly so, and if your engine temp doesn't continue to climb and then overheat I wouldn't worry about it.

[wrench87]

pat, i still have to readjust timing and set carb etc, i just took it for its first ride with the big block. Yes the temp does come back down, i dont have a sensor to turn on my fans right now, on my small block i had a aluminum degas tank with the sensor in the bottom. I have to find a new set up i just have the back up toggle under the dash to turn on the dual fans.
I was thinking of one of the adjustable probe style ones?.

[patrickt]

OK, I have a 16" straight finned SPAL puller and the dual pushers up front. The SPAL is on a thermo switch from the lower radiator hose. The pushers are on a manual bypass switch (which also engages the puller as well). This past weekend I took her to a Wounded War Veterans show and it was hot. Really hot. I paid particular attention to my temp gauge and, after driving it at highway speeds, I got stuck in stop and go traffic. My puller fan alone kept the temperature in the low 90's -- I did not need to throw the manual switch for the pushers, which generally brings the temperature down in to the high 80's when I'm not moving. I don't really need the pushers, they're mostly a redundant "backup" system in case the puller, or the puller relay, fails. Once traffic cleared and I moved at a decent pace the air flow alone brought the temps down to 90 or a little below.

[SoTxButler]

Something to think about...cavitation can occur when velocity of the fluid is moving to fast and reaches the point where the fluid backs up as it moves past obstructions (like sharp turns, etc.) rather than flowing smoothly. Turbulence occurs, bubbles form and so forth and so on. Overdriving the pump to this extext could be causing such cavitation and that can affect the cooling efficiency of the system.

Others with much more knowledge than me will undoubtedly shoot this down or explain it better.

Hope you can solve the problem.

[patrickt]

FWIW, the original pulley ratio on my 428, straight from the factory, was 1.34 -- maybe those fancy-schmancy 427s were different.