Author Topic: Water pump pulley size  (Read 1127 times)

dalekerr

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Water pump pulley size
« on: March 20, 2020, 11:12:45 PM »
I have a 67 with sbc motor and  I added vintage air. Since adding the air the car runs hot up to 230 degrees while sitting idling  after 10 minutes or so. It never gets above 190 while driving at highway speeds. The car has a new 3 core aluminum radiator with shroud, new 7 blade fan and clutch. I noticed that the crankshaft and water pump pulleys are the same size.

I can rev the motor rpm up and bring the temperature down.

My question is would possibly  changing the crankshaft pulley to a larger size or putting a smaller water pump pulley solve my running hot while idling issue?

Yes the timing is set correctly.

Opinions please

Thanks in advance

Dale Kerr
Dale Kerr
1967 Y 2 350 M20 12 Bolt Vintage Air
03D

KurtS

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Re: Water pump pulley size
« Reply #1 on: March 21, 2020, 02:47:19 AM »
I'd start with the pulley sizes used with AC vs non-AC cars.
http://www.camaros.org/engine.shtml#PulleySpreadsheet
Kurt S
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z28z11

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Re: Water pump pulley size
« Reply #2 on: March 21, 2020, 04:40:05 PM »
I notice you didn't spec what thermostat you are using, 180 or 165 degrees ? Stock water pump, OE rebuilt or aftermarket ?

Regards,
Steve
1968 Z28 M21/U17 BRG/W 1967 Chevy ll Nova SS 
1969 Z28 X77/M20/VE3 LeMans/W
1969 L78 X66/N66 Cortez/BVT
1969 Z11 L48/M35/C60/C06  1949 3100 5wd 235/6

dalekerr

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Re: Water pump pulley size
« Reply #3 on: March 22, 2020, 01:41:52 PM »
180 stock water pump.
Dale Kerr
1967 Y 2 350 M20 12 Bolt Vintage Air
03D

dalekerr

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Re: Water pump pulley size
« Reply #4 on: March 28, 2020, 06:41:00 PM »
Ok I ordered and installed a new crankshaft pulley 7.25 and a new water 6.3 pump pulley today. This seems to have solved my running hot while idling. The car is now running about 10 degrees cooler while driving and idling. 

I read on another site about pulley sizes and  cooling.


Dale Kerr
1967 Y 2 350 M20 12 Bolt Vintage Air
03D