Need some help on pulley sizing

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Pulleys are at swap meets, saw an absolute ton of them at Stillwater 2 weeks ago. You have to know exactly what you are looking for and have a tape measure with you. Pump pulleys are different from aluminum and cast iron pumps. I have a set of single groove pulleys off a '68 318 cast iron pump, they are different than what's on my cast iron '69. We don't know where or what this stuff comes off of before we get them. We are just the caretakers! We're getting away from the OP here.

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When you buy those fancy alum pulley kits that advertise 'more hp' because they have reduced the size of driven pulleys, they do not tell you that the overheating you are going to get is included in the price!!

Use a 160-180 t/stat, not a restrictor. Use a shroud & plug any gaps so that ALL the air is pulled through the rad core, not though gaps.

More pulley info: www.stewartcomponents.com
 
daddio4048 said:
I have a 340 with the dual crank pulley & single water pump pulley. Rear crank pulley is a 6-1/2" diameter & the water pump is a 6-7/8" diameter. From what I'm understanding that combo gives you a slight under drive on the water pump. I'm needing to get a little more fan speed at idle. I'm looking at CVF's pulleys where they are a 1 to 1 ratio on the pulleys & say they are for high flow applications. Is there a stock combo that I could use to achieve this?
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The fan speed is important, but the water pump speed is just as important or maybe even importanter. If you know what I mean. lol
 
That fan blade is not properly placed in the shroud. The blades should be half way into the opening.
 
Yes, I know that, 418 cools just fine with that set up, have never had a problem.
 
it looks like you've got all the i's dotted and t's crossed with that set up.

i'd circle back and try another t-stat. maybe the one you got was faulty in some way-- just because it's new doesn't mean it's any good.

from there another possible is that the thermostatic clutch isn't performing correctly, i'd have a look there too.

is it possible that your condenser and trans cooler (if you have one) is somehow limiting the airflow thru the radiator?

have you temped the flow on the radiator with an IR gun to make sure that there's no internal blockages, flow is correct, etc, etc?
 
I run or place a screen door screen in front of all my cars, you would absolutely be surprised to see what it catches. I have to clean or replace them periodically. Is your condenser and radiator plugged up with bugs, cottonwood fuzz, thistle, I don't know, you fill in the blank.
 
junkyardhero said:
it looks like you've got all the i's dotted and t's crossed with that set up.

i'd circle back and try another t-stat. maybe the one you got was faulty in some way-- just because it's new doesn't mean it's any good.

from there another possible is that the thermostatic clutch isn't performing correctly, i'd have a look there too.

is it possible that your condenser and trans cooler (if you have one) is somehow limiting the airflow thru the radiator?

have you temped the flow on the radiator with an IR gun to make sure that there's no internal blockages, flow is correct, etc, etc?
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All the components are basically new. Car has about 3500 miles on it since I finished it. I'm considering going with a bigger radiator. Mine is a ECP brand; but I'm leaning toward BeCool
 
daddio4048 said:
All the components are basically new. Car has about 3500 miles on it since I finished it. I'm considering going with a bigger radiator. Mine is a ECP brand; but I'm leaning toward BeCool
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If you are going to change radiators I’d do Cold Case and get the FABO discount.

Very nice and reasonably priced
 
daddio4048 said:
All the components are basically new.
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my mantra: trust but verify

my other mantra: death by 1000 cuts

you have all the pieces, and this should provide adequate cooling. but maybe you've got a little off the ledger across the board: radiator is partially clogged internally or externally, t-stat wasn't working just right, pulley is just a bit off size wise, the thermostatic clutch isn't operating properly, you've got the timing off a little one way or the other so it's adding a little more heat at idle.

give each of those 5 degrees to play with, and you're +25 and into that 225~230 rather then 200~210

it has the capacity to cool, as evidenced that it runs cool on the highway. now to figure out why it doesn't work at low speed.

personally, i'd probably throw an electric fan at it before splashing the cash for a whole new radiator.
 
junkyardhero said:
my mantra: trust but verify

my other mantra: death by 1000 cuts

you have all the pieces, and this should provide adequate cooling. but maybe you've got a little off the ledger across the board: radiator is partially clogged internally or externally, t-stat wasn't working just right, pulley is just a bit off size wise, the thermostatic clutch isn't operating properly, you've got the timing off a little one way or the other so it's adding a little more heat at idle.

give each of those 5 degrees to play with, and you're +25 and into that 225~230 rather then 200~210

it has the capacity to cool, as evidenced that it runs cool on the highway. now to figure out why it doesn't work at low speed.

personally, i'd probably throw an electric fan at it before splashing the cash for a whole new radiator.
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Already tried that with one of Proforms new brushless fans & it didn't make it 10 miles before it puked out
 
Well, I forgot I had a Stewart performance thermostat installed. I removed it & reinstalled my restrictor & found my flow rate increased. Drove car & found temp to drop to 180 driving down the road in 90 degree weather conditions. Idling temp seems to level out at 215. Starting to think high flow pumps don't work well with certain thermostats; but not really certain of this.
 
daddio4048 said:
Well, I forgot I had a Stewart performance thermostat installed. I removed it & reinstalled my restrictor & found my flow rate increased. Drove car & found temp to drop to 180 driving down the road in 90 degree weather conditions. Idling temp seems to level out at 215. Starting to think high flow pumps don't work well with certain thermostats; but not really certain of this.
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How did you measure flow rate?
 
doesn't flowkooler spec out specific t-stats for their set up? i know that stewart performance has a pretty good reputation but in this instance i'd 100% defer to their expertise.

i do know that you really need a "high flow" t-stat when running a high flow pump. i personally have never been a fan of restrictors in the system, but that's how some people roll.
 
Watching flow when thermostat opened @ 160 & then putting restrictor in & watching flow. Was a good bit different.
 
The Flowkooler will move water, it blew my Real Gasket out twice after installing. So went with the Flashpower o-ringed housing, that cured that. Do not know if the Robert Shaw 370 style thermostat let's more water through, but that is what I run. Pictures, Robert Shaw on the left, don't know what the one on the right is. It was in one of my cars when I bought it.

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