[68WarDog]

David if you're running any of the Hayden heavy duty clutch fans, I would recommend doing the clutch spring modification linked to by mgarblik and grivera. It was worth about 10 degrees on my junk. Maybe better on yours?

[max 93]

Did you ever tell us the diameter of the water pump pulley?

[64speed]

Originally Posted by 68WarDog

David if you're running any of the Hayden heavy duty clutch fans, I would recommend doing the clutch spring modification linked to by mgarblik and grivera. It was worth about 10 degrees on my junk. Maybe better on yours?

GRIVERA sent me a modded one. We are gonna revisit it with this bigger fan.

[64speed]

Originally Posted by max 93

Did you ever tell us the diameter of the water pump pulley?

I will have to measure but CVF assures me it’s the best they make. I am certain that it’s an air CFM issue. It almost overcools on the road but does not like to idle

[max 93]

Just because it’s “ the best they make” doesn’t mean it’s the best for your car

[max 93]

Just for reference, My factory ac pulleys are about 5-3/4” for the water pump and 8” for the crank. If you don’t have a similar pulley ratio, that may be the problem.

[64speed]

Originally Posted by max 93

Just because it’s “ the best they make” doesn’t mean it’s the best for your car

So I have an alternator a power steering pump and a sanden AC compressor. What setup should I be looking for? CVF says I have the hi flow matched pulley set

[tom s]

Small water pump pulley is important!

[max 93]

I was looking at CVFs website and see that they say the water pump pulley is 8” and the high flow crank pulley is 7.4”. I’m not sure that I was looking at the same setup that you have though.

[68WarDog]

CVF says I have the hi flow matched pulley set[/QUOTE]

You may have to call BS on CVF, as I requested the high flow crank pulley, but in the std( wp- ps and alt pulleys) I received the 6.25 crank pulley . I will be changing it out for either the 7.4 or 8" before putting this engine into service.
Measure the unit and not take CVF word.

[HWYSTR455]

So you picked up some vacuum with adjusting idle speed, that's a positive sign.

You are running your vacuum advance on full time manifold vacuum, correct? You need to know what your total advance is at idle. You should have over 20 degrees at idle, where you need it.

You did set your timing at idle with the vacuum advance disconnected, right?


.

[tempest1964]

Originally Posted by 68WarDog

CVF says I have the hi flow matched pulley set

Measure the unit and not take CVF word.[/QUOTE]
This!

[Singleton]

He's running the 8.0" crank pulley and the 6.2" water pump pulley, overdriving the water pump 29%. Pulley ratio is not the problem

[JSchmitz]

Do you have one of these or equivalent? https://www.summitracing.com/parts/h...yABEgK3UvD_BwE

If not, get one.

[grivera]

Originally Posted by JSchmitz

Do you have one of these or equivalent? https://www.summitracing.com/parts/h...yABEgK3UvD_BwE

If not, get one.

That is what I sent him with the spring mod already done

[JSchmitz]

Originally Posted by grivera

That is what I sent him with the spring mod already done

Roger that. Nothing better, that I've found, for severe cooling needs. What do you think cools my 3/4 ton GMC truck? A big a$$ engine driven fan. I didn't have to do a thing to the clutch on my GTO. Worked flawlessly right out of the box. You could hear it engage and roar. Would show on a timeslip if it kicked in at the track. Don't recall exactly how much. It puzzled me for a while. lol

[64speed]

Talked to Derale. Ordered the 17118 and gonna use it with the fan clutch I got from Grivera. I am also gonna take the car to my friends shop that races a Pontiac when I have some money to pay him and see where we are.

[TB1]

Originally Posted by 64speed

Talked to Derale. Ordered the 17118 and gonna use it with the fan clutch I got from Grivera. I am also gonna take the car to my friends shop that races a Pontiac when I have some money to pay him and see where we are.

Not to be the the bearer of bad news but the 17118 will hit the fan shroud unless you sold it, I saw it up for sale the other day? The 17117 will fit without interference and proved to cool my car just fine. I initially bought the 18" thinking no problem with the shroud but no luck, tried moving in around but didn't have the clearance and as soon as the engine torques over its a mess.

[grivera]

Originally Posted by 25stevem

Here is a issue that may be a big part of your problem and forgive me that it just came back into my mind.

If your running a Edelbrock intake they have a big potential problem with the water crossover.

That being the opening in each side of the cross over is at least 1/4” smaller all around( circumference) then the outlet in each head!

This makes for a massive restriction and when I gasket match a Edelbrock intake it’s the first thing that I go after and gasket match!
I would be willing to bet that if you address this your hot running issue is reduced by 75%, if not completely.

Is this proven to help with cooling? If so I will do mine as I have a separated x-over in my RPM intake.

[64speed]

Originally Posted by TB1

Not to be the the bearer of bad news but the 17118 will hit the fan shroud unless you sold it, I saw it up for sale the other day? The 17117 will fit without interference and proved to cool my car just fine. I initially bought the 18" thinking no problem with the shroud but no luck, tried moving in around but didn't have the clearance and as soon as the engine torques over its a mess.

Do you have the small radiator?