Cooling issue with underdrive balancer
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Teching In
Joined: Oct 2010
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From: Trinity, FL
Cooling issue with underdrive balancer I have an LS3 crate motor in a '64 Skylark. I'm using a Holley LS swap accessory drive with an underdrive power steering pulley, necessary to clear the power steering box. After ignoring Holley's recommendation that I use an underdrive harmonic balancer to reduce the speed of the power steering pump, I blew out the power steering pump. I installed a Powerbond 25% underdrive balancer along with the new pump and now the engine is running hotter. Hotter but not overheating. I do get a little uncomfortable at a red-light or in traffic as the temps starts creeping above 210 and the Spal fan is running overtime. As soon as the car starts moving everything is fine. A smaller water pump pulley is an option but not with a stock water pump. Has anyone tried the Edelbrock LS water pump? They claim increased flow at low speed but without any numbers to back that up I'm skeptical it will solve this issue, and at $500 it's a little pricey to experiment. That pump also has a traditional hub with a bolt on pulley so there is always the chance I can find an after market pulley with a smaller diameter. Thanks.
Bill
Bill
Thread Starter
Teching In
Joined: Oct 2010
Posts: 5
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From: Trinity, FL
Smaller. Water pump needs to spin faster. The stock balancer/water pump pulley ratio is 7.36/5.89, or 1.25:1. Current ratio with the smaller balancer is 5.53/5.89, or .94:1. I would need a 4.4" water pump pulley to keep the 1.25:1 ratio. Right now the water pump is turning less RPM than the engine. The Edelbrock water pump has a hub that accepts a bolt on pulley, so I would need to find one with something close to the 4.4" diameter and same backspacing. Maybe I should look into an aftermarket power steering box that is smaller than the stock GM box and go back to the stock size power steering pulley. Might be cheaper that way.
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Joined: Aug 2010
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From: Ann Arbor, MI
Are you using a modern aluminum radiator?
Are the electric fans working well?
Have you considered adjustable LS mounting brackets to perhaps move the engine forward or back a bit to clear the PS box?
Are the electric fans working well?
Have you considered adjustable LS mounting brackets to perhaps move the engine forward or back a bit to clear the PS box?
What's your idle RPM at? That LS3 Engine should have a Cam in it so I'm pretty sure it's not 500RPM like something stock.
Radiator and Fans are my question also. 25% that's a decent bit to underdrive it.
Radiator and Fans are my question also. 25% that's a decent bit to underdrive it.
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Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
I'll bet $5 it has nothing to do with the pump speed, but instead the radiator, the thermostat or cooling fans. If it turns out to be just the pump speed, I'll Paypal $5 to the OP.
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Verdad Gallardo I have a 10% UD Pulley on a healthy Cammed 6.0l in my Monte SS, idle is 820RPM because that's what it wanted to be stable. Going lower yea I can get some more chop out of it but it starts getting sketchy with the tuning. When I was doing the tune that's just what it is. Car drives like it's stock.
25% UD in my case the Accessories with stock sizes would be spinning at the speed of the Engine being at 615RPM. As said above there's a few questions here.
25% UD in my case the Accessories with stock sizes would be spinning at the speed of the Engine being at 615RPM. As said above there's a few questions here.
Teching In
Joined: Apr 2018
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When I put the 6.0 in mine, used a 25% underdrive. Always ran hotter than I liked. Hard time keeping it below 210. Finally gave in and installed a ATI standard size balancer, it made a difference. It now runs usually 200 to 205. That is where I want it. Keep in mind i do live in the Phoenix area.
Edelbrock pump pulley is actually slightly larger dia vs stock. It has to be to clear the removable cartridge design while spinning.
there was posted figures a long time ago when evans was still in the waterpump biz. Theirs and edelbrocks were about the same increase in flow, (10-15% iirc) but the bigger improvement was putting equal flow to ea side. Stock pump is kinda bad at distribution, so one head will be hotter than the other.
there was posted figures a long time ago when evans was still in the waterpump biz. Theirs and edelbrocks were about the same increase in flow, (10-15% iirc) but the bigger improvement was putting equal flow to ea side. Stock pump is kinda bad at distribution, so one head will be hotter than the other.