Post by racer96m on Oct 18, 2014 23:59:58 GMT -6
I continually get asked questions about overheating, so I thought I would post my experiences with cooling systems. Hope this helps someone. Let’s start with the basics. Nothing cools better than water, so don’t mix any antifreeze in with it. I like to use Water wetter or an additive like it not so much as a release agent but as a corrosion preventive in the water.
Next, water pumps. Stewart makes a nice pump, put they are pricey. I have 2 friends that build engines. One builds engines for Mullins and one builds cup engines for PME in Charlotte. They both race mods and both use an Allstar ALL31105 pump. Nothing special $85.00 Alum pump, that works just fine up to 9000 rpm.
The biggest thing with cooling is the pump and fan speed. 1 to 1 ” V” belt pulley setup works best for a gas motor and you can go with a 15 or 20% reduction for alcohol. Here’s the thing, a lot of people will use reduction pulleys and run to hot because all “V” belt setups slip and it’s very hard to calculate the slippage. As the pulleys get older they wear from the slippage and now slip even more. With your motor not running, grab your fan and try and turn it. If you can move it, its slipping big time at 6000rpm and above, so a 1 to 1 pulley setup slips so bad that it ends up acting like a 15 to 20% reduction, that’s why 1 to 1 works better on gas. I got tired of changing worn out V pulleys so I went to a Jones Serpentine Pulley setup. Serpentine has Zero slippage so I run a 20% reduction for 8000rpm.
Fans, best fan ever made was the Chevy 4 blade fan. It has the most pitch on the blades, so it moves the most air. Pretty much the standard used by all. They reproduce the fan, I believe Allstar has it ALL30105, but many carry them.
Radiators, I like a Double pass, but nothing wrong with a single pass. I don’t see the need for a triple pass, way too much restriction. I never run a restrictor, ever. If everything else is correct with your cooling system, you will be able to run cool in the longest race on the hottest day. Last thing to talk about is a fans shroud. It’s a must! It needs to be tight, no more than 1/2 in clearance from the blade tips and the fan blades should be half in and half out of the shroud for maximum cooling effect. One other thing. If you run a closed nose car, no need to cut a bunch of holes in the nose, it just lets more dirt in. I like a 4in wide strip of plastic mounted below the radiator to deflect air from under the nose, up into the radiator. It has a big effect.
Well, that’s about it. Hope it helps you some if you are having cooling problems.
Dave
Next, water pumps. Stewart makes a nice pump, put they are pricey. I have 2 friends that build engines. One builds engines for Mullins and one builds cup engines for PME in Charlotte. They both race mods and both use an Allstar ALL31105 pump. Nothing special $85.00 Alum pump, that works just fine up to 9000 rpm.
The biggest thing with cooling is the pump and fan speed. 1 to 1 ” V” belt pulley setup works best for a gas motor and you can go with a 15 or 20% reduction for alcohol. Here’s the thing, a lot of people will use reduction pulleys and run to hot because all “V” belt setups slip and it’s very hard to calculate the slippage. As the pulleys get older they wear from the slippage and now slip even more. With your motor not running, grab your fan and try and turn it. If you can move it, its slipping big time at 6000rpm and above, so a 1 to 1 pulley setup slips so bad that it ends up acting like a 15 to 20% reduction, that’s why 1 to 1 works better on gas. I got tired of changing worn out V pulleys so I went to a Jones Serpentine Pulley setup. Serpentine has Zero slippage so I run a 20% reduction for 8000rpm.
Fans, best fan ever made was the Chevy 4 blade fan. It has the most pitch on the blades, so it moves the most air. Pretty much the standard used by all. They reproduce the fan, I believe Allstar has it ALL30105, but many carry them.
Radiators, I like a Double pass, but nothing wrong with a single pass. I don’t see the need for a triple pass, way too much restriction. I never run a restrictor, ever. If everything else is correct with your cooling system, you will be able to run cool in the longest race on the hottest day. Last thing to talk about is a fans shroud. It’s a must! It needs to be tight, no more than 1/2 in clearance from the blade tips and the fan blades should be half in and half out of the shroud for maximum cooling effect. One other thing. If you run a closed nose car, no need to cut a bunch of holes in the nose, it just lets more dirt in. I like a 4in wide strip of plastic mounted below the radiator to deflect air from under the nose, up into the radiator. It has a big effect.
Well, that’s about it. Hope it helps you some if you are having cooling problems.
Dave