602 crate motor radiator size

[pigpen52]

Will a 19x26 single pass (which I have) radiator cool a 602 crate engine...or do I have to have a double pass radiator.

[claybuster]

We are using a 10yr. old single pass 19xwhatever the common LM radiator with 1:1 pulleys, shroud, 4-blade GM fan,no holes in the front, with a little duct work under the nose.
This is on a 604, bad thing is the 602 dont have the 4-corner cooling. (right?)

[Egoracing44]

Clay buster. We run a 604 just like you said without any of the external cooling lines. They were trapping air and were causing overheating problems so we got rid of them and out temp problem went away also.
1:1, Shroud, GOOD PUMP!!!!!, nothing in the neck, GM 4 blade fan and a little ducting. No holes in the nose and 170temps. Don't just buy ANY steel 4 blade fan as I have seen some that were having temp problems and the fans were not pitched enough. They got them for a few $'s less than the AFCO/GM ones and they would not move the required air.

[pigpen52]

Thanks, so afco is like the gm one...I dont like the gm because it is not slotted for larger bolt pattern....I will also be running the grooved (not v) belt, I heard once you have to run an aluminum fan with this...any truth to this?

[claybuster]

Like Ego says, beware of the imitation 4 blade fans I have seen one and noticed right of the bat it dont have near the pitch. I think that Terry at performance connection has the good ones. We use the GM ones. www.theperformanceconnection.com

[Egoracing44]

Thanks, so afco is like the gm one...I dont like the gm because it is not slotted for larger bolt pattern....I will also be running the grooved (not v) belt, I heard once you have to run an aluminum fan with this...any truth to this?

NO we run a steel fan along with probably about 99% of all of the other racers.

[billetbirdcage]

Thanks, so afco is like the gm one...I dont like the gm because it is not slotted for larger bolt pattern....I will also be running the grooved (not v) belt, I heard once you have to run an aluminum fan with this...any truth to this?

Ego, could better answer this since he runs crates and if they can use them on a crate engine: Be careful with some of the serpentine belt set-ups as they don't rap around the water pump pulley enuff to give enough belt contact so it doesn''t slip with a good fan.

I seen far to may people have problems with them on open LM's, so myself I'd stay clear of the serpentines and stay with a good double v belt set-up.

[claybuster]

Grooved, meaning serpentine? I heard of a lot of slip issues, and then they come out with a kit that uses a idler pulley.
BB, have you heard af slipping even with the idler setup? I remember a while back there was discussion on good v-belt pulleys vs. cheap, one being Coleman and I thought you had mentioned another that will last a lot longer?

PP52, I was curious how one of them aluminum fans would work, we have one but never bolted it on cause of the max rpm that is recomended, it would probably hold up on a crate but dont know if it will move enough air. Just didnt want to risk taking a radiator or a motor out for a few HP.

[3dirtLm]

if a person can cool a 750 hp 14-1 engine with a single pass rad theres no reason to think you need a double pass with a 9-1 400hp engine. Most cooling problems come from the lack of understanding of how to move air though the radiator not the capacity of the rad to disapate the heat.

[Egoracing44]

if a person can cool a 750 hp 14-1 engine with a single pass rad theres no reason to think you need a double pass with a 9-1 400hp engine. Most cooling problems come from the lack of understanding of how to move air though the radiator not the capacity of the rad to disapate the heat.

A LOT of the engines I have seen over heat that were running a shroud had an aluminum box with a hole in it. This only allows air to come through right in front of the fan. The air in the corners actually comes through and stops so even while running there are high pressure areas in the corners of the box. This gets compounded by the air "sling off" from the fan. As it rotates some air spills over the tips and will get trapped in the box and further stop air motion. A good shroud should funnel air from the whole width of the radiator to the fan and allow it to flow from the rectangle shape of the radiator to the round shape of the fan. The best I have ever made was an aluminum mount at the radiator and it was plastic to the fan. The plastic was a material like the typical race car plastic but a little thicker. At the fan we made a round shape from aluminum and glued it to the plastic. This was all glued to keep air flow smooth and keep any turbulence to a minimum. In front I made a top piece like a stretched out backword S that went from the top of the radiator to the nose piece. I placed sides on it from the radiator to the maximum width of the piece I could fit on the top but no bottom only a 4 inch piece of plastic to slightly scoop air up. This was on a dirt limited late model running a flat top 2 bbl motor. This car was run with a 6 blade plastic fan and never overheated. We even tried running 10 laps in practice with no fan and during the run the temp stayed around 170 but when the car slowed the temp shot up to 220 and we pulled off.
3dirtLM the crate engines are built tighter and do run hotter than almost any other engine I have ever been around. As for the double and triple pass radiators I do not agree with them. A lot see success but they also go from running an open system with the single pass to a closed system with the double an triple pass radiators and I believe that is what makes the major difference. Also is the fact that the double and triple remove the radiator cap from the pressure side of the radiator like a closed system and the pumps stop lifting the cap and causing the system to loose water.

[2dumb2kwit]

Thanks, so afco is like the gm one...I dont like the gm because it is not slotted for larger bolt pattern....I will also be running the grooved (not v) belt, I heard once you have to run an aluminum fan with this...any truth to this? It's not a crate motor, but limited motors, around here are around 475hp 2bbl, turning 6800 to 7000 rpm. Alot of guys (including me) run serpentine set-ups, with 4 blade steel fans, without problems. One thing to watch out for, is that alot of the serpentine set-ups have alot of reduction. The one that I run is 12.5% reduction, but alot of kits are 30% reduction.

[Egoracing44]

It's not a crate motor, but limited motors, around here are around 475hp 2bbl, turning 6800 to 7000 rpm. Alot of guys (including me) run serpentine set-ups, with 4 blade steel fans, without problems. One thing to watch out for, is that alot of the serpentine set-ups have alot of reduction. The one that I run is 12.5% reduction, but alot of kits are 30% reduction.

I agree, I looked at some once that were advertised at 30% but the numbers were more like 43%. Be careful if you go this way. We just use a regular AllStar 1:1 pulley/Belt set.

[billetbirdcage]

Grooved, meaning serpentine? I heard of a lot of slip issues, and then they come out with a kit that uses a idler pulley.
BB, have you heard af slipping even with the idler setup? I remember a while back there was discussion on good v-belt pulleys vs. cheap, one being Coleman and I thought you had mentioned another that will last a lot longer?



Most of the problem comes from the small diameter they use when they make them pulleys. Alot of your v-belts will have a water pulley around 7", so if the belt goes around the pulley 90 degrees that is 1/4 of the circumference (Pie- R - squared = 3.5 x 3.5 x 3.14 = 38.465 / 4 = 9.61" of belt contact of on pulley). Alot of the serpentine pulleys are small diameters like 4" or so, that works out to only 3.14" of belt contact and even at 5" that is only 4.90" of contact. You can see as you get smaller diameter you loose alot of contact area with the pulley to turn it or keep it from slipping.

An idlers is usually used to make the belt rap farther around the water pump pulley and gain contact area, but now you have one other thing to go wrong. Also dpending on sizes, if the idler is 25% smaller then the lower pulley it is going that much faster then the RPM of the engine. Dpending on the sizes you could get an idler going pretty fast on a open engine. Just one more thing to worry about.

Any pulleys you buy should be hard anodized as they will last much longer then the plain aluminum ones as they always wear out the lower pulley after a year or slightly more. The gooves get wide and the belt runs on the bottom of the groove not the sides of the v like it is supposed to and will cause the belt to slip when there is high load from the fan pulling air and then over heating or belt throwing.

[2dumb2kwit]

(Pie- R - squared = 3.5 x 3.5 x 3.14 = 38.465 / 4 = 9.61" of belt contact of on pulley).


Billet, I hate to disagree with you, but pie-r-round.........cornbread-r-square.

[pinionangle]

Billet, I hate to disagree with you, but pie-r-round.........cornbread-r-square.

HAHAHAHAHAHAHAHAHAHA Now thats funny!


All joking aside, I run the KRC "Crate" kit on my 604 and it works great with a double by-pass radiator and minimal duct work. I have over heated it once when the power steering pump loosened up a bit.

You have to stay on that belt. Its just part of it.