602 crate motor radiator size

[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.