Radiator Question

[Ralphy]

Of the two, single pass or double pass, which radiator does a better job cooling a limited late model all steel 358 motor?

[perfconn]

Never used anything but a single pass.Never needed to.

[26-62 racing]

We have always ran an afco single pass, with no problems. What you are looking for is a complete package. Fan size, pulley sizes, type of belts, and the shroud is very important. Buy or build the proper shroud to make the fan pull all the air through the radiator. We have not put holes in the front nose for years, overheating has not been a problem. Once the cooling system is properly set up, it will be one less thing to worry about. Mike

[Ralphy]

Thanks guys. Going to drop a single pass in it.

[hpmaster]

I went to a double pass about 5 years ago, threw away the shroud, closed the nose, no holes. Only thing is to get a fan spacer or move the radiator back so the fan, a 19 inch GM 4 blade is a REAL one inch away from the radiator. Been runing that on a 18 degree 421 and a 12 degree 440 LM open motors with zero heating issues.

[TWISTER]

We have been experiencing some warmer water temps than normal conditions as well this year. We run a double pass radiator with a shroud and still have trouble sometimes running warmer than we like. Was gonna try and put some duct work in it this week to see if that helps. Our car has the nose "planted" all the way around the track so i know thats not helping any. we run all steel 365 limited motor. Any ideas to help?

[hpmaster]

We have been experiencing some warmer water temps than normal conditions as well this year. We run a double pass radiator with a shroud and still have trouble sometimes running warmer than we like. Was gonna try and put some duct work in it this week to see if that helps. Our car has the nose "planted" all the way around the track so i know thats not helping any. we run all steel 365 limited motor. Any ideas to help?

I am real believer in a double pass radiator and the GM 19" fan #405442 when put an inch away from the radiator. Did that and never had a problem again. I must of tried a half a dozen fans and shrouds before that one without a shroud.

[TWISTER]

We are using a PRC double pass radiator with the GM 405442 fan about 1 1/8" from the radiator. I dont see a lot of people running shrouds in my area, maybe i am going the wrong way?

[26-62 racing]

Their is always more than one way to fix a problem, we have always ran a shroud with the GM 19'' fan and that has solved any cooling problems. We have always built our shrouds and they are a LOT of work. If you are having no problems with over heating LEAVE it alone. I have been on this earth long enough to finally figure it out , THAT IF IT AIN'T BROKE DON'T FIX IT....... MIKE

[Lizardracing]

I went to a double pass about 5 years ago, threw away the shroud, closed the nose, no holes. Only thing is to get a fan spacer or move the radiator back so the fan, a 19 inch GM 4 blade is a REAL one inch away from the radiator. Been runing that on a 18 degree 421 and a 12 degree 440 LM open motors with zero heating issues.

Why do you say a n inch? Why not closer?

[RW57]

Talking about shrouds I saw a Feature on an asphalt modified in speedway illustrated that only had the fan enclosed with a circle the driver said when they had normal type shroud it ran hot so his Dad came up with that. I did one on my sons limited type late model it was super easy to make no over heating at all and it pulls the heck out of air thru the radiator much better than the full shrouds I have built now it is limited to the fan diameter anyone got any thoughts on this.

[Lizardracing]

Talking about shrouds I saw a Feature on an asphalt modified in speedway illustrated that only had the fan enclosed with a circle the driver said when they had normal type shroud it ran hot so his Dad came up with that. I did one on my sons limited type late model it was super easy to make no over heating at all and it pulls the heck out of air thru the radiator much better than the full shrouds I have built now it is limited to the fan diameter anyone got any thoughts on this.

My guess is the pressure drop across the core is greater due to the controlling of air spillage off the end of the blades.

[hpmaster]

Why do you say a n inch? Why not closer?

A couple of different fan manufacturers over the years said an inch alowed enough room for most clearance possibilities and insured the air was pulled thru the radiator. Past that I have no other reason other than an inch is pretty darn close.

[Lizardracing]

Great to know.
On my car I can only get 3/4" but no further. I've haven't chewed up any radiators. Yet.