cooling a 400 sbc

Kyle · August 07, 2012, 06:29:08 AM

I had my 400 in my truck for a while. Got tired of it rummimg at 210 degrees on the really hot days so I picked up some electric fans. But they don't seem to cool as well as the mehanical and it don't make sense.... the manufacturer claims they pull 4000 cfm together which in the fan world is good cuz the realy expensive ones only pull 3k a peice. And these are 14" fans. I don't have a shroud around them, does that matter? Cuz I can still feel them drawing air thru the grill... sitting in idle at work tonight it was runnin 190, I turned the fans on and the tem just stayed there, didn't drop at all. And I have a 160 stat in the truck too....

MR NASTY · August 07, 2012, 11:32:43 AM

You need a dual pass aluminum radiator with some b cool additive

betterbeaters · August 07, 2012, 01:41:41 PM

what size rad is in your truck 4 core?

doughchvy1 · August 07, 2012, 01:46:06 PM

pull that 160 degree thermostat out and put a 180 degree in. with the 160 degree t-stat in there it is not allowing the coolant to stay in the radiator long enough to cool down before re-entering the motor. 180 is normally a happy medium or if this is not a daily driver you can purchase a t-stat restrciter plate which will slow the flow down enough so the coolant and cool of before re-entering the motor

4x4xdodgeman · August 07, 2012, 03:15:08 PM

there kit out that you drill into the rear of the intake water jacket and run hoses up to the t-stat that help cools the rear of the motor cool. but if your timming is off that will cause it to run hot and running lean will do it to.

Hammerlane · August 07, 2012, 04:20:51 PM

Nothing wrong with 190 deg..
even 210 is well within tolerance..
and yes, a shroud will help ALOT!

check radiator for mud in the cooling fins too.

Kyle · August 07, 2012, 07:15:12 PM

Quote from: Hammerlane on August 07, 2012, 04:20:51 PM
Nothing wrong with 190 deg..
even 210 is well within tolerance..
and yes, a shroud will help ALOT!

check radiator for mud in the cooling fins too.

cooling fins are all clear. i even pulled out the ac condenser unit so there is NO RESTRICTIONS of air at all. i wasnt sure the shroud was gonna make a difference cuz its dual fans and they cover most of the rad as it is....

Quote from: 4x4xdodgeman on August 07, 2012, 03:15:08 PM
there kit out that you drill into the rear of the intake water jacket and run hoses up to the t-stat that help cools the rear of the motor cool. but if your timming is off that will cause it to run hot and running lean will do it to.

my intake already has the holes drilled and tapped in the coolant passages in the front and in the back. was trying to avoid it cuz it would be a pain in the ass to do in the truck and my fuel press regulator and wiring goes along the back of the intake....

Quote from: doughchvy1 on August 07, 2012, 01:46:06 PM
pull that 160 degree thermostat out and put a 180 degree in. with the 160 degree t-stat in there it is not allowing the coolant to stay in the radiator long enough to cool down before re-entering the motor. 180 is normally a happy medium or if this is not a daily driver you can purchase a t-stat restrciter plate which will slow the flow down enough so the coolant and cool of before re-entering the motor

but it will cool down when i start driving... how does that make sense? would the thermostat really effect that?

Quote from: betterbeaters on August 07, 2012, 01:41:41 PM
what size rad is in your truck 4 core?

stock for a 350. not sure if its dual or single core. but its brand new...

RaZiN KaNe · August 07, 2012, 07:49:12 PM

Quote from: MR NASTY on August 07, 2012, 11:32:43 AM
You need a dual pass aluminum radiator with some b cool additive

when i was running my lil 406 it would run around 210-220 and that was with a tripple pass be cool radiator with dual 12" fans that were shrouded..400s are known for running hotter than other small blocks....unless u get above 220 i wouldnt worry about it to much...

betterbeaters · August 07, 2012, 09:20:02 PM

buy a bigger rad.

BAD APPLE · August 07, 2012, 10:34:03 PM

Run two radiators

Mudbuster · August 07, 2012, 11:20:33 PM

Quote from: betterbeaters on August 07, 2012, 09:20:02 PM
buy a bigger rad.

x2 and make a shroud...

Kyle · August 08, 2012, 02:06:50 AM

Bigger rad is on the list. Gonna run some cooling lines from the back of the motor to the front to help flow. Might as well anyways since the coolant is gonna be drained anyways

Jthomas · August 10, 2012, 07:38:33 PM

the 400 blocks are symese cylinders, so yea they will make more heat, but a bigger rad and shroud will make all the difference

xjs3667 · August 10, 2012, 08:59:37 PM

yep you need a shroud for a fan to work effectively

Boggen Joe · August 10, 2012, 10:39:07 PM

You can run a cooler plug like a ac r43t that helps a lot. If your running over 12* of timing it will run little hotter
A fan shroud is a must. Also run some wetter water in it, it cooled mine bout 15*

Jthomas · August 11, 2012, 12:20:48 AM

^^^ x2

Actually the motor runs cooler with more water instead of more coolent.

Ie: if u ran 100% coolant and no water, it would run hotter than if u had a 60-40 ratio or more

Kyle · August 11, 2012, 06:23:07 AM

I knew from the very start it was gonna hold more heat. The way it is works but just on the hottest of days it runs a lil on the high end. I ant run cooler plugs due to the headers and can only fit accell shortys. I've got the hyper lubbe in the coolant with about a 5050 mix. And my timing is around 14*.... I just gotta wait till the next chek and I can order the rad. Goin 4 core so I know ill have enough cooling to it