View Full Version : hot running Chevy 350

16-08-01, 03:39 PM
has anybody experienced the same and can give advice....
I am running a modified 350CUI Chevy in my car with two 12" SPAL pusher-fans (no shroud). When driving under hot conditions (30+ degree C.) on all kinds of roads, the engine-temp rises constantly up to 95 degrees and more, even with the fans on (manual switch). I understand that the temp goes up when idling but it confuses me, that it doesnīt cool down when cruising through countryside or on motorways.
There is no problem at all with the outside-temp up to 25 degrees C. but if itīs getting warmer, there is no way to lower the temp again.

Has anybody experiences something similar and found a solution ? Is it a timing-problem? do I need to have a shroud ? change pusher to puller-setup ? Any ideas ?

16-08-01, 04:01 PM
I had a similair problem - cured completely with a change to a lower temp thermostat

16-08-01, 08:04 PM
Hi there two questions one where is your temp sender fitted two where is your fan sensor fitted

16-08-01, 08:15 PM
You may also want to check your carb adjustment - my engine (Chevy 350) used to run hot when the carb was set too lean.

Nigel B

17-08-01, 02:01 PM
Joker - you might want to bear in mind that "Puller" fans are more efficient for cooling than pushers. The lack of any shrouding in your installation also won't help.

If changing the thermostat/checking timing/carb mixture etc doesn't help, you might think about adding a third, "pulling" fan to assist airflow through the rad. I have two 12" puller kenlowes on my 408 cu in stroker 351W (using a 3 row SD1 rad), have no cooling problems at all, even in latest hot weather and pushing it! Also have been stuck in traffic for an hour in hot weather with no problems, apart from hot footwells!

hope this helps


17-08-01, 03:02 PM
Paul, my temp-sender is fitted on the intake manifold, no fan-sensor since I run a manual switch-setup.

Wilf, I heard about the puller being much better than the pusher-fans quite often in the meantime. I guess, Iīll rebuild it (or possibly add a third one as a puller) and then see if it works that much better. Are you using any shrouds with your puller-fans ?

Does an aluminium-rad lead to significant changes ?

17-08-01, 08:05 PM
Be aware that to change a pusher fan into a puller fan requires flippling the blades around because their profile is such that they are MUCH more efficient one way round than the other. Also, make doubly sure you have no air locks in the system. Is you expansion bottle at the highest point, and does the air bleed line to the tank come off the highest point of the engine? ie the thermostat housing.

Finally, are you using SMITHS instruments?, they require a voltage regulator which needs wiring in the circuit and also has a right way up in which to physically mount it. If not you will read higher values.

RigMan :-)

18-08-01, 12:46 PM
Joker - yes, the twin kenlowes I am using come with their own shrouds. It significantly improves the efficiency of airflow through the rad. Not sure whether ali rads are thermally more efficient - it would depend on the thermal coefficient of conductivity of ali vs copper, and I don't have an engineers handbook to hand to look it up. Ali rads lighter tho', and definitely have more "pose" value!