Why control dual cooling fans seperately?

[JRouche]

JR I am experiencing the same issue as you: 1970 Camaro RS with a GM zz383 properly timed, carbed. Running a large Alumitech radiator and Lincoln Mark VIII fan, 180 Robert-Shaw stat, manual trans.

Driving around town at low speed the engine will be perfect around 185-190, but when I go for a long cruise on the freeway (especially in 5th gear) the engine will be down around 165-170 which is way too cool; you can definitely notice poor fuel atomization occurring. The engine wont tug as hard, especially in 5th gear.


I THINK part of my issue is having a cowl induction hood which is not sealed to the air intake causing extreme airflow through the radiator and out the cowl scoop at 75mph. Since the cowl scoop is above the engine (obviously), all heat rises out. If it was sealed I have a feeling that engine heat would remain trapped under the hood, resulting in more stable temps.

Also possibly running a higher concentration of antifreeze in the coolant (I'm at 30% AF and 70% H2O right now) will reduce its thermal efficiency and get the temps where they should be.

Any ideas and/or insight would be greatly appreciated.
Matt

Oh Cool Someone else with a cold engine.

You might be able to keep some of the heat in the engine compartment by reducing the air flow. Not a bad thought.

But Im thinking it will increase the under hood temps more than getting the block warm. You really want a warm block and the under hood temps cool (specially if you are pulling intake air from inside the engine compartment) .

An internal combustion engine is really inefficient. But, thats what we are working with.

For it to be efficient, meaning fuel use and max power it needs to be really warm, but be able to shed the heat also. Thats where the radiator comes into play. We want the combustion chamber to be pretty hot but not heat soaked.

Ideally it would be a very cold chamber on intake then be a really hot chamber on firing. The perfect engine isnt here yet. But EFI is the closest.

I dont think increasing the under hood temps is a fix.

A happy engine is one that produces ALOT of heat but that can still bleed it off so its not heat soaked. Cool on the outside and warm on the inside.



Ideally its an engine that is really hot running but the cooling system can keep it within a certain temp.

I like to see 185-190 for my EFI engine throughout the driving range.


I dont know. Im ready to install a cooler for an A/C unit next, I need more blockage. My stat is perfect for idling around town, it sets at 180 on the button. But with highway speeds the engine is a lil too cold at 165* JR