Hi Guys,

I am trying to find out the maximum safe working temperature for a K motor (7K-E) is. Hope you guys will be able to help me out. I put in a 7K motor and kinda have a DIY radiator setup. I need to calibrate the start and stop for the radiator fan but do not know what range I should set it for. Also, I want to fix up warning light for the max safe temperature. I do not have a dash indicator for the same motor and even if I have one I am not sure if it would be accurate. I would like to get the values in degrees.

Give me a shout if you can help me here please.

Cheers!

Most K engine thermostats I've seen open up between 82*C to 88*C. And I'm pretty sure engine coolant mixed at 50/50 will boil around 110*C with a 1 bar radiator cap (couldn't be bothered calculating it). So I guess those are the parameters.

 

The coolant temp for under normal driving conditions is probably going to sit at around whatever temp the thermostat opens, so you would probably want the thermo fan to kick in a bit higher so it isn't running all the time. I can't really give you any values because I've never owned a thermo fan nor a proper water temperature gauge until now, but neither are hooked up.

 

And I think Autometer or VDO (can't remember which one) make temperature warning switches/senders in varying temperatures, they would be good for hooking up your temperature warning light.

 

Edit: The Tridon website says the factory K engine thermo fan switch kicks in at 95*C and cuts out at 90*C.

Edited February 4, 201313 yr by rian

Yeah k's should run at 79-83°c iirc.

I got've my ecu turning on the thermo at 95 and off at 85, but I've also got a big commodore radiator.

Simliarly when i had a simliar controller on my car with the 4k, i turned it on at about 95 turned it off around 85.

 

Though it pretty much never came on unless i was sitting in traffic for more than about 10mins.

 

When driving normally the cooling system should regulate the temperature around 85 deg. Only when you stop you will see it starting to creep up above this.

We make max HP on the dyno at about 72 degrees, and never go past about 90 otherwise we start seeing bits of piston on the plugs.

i use a digital controller for my thermo fan. It turns on at 95 and off at 85. car usually sits around 78-82 in mild weather, 75 at night. is a 4k oversize pistons, hot cam, elec dizzy, 4-1 extractors stock carb.

ive always wanted to know this. i put up a post months ago about a perfect operating temp, i know some motors will run better colder, some hotter, i guess a dirty stinkin old pushrod non-crossflow would benefit from cooler temps. i guess run the fan cool but it all suits your outside temps and other factors.

Thanks guys... Brilliant inflow of information... :thumbsup: I guess I should make it 85 - 95 then. My radiator is small so I thought of using a remake one and try to get same area as the radiator for KR 42 (out of which the 7K came out). It is a twin row and i approximated it to count twice the area (I heard that it will not be doubled as the second row will not get same temperature difference as the first row). I cannot fit the same radiator as the KR 42 so I am fixing this. Hope I am doing right and anything to share, advice is welcome.. :paperbag:

 

KR 42 - 678 (w) X 452 (h) X 1 (rows) = 306,456 mm2

Project - 540 (w) X 360 (h) X 2 (rows) = 388,800 mm2

Edited February 5, 201313 yr by hasitha