Hey there.

I'm having temp issues again (I think). I'm running twin electro fan (between grille and radiator) with no permanent fan fixed on the engine. I moved to this setup cuz I wanted to free some ponies, cuz I love the cool look of the engine w/o the steel fan, and not primarily but important enough cuz I was having temp issues (annoying tendency to run on the HOT side). I've tried my setup with no thermostat, then I installed a 213 °F thermostat. In this both cases I've tried several senders for my fans... I'm using the one that seemed to work better, but still I'm not 100% satisfied. My sender is actually a 239/226 unit. So far I've tried this temp ranges: 213/195 - 215/202 - 226/213 etc etc. It seems like after a while of using the car the fans wouldn't cool under 220 or so, so the senders keep the fans on working almost permanently in city and highway drive. I took the car to the road and noticed that if the sender starts the fans, it wouldn't cut the signal till I, i.e. stop for refuel and the fans have the chance of lowering all the rad temp to almost 180, then I hit the road again and they wouldn't start.
My engine has shaved head and block, but not over .100 (I think that numbers are around .075 to .060 overall) with steel gasket...
May I point to the radiator itself?

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Juan Ignacio Caino

Please use e-mail button istead of PM'ing. I do log in sometimes but I'll be answering quicker thru e-mail.

Happy New Year, Juan.

A few things:

• The correct thermostat rating is 82°C (180°F).
• Does your overheating occur at low speeds (idle, stuck in traffic) or at high speeds (say, over 70 km/h)?
• What indication of overheating do you have, aside from the dashboard gauge reading high?
• Any luck on my Valeo lights?

And where did you install the temp sensor for the fans?

I use a two speed ford-taurus fan with the temp sensor mounted on the top radiator tank, the side towards the engine. Works well.

Those thermostats do seem kind of high. I believe I am using a 180thermostat and set the fan controller to come on at 190-200 give or take. It has a built in 10 degree window, so will turn off when temp reaches 180-190.

hey guys

thanks for your tips. seems like I misconverted between F and C

my thermostat is 82°C

senders ive tried so far are

92°/87°C (this is the one I'm using)
87°/79°C
83°/79°C
82°/79°C

all the cooler ones stayed on almost permanently after a while of town driving. In the road, all the cool senders would remain off if the temp was low enough before hitting the road, but if they where on before cruisin (say, if I got stucked on traffic before I could hit the highway) it wouldn't go off even after 200 km of driving and with temp gauge on the middle. Even the hotter one (the one i'm using) would do this (less frequently) so I wired the sender to a 3 position switch so I could choose between auto, permanently on or permanently off position.

I swithced to a hotter sender cuz with the cooler ones, having those twin fans on for long periods, my firewall would get too hot boiling my feet not only blowing hot air from the radiator but "cooling" my dual hooekr headers (I have one branch kinda close of the firewall below my feet)

I guess that maybe my radiator ain't enough for my engine (having auto tranny and increased compression ratio. (???) )

my hoses ain't colapsating on hig revs, I have my sender installed on the top radiator hose with a brass T adaptor I welded. I was looking over a non permanent solution wich let me know how things are before taking any permanent decision and solution. I guess that top tank would be a fine choice for me if I have to get the rad replaced (or rebuilt again) ;(

dan: tomorrow would be the day that valeo sales representant (the only one that was or seemed to be sensitive to deal with international requests) is coming back from his summer break. I'll keep you posted and let you know any news as soon as possible.

i'd love to hear any other input you may have now that you have correct temp ranges (in °C) and if ain't too much asking I'd like to know the conversion rate between F and C

Other than that I don't have other heat up signs such as water consumption or boiling. After cruisin or driving when I think is super hot, if I pop open the rad cap it would have some "compression" but it wouldn't boil when opened. I should get a proper °C reading with some thermometer when hot. Maybe I just need to use a diffrent sender, i have to say tho that my car seems to run more happy when ain't that hot anyway... like before the middle of the temp gauge or so.

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Juan Ignacio Caino

Please use e-mail button istead of PM'ing. I do log in sometimes but I'll be answering quicker thru e-mail.

OK, so you're running the correct thermostat. Good. (I was kind of wondering where you were finding thermostats hotter than 195°F!)

Still need to know if your overheating occurs primarily at idle and low "stuck in traffic" speeds or if it's more at high "open highway" speeds. This information can be used to help determine if it's an airflow issue or a waterflow issue.

And yeah, we also still need to figure out if your engine is actually overheating, or if it's just the gauge misbehaving. A good place for the gauge sender is drilled and tapped into the water outlet (thermostat cover), where the top radiator hose attaches to the cylinder head.

It's quite possible you simply need more radiator capacity, but there are other possibilities, too. Sometimes rust and gunk can collect inside the engine block; this can be cleaned out by removing the freeze plugs and physically scratching-around inside the block with stiff pieces of wire, then removing the lower radiator hose and reverse-flushing the block with high pressure through the core plug holes.

You say these heating-up issues started before you installed the electric fans?

Great news on the Valeo guy, thanks for your time and trouble. (I suppose one other method is for me to buy them from you, so the Valeo guy doesn't know where they're going to wind up). Summer vacation sounds great to me, please send some summer up here; I am fr-fr-fr-FREEZING!

(How's your hand?)

DS

C = (F-32)*(5/9)

F = C*(9/5) + 32


Is your coolant in the range of a 30-70 to 70-30 mix?

IIRC timing too advanced wasn't an issue?

-S/6

S6: Remember, retarded timing drives up the operating temperature of the engine. Advanced timing drives it down.

I have had overheating problems on the highway from too much spark advance (anything below consistant 2500+ rpm was fine)....backed the initial timing off from 14* to 10* and cruised all day at normal temp???

This happened after converting to MSD from lean burn, during my timing trial & error, as I had no spec to start from.

-S/6

Sorry, I should've been more specific. If the timing is advanced so far that the engine pings and/or is fighting itself, that too will make the engine run hot.

thanks again.

I think that is a combination between airflow issues and waterflow issues, but the waterflow issues can be dued to poor rad air circulation... hmmm i dunno if you can understand what I'm saying.... If I park the car 5 min, the twin electrofans will cool down almost to zero all the water in rad in about 4 to 6 minutes (depending on how long the run plus how hard and heavy my right foot was)

I think that I need more rad capacity plus more separation between each inner duct, to avoid dense configuration wich may result in poor airflow thu the rad.

overheating occurs when I have no mercy on accel, especially in town, but kinda likely to do it after long sustained high speed (say, near 100 mph or 160 km/h)

I'm guessin that maybe I have a non-permanent obstruction (some kinda mean flake) inside the block or head, since it won't overheat all the time... if I go easy on the beast, it would be happy for a longer time...

and BTW, my initial advance is 14° not going beyond 31 or 32° (recurved unit). Pod is according to this configuration (not pulling more than 6 to 8 crank degrees) since I have two light springs.

keep on talking to you guys. Thanks. Juan.-

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Juan Ignacio Caino

Please use e-mail button istead of PM'ing. I do log in sometimes but I'll be answering quicker thru e-mail.

D'OH! coolant is 30% glicol based coolant and 70% distilled water. Fresly installed 2 weeks ago.

"Overheating" occurs mainly after periods of heavy acceleration and braking alternated. Since ain't cools down at sustained high rpm I'm guessing that this would be an indication of some sort of airflow issue ??? am I right?

my gage sending unit is where I believe to be standard placing for /6s, that would be on a tapped hole above the head, right below the head side of the thermostat. My voltage limiter is fairly good, since I get low gas tank and oil pressure readings (consistent with limiter being a tad down) this means that my "normal" oil pressure is from 2/3 to 1/2 scale, and full tank is right on the top line, where it sould be a li'l above that mark for gas and 3/8 to 5/8 on the oil gage.

still wanna get a temp meter to see how much actual degrees the beast is working at.

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Juan Ignacio Caino

Please use e-mail button istead of PM'ing. I do log in sometimes but I'll be answering quicker thru e-mail.

A $2 meat thermometer in the radiator after the thermostat has opened works well for this. Not 100% accurate, but should get you close (I would guess +/- 3* C )

Your coolant mix should be fine, as long as it contains enough glycol to keep it from freezing in your area (probably not a problem, eh? )

What radiator do you have (dimensions of the core)?

-S/6

Possibly so, though "insufficient radiator capacity" is still a possibility. Are you very sure the fans are installed to push air through the radiator front-to-back, and not spinning the wrong way round (trying to pull air from back to front)? It's possible the fan frames themselves could be blocking too much airflow...but here again, if I understand you correctly, you say that the problem existed even before the electric fans were installed, is that correct?