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View Full Version : 180 in town 210+ on highway....


FJBen
06-18-2007, 05:25 PM
350 w/RV cam, new 4 core toy radiator, taurus fan.

In town fan runs and she stays at 180. out on the highway going to loveland in the 100 degree heat on sunday, she kept slowly creeping up to 210ish plus but didn't get higher than 212`213ish as I was usually pulling up to a stop in town at that point. Then in town it would cool back down.

is that too hot??? What are my options other than an aluminum radiator or different fan or?

Shark Bait
06-18-2007, 05:34 PM
Do you have a fan shroud installed? ;)

Corbet
06-18-2007, 05:44 PM
what temp thermostat are you running? Mine aways run 195 with a stock radiator, no shroud, and clutch fan. My 383 was pushing 400HP. This was in SLC and Moab temps, 100+ degrees.

Do you have a high volumne water pump? That made all the difference for me.

wesintl
06-18-2007, 05:52 PM
damn.... 180 round town and 213ish on the hwy. I knew an 350 would go fast... maybe it's the rv cam :lmao:

FJBen
06-18-2007, 05:57 PM
She's screamin'!!!!

I have the taurus fan so it's already shrouded. I have the stock waterpump, the long one from chevy.

The fan appears to be running on the highway as when I slow down at an intersection it's already running. I suppose I should put a light in series so I know when the fan is on.

I'm not sure of what the thermostat is,,,how's that for a good answer? :D I could assume, but I'd imagine it's the stock one for a 77 chevy.

SteveH
06-18-2007, 06:04 PM
I'd run a 180 degree t-stat for test purposes - but you can buy a 160 or a 195.

Isn't the Taurus fan so loud (or drawing so much current) that you can tell when it's on? If not, you might make a hot-wire switch (DPDT) for the fan so that you can manually turn it on, on the freeway, to see if that makes a difference. In one position, it runs automatically, and in the other position, it runs manually and disconnects that other circuitry (so you don't backfeed or fry something).

You might buy/borrow an IR thermometer and aim it various places on the engine to see where your heat problem might be. If it's overheating, but the lower radiator hose is cool, then you may have a flow issue (for instance).

Steve

Corbet
06-18-2007, 06:04 PM
replace the thermo with a high flow 195 degree see what happens. Then you could try a high flow water pump.

You could also try a coolant additive like "water wetter" I have not used it but have had friends see lower temps after adding it to coolant.

treerootCO
06-18-2007, 06:53 PM
The thermostat is probably a 195. Take it for what it's worth but emissioned vehicles were designed to run hotter for a cleaner combustion. My Tahoe ran 210 as it's normal operating temp.

If your fan is not turning off when on the highway, it is restricting airflow to the radiator.

Make sure your radiator cap is keeping the system pressurized as well.

nuclearlemon
06-18-2007, 07:36 PM
is it an older carbureted engine, or a newer fuel injected engine?

Corbet
06-18-2007, 10:58 PM
I'd imagine it's the stock one for a 77 chevy.

I guess the block is from a '77 so carb, probably a Q-jet.

FJBen
06-19-2007, 10:44 AM
Quadrajet carb.

The fan is easily detectable in town....it blows :D

I can adjust the setting on the fan to come on higher if that works? I just thought it was ok at 180. But if it has a 195 thermostat, i'm not even opening the thermostat....which I don't think is right as I wouldn't have heat(er)...correct? And I have plenty of heat LOL...i need to put in a shutoff valve.


I'm using a temp probe for the thermostat on the taurus fan.

That doesn't seem right that the taurus fan would be blocking flow on the highway??? :confused: seeings as so many people run that....not saying it isn't possible at all...just the whole thing is confusing me...

Uncle Ben
06-19-2007, 10:54 AM
The thermostat is probably a 195. Take it for what it's worth but emissioned vehicles were designed to run hotter for a cleaner combustion. My Tahoe ran 210 as it's normal operating temp.

If your fan is not turning off when on the highway, it is restricting airflow to the radiator.

Make sure your radiator cap is keeping the system pressurized as well.


I agree with Rootster....if your fans are not shutting off that could be your problem!
How close is the engine to the firewall? A lot of folks save time on conversions and mount the engine too far back, this creates an air flow problem as the super heated air creates an air dam and stops all cross flow air from circulating around the engine.

Try pulling your hood and see if it stays cooler on the highway. If it does you need to find a way to create some air flow under the hood.

FJBen
06-19-2007, 11:38 AM
Hmmm...

here's some info from the PO:

I believe it is a 180 thermostat. I think that the water pump is a high flow unit, it may be running the water thru the radiator too fast. We were having that problem with the race truck because a flow restrictor was not put into the system to slow down the water enough to cool when at speed. I would definately look into that! See if the stock 77 chevy pickup system has a restrictor. I did not put one into the system I know that, and I did not reuse any of the original cooling system. So it may have had one in the pickup and it was not reinstalled on the rebuilt motor. Are you still running the stock radiator? A suggestion was to build a shroud from the radiator to the grille. The air may be going around the radiator instead of thru it.

I guess the fan spinning at highway speeds creates a flat surface and blocks the wind. Remember these pieces of advice are only worth what you paid for them. ; ) Let me know how this works out please, as I will add this to my Knowledge for future reference.

That may help out some more info:

here is a pic of the enginefor radiator placement: yes it's purple...no I didn't do it...yes I'll change it

Corbet
06-19-2007, 02:18 PM
I 2nd the coolant going through the radiator too fast. I had problems with a 180 degree t-stat. Changing to 195 made a difference.

FJBen
06-19-2007, 04:24 PM
I 2nd the coolant going through the radiator too fast. I had problems with a 180 degree t-stat. Changing to 195 made a difference.


I may go pickup a 195 thermostat and try that.

I went at lunch and picked up a caddy fan/clutch mechanical style...I may throw that on and see if that does any difference.

Corbet
06-19-2007, 04:26 PM
I went at lunch and picked up a caddy fan/clutch mechanical style...I may throw that on and see if that does any difference.

And that would be the fan I used as well. ;)

FJBen
06-19-2007, 04:36 PM
And that would be the fan I used as well. ;)

Are you running a shroud?

Corbet
06-19-2007, 10:05 PM
No. It was set up with:

Stock Rad, no shroud, caddy clutch fan, High flow water pump and 195 T-stat. All in front of a 383, with 400 +/- HP. Never got hot, run 195 steady off my mechanical gauge.

I highly recommend a mechanical gauge. It was so sensitive you could see everytime the t-stat opened and closed. I had the sending unit in the t-stat housing. Stock guage hooked up to a second sending unit in the head.

FJBen
06-20-2007, 09:20 AM
Caddy fan won't fit :rolleyes: hit's the bottom hose, so I guess thats out. I pu the electric back on, the 195 thermostat in and now I'm fighting the electric fan contoller :rolleyes:

Where should I set the taurus fan to come on?? I have a mechanical gauge and I can definitely see when the thermostat opens....my guage sender is in the block and showed a little over 200 before the t-stat opened and then rapidly dropped.

Should my fan be set to come on at 180? 195? 200?

thanks!

Uncle Ben
06-20-2007, 09:41 AM
I guess the fan spinning at highway speeds creates a flat surface and blocks the wind. Remember these pieces of advice are only worth what you paid for them. ; ) Let me know how this works out please, as I will add this to my Knowledge for future reference.




Sorta.....definitely some of the factor. The biggest problem is the fan flows it's intended CFM. The incoming hi speed flow of air on the highway cannot over run the fan so it creates an air dam diverting excess away from the radiator. This happens with all electric fan cars if the fan actuator is stuck and the fans don't shut off on the highway they will heat up when they should be the coolest.

Uncle Ben
06-20-2007, 09:43 AM
Caddy fan won't fit :rolleyes: hit's the bottom hose, so I guess thats out. I pu the electric back on, the 195 thermostat in and now I'm fighting the electric fan contoller :rolleyes:

Where should I set the taurus fan to come on?? I have a mechanical gauge and I can definitely see when the thermostat opens....my guage sender is in the block and showed a little over 200 before the t-stat opened and then rapidly dropped.

Should my fan be set to come on at 180? 195? 200?

thanks!


Same as T-stat

FJBen
06-20-2007, 11:33 AM
Same as T-stat

Thank you kind sir! Thats what I figured...:beer:

Uncle Ben
06-20-2007, 12:17 PM
Thank you kind sir! Thats what I figured...:beer:


Have you spotted this? (http://denver.craigslist.org/pts/344594201.html)
Looks like a few upgrades you could use. Hope the wife doesn't hate me now..... ;)

FJBen
06-20-2007, 03:23 PM
Have you spotted this? (http://denver.craigslist.org/pts/344594201.html)
Looks like a few upgrades you could use. Hope the wife doesn't hate me now..... ;)

the engine is tempting :) the links are gone :(

now the stupid fan isn't kicking in correctly :rolleyes: or should I say at all...grrrr...

corsair23
06-20-2007, 06:34 PM
the engine is tempting :) the links are gone :(

Sill working for me...Were you looking for a pic of the engine? Here you go...

No purple on it though :hill:

http://i6.photobucket.com/albums/y206/twiztidscout/scout24.jpg

FJBen
06-21-2007, 09:59 AM
Had to redo the thermostat last night...a classic case of crappy non-sealing parts :rolleyes: Got another gasket...took another small coolant bath.

Still fighting my electrical fan :rolleyes: but I think I got it to work/come on at 200`201 in town. I'm going to go cruise around at lunch since it's going to be super hot today and see where I stand.

if i cure this, I only have the smoking/leaking seals to deal with :rolleyes:

Kipper
06-21-2007, 10:36 AM
I had some airflow problems with LongGrain and decided to try out an electrical fan after ripping a motor mount and trashing the really sweet fan shroud UB had made. Those Taurus fans move tons of air and it definitely helped some of the under hood heat issues, but I never like it. I was never cool (pun intended) with having an electrical fan keeping my truck cool. It took several tries to get the wiring and relays setup to be reliable and end the end, I wish I had just stayed with mechanical for peace of mind (which is why I drive a cruiser in the first place). I'm crappy with electrical stuff though. Just my :twocents:

FJBen
06-21-2007, 05:08 PM
It's making me slightly nervous...I do like the mechanical...I"m just going to have to keep looking in the yard to find a slightly smaller clutch fan.

How would I wire in an idiot light to let me know when the fan is on? My relay is the old Ford starter type relay, and on the highway I can't tell if it's on or not.

Can I splice inline with the fan for a light or will that juice pop it???

Uncle Ben
06-21-2007, 05:50 PM
It's making me slightly nervous...I do like the mechanical...I"m just going to have to keep looking in the yard to find a slightly smaller clutch fan.

How would I wire in an idiot light to let me know when the fan is on? My relay is the old Ford starter type relay, and on the highway I can't tell if it's on or not.

Can I splice inline with the fan for a light or will that juice pop it???

If you jumped off the positive lead to the fan in parallel it would work and the voltage drop should be minimal. you should be able to pull the light lead right of the fan terminal on the relay. Make sure you fuseable link the light or at least fuse it so the high currant 12 volt from the relay doesn't weld something if something is not in it's happy place!

Corbet
06-22-2007, 10:59 AM
My electric fan (FJ60) is on a back lit switch and relay. So when the light is on so is the fan.

I have be meaning to get a on/off/on switch and set it up with ignition hot and cold loops. With ignition hot I want it wired with a thermo switch as well. This would be the standard setting like a stock fan would run. Ignition cold always on like now. I often leave my fan running if pumping gas or quick trip into the store etc... Or off so you can kill it for a water crossing if you felt the need. Of course with a back lit switch again so I know when its on.

Look hear for a switch

http://4x4mods.com/Product/Jeep/Rockerswitches/rockerswitch40.html

FJBen
06-22-2007, 03:06 PM
I like those switches! I may have to try that...So far it's behaving in town but it always did, so we'll see where I'm at over the weekend.