Very discouraged over temperatures (1 Viewer)

[F-junker]

It's been a little while since I've been here, many family issues however. I've got this 78-ish truck, new radiator (radiatorbarn.com), rebuilt head, toyota h20 pump and fan clutch, thermo(195ish??). The works basically.
this thing runs fine around town, temp is 180-190 max. As soon as I get it on the highway and run it, temps go up. I ran to Dulles airport the other week. temps went past 200 towards 210. I'm getting really pissed over this. too much time and money in that POS 2f, I regret not going SBC everytime I look at it.

CARB running too lean??? What else could it realistically be??? The carb is cobbled together from several different years, I did this to get rid of the egr tubes etc. Any advice. Primary and secondaries switched? jetting backwards. help is appreciated.

 

[fj404life]

Seems I read a post recently that said bad timing can cause this...it was with in the last couple weeks.

 

[craptabulous]

im gonna just piss you off a little bit here .

my electric fan quit working for about 2 weeks with my sbc . the thermostat was probably closing when i hit the highway .



clutch fan ? mechanical fan ? swapped in electric fan ?

how many core's did the radiator have ?

 

[Radd Cruisers]

It's been a little while since I've been here, many family issues however. I've got this 78-ish truck, new radiator (radiatorbarn.com), rebuilt head, toyota h20 pump and fan clutch, thermo(195ish??). The works basically.
this thing runs fine around town, temp is 180-190 max. As soon as I get it on the highway and run it, temps go up. I ran to Dulles airport the other week. temps went past 200 towards 210. I'm getting really pissed over this. too much time and money in that POS 2f, I regret not going SBC everytime I look at it.

CARB running too lean??? What else could it realistically be??? The carb is cobbled together from several different years, I did this to get rid of the egr tubes etc. Any advice. Primary and secondaries switched? jetting backwards. help is appreciated.

With a 195F thermostat, you can expect it to sit on the thermostat at 195+ in hot weather on the highway.

If you want cooler temps, then you should run a 180F 'stat. Make sure that there's nothing blocking the rad, and that you have all of the proper shrouding in place.

A few things need to be considered... what coolant mix are you running? What are the ambient temps? How well tuned up is the engine?

An SBC is nothing to aspire to, they have lots of issues as well.


~John

 

[shelfboy1]

if you have cooling problems with the 2 f you will have them with the sbc .is there a shroud and are the air passages around the rad sealed so the air can only come in through the grill .when i ran the big v8s i had to run wthout the bezel to get enough air for cooling gains about 24 square inches of air flow .you dont by chance have a winch or grill gaurd blocking some air space ?.GOOD LUCK

 

[sfrolich]

If you have problems with temps on the highway you have a cooling capacity problem. The engine is running harder on the highway and needs more cooling but the radiator sounds like it can't handle the job.

 

[3jvj]

Advanced timing will make you run hot. Check your plugs for a lean condition (just to be safe).

I'd throw a 180 stat at it and see what it gets you.

 

[D'Animal]

Radd Cruiser mentioned it.

Do you have a fan shroud in place?

 

[FJ40 TOOLMAN]

Are you losing water if not don't worry about it.

 

[M5driver]

FJunker,
Don't forget to check the viscous fan clutch. It can be a head-scratcher, but if the clutch is weak, you can get the symptoms you describe. Replacing that piece took care of the same sort of problem on my Malawi Blue Mule.


Dan

 

[F-junker]

Thanks to all who responded.
New radiator-4 core. oem fan shroud in place. fan clutch is brand new toyota as is the h20 pump.
I run a DUI disty set on the recommended specs.

update: I ran some waterwetter by redline in it today and it has helped a little. Where are you all finding 180 deg thermos? Napa sold me a 180 and it turned out to be marked in Cel=195F??? WTF.
just running about town under 50 mph I run less than 180.
oh BTW-I gave up on the oem temp gauge and installed a modern quality unit. installed in the head. oem gauge is pegged on hot almost all the time, sending unit was a CCOT crapper.

I'm going to pull the plugs and have a looksee today.

 

[subzali]

I think the Toyota t-stat is a 180F t-stat (82C). At least the one I got from Toyota was. Make sure you have the o-ring that sits on top of the t-stat so all the flow goes through it.

 

[Pin_Head]

If it is running at 210 degrees on the highway, it is a cooling capacity problem as noted by sfrolich, and not a thermostat problem. Changing the thermostat won't help. Either the water isn't circulating properly, the radiator has too low of a exchange capacity or the engine is producing too much heat. An EGR might help with the latter issue as it lowers the combustion temperature, but I doubt that it is the root of your problem. Things to check might include: flushing out the entire system, including the rust that accumulates in the block castings, collapsing radiator hoses and missing top gasket for the thermostat, obstruction of air flow across the radiator.

 

[LLEE]

x2 on pinhead's comments

did you use the old cap on the new radiator?

also check your heat riser.

 

[morrison]

And on the timing. . . it's overly retarded timing that causes heat buildup, not advanced (unles it is so far advanced that it is causing detonation). Retarded timing causes the flame front to occupy most of the downstroke and doesn't give enough time for hot exhaust to clear the cylinder before the next cool air/fuel charge comes in.

 

[1Fine40]

Just a thought here, but are you sure it is running hot? I mean if the gauge is accurate? I had a similar problem, and found that the grounds in my instrument cluster were not...um, well -grounded so to speak...Try cleaning off your grounds to be sure you are reading accurately...maybe a mechanical gauge to confirm the over hot temps could assist you. The old instrument clusters were not exactly well grounded to begin with...

Cheers!