how how can they get??

[Don Tanklage]

i heard these old 2v heads were notorious for cracking (if you get them hot)



whats the max safe temp?



i am running a 180 stat and propo glycol in a huge 4 core rad



level ground no prob - 180



hit the grapevine and watch out - it will get to 230 in a few minutes



at the top i usually pull over and let it cool but i am exceeding its limits?



i guess with a 160 stat it would make it further up the hill before getting to 230 but i dont know what else to do?



i take my leg out of it and down shift - 4th over to 4th, 3rd over, 3rd (which even with 35's is crawling thanks to the 4. 10's)



what is the max safe temp and what to do?



thanks



don



ps - i am sure you guys have grades but that grapevine is nothing nice

 

[Leper]

That seems way too hot. How is your fan clutch? After driving for a while, if you look at the fan when you shut the motor off, does it free spin at all? It shouldn't. Have you pressure washed the radiator from the motor side in a while? Is the Ic or AC condenser clogged with soot-n-stuff?

 

[Don Tanklage]

thread is posed to read how HOT, not how how... lol



yea, i thought about the fan clutch, thought i could hear it come in tho



prolly oughta replace it



everything else is really clean



this one doesnt hardly leak oil at all (my buddies leaks like crazy, bet his rad is coated)



i heard someone say that 200 was max for these heads



yikes



n thnx

 

[SAndreasen]

ru pulling a massive trailer to get that high of engine temp ? my truck dosent even have a shroud and i cant hit much over the center of the gauge hauling 25,000 up some pretty big hills

 

[Philip]

thought i could hear it come in

When one of our fans comes on from high heat. You will know it. There will be a loud roar from the engine compartment. It will sound just like a fan on a semi kicking in.



I bet yours isn't working properly.

 

[Don Tanklage]

thanks



total weight is always right around 22k



ill go look for a new clutch



where do you guys get yours?



don



ps - the factory gauge does not always correspond exactly with the sw

 

[Don Tanklage]

pps - the grapefine is 8% (or better) grade that keeps going and going



by the time it hits 200 deg the windows are down, the a/c is off, and at 25 or so psi you cant hear much other than the motor



4" exits infront of rr tire

 

[cerberusiam]

i heard these old 2v heads were notorious for cracking (if you get them hot)

Hot, as in EGT's out of control. IIRC, most of the cracks that are problems are around the exh valves and that is due to extended high EGT's. The 230 doesn't sound out of line with the load you are pulling on that grade.



Either of my trucks will hit that on long hard pulls, and, I don't shut off the AC and roll down the windows. :-laf

 

[Don Tanklage]

the egt's were worse until i totally sealed up the turbo



i guess i could give up 20 hp and go to a 16 housing but now that i have it all sealed up the motor is getting more air and the egt's are not that bad



level ground i might see 900 (gotta remember i have to tow thru hot areas to get to where ever the races are. there are is no racing so of here, unfortunately)



when it hits a rise in the frwy it might go to 1000, 1100



the simerly's told me not to let it go over 1000. that didnt last long. i figure the melting pnt of straight alum is 1220 but these pistons must be of a alloy that melts a lot higher than that. wish i knew what their melting pnt was.



going over a grade i usually dont like to let it get above 1250



thus the downshifting



but, the egt is no longer the problem, now it is the h2o temp



don

 

[DValentine]

Sam had a post a while back about how much horsepower can you get and still use the truck for pulling a trailer with some weight. I know guys say just get out of the throttle and shift... . but a guy still needs to get over the hill. My truck with mild mods and pulling my 9000 pound fiver will get hot like you mention. I tried electric fans and for me they didn't work. Someone mentioned an update on the fan and clutch. I have not looked into it.
I agree you should hear your fan running. It makes a racket.

From what I remember, the later trucks... 94 on got bigger radiators.

Dave

 

[pepecat]

Don watch out where your logic is taking you because sure aluminum alloy has a much higher melthing point than pure alu @ 1220 or whatever... But figure that if you're reading 1200 @ the exhaust manifold off the pyro, expect at least 100+++ degrees higher INSIDE the combustion chambers (where the pistons are) Stick with the tried and true 1200 all day long mentality and you're good to go. (this is the pyro reading Pre turbo)

 

[glhs]

I'll trade my new Napa fan clutch for your old one. This one seems to kick in too early for me and yes, you can hear it.

Your radiator cores aren't plugged are they?

Don, I'm not sure what turbo you have but if you have the stock h1c a PDR HX-35 or a HTT HTB2 62/12 would cool beter for what your doing.

 

[cerberusiam]

The EGT's sound Ok for the load. I wouldn't sweat the coolant temp too much. If you haven't, have the tanks pulled on the radiator and rod it out to make sure it is flowing good.

the simerly's told me not to let it go over 1000. that didnt last long. i figure the melting pnt of straight alum is 1220 but these pistons must be of a alloy that melts a lot higher than that. wish i knew what their melting pnt was.

Well, a little higher at 1325 on the alloy in the pistons, but that is direct heat. Combustion temps in a Diesel can easily hit 5000 degrees, just not on all the surfaces. What a pyrometer is measuring is the waste heat that the cooling system has not taken away and hasn't been converted into energy to drive the engine. Sounds like the cooling system is working quite well. You are probably close to the HP limit of what you can run in a daily driver for towing. All that extra power comes with a price, extra heat.

 

[pepecat]

yes those "heavy duty" haynes fan clutches they sell @ napa are almost like having the fan on full time! I am interested in one that actually works, is quiet around town and on the freeway unloaded or @ night and in the winter when it is not needed. I have taken my truck out without the fan/fan clutch installed and man what a difference! It is sooo quiet. Especially I think the smaller fans the non i/c trucks have are very noisey compared to the newer, larger ones.

 

[Don Tanklage]

the pyro is in the std boss in the three pc manifold, before the turbo, would be nice if they could figure out a way to put it in the chamber, huh?



bob had this rad made for the truck. it is huge. true, it was a while ago but he was a stickler for maint and i am sure he changed the coolant every year like you have to with ethyl gly. i prolly oughta pull the tanks and check it out, but it almost seems dumb, it looks so clean inside



i dont know if the stock pistons are cast or forged? but the drag bikes we run, the turbo nitrous gas ones anyways, see 1500* all the time. true, it is only for 6 secs, but still, he is heat, right?



glhs, do you have an accurate temp gauge on your truck? at what temp does the napa fan kick in? or does it vary? i may be interested in the trade. i drove mine today, got the water to 185, pulled over real quick popped the hood and shut it off. the fan mighta turned 90-180* after the motor stopped. is that good enough? (motor idles at 600 rpm). i felt it and it def had resistance. i know you are right about a different turbo, and i am looking over my options, thanks



do you really think the late model fans are quiter? mopar cant charge too much for a fan, can they? (lol) i'll check into that too, thanks



found that really expensive dual fan set up online but man, 6 bills sounds insane



what about the stat???? i just replaced it with a 180 from cummins right before my last trip. what about removing the stat and making a restictor? yea, what size orfice would it need would be the question. or, do you think the rad has enough surface area to transfer the heat if the coolant was flowing thru it with no other restrictions???? (no stat, no restrictor)



thanks everyone



bob loved this truck - he must have, he drove that thing with no springs in it for years and years. poor nancy. they are not as young as i am



don

 

[DVolk]

how how can they get ??

Id say your radaitor and heater cores are both clogged up



Do you have a genuine cummins water pump ?



a 160 therms stat wont make it run cooler it just starts to open at that designated heat range .



Check your timeing of your engine will make it run way to hot



1300 things are getting to hot ,any way i get nervouse at 1200

 

[Don Tanklage]

yes, genuine cummins pump, why?



will pull the rad and take it apart (buddy owns a rad shop)



how hard is it to get the heater core outta one of these things?



it had a high flo stat in it when i got it but that one started sticking



the 160 wont make it run cooler on a grade but wont i get a longer running start at the 200 number (or 230, or 260 jk). be able to go faster for longer before having to lift no?



thanks



don

 

[dpuckett]

How many RPMs are you running when towing up Grapevine Hill? (my mom was disappointed- said it wasnt any steeper than some grades in the Rockies in Colo). I'd keep it at 2200+ when you get to the 8-9% grade. Turbo will flow more air, the fan will pull more air in, and unless your EGt shoots up fast, you wont hurt anything. Lugging at that load (<2000) will kill the engine as well as the transmission.



How fast are you trying to top the hill? If you want to do 70 at the top, you may be SOL; if you can settle for 50-55, it may be doable. I'd do 55in 3rd over or 4 direct with 4. 10s.



Daniel

 

[pepecat]

unloaded I haven't had trouble doing 85 by the top of the grapevine. This is stock fueling

 

[Don Tanklage]

55... woulnt that be great!



no, i am going way slower than that by the top (more like 40)



i kept the r's right around 2100 but you have to remember, that was with the stock (almost dead) lift pump. sometimes i would have my leg dead in it and it wouldnt go over 2k! it is gonna be better now with fuel to the ve, i can already tell. i went and picked up the trailer today and what a difference! hardly any throttle and it splits right thru the gears.



i prob should post this in the "how hot?" thread (how how when in a hurry... lol) but i paid close attn to the fan clutch while towing the trailer home from storage. it locks up at 185* (now i see why GL wanted to trade). when i got here i popped the hood and shut it off real quick and it is locked soild to the motor at that temp (stopped instantly)



got the turbo all sealed up, propo glyc in the rad, fuel to the ve, bring on the grapevine!



leaving tomorrow sometime



wish my luck everyone, i have not been able to win a round lately...