yet another LJ78 bites the dust (1 Viewer)

[crushers]

just got a call from Kamloops from a guy with another dead head...
he had replaced the rad with one with more cooling, larger exhaust, pyro guage etc etc BUT he did not increase the boost and his EGTs were high. (with 14 lbs of boost you have to struggle to get over 1000F...)

i feel compassion for his problem...

 

[prado t]

these 2ltes are bombs

man it happened to your wifes machine now this guy in kamloops.
are you guys pulling the c-clips off the thermostat to keep the water pump from starving?so far so good for my prado . after hearing about it a year ago i just took the thermostat out so it smokes more until it warms up

 

[brownbear]

Is it hot enough to run properly with the thermostat removed? Running an engine cold just increases wear and fuel MPG.

If it maintains proper temps I can understand pulling....but.....

 

[light_duty]

the other thing pulling the thermostat can do is cause the coolant to circulate too quickly, so that the rad doesn't get a chance to do its job - the coolant leaves the rad before it has a chance to exchange the heat. this can lead to overheating.

let's think about this for a second. i'm no metallurgist, but I think the notion of trying to prevent head cracking by upgrading the cooling system does not necessarily have merit. At most, the coolant circulating through the engine is going to hit maybe 250F. If you're in boil-over situation, it'll be higher than that, with some steam. Temps like this are nothing for cast iron. what causes cracking is either extreme temp fluctuations or variations, or fatigue over time due to heating and cooling of the metal (expansion and contraction). it could be that these trucks, now 15 years old, are starting to see some fatigue set in, and cracks are developing. it could also be that there's a design flaw in the head itself that doesn't allow enough coolant pressure in the head, so there are cavities, perhaps localized steam. since air and steam to not absorb heat, you get extreme temps in some parts of the head that are not being cooled, while other parts are being cooled as normal, so there's a temp differential that causes stress and cracking.

so, it seems to me that the important thing is to make sure your coolant is fresh, and that your rad cap holds pressure, to prevent steam and cavitation. beyond that, a larger rad or fixed fan might not help the situation as much as we think it would.

the last thing, of course, is to drive it like you ought to drive a 5000lb truck with a 97 hp engine. it's slow. that's all there is to it. I've taken trips out to the mountains into a howling headwind...the needie sits at 80kph until i hit the shelter of the mountains. egts sit at 1000F the whole time. if you're in a hurry, forget it. that little engine is pushing a big ole brick into the wind.

i don't know what's going on with these 2L-TEs, but it's crazy out there. oh well, looks like i'll have a decent selection of parts rigs for the forseeable future!

 

[nickw]

What would be a good swap for these things?
It would need to be solid, and plentiful (lots of dead 78's) and cheap is good too.
Perhaps a 3B/H55? The 78's themselves are solid, just a bad engine.
Find an old rust BJ60 with a bad frame and go to work?

Cheers,
N.

 

[denis]

What would be a good swap for these things?

2LT2 and learn to drive it slow

 

[champjack]

just a thought .....i was told by the guy that replaced my head that he takes his thermestates and drills a sixteenth of an inch hole in the top as to avoid gas or steam build up.

 

[Psilosin]

What would be a good swap for these things?

If my 2LTII in Surf1 or 2LTE in Surf2 ever blow my first choice would be to swap in the Lexus 4.0L V8. Guys are doing that in Australia and it looks like a juicy combo.

if you're in a hurry, forget it. that little engine is pushing a big ole brick into the wind.

On that note I have noticed that since taking off my roof rack & basket for spring cleaning my 100kmh highways EGTs have dropped on average 100oF from 700oF to 600oF pre-turbo. So even mild extra wind resistance has a noticable effect so in the name of good gas milage and lower EGTs remove as much of your 'extras' off the roof when they are not actually needed.

 

[bruzer]

Thanks PRADO T for the tip about the c clip on the thermostat

 

[prado t]

anytime bruzer it was nice talking to you