Doesn't seem overboard to me either especially since the block sending unit was saying 200-210. Certainly not enough heat expansion to split the cast manifold, is it?

Hey thumper, how about those high quality plastic oilers!? ...sty

Where's the weak link here?

 

How did you get them to give you a new engine running aftermarket injectors? I assume you took the EZ off before they saw it. These days you can't do anything to the truck without losing your warranty.

 

900-950 degF post-turbo can be as much as 1400-1450 pre-turbo, according to the delta T of up to 500 degF noted at full load by those running dual thermocouples. That's enough to do some hurt on a long, long grade, I suspect. The old 200 degF or 300 degF rule of thumb has been proved to be inaccurate by too many people.

I've noticed that, in the summer with our new 5th wheel, I really have to drive by the pyrometer. I generally try to hold temperatures down to 1100 to 1200 degF pre-turbo, 1000 degF on the long grades, and you'd be surprised how little throttle it takes to reach these temps. If I just closed my eyes and nailed the right pedal to the floor, I'm sure that I could melt it down. Coolant temps really aren't a very good indicator of EGT - my coolant temps are fine even on a 100 degF day pulling long grades.

Rusty

 

i suspect that having had my cooling system serviced by chrysler a month prior and them putting straight antifreeze and not noticing a 35% flo restriction in the radiator may have had something to do with their desition. also the aftermarkets were not anything radical . they were the bosh 300's (witch i am told are what we refered to forever as the 275's)

 

Thanks Rusty, runnin in the 1400s makes the cheese more binding as they say round the milk house! What setting on ez do you run? Have you noticed significant delta t between adjustments to box while towing?

For example, could Herb zero the box and run with a margin of safety until egt monitor is online, considering the injector upgrade?...sty

 

i do not have the adjustable edge box mine is just the smaller plug n' play

 

I run on setting #2, but it really doesn't matter - once over 20 psig boost, the EZ is on full fueling, regardless of the jumper setting.

If I want to minimize EGT's with the EZ, it's as easy as unplugging the EZ's data link (CANbus) cable, leaving the MAP cable in place so that the EZ only acts as a boost fooler. In this configuration, I only see 1100 to 1150 degF maximum pre-turbo EGTs at around 30 PSIG boost when towing.

Rusty

 

what is psig boost? would unplugging the non adjustable ez be necesary to control egt's

 

PSIG = pounds per square inch gauge (or above atmospheric pressure) as opposed to PSIA (pounds per square inch absolute, or pressure above a perfect vacuum.) Basically, PSIA = PSIG + 14.7 PSI atmospheric pressure.

Yes, just unplug the one data link cable but (assuming you have a turnbuckle or equivalent on the HY35W-9 turbo's wastegate) leave the MAP cables plugged in so that you can take advantage of the higher boost (which lowers EGTs) without setting overboost codes in the ECM.

Rusty

 

Bingo! The specific heat of EG coolant and PG coolant is MUCH higher than just pure water.

IOW, the lower percentage of water, the less efficient your colling system is. I'd bet that the 35% restriction combined with the wrong antifreeze is probably enough to explain the engine damage.

You can't trust the Dash gauge for water temp. It's likely not that accurate.

Shoot, if you were running in hot weather all the time (and never had a risk of freezing), I'd just run water and Redline Water Wetter-- no antifreeze. Runs cool and no corrosion.

Justin

 

To Justin's point, the specific heats of various coolants and coolant solutions at 200 degF is given below. Percentages are by weight.

100% water - 1.0052 BTU/lb/degF
60% water/40% ethylene glycol - 0.914 BTU/lb/degF
100% ethylene glycol - 0.660 BTU/lb/degF

60% water/40% propylene glycol - 0.944 BTU/lb/degF
100% propylene glycol - 0.699 BTU/lb/degF

Ref: Cooper-Bessemer Engineering Standard SB-20-3 and "A Guide to Glycol", copyright 1992 Dow Chemical Company (used by permission in the above-referenced engineering standard)

I believe I'd be looking at the dealer who put straight glycol into the cooling system to open up his wallet to at least contribute to the engine fund!

Rusty

 

 

A specific heat of 0.660 BTU/lb/degF for 100% ethylene glycol just means that it only takes 0.660 BTU to raise the temperature of 1 pound of ethylene glycol 1 degree Fahrenheit at 200 degF coolant temperature. On the other hand, it takes 1.0052 BTU to raise the temperature of 1 pound of pure water 1 degree Fahrenheit, again at 200 degF. This means that the ethylene glycol can only absorb about 66% as much heat as pure water from the combustion process for a given coolant temperature rise and flow rate. The combustion heat isn't being transferred to the coolant to the extent that it would be with plain water or (almost as efficient at 0.914 BTU/lb/degF) a 60% water/40% ethylene glycol mix. Therefore, your engine quite possibly gets roasted.

Not to get too technical, but if you know the flow rate of the coolant through the engine (in pounds per minute) and the temperature rise from the water pump inlet to the back side of the thermostat (in degrees Fahrenheit), you can calculate how much heat is being rejected from the engine to the coolant each minute if you know the specific heat of whatever's circulating through the cooling jackets.

Rejected Heat (BTU/minute) = Flow (lbs/minute) x Temperature Rise (degF) x Specific Heat of Coolant (BTU/lb/degF)

Rusty

 

Jeez Rusty, maybe I'll learn some of that this year in AP Chemistry

 

Rusty, with no turnbuckle on HY turbo I did a test run today pullin a 9 ton tagalong with 5000 lb up a long 2-3% hill accelerating from 60 to 70 mph at max 20 lb boost [thats all it does] and egt hit 1250 before I reached the top. I backed off at 70, but think had I stayed with it the temp would have kept going to. Had a hub and drum gettin hot on the trailer, didn't want to burn it up. accually, I had to pull the wheels off that axel and limp back 3 legged after the test.

nice scoop on the coolant" mix up" good 'did ya know' dope. htanks...sty