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The "competition"..summary of changes to the Duramax for 2002

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First tow today and beat a Powerstroke

How to keep wastegate shut?

I clipped this from the 6. 2/6. 5 GM Diesel site.



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LB7 Truck Engine

"Duramax 6600"

Model Year 2002



SUMMARY OF NEW OR CHANGED FEATURES FOR 2002



Exhaust Gas Recirculation (EGR) for California

Revised Cylinder Heads for California

Catalytic Converter for California

Accessory Drive Belt Tensioner Relocated

Software for Engine Control Module (PCM)



FULL DESCRIPTIONS OF NEW OR CHANGED FEATURES



EXHAUST GAS RECIRCULATION (EGR) FOR CALIFORNIA

To meet new Low Emissions Vehicle (LEV) standards for medium-duty vehicles, 6. 6L LB7s built for registration in

California will be equipped with EGR. The system

features a unique cooling process that increases its effectiveness. Hardware required includes: plumbing that

carries some exhaust gas from the turbocharger outlet to

the intake ports; an EGR control valve; an intake throttle plate that creates vacuum to induce the flow of exhaust

gas back into the combustion chambers; and a

stainless steel cooling element. The cooling element bolts to the right side of the engine block, inside the cylinder

head, with jackets fed by engine coolant.

Returned exhaust gas passes through a spiraled passage in the element, and the temperature of the gas is lowered

before it returns to the combustion process. The

EGR valve and intake throttle are managed by the PCM.



REVISED CYLINDER HEADS FOR CALIFORNIA

Heads for California 6. 6L LB7s have a new, slightly different casting which modifies the intake ports to

accommodate EGR. The ports are repositioned relative to the

combustion chamber, entering the chamber at a slightly greater angle and increasing the swirl or mixing effect

inside the chamber. More swirl is necessary to

thoroughly blend returned exhaust gas with the air-fuel mixture.



CATALYTIC CONVERTER FOR CALIFORNIA

California 6. 6L LB7s will be equipped with a catalytic converter supplied by Delphi. This high-capacity converter

measures 309 cubic inches in volume. LB7s built

for registration outside of California will not have the catalytic converter.



ACCESSORY DRIVE BELT TENSIONER RELOCATED

The device that automatically adjusts tension on the 6. 6L LB7's serpentine accessory drive belt has been

relocated. The tensioner has essentially swapped positions

with one of the idler pulleys: The pulley is now located outside the belt, while the tensioner is inside. A new,

slightly longer drive belt is required to accommodate

the change (Gates PV6). The new location provides a more stable mounting for the tensioner, minimizes its

movement and extends its anticipated life.



SOFTWARE FOR ENGINE CONTROL MODULE (ECM)

Control software has been revised for model year 2002 in cooperation with Delphi, the ECM supplier. The new

program was developed primarily to accommodate

EGR for California, but it will be used to manage ECMs on all 6. 6L LB7s.



The control software includes thousands of calibration values and potentially millions of variables-essentially

"switches"-that allow Powertrain engineers to turn on,

turn off or adjust various engine management operations, from ignition timing to fuel delivery. The switches must

be programmed in the software; engine

management engineers then calibrate-or set-those switches for the desired result. The 6. 6L LB7's software adds

more switches to manage more functions, including

the EGR system on engines for California. The ECM is shipped with the control software installed; control

calibrations for the engine and specific application are

then ''flash programmed'' (as with a compact flash card reader on a personal computer) into the ECM at the truck

assembly plant.



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Very interesting! Doesn't look like very serious changes for something that's plagued with so many problems! I guess GM has decided to live with all those major engine problems! I'm sure people will stop buying them soon!
 
Reminds me of the external fuel tanks on the trucks... GM sure revised and recalled them didnt they?? We all know that GM would recall or revise faulty / unsafe vehicles... Dont we??? Of course they would! What was I thinking???
 
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I had a few of those trucks with the side saddle tanks and never had a problem with them. I four wheeled it all the time. Got the tanks dented from rocks and hill climbing never a problem until a jump broke the rear cab mount and the cab rubed a hole in the top of it. No fires though.

GM gave out those certificates towards a new truck. I don't think they ever recalled or fixed them. How many fires were caused by them? I know of the news station that rigged the truck with a small charge to explode on impact and they got sued for it. Was GM also sued by someone for the design to?
 
Originally posted by jdecampo

I had a few of those trucks with the side saddle tanks and never had a problem with them.

Sure glad you wernt one of the HUNDREDS of people who died (burned to death) when the fuel tank ruptured after a minor side impact. Yes, there was a class action lawsuit but our fearless leaders had the suit dismissed because GM would buy baby seats and move the fuel tank inside the frame. :( Wonder how many politicians were bribed by GM??? Remember the internal memos that were leaked saying that GM knew about the safety issue with the fuel tanks and they refused to line the tanks with a plastic bladder because it would cost $5, wonder if the spouses would have paid $5 not to have their wives/husbands burn to death. NOTE: GM NEVER admitted that the tank placement was bad... Then why did they move them to inside the frame?? But, GM always, always, fixes / revises problem designs. Remember the Vega? Corvair? and the Diesel engines of the 80's. I am sure that GM would admit a design prob(s) with the maxipad :rolleyes: It is our short term memory that allows GM to keep selling us inferior trash.
 
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Side saddle tanks?

Big whoop! For a good many years, you sat on it (Jeep). Or in front of it (GM, Ford, IH, Dodge, maybe Studebaker?)
 
My point is it used to be worse. By the way, how do you feel about sharing the road with trucks? There certainly is a lot of gas and fuel hanging around out there.
 
You're right, it is getting better. Never thought much about commercial gasoline haulers. They are large and easy to see and dont seem to be involved in many accidents. But you have a good point. Actually it was the way GM wormed out of any resposibility for the outside frame rail fuel tanks that really made me mad. Any one can make an engineering mistake but they should be held accountable for it.
 
Texas Diesel,



I was thinking more on saddle tanks on trucks in general.



I won't sit here and defend GM either. Ford had their own problem with gas tanks (Pinto). I don't remember if Chrysler did or not.



What does bother me is excessive "send em' a message" jury awards. Especially when some nitwit who can't tie their own shoes has an accident but the blame is shifted to the deep pockets. In the end, who really gets the message? Everything has a price.
 
Come on guys GM made up for all the fuel tanks by sending a $1,500 cash back certificate for a new GM truck. :D It sure made me feel better. :) Mine went strait to the trash(who could drive a cheby after driving a dodge any way, might as well by a Kia):D



Big D
 
GM isn't the only truck out there with saddle tanks outside of the frame. I worked for a place that installed aux. saddle tanks on Fords and Dodges outside of the frame and I don't remember any fire in those old trucks.

Chris
 
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