CK5
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k5 military diesel
- Thread starter TC4x4
- Start date
The CUCV's are basically a stripped-down stock truck or Blazer, with the J-code diesel, and a whacked electrical system.
The truck CUCV's (M1008, 1028, 1010, etc) have 4.56:1 gears in a D60 front and 14BFF rear with a Detroit (duallies had a D70 rear, and some of the D60's have an Auburn or somesuch.)
The Blazer CUCV's (M1009) have 10-bolt axles, 3.08:1 gears, and so are not terribly exciting as 'wheelers. Great highway trucks, as long as you keep your foot out of it.
The 6.2/6.5 diesel gets a bad rap as many people confuse it with the Olds 350 diesel, which was REALLY misunderstood (and IMO should never have been in passenger cars.)
That said, the 6.2/6.5 aren't in the same category as a Cummins; they're okay, put out decent torque, and can live a long life if well-maintained. I'm not aware of much aftermarket stuff in terms of performance upgrades and I would imagine such a motor would NOT live a long life if pumped at all.
(I owned an M1009, bone stock, for a coupla years, and loved it. Go figure!)
-- A
The truck CUCV's (M1008, 1028, 1010, etc) have 4.56:1 gears in a D60 front and 14BFF rear with a Detroit (duallies had a D70 rear, and some of the D60's have an Auburn or somesuch.)
The Blazer CUCV's (M1009) have 10-bolt axles, 3.08:1 gears, and so are not terribly exciting as 'wheelers. Great highway trucks, as long as you keep your foot out of it.
The 6.2/6.5 diesel gets a bad rap as many people confuse it with the Olds 350 diesel, which was REALLY misunderstood (and IMO should never have been in passenger cars.)
That said, the 6.2/6.5 aren't in the same category as a Cummins; they're okay, put out decent torque, and can live a long life if well-maintained. I'm not aware of much aftermarket stuff in terms of performance upgrades and I would imagine such a motor would NOT live a long life if pumped at all.
(I owned an M1009, bone stock, for a coupla years, and loved it. Go figure!)
-- A
SKNTWSTDK5
Newbie
If you take the injector pump out and take it to a pump shop they can increase fuel flow and pressure to create more power but with it smoke increases mileage drops and engine life shortens. There used to be a shop in Portland Or. that hopped up 6.2 pumps with good results.
86-1ton
1/2 ton status
my diesel teacher suggested that the problem with 6.2/6.5's was the injection pump... he said they were built to make the engine run lean, and it would burn it up... what do y'all think about that...?
Or you can pop the hood on the truck and spend an hour with a few handtools to do the same thing
As long as you stay within reason it shouldn't cause any issue with shortening engine life, and if you keep your foot out of it there is really no mileage loss.Correct me if I'm wrong, but the whole "too lean" theory is only true with a gasoline engine. Technically I do not believe "lean" or "rich" really even applies to diesel engines. The air intake is not modulated on a diesel, so it's all about the quantity of fuel you put into it. Less fuel just equals less power, more fuel equals more power...to an extent.
86-1ton
1/2 ton status
that's what i wondered, too, but thinking about it i've come to the conclusion that too little fuel and the diesel would try to work harder... i know it has a mechanical pump and all, but even with regular maintenance, and keeping up on pressure readings, through the RPM curve it could change the flow, right...?
SKNTWSTDK5
Newbie
I agree with you on the "to lean theory" as you said the air intake is not regulated.
The basis of my original comment is that I have had three 6.2's and of the three only one actually had decent power and it smoked, and only got around 20mpg with 3.08s 700r4 and 33''s. the other 6.2's I had got between 28 and 30 mpg with hardly any smoke and same gearing w/TH400 . I have a buddy who has had a couple pumps built up,plus he ran a electric fuel pump before the stock pump he had these in a suburban on 35''s and it had alot of power but smoked like crazy, fuel mileage was in the mid to low teens and in the four years he ran this setup he went thru two motors.
smalltruckbigcid
1/2 ton status
Gas engines are meant to use a controlled burn. Diesels use an uncontrolled burn. Stoichometry isn't really a factor here like a gasser. Not enough fuel means no bang at TDC.
Fuel scoring is a different topic if the pump had been turned up or it has a bad injector nozzle.
The 3.08/700r4/33" tire combo was definitely lugging the engine bad on the highway...too low of cruising rpm can be just as bad as too high of rpm in regards to fuel mileage. It can actually take more throttle (more fuel) to maintain speed. The non-OD trans with 3.08's and 33" tires was probably a much better combo to optimize fuel economy. But in any case it still depends on how you drive it.
For the guy with the Suburban, sure if you turn up the pump enough you have lots more power but also higher EGT's that will cook the engine. My reference for a turned up pump not causing reliability issues is assuming you keep it in moderation.
Just to clarify, not trying to argue with you or anything.
SKNTWSTDK5
Newbie
Hey 6.2 Blazer, Sorry if I came across like I was being argumentative, I didn't mean it that way at all I was just trying to explain where my thoughts came from on the subject. I by no means am an expert on any of this.
moneypit_K5
1/2 ton status
(hijack in progress)
I'm all ears when it comes to tuning up the 6.5 injection pump, mine seems a little sluggish and starts hard. Dont know much about the chev diesels other than they dont compare to my cummins....
I'm all ears when it comes to tuning up the 6.5 injection pump, mine seems a little sluggish and starts hard. Dont know much about the chev diesels other than they dont compare to my cummins....
No, didn't think so at all.....also just explaining my thoughts on the topic.
Mr. Pickle
1/2 ton status
So what do the different 'code' manifolds do for you? More power, reliability, etc?
There are "C" and "J" code intake manifolds.
C = light duty = more emissions = there is an EGR valve that is located right in the center of the air intake that restricts the opening quite a bit. Less air, less power.
J = heavy duty = less emissions = there is NO EGR valve restricting the air intake. More air, more power.
