Engines in the CUCV?

[hwcurtice]

Just for clarification, because of a craigslist ad, would you say the diesel engines in the CUCV, the mid 80 GM version, are junk? I had thought that these engines, while similar to the ones that came out for civvy use, at that time, were better engines, due to being built, designed, or what have you, for the government.

So, this guy buys a used one, (Duh), drives it home and one injector craps out on him. So he swaps a gas engine into it. His reasoning was, "Those 6.2 diesels are junk anyway." I know many people prefer gas engines, none here, but I think this guy just lost his hat on doing this.

 

[Recovry4x4]

Not junk at all. These were designed as a fuel miser not a powerhouse. As long as you factor that in, they are a decent, low cost diesel. Having 6.2 haters keeps the price reasonable.

 

[Warthog]

The military and civvy 6.2L blocks where that same. The heads and injector pumps are slightly different. There are two types of heads, the smog version that most of the light duty civvys got and the smog-free versions that military and heavy-duty trucks got. The military injector pump has the fuel turned up slightly.

Like Recovry4x4 said, the engine where not designed as powerhouses and the general public abused them and they did fail. That is why they got a bad rap.

Use them as they are designed and they will last a long time.

There are many people that have improved the engines and get great power out of them. One guy set a land speed record with the engine. Over 200+ mph.

Let the general public bad mouth them and they stay cheap for us.

 

[Skinny]

As long as you address some of the week points, I think the 6.2 will serve anyone just fine as long as you don't think it will perform like a Duramax. I agree, the haters keep prices down

I personally love to see it compared to the Olds 5.7 diesel or how the CUCVs make great bug out vehicles because it runs on anything. Pretty sure that no 6.2 has been advertised as a multifuel and that people claiming they are the same as the Olds engine suck at math.

 

[paladin1176]

A lot of people call the Junk because of early issues with the injector pumps. They were notorious for failing without notice and like all IP's...they were fairly costly to replace. A few upgrades later and an injector pump is just as reliable as the fuel you run, filters you keep and rebuilds you get. There were some issues with cracking around main bolts and cracking heads, but there are very few instances where the cracking caused a failure, just means you can't rebuild it. Keep up with maintenance issues and replace things like the harmonic balancer and you will get a nice long life out of it.

 

[Recovry4x4]

I used to entertain the converted gasser debate but I no longer argue it. The more misinformed clowns there are out there, the lower the prices remain.

 

[Skinny]

I think you are missing the entertainment value

Plus you could always get them to ponder converting a Detroit 6.2 diesel back to gas by swapping a carb and distributor. This will keep a moron busy for weeks...

 

[TXFirefighter]

A lot of people call the Junk because of early issues with the injector pumps. They were notorious for failing without notice and like all IP's...they were fairly costly to replace. A few upgrades later and an injector pump is just as reliable as the fuel you run, filters you keep and rebuilds you get. There were some issues with cracking around main bolts and cracking heads, but there are very few instances where the cracking caused a failure, just means you can't rebuild it. Keep up with maintenance issues and replace things like the harmonic balancer and you will get a nice long life out of it.

I have my '84 CUCV engine apart right now. It was a running engine I WAS going to use to swap into my M715 but......
I found cracks in 3 of the 5 main bearing webs
This is an '84 model and was showing 50K miles! heck it even still has the cross-hatching in the cylinder bores!

 

[mutt1966]

How do you come to the conclusion that there were only 50,000 miles on the engine........

 

[Recovry4x4]

I think you are missing the entertainment value

Plus you could always get them to ponder converting a Detroit 6.2 diesel back to gas by swapping a carb and distributor. This will keep a moron busy for weeks...

I shall reconsider.

 

[Mainsail]

LOL I saw that ad today.

I like my 6.2. My jeep has a 5.7 Hemi, so if I want push-you-back-in-the-seat action I drive that.

 

[Sharecropper]

Keep up with maintenance issues and replace things like the harmonic balancer and you will get a nice long life out of it.

I truly believe the harmonic balancer is one of the most important parts pertaining to an engine's lifespan, and the most overlooked when considering what to replace/rebuild. I would venture a guess that a majority of young folk don't even know what it is, much less what it does. The fact is, without a properly functioning HB an engine probably wouldn't last a thousand miles. A good explanation of what a HB does is here - http://auto.howstuffworks.com/harmonic-balancer.htm .

I was fortunate to have found my M1028 with only 12,338 original miles. When I made the commitment to completely rebuild/restore the truck, a new HB was one of the first mechanical upgrades on my list. Before injector pump, injectors, glow plugs, Doghead thingy, brakes, bearings, etc., etc. Although my truck had an easy life cruising around a National Guard base in Arizona, when I first got it there was a definite vibration in the engine. I opted to install a new Fluidampr HB and afterwards the vibration was completely gone. My engine now runs as smooth as the one in my 2013 Avalanche.

All rubber eventually hardens and looses its elasticity. A Gm factory HB has but 3 parts - a steel outer ring, a steel inner ring, bonded together by rubber. It is this rubber that absorbs the torque which is transferred to the crankshaft as each cylinder fires. As this rubber gets old and hard, it looses its ability to absorb the torque, and that's where the stresses come from that cause cracks in the bearing webs.

I would recommend the first money spent on these trucks should be a new HB.

Hope this helps.

 

[TXFirefighter]

How do you come to the conclusion that there were only 50,000 miles on the engine........

AHH there is that thingy in the dash, has a needle that sweeps to the right and a little rolling thing just below it, was showing 53456
I think that is what you would call a clue

 

[MarcusOReallyus]

AHH there is that thingy in the dash, has a needle that sweeps to the right and a little rolling thing just below it, was showing 53456
I think that is what you would call a clue

No, no, no, no. That's not how it works! That engine could have been in 5 different vehicles already! It's probably got more than 3 million miles on it!

 

[TXFirefighter]

No, no, no, no. That's not how it works! That engine could have been in 5 different vehicles already! It's probably got more than 3 million miles on it!

Nah, From looking at the main and rod bearings, cam bearings and wear on the std bore cylinders, this engine does not have 100K plus miles.
Everything looked good inside except for the cracks. Heck, it even ran good before I pulled it out.

 

[paladin1176]

Sad thing is if you hadn't pulled it you would have another 100k miles on it. But...this gives you the ability to upgrade to a 6.5l with serpentine.....

 

[Cucvnut]

I saw that add the owner sounded stupid saying what he said.

 

[Soaper]

taking note on the multi fuel.. not an cucv. but my 6.2L van. if its petroeulem based ill run it.
after i filter waste motor oil . well. 70%WMO-30%unleaded. i run this this in the summer and never had an issue. just when high revs *freeway* or towing id run reg diesel. never had an problem with my injectors or IP. just boils down to how much you want to filter.

6.2L is an **** good engine as long as you treat it like an 6.2L.. ive been around 7.3L and commonrails but would never abuse the 6.2. i like my high mpgs.

ooo first post.

 

[Sharecropper]

Good fuel + good lubrication + good maintenance = longer life.

 

[Skinny]

I think the serpentine setup would be nice if you could drop the two alternators for one large commercial sized 24v like a HMMWV and be able to run an A/C compressor. This would be a slick setup...