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So lets have a serious Cummins vs 6.5 discussion

hahaha. No then. I don't.

I have just always heard them called detroit diesels. I wasn't trying to bump the DefCon level or anything.
 
I offer my serious opinion to a serious discussion: I like my 6.2/6.5 turbo.

It's not a Cummins, and I don't ask it to be one. No 20,000 lb loads, no sled pulls, and it won't peg the needle on a dyno. But, it's very effective for my needs - trail driving and pulling the occasional hot rod.

Also, I'm so hard headed that I refuse to deviate from, what I was told as a kid is, an engine cast from the iron of Thor's own hammer.

David
 
Phil, the story starts like this GM asked its detroit diesel division to build them a nice light duty diesel to be a alternative to the 305/350. So they worked day and night to build an excellent engine with forged crank, and other excellent engine components. GM said, while that is real nice, it is too expensive, cheapen it up. Detroit told them to F off. So GM redesigned it with an eye on cheap using a cast crank and other lighter parts. Martin worked for detroit and they offered no.parts for the 6.2 nor did they ever do any warranty work. For example if you have a new Silverado with an Allison transmission you can take it to a detroit dealer and have it worked on under warranty. In fact I am sure when a dealer works on an Allison, that eventually gets billed to Allison. Clear as mud?
 
I can't say I will never pull 20,000 but it will be at 35-40mph. I may ask it to pull 15,000 at 70mph though. If it can't I will go back to my 8.1 for crawler pulling.
 
Yep, I got it. Thanks for explaining it to me. Go corporate 'murrica.
 
Yea I read the engine got cut by the bean counters I didn't realize it was Detroit that told em to take a hike! I hear the newer motors for the hammers have the forged crank and better block to handle some abuse, considering a lot of 6.2's got the banks retrofit I'd be surprised to know how many actually survive. A note on the 6.2 from my reading the heads are supposed to flow pretty decent?? And considering the rpm range that should hypothetically make a decent towing motor.. Once you deal with the weak spots no? Or should he ditch it for a 4-53T Martin?
 
That is why the 1982 6.2's were red, and not alpine blue.

Martin
 
My 00 should be the improved block. There is a optimizer block that is rated at 300hp.
 
There's also the P 400 block that's slightly better than the optimizer ( no personal experience here).

The 6.5 is probably the most improved engine out there. Over its life, mostly after gm, seems like all the problems were addressed ,its a serious engine now with very few problems.
 
Yes but I can only afford the "try number 2000, I think we got it fixed this time".
 
Yes but I can only afford the "try number 2000, I think we got it fixed this time".


Yep with the optimizer price mine as well swap a Cummins

I keep watching the gov surplus sites. Have seen one or two optimizer cone up for sale.........in like 5 years lol
 
Phil, the story starts like this GM asked its detroit diesel division to build them a nice light duty diesel to be a alternative to the 305/350. So they worked day and night to build an excellent engine with forged crank, and other excellent engine components. GM said, while that is real nice, it is too expensive, cheapen it up. Detroit told them to F off. So GM redesigned it with an eye on cheap using a cast crank and other lighter parts. Martin worked for detroit and they offered no.parts for the 6.2 nor did they ever do any warranty work. For example if you have a new Silverado with an Allison transmission you can take it to a detroit dealer and have it worked on under warranty. In fact I am sure when a dealer works on an Allison, that eventually gets billed to Allison. Clear as mud?

I think the largest confusion comes from the fact that GM advertised it as a "Detroit Diesel." If they hadn't done that I don't think this issue would have happened.

So...blame GM's marketing team? :dunno:

diesel_62_engine_stand.jpg




It is amazing how clean and pristine everything in the adverts is. I'd love to have such a clean rig (although I clearly don't want it badly enough to put in the work :rolleyes:).
 
There's also the P 400 block that's slightly better than the optimizer ( no personal experience here).

The 6.5 is probably the most improved engine out there. Over its life, mostly after gm, seems like all the problems were addressed ,its a serious engine now with very few problems.

Unless you're prone to overheating it...the heads still don't like that, IIRC. :doah:
 
So I have a 2000 OBS with the 6.5

Is that this optimizer I've been hearing about?
 
It could be the improved block like I have, then came the "navastar" block, then the GEP "optimizer".
 
So the improved block is the best that could possibly be in it?

Sorry, I'm a crayon eater. I don't read much.
 
Yes and it could be worse since "2000 model year" is more than like a 98-99 block. Of course it have been repowered in between and has a GEP engine.
 
That is literally the ONLY ad I have ever seen that says that. I can find 50 pieces of GM literature that do not call it a Detroit Diesel.

Martin
 

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