88GMCtruck's never ending 88 GMC build thread

[88GMCtruck]

I aware of the flaws, potential problems and all that of the 6.5L motor. Not sure that is what I will do. I really do like them, have maintained more than one and owned one myself. So, in the end if it happens it'll happen, i'll enjoy it and it would be pretty awesome.

There is just something about the indirect clanky clank of them that makes my pants tighter.

 

[Sampuppy1]

The 4bt and old 12 valves have the clatter too. Hell even the later 7.3 power strokes. But nothing sounds like a 6.5. It's funny because I've never heard two 6.5s that sound the same. Similar maybe but never exactly the same.

sent from a likely flagged smartphone.

 

[bluex]

No 6.5 will ever sound as bad ass as that 454 does. I wouldn't change it personally, it's awesome as is....

 

[skylark]

There is just something about the indirect clanky clank of them that makes my pants tighter.

LMAO!

 

[Darkrider]

Ok I'm gonna throw this in here....if the 6.5 is such a bad engine why the hell did they use it in the Humvees that see a lot of the same conditions that Dave will see with his truck? With a mechanical IP and the NV4500 and being in a lighter 400 it would do just fine. Especially if it is a P400 Humvee block with its stud girdle or a later Optimizer 6500.

 

[skylark]

Ok I'm gonna throw this in here....if the 6.5 is such a bad engine why the hell did they use it in the Humvees that see a lot of the same conditions that Dave will see with his truck? With a mechanical IP and the NV4500 and being in a lighter 400 it would do just fine. Especially if it is a P400 Humvee block with its stud girdle or a later Optimizer 6500.

The mechanical injection pump only solves part of the issue. The hummer was severely under powered. Ask anyone who has ever drove one. The hummer was originally designed with a 6.2 and a mechanical injection pump. It wasn't there for power, it was one of the few diesels that were available in the mid 80's and the military wanted diesel power. The hummer suffered the same fate as our beloved GMT400's, during the production run the electronic injection pump, crappy metallurgy, weak turbo and an engine that wasn't built for power was being forced to complete with the powerstroke. The results were dismal in my 6.5 owner opinion. The military had the power to change things and with all of the issues of the 6.5 not being reliable the 6500 optimizer was born. The P400 being called comparable to a standard 6.5 is like calling a 5.7 gen 1 comparable to a 5.7 gen 2 as well as comparable to the 5.7 gen 3. They are all 5.7's but they are worlds apart.

 

[bluex]

Also from what I understand they either swapped out the 6.5s with a duramax as soon as they could or just replaced the while truck with a duramax powered one. So the military using it is a moot point imo...

 

[thz71]

I don't think the put duramaxs in humvees but I could very well be wrong. I do know that the military using something is far from meaning it's the best option.

 

[88GMCtruck]

Ok I'm gonna throw this in here....if the 6.5 is such a bad engine why the hell did they use it in the Humvees that see a lot of the same conditions that Dave will see with his truck? With a mechanical IP and the NV4500 and being in a lighter 400 it would do just fine. Especially if it is a P400 Humvee block with its stud girdle or a later Optimizer 6500.

The mechanical injection pump only solves part of the issue. The hummer was severely under powered. Ask anyone who has ever drove one. The hummer was originally designed with a 6.2 and a mechanical injection pump. It wasn't there for power, it was one of the few diesels that were available in the mid 80's and the military wanted diesel power. The hummer suffered the same fate as our beloved GMT400's, during the production run the electronic injection pump, crappy metallurgy, weak turbo and an engine that wasn't built for power was being forced to complete with the powerstroke. The results were dismal in my 6.5 owner opinion. The military had the power to change things and with all of the issues of the 6.5 not being reliable the 6500 optimizer was born. The P400 being called comparable to a standard 6.5 is like calling a 5.7 gen 1 comparable to a 5.7 gen 2 as well as comparable to the 5.7 gen 3. They are all 5.7's but they are worlds apart.

Skylark pretty much hit the nail on the head, but even still, i can dream of one. I do like them, despite their issues.

Also from what I understand they either swapped out the 6.5s with a duramax as soon as they could or just replaced the while truck with a duramax powered one. So the military using it is a moot point imo...

I don't think the put duramaxs in humvees but I could very well be wrong. I do know that the military using something is far from meaning it's the best option.

I'm not sure on the military sector, but the civilian hummers were offered in 2006 only with a factory duramax called the H1 Alpha.

 

[Darkrider]

Quick question for ya...did you need to make any changes to the CUCV rear axle to bolt it to the truck?