6.5 detuned to a 6.2

[mudguppy]

Chief is correct about the 'detuned' 6.5s replacing the 6.2s. the only thing i'd add that may differ from my experience is the time table. i was in a maintenance co. at Ft. Stewart from '02-'05; even as early as '02 (and maybe before that?) we never put a 6.2 into a HMMWV, they were always 6.5s. it wasn't choice or policy; if you ordered the 6.2 NSN, the requisition was automatically changed to the updated 6.5 NSN by TACOM through the logistics management process.

also, our sister GS unit was not rebuilding 6.2s at the time, 6.5s only (and few at that).

in my estimation, if you have a 6.2 in a can, i would guess it has to be at least 9 or 10 years old and used.

 

[Preacherboy]

Look at the casting number on the block, if it is a 6.5 and it is a 599 casting, I wouldn't bother rebuilding it.

You can do a search for the what numbers a good block will have. I have a 6.2 totally rebuilt with my 6.5 IP and turbo on it and it runs great! Didn't bother to rebuild using my 6.5 block as it was a 599 casting so very prone to blowing on 6 & 8 cylinder walls.

 

[Chief_919]

Chief is correct about the 'detuned' 6.5s replacing the 6.2s. the only thing i'd add that may differ from my experience is the time table. i was in a maintenance co. at Ft. Stewart from '02-'05; even as early as '02 (and maybe before that?) we never put a 6.2 into a HMMWV, they were always 6.5s. it wasn't choice or policy; if you ordered the 6.2 NSN, the requisition was automatically changed to the updated 6.5 NSN by TACOM through the logistics management process.

also, our sister GS unit was not rebuilding 6.2s at the time, 6.5s only (and few at that).

in my estimation, if you have a 6.2 in a can, i would guess it has to be at least 9 or 10 years old and used.

True. We tended to keep using rebuilt 6.2's longer on the Reserve/Guard side in some cases. Some NG mATES shops were rebuilding 6.2's up until a few years ago to save $$$$.

 

[mudguppy]

ah - gotcha.

 

[hre513]

Look at the casting number on the block, if it is a 6.5 and it is a 599 casting, I wouldn't bother rebuilding it.

You can do a search for the what numbers a good block will have. I have a 6.2 totally rebuilt with my 6.5 IP and turbo on it and it runs great! Didn't bother to rebuild using my 6.5 block as it was a 599 casting so very prone to blowing on 6 & 8 cylinder walls.

I thought the 599 casting was the best 6.5 casting, other than the GEP 506.

 

[patracy]

Pick your poison. The 599 was a better casting, but doesn't have oil squirters like the 506.

 

[Preacherboy]

I thought the 599 casting was the best 6.5 casting, other than the GEP 506.

You are right, I was mixed up! The 599 is the good block, the 506 is the bad one. Mine was the 506!

 

[strelnik]

6.2 production stopped in the early 90's. There was still a need for engines meeting the 6.2 specs for HMMWV's, and it was far cheaper and easier to just turn the fuel down on 6.5's that were in production than keep two lines open.

The military was rebuilding 6.2's as well up until a few years ago, but now when a 6.2 is replaced it will always get a 6.5 in its place, and the 6.2's will not be rebuilt any longer.

I saw the Army WO crest in your avatar. Are you a WO?
I am a soon to retire CCWO

 

[Chief_919]

I saw the Army WO crest in your avatar. Are you a WO?
I am a soon to retire CCWO

Yep- 919A in the USAR.

 

[SmokeyDod]

First I heard of a "de-tuned" 6.5L. Are the engines in ? 6.2 or 6.5L? You can ID which ones they are by looking at the front on the pass side of block where the head bolts to. It will have stamped 6.2 L on the flat area of the block. If it is a 6.5L, it will not have anything stamped in that area.
Also if it is a 6.2 it will have the IP starting with letters DB2829-xxx and if it is the 6.5: they used the better pump with more fuel with letters DB2831-xxxx. The std 6.2 had from 140-155 hp and the 6.5L had 160+hp. The 6.5L has larger dia. pistons and later models had the improved blocks which have the thicker main caps and with the 12mm bolts on inside row and the 10mm bolts on the outside of the three center main caps which helped prevent the crank and block premature failures. Anyway, this is my understanding.

 

[danoscooter]

I recently picked up a rebuilt detuned 6.5 that came with the copy of its dyno when it was tested earlier this year. It maxed out at 223 lbs. of torque @ 3600rpm. It did not show hp numbers though.

Stonepicker1, would I be able to use the injection pump on it or would that need swapped out?

Thanks,

Daniel

 

[Stonepicker1]

You can keep the 24 volt injector pump that is on it. You will have to run 24 volts to the top of the injector pump for it to work ( with a switch in the cab to turn on or off the engine ). Or just swap the top cap from a 12 volt injector pump. ( best way to go ).

 

[danoscooter]

Thanks Phil, I was planning on putting this 6.5 in my m1009. My 6.2 is running fine but plan on replacing it once it goes out or when I get tired of seeing the green can in my garage. This will be my first engine swap and looks like it will be a good learning experience!

Daniel

 

[epartsman]

You need to ground hop them before you get too excited as you may have either just won 2 parts motors or 2 boat anchors especially if they are used. Buyer beware.

 

[PaulbusMax]

I just picked up one of the IMMA-DOL rebuilt 6.5s from Hooks. Mine also has the dyno report,and after run oil analysis report. Serial numbers on the can matched the engine. Forms also state detuned as other folks noted. From what i am gathering, an adjustment to the IP brings back up to 6.5 output specs. Aside from that, would i be correct in thinking that the 6.5 turbo goodies will be a "drop in" option?

 

[chevyCUCV]

Yes you are correct, The IP is easily turned up and all turbo stuff will bolt on.
What does the dyno say for power for your engine?
What block?
Just curious

 

[PaulbusMax]

I don't have the paperwork in front of me, but i think the peak dyno numbers were 234 lb at 3650 rpm..... I haven't checked which block, i'll do that.

 

[danoscooter]

I also got mine at Hooks, that place took longer to get into than I was expecting. Good thing I went there early.

The block is a 506. I'm not all too familiar on which blocks are good but I figured with all the paper work that it came with it, that it wasn't a bad deal.

PaulbusMax what are your plans for your 6.5? I was thinking turbo myself.

Daniel

 

[chevyCUCV]

Depending on the year a 506 can be the best, or worst block
Gm 6.5 with 506 casting are known to blow out the #7 cylinder wall.
The new optimizer castings are also 506 blocks, but have a better metal content in the block.

That said i am bolting in a 506 6.5 goodwrench, into my second truck right now. Price was right and it is staying na for now.
Paulbusmax, thanks for sharing the torque numbers

 

[PaulbusMax]

I also got mine at Hooks, that place took longer to get into than I was expecting. Good thing I went there early.

The block is a 506. I'm not all too familiar on which blocks are good but I figured with all the paper work that it came with it, that it wasn't a bad deal.

PaulbusMax what are your plans for your 6.5? I was thinking turbo myself.

Daniel

Yes,it does take some time to get into Hooks, took me at least 45 minutes to clear all the security. But it sure is neat driving thru there. MV's lining the roads, parked in the woods, stuff everywhere! I thought i'd snatch one of those 6.5s up for future use, although i'd like to find the complete turbo setup for it to have as an option. Ah, but where to look for those?