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6.5 L diesel question

dave_90_blazer

dave_90_blazer

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what bellhousing pattern do these have?

I have a chance top buy an ex military HMMWV (hummer) for $700, but the motor(GM 6.5L) is blown

If the bellhousing is the same as a SBC, I might buy it and drop in an LT1 I have laying here
 
No help really, but won't the 6.5L HMMWV be coupled to a 4L80E?

Probably only matters if the 6.5L itself uses a computer, but something to find out first I suspect.
 
dyeager535 said:
No help really, but won't the 6.5L HMMWV be coupled to a 4L80E?

Probably only matters if the 6.5L itself uses a computer, but something to find out first I suspect.
Click to expand...

does anyone know if the programming is the same for a 4L60E as it is for a 4L80E? If it is, I have an LT1 from a camaro to drop in :)
 
99% sure that they are not the same.

I believe someone over on thirdgen.org was working on running a 4L80E, and found that they aren't controlled the same way.

Just to make it easy 4l80e

Still need to know if the 6.5L WAS controlled by a PCM, or if it is a "standalone" unit. Depends on if the 6.5 required an ECM or not I'm sure.
 
dyeager535 said:
99% sure that they are not the same.

I believe someone over on thirdgen.org was working on running a 4L80E, and found that they aren't controlled the same way.

Just to make it easy 4l80e

Still need to know if the 6.5L WAS controlled by a PCM, or if it is a "standalone" unit. Depends on if the 6.5 required an ECM or not I'm sure.
Click to expand...

I need to look into it, but I think the 6.5L was usually controlled by a PCM
 
different torque converter???

The diesels use a different torque converter stall speed(at least the 6.2's did--I assume the 6.5 would be the same)--will a gas motor "creep" too much with a diesel converter??(I have seen other trucks using a diesel tranny coupled to a gas motor,didnt seem much different to me.:dunno: .)
 
I thought the no-BS military HMMWV's had mechanical motors, regardless of displacement????
 
I just don't know for sure. The 4L80E needs a controller regardless of whether the engine needs one or not, so if they didn't use a PCM, the controller for the tranny alone would be worth $500 or so, at least from what they cost in the outside world.

I was surprised to see 4L80E's in HMMWV's myself, (for the electrical part, they went from a TH400 with no park position to a 4L80E??) but then again the FMTV's are using ABS, so who knows anymore.
 
Yeah, I know the 4L80E needs a computer; just seems a bit silly to put a computer-controlled tranny behind (what might be...) a mechanically-controlled diesel. Then again, we ARE talking about the Government...

The new MTVR (Medium Tactical Vehicle Replacement - the "new" 5-ton that actually has a 7.5-ton capacity) has a computer-controlled motor and tranny with BITE capabilities and plug-n-play diagnostics. I think it's a Cummins/Allison combo feeding a full-time Rockwell transfer case, but I'm not sure. I think it has ABS, too.
 
I'm not trying to tell you what to buy but if you end up with the 6.5 dies you'll probably be disapointed.

Before you buy that thing you might want to read this post.

The military doesn't build motors for power or ability they build em as cheap and as efficient as they can. The only reason the hummers could make that motor work is because of the low gears and all the weight. With a 6.2 or 6.5 K5 you will get stuck it the mud faster than the stock 350. Real bad on hill climbs too.

They aren't a whole lot better than the old put put 6.2's and you will get stuck real quick with that motor. Only makes about 170-180 hp but has around 320+ torque. If you got 700 to blow look for a good used 383. I've seen used 400 hp complete turnkey 383's on ebay for 700. Problem is you can't do a compression check on ebay.

I would look around for something with some guts if i were u. check your paper for a 400 or a 350. Anything besides that military mobber. Just my 2 cents

good luck
 
I half expected there to be just a plain "4L80" in the HMMWV's too, but I haven't seen reference to anything OTHER than the 4L80E anywhere, so I suspect it's a matter of "no one will make it, we'll use whats available" for the most part.
 
What gengeration Hummer is it? Gen 1's had TH400s. I'm not sure at what point they changed to and overdrive tranny, but I'm sure that it would be pretty easy to adapt a small block to fit. For $700, I'd buy the damn thing and worry about the details later.
 
i believe if it is a true military truck, it will have a mechanical engine only- Also a fully mechanically controlled tranny. Something about computers and wires didnt fit. 700, I'd get it.

If the stock 6.5 isnt enough, you can bolt on the 6.5 turbo.
 
isn't the 4l80e a 4speed auto? and if so I believe that the hmvv uses the 400 as last one I drove was a 3 speed auto. just my $0.02 for the day :dunno:
 
I believe the breakdown difference (among other things) in the basic HMMWV is M998=TH400 (with no park position) and M998A1=4L80E.

If a non-electric 4L80E actually existed, you know full well we (or someone somewhere) would have heard about it, and would mean a $500 standalone tranny controller with the 4L80E wouldn't be the only option in a really heavy duty overdrive transmission.

More research:

ETMS If that link doesn't, work, just back up to the main site and select "enter the site". I typed M998 into "pub title text" and it's the second TM listed. Page 7-26 clearly shows the 4L80E and mentions the transmission wiring connector.
 
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There is a standalone computer for the 4l80E...came in some of the early diesel one ton truck and vans. There not super common but are available in some junkyards for under $50.00.Just remember that if you break the 4l80e its major league money to fix, I was told $1500. if you carried it in the door was a starting point, more commonly its $2500-3500. and I cant justify that kind of money for my use.
George
 
I'm definately looking into this truck, i will keep you guys updated, and on the torque converter issue, I will just put a gas engine convertor in it, no big deal
 
As previously mentioned, the 6.5's in military trucks use a mechanical pump. Those in civilian trucks (turbo's anyway) are throttle by wire. Don't know about performance, but from a robustness viewpoint the military 6.5 injector pump would be the one to have.
 
...my brother had a Hummer w/ a 6.2 and it had an Allison tranny.... I thought that all Hummers did???
 
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