Anyone got some numbers from a 6.5?

[Offroadaddict]

Im thinking about trading my 98 z71 with the vortec for a 92 6.5 turbo diesel. Im starting to do alot more towing for my dad and i dont think my 5.7 has enough low end grunt. I found a 1992 6.5 3/4 ton truck and most likely im going to trade him but im just curious to see some numbers you guys have gotten from them with some mods to em.

 

[1993GMCSierra]

I think your 5.7L has around 260HP, and 330 ft. lbs of torque.

The 1992 6.5L Diesel would have 190HP, and 380Ft Lbs of torque.


Swapping to a 6.5L for towing is a really bad idea. They were designed primarily for better fuel economy, and designed poorly at that. They are plagued with issues, including cracked blocks, etc. Any of those engines that saw towing use back in the day rarely saw 100,000 miles before they blew up.

If you want a truck to drive around in that gets 20-24 MPG, it's good for that, but it's a delicate engine, and I sure wouldn't use it for towing. The 454 or 6.2L is better suited for that.

 

[Blue95]

With the proper upgrades it will be much better for towing than your half ton, better frame and suspension. THe biggest thing with the 6.5's is heat and the PMD. First thing is to get the cooling system in tip top shape, re locate the PMD, free up the exhaust and intake and it isnt bad.

 

[skylark]

92-93 were mechanical injection with a DB2 pump, no PMD to worry about.

 

[Blue95]

Thanks, I knew they were mechanical pump, but wasn't sure what the PMD all did,

 

[Puller]

Owned two 97's with 6.5's. Both needed injector pumps by 120k (not a bad job to do and upgrade to a marine pump). Kept them both till they had about 200k and never had any other problems. They were landscaping work trucks which involved pulling skidsteers daily and plowing in the winter. Fuel mileage will not be any better than what you have. Turn the fuel up a little get a adjustable wastegate rod, 3" exhaust, tow shift kit, turn the boost up a couple of #'s and it will pull real well. They do pull better than the 5.7's (I owned a couple of them at the same time too) in stock form but much better with about $400 in mods.

 

[Offroadaddict]

Hey skylark I'm from Oregon too, I'm actually moving back Tuesday! Can't wait to get outa this hell hole.. Anyways back to the 6.5 so I'm going to meet up with him this coming weekend. Gonna test drive both trucks. I mostly would be towing some tractors and logs. But my dad has a 55 foot gooseneck that I will eventually end up pulling with 2 travel trailers on it (sometimes 3 depending on length of the travel trailers) but il only be moving those 15 miles at a time.(dad will pay me $8 a trailer)

 

[96-1500]

Swapping to a 6.5L for towing is a really bad idea. They were designed primarily for better fuel economy, and designed poorly at that. They are plagued with issues, including cracked blocks, etc. Any of those engines that saw towing use back in the day rarely saw 100,000 miles before they blew up.

I think that's a little harsh on the 6.5s. I've towed lots with 6.5s and haven't had any problems (not my personal trucks, these were trucks for work). All of them had high miles and worked and pulled fine...considerably better than any small block, no questions asked. There were some early mechanical failures with these motors...but any of those motors aren't around anymore....because they failed. I think a lot of that was warrantied stuff but I'm not positive.

I'd like to see 88GMCtruck chime in on this. IIRC he had a '99 6.5/NV4500 he had for a tow rig.

As for the truck itself (motor aside), a 3/4 ton will be considerably better for just about everything. I used to own a 1500, now a 2500, and wouldn't go back. So much less frame flex for one, heavier suspension, axles, transmission...basically everything important is more rugged.

 

[88GMCtruck]

Yup, I had a 99 K2500 ECLB 6.5/NV4500 truck. I towed my 6k travel trailer with it regularly, as that was the intended use for it.

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I would say, smaller towing duties the 6.5L is fine. But you can't stack this against a Cummins of Powerstroke the same era: they are just not in the same category. But they are honestly a better motor for transportation, why do you think GM put these in 2-door tahoes/yukons and 1/2ton pickups? Ford and Dodge didn't. With my 3/4ton I saw a regular 22MPG empty on the highway.

As mentioned above, these trucks are prone to overheating due to the IDI nature and the fact they are non-intercooled turbos. This really made the other downfalls such as the cracked heads and webs show up. The next issue is the PMD (pump mounted driver) which controls the fuel in the 94+ models. Again, another bad design.

If you get one, exhaust, relocated PMD and EGT/boost gauges are a must. 99+ trucks are the way to go, as they had a better block than the older models, and received all the best cooling upgrades over the years.

I bought the truck to tow instead of using my K1500 TBI350 truck, had it awhile, and I have since sold the truck. I have now built a 454 for my 88 Sierra. My 454 is worked over a bit but it outpulls the 6.5L in every way shape and form (without worrying of overheating) with the exception of one area: fuel economy.

Would I buy a 6.5L again? Yes. But not as a dedicated tow rig. For something that you commute/distance travel in, and haul occasionally or tow light loads, they are great.

 

[Offroadaddict]

Thanks for all the help and advice guys. What should I be looking for when I go look at the truck this Friday?