Starting planning for the long term.....opinons?

[great white]

Well, my 6.5 is finally up to snuff and running OK, but it's got a fair bit of ring blowby going on.

It's got great oil pressure, but at around 300,000 kms it closer to the end of it's life than the beginning.

She's good for a couple more years, but I need to start planning for the eventual engine failure.

With this in mind, I'm sussing out a plan for the trucks future.

My priorities are:

1. Reliability. I'm Search and Rescue and I fly the CH149 Helicopter. We do everything from medivac to pulling people off sinking vessels. When I get called out in the dark of night or dead of winter I need the truck to go and I need it to go right now with no fuss nor muss.

2. MPG. Yup, it's expensive to run a rig and it's not getting any cheaper. MPG is King....

3. Comfort. Hey, I'm old and not getting any younger. The basic GMT400 chassis is fine, but the less diesel noise the better.

4. Performance. Yup, still a kid at heart. More power the better. But notice, it comes in dead last on priorities...

Looking at options for swapping/rebuild, it seems these are what's available to me:

1. Replace, rebuild or build a short block while waiting.
pros- swap in swap out, no muss no fuss. Good mpg. readily available parts and not that expensive.
cons- all the problems that plague the 6.5 (cracking, low power, no aftermarket, etc). loud. low power and will probably always be that way. the design is getting pretty long in the tooth...

2. P400.
pros- reliable lower end, bit more modern design. Slight fabrication required but mostly a drop in solution.
cons- HOLY FREAKIN' PRICE TAG BATMAN!!!!!!

3. Cummins swap
Pros- good aftermarket support. decent MPG. fairly easy swap and it's been done many times before.
cons- bone crushing front end weight, kills IFS. Expensive. Requires lots of fabrication and downtime. Loud. depending on year electronics can be an issue.

4. Duramax
pros- power. quiet (relatively). modern design. it fits. It's been done before so a knowledge base is out there.
Cons- Expensive if you can even find one, lots of custom fabbing. Electronics, lots of 'em.


Honestly, I'd probably just stick with the 6.5 if it didn't have all it's little quirks an issues. Power has never really been an issue (I don't tow) and the MPG is good (better mpg would be nice). Quieter would also be nice, but this ol' IDI is only ever going to be so civilized.

Feel free to comment and discuss.....

 

[btfarm]

Obvious (and simplest) choice would be a new 6.5. Cummins is a much easier swap than the DMax but yeah... mighty heavy. DMax is a nice end to your problems (just ask Fermin) but the means is a bugger. Read Fermin's build thread if that's your choice.
JM2c

 

[Acesneights1]

It's not worth swapping these motors into these older trucks unless it's a labor of love. It's cheaper to just sell it and buy something newer. That said what is a P400 ?? Lost me on that one. If your gonna go for a dmax or cummins swap, plan on keeping the truck till it dies cause it won't be much. Probaly be worth more with the Dmax swap I would think.

 

[great white]

That said what is a P400 ?? Lost me on that one...

http://www.thedieselpage.com/feature.htm

About 1/3 down the page...also called 6500 Optimizer I believe...

 

[ak diesel driver]

http://www.thedieselpage.com/feature.htm

About 1/3 down the page...also called 6500 Optimizer I believe...

not the same as the optimiser. biggest diff is the cast girdle. optimiser simply uses the better block (not chinese) also the p400 uses a forged crank

 

[red]

another option is the cummins 4bt 3.9L. just as reliable as its big brother the 6bt 5.9L but with 2 fewer cylinders. if fuel economy is your top concern along with the truck lasting a very long time its a great motor.

 

[great white]

another option is the cummins 4bt 3.9L. just as reliable as its big brother the 6bt 5.9L but with 2 fewer cylinders. if fuel economy is your top concern along with the truck lasting a very long time its a great motor.

I did think about the 4 BT. I've seen a couple conversions and it looks good.

Very hard to find one around these parts though....and it's so loud it makes my 6.5 sound whisper quiet:

http://www.youtube.com/watch?v=ioOCTP6-NW0

http://www.youtube.com/watch?v=wG_Arpq5oKY&feature=related

http://www.youtube.com/watch?v=4qwpbUDL1BU&feature=related
(the last one actually sounds pretty cool although it's not a 4BT)

So what? it's a diesel right? And it can get 25-30 MPG if it's set up right. But, Momma doesn't like the 6.5 right now, a 4BT will drive her right out of the truck for good.....

I'm leaning towards a Duramax for the ability to integrate it into the 98's systems. But it's quiet (relatively), powerful and gets good MPG ( according to most accounts). Lots of electrical work to sort out though, LOTS......nothing I can't figure out without he proper diagrams, it's just tedious and frustrating at times and results in a lot more down time than a more "mechanical" conversion.

The P400 replacement is a viable option also. I figure I'd be somewhere close to 6-10 grand to do a duramax anyways and the P400 will pretty much "drop in" with minimal work for a significant savings in down time and frustrations. It should be able to reach 300 hp, but it'll still be IDI diesel "noisy". But replacement parts are a lot cheaper than a duramax also.

I've recently been thinking about sourcing a good block (there's gotta be some out there somewhere!), splaying the mains, 18:1 pistons and turning up the boost (among a few other things) to get me to 300 or so Hp and some good torque numbers. Not sure what that will do to MPG though....


Decisions, decisions......


Only thing I've got on my side is the ol' 6.5 is going to give me a couple years to figure it out.

:thumbsup:

 

[great white]

Well, pretty much have decided a 6BT is out:

on diesel page one guy was showing the weights of each and the 6.5 weight is adout 750 lbs and the cummings was close to 1150lbs i have talked to folks who has done the conversion including the guy at auto world that does the conversions full time and he said that the front end on the 2500 or 3500 has to be reworked once or twice a year depending on use of the truck

Pretty much what I knew already. Since my truck carries a plow in the winter, the 6BT is definately out. There's no chance of me swapping in a solid axle, so the IFS need to live more than a year at a time. 4BT is not what I'm looking for either.

So that leaves me with a DMax swap and sorting out hte electrical nightmare, or rebuilding a 6.5 and settling with teh design flaws and other limitations in the design....

 

[THEFERMANATOR]

A 4BT CUMMINS with a P7100 inline injection pump could easily make 250HP+ with loads of torque, and wouldn't weigh much more than a 6.5. The milage would be awesome as well as people with them in the BURBS have reported mid to upper 20's. The downfall though is they tend to vibrate quite a bit being a 4 cylinder diesel.