Manny 6.5l Diesel kit

[Believer007]

I ran the numbers as well, for me, it's 50k miles...by then the engine won't even be broke in yet, and I still will not have changed a spark plug or rotor and cap.

It doesn't make sense when replacing a good 455, but once it fails, the 6.5td pays for itself...especially in longevity. It's a no-brainer...especially when dependability hinges on the drive train, and that's what buyers are interested in, amongst other things. The drive train is the single largest expense, outside of original purchase.

One could argue paint would cost the same, but one could also buy an S & J engine for 3750, and have no dependability, and rattle can it for even less...

 

[tmsnyder]

I ran the numbers as well, for me, it's 50k miles...by then the engine won't even be broke in yet, and I still will not have changed a spark plug or rotor and cap.

It doesn't make sense when replacing a good 455, but once it fails, the 6.5td pays for itself...especially in longevity. It's a no-brainer...especially when dependability hinges on the drive train, and that's what buyers are interested in, amongst other things. The drive train is the single largest expense, outside of original purchase.

One could argue paint would cost the same, but one could also buy an S & J engine for 3750, and have no dependability, and rattle can it for even less...

This is just a debate over fuel savings but there's more on my mind. I'm not a huge fan of the 455 b/c it's an orphan. I can't dial up GM and order a brand new crate motor anymore.

We're at a point in time where finding a good replacement 455 is hit or miss. Yes, you might have a good 455 right now but what about the guy that just spun a main bearing? What's he/she supposed to do?

6.5L is still being sold as a new crate motor for $7200 direct from GEP (actually through a few distributors).

After hearing nightmare stories about Mondello, S+J and other rebuilders, I would prefer to just get a new crate motor from GM or GEP. We're getting to that point in time where replacing a broken 455 with a rebuilt 455 just might not be a great option anymore. Cad 500s were a great option at one time, but now those are all what? 40 years old sitting in a scrapyard if you can even find one?

When it comes to needing an engine replacement, I'm not sure there's a good 455 or 403 option anymore. We might not have a choice in the very near future.

 

[LQQKatJon]

Having been around enough vehicles over the years and diesels. You just cant compare diesel to gas. You van try to justify the better mileage of a diesel, but then you need to have a $1000 injector rebuilt, or de-carbon an intake. It ends up either money lost, money saved or cost upfront or retained value in the end. No two cars are the same. I have seen TDI vw’s last forever and the other one seems to be constantly in the shop. I see that with out fords and chevys. My father-in-law’s duramax’s has seen plenty of time at the shop too.

I still wonder about our transmissions behind a diesel in the long run.

Nice to see people trying. Maybe 10 years from now we will know what works. I have had my coach for 10 years and the cutting edge for our gmc’s in 2010 is much different then today. And parts can be scarce now on some of those things installed in 2010.

 

[Believer007]

Well, I know Bill Travato builds one hell of an engine... but in the long run, for cost of operation, and shear grunt, diesel is the way.
VW screwed themselves with some engine models... Germans never look backwards, like to what worked...like the ALH engine.
I ain't sceered.
Getting closer, waiting on some more parts.
Eventually I'll get a post together detailing, to some degree, the conversion process.

 

[tmsnyder]

I still wonder about our transmissions behind a diesel in the long run.

Yeah I wonder that too, the only good thing about the 6.5 is that it's pretty anemic. 190hp and 400 ft-lb of torque. The tq is right there with the 455s , and the TH425 help up to that ok. How long would a TH425 hold up to an engine putting out less tq I wonder? Probably it would be bulletproof.

 

[LQQKatJon]

Yeah I wonder that too, the only good thing about the 6.5 is that it's pretty anemic. 190hp and 400 ft-lb of torque. The tq is right there with the 455s , and the TH425 help up to that ok. How long would a TH425 hold up to an engine putting out less tq I wonder? Probably it would be bulletproof.

What was told to me about diesels was that it is kinda like a rotary hammer drill. You can have a. Drill with same torque but if you hust set the drill on “drill mode”. And try to drill a block. Then set the drill on the hammer drill mode and drill the same block. I was told that is how a diesel can be much harder on drive train then a gas engine.

Maybe that is incorrect. I was just told a diesel can be hard on transmission when you look at swapping. That came from the full size jeep world when they loved to swap in diesels for better mpg.

 

[LQQKatJon]

What was told to me about diesels was that it is kinda like a rotary hammer drill. You can have a. Drill with same torque but if you hust set the drill on “drill mode”. And try to drill a block. Then set the drill on the hammer drill mode and drill the same block. I was told that is how a diesel can be much harder on drive train then a gas engine.

Maybe that is incorrect. I was just told a diesel can be hard on transmission when you look at swapping. That came from the full size jeep world when they loved to swap in diesels for better mpg.

I should add. It seems that there is some difficulty lately too in keeping a transmission working behind a 455. I am one who only had 3000 miles on a rebuilt tranny before it died. I see some posts that sirum has been trying to figure out why some rebuilds have failed. I also know of a fee “manny” tranny early failures.

So maybe just a th425 concern rather then related to a diesel. Probably same reason people like the idea of a diesel as there are plenty of rebuilt 455/403’s failing folks.

 

[kidjedi]

From rumors- it is loud. You see Jim Bounds was working hard at sound proofing. But my gas coach is loud too??

My previous Airstream Motorhome had an engine fire, so when I got my GMC I went overboard with the fireproofing (and thus sound proofing) in the cabin. I think my fuel injected 403 is pretty smooth running and thus already relatively quiet, but once I added kilamat and other heat/sound padding, carpet padding, and carpet along with modifying the engine bay "lid" (added thickness, EPDM gasket seal all the way around, etc.), the GMC cockpit is now quite a bit quieter than my Prius. You can have "whisper conversations," no joke. I wonder how it would sound with a diesel.

I often dream of the added torque and longevity of a diesel swap, but unless something catastrophic happened (knock on wood), there would just be no good reason to abandon my gas powered 403. Now... I am still looking for a rolling 23' '77/'78 that will be my electric project, but I plan on driving the gas powered 1977 for many years before that comes to fruition.