6.2L Dream Build

Okay folks, I have been searching around SteelSoldiers as well as throughout the net regarding performance upgrades for this 6.2L diesel. I have found a few things here and there scattered around, but nothing that is devoted to turning the 6.2L into a power-house. I'd like to get a thread going that is devoted to just what the forum implies, "CUCV Hot Rodding and Modification" with the focus of this thread to be on the 6.2L diesel.

Assumptions:

-Money is not an issue (unrealistic, but as the thread implies, "Dream Build");
-Parts are available (some performance parts may already be available, some may have to be custom machined, but this will let us know what to look for);
-Utilizing a 6.2L J Code block from a CUCV (some components on the civilian versions differ, while it would be good to point out the specific differences, lets assume we are working with the military units to start with)
-A 'properly' set up 4L80E transmission will be backing this engine, lets assume that the transmission is built to withstand what we are going to be putting out of this dream build.
-Axle ratio of 3.73:1
-37x12.50R16.5 Goodyear tires (seems to be a common upgrade for the CUCV, so lets not reinvent the wheel, literally in this case)
-All components will be Cryo-ed when/where possible to increase strength. longevity, and integrity.

Goals:

-Three separate goals: (1) MPG; (2) Power (HP/Torque); and (3) a comfortable balance of both MPG and Power that will be an improvement over a stock CUCV (should have room to play when the transmission, gearing, and tire upgrades already being done as assumed above).
-Use as many "off the shelf" components as possible, modifying what we have available when necessary.
-Can we "hide" the upgrade from the naked or untrained eye? Do it where we can, but otherwise, stick to our primary 3 goals.
-Dependability. No sense in building this if it will only last us a week. Let's make it strong and dependable.
-Needs to be able to accept WMO or WVO and bio-diesel. This focus it basically to be aimed as materials for hoses, O-Rings, and gaskets. I don't want to get into a debate about what is better or worse with these fuels, let the end user decide if he/she wants to run these, I just want to ensure that the seals and such won't degrade in these fuels.

Examples:

-Turn up the injection pump (How? To what extent? What are the concequences to watch out for? What else do we want to do to the engine to allow us to crank the IP up even more?);
-Stronger lift pump, larger fuel lines;
-6.5L Turbo Upgrade. (What components do we retain from the 6.5L? What modifications do we need to do to the parts?)
-Spin on Filter/Water Separator upgrade (Been discussed constantly, but can we reach a consensus on the filtration system in an ideal situation.);
-Marine injectors. (Are they available, where are we looking to scavenge them from, or where can they be bought new? What specs are we looking for and what are the advantages/disadvantages?);
-Propane injection/Water-Methanol Injection;
-Etc.

***

Like I said, a lot of this has been touched on on this site already, but the information is scattered around everywhere, and some information conflicts with other info available. I figure if we keep this thread to the best option available, leaving the monetary issue out of the equation, we can make some headway. Links to other threads are acceptable to the proper users get credit for their "finds," but I'd like to see a central location for all this information, with hope of this thread becoming "worthy" of being a sticky in this forum.

Let's Git-R-Dun!

Buy "6.2 diesel volume I" and most of what you are asking has already been answered. Volumes II and III really round out anything missed.

Those books are located at www.thedieselpage.com

http://www.thedieselpage.com/62book.htm
http://www.thedieselpage.com/62bookii.htm
http://www.thedieselpage.com/65book.htm
http://www.thedieselpage.com/65bookii.htm
http://www.thedieselpage.com/t&rguide.htm

They have spent countless hours devoted to fine tuning the GM line of diesels. Alot more info there than there is here.

I did not know about those books. I will have to look into them.

However, I still like the idea of getting a one stop shop for information set up here. Ever since I bought my XM211, this site head been my first stop for trusted information, an continues to be the first place I look (after the TMs) when I am stumped. I do believe that credit should be given where it is due though.

If money isn't an option, why use a j-code cucv block? a new and improved optimizer block would let you reliably make some good power numbers.

USAWEAPON777 said:

If money isn't an option, why use a j-code cucv block? a new and improved optimizer block would let you reliably make some good power numbers.

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I'm intrigued. What is this "optimizer" block? And what is it about this block that makes it superior to the J- Code block?

My focus on the J block is due to availability more than anything, and the fact that the CUCV is already designed to use this block without modification, and it can be used in the HMMWV with only a couple of bolt on modifications.

But if the Optimizer can bolt to the stock mounts, has a standard GM bolt pattern for the transmission bell housing, and accepts or can be made to accept the accessories designed for the CUCV, then I think we should consider it.

Thanks for the link doghead.


the 6.2 engines aren't that durable in high performance builds. Along with heads often cracking, the main issue in performance builds seems to be cracks forming in the lower end around the mains. The optimizer blocks are what are currently being used to produce new 6.5's They are a lot stronger in the bottom end and address most if not all of the issues our 6.2's are known for. These newer blocks are basically a direct swap in. If your going to keep the current block I'd recommend getting a stud girdle built to help hold the bottom end together under heavy load with boost.

doghead said:

http://www.enginebuildermag.com/Item/1458/the_optimizer_6500.aspx

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That is very interesting, I have converted the article to PDF and attached it. Really good information on the cylinder heads. But I need to look more to see if this block is publicly available, or if AM General is hold in on to it tightly for military use.... The best block is useless to us if we can't readily access it.

View attachment Engine Builder - Optimizer 6500.pdf

At least it would appear to be available, in a marine application as well. http://www.amgeneral.com/vehicles/gep/

It would appear that the marine application has a higher HP rating, and comes in both supercharged AND turbo charged variants. I still haven't found a "where to buy" link yet, nor have I found out if a "crate" engine is available (e.g., complete engine with computer and harness set up for retrofit as designed for up-fitting the HMMWV's). I think it would be best, if possible, to go after the 2000-2004 variants if possible so we don't get hammered with the 2007+ emissions controls that we would have to overcome... I think the marine engines are exempt from the emissions standards and may be the better option? I guess that would depend on the crankshaft rotation of the marine units and if there are fewer emissions control devices built into the systems.

http://www.optimizer6500.com/default.asp?section=marine

EDIT: It appears to be available, here the long block High Output Variant for $6,800.00. (Cheaper than I thought it was going to be.)

Details:

Long Block includes :

• Oil pump
• Valve covers
• Front cover
• Gasket set
• Oil pan

OPTIMIZER P-400 6500 H.O. FEATURES:

250 HP Power Rating
550 LB-FT Torque Rating
High Durability Components
Including Forged Steel Crankshaft,
Stronger,Thicker Cross Section
Connecting Rods and Ladder

Click to expand...

you can get the optimizer block, i just cant remember where.. but if it were me, i would use the P400 block (used in the new up-armored HMMWV's) they will work in the CUCV's with a small lift to clear the oil pan.. with that block i would add
- .010 thicker head gaskets
- HX35 turbo, wastegated at 22-25psi
- DB2 (manual) injection pump, turned up to match the turbo
- intercooler
- ARP head-studs (unsure if the P400 comes with them or not)
with this set up, you should be able to push above 400hp not sure about MPG

jdknech said:

you can get the optimizer block, i just cant remember where.. but if it were me, i would use the P400 block (used in the new up-armored HMMWV's) they will work in the CUCV's with a small lift to clear the oil pan.. with that block i would add
- .010 thicker head gaskets
- HX35 turbo, wastegated at 22-25psi
- DB2 (manual) injection pump, turned up to match the turbo
- intercooler
- ARP head-studs (unsure if the P400 comes with them or not)
with this set up, you should be able to push above 400hp not sure about MPG

Click to expand...

Any idea what size studs the heads are set up to run? I'd opt for 7/16" ARP studs and fire ring the heads with the 0.010" thicker head gaskets cut to match the fire rings.

Also, why the HX35 turbo? Why not run parellel twin turbos plus a supercharger? Optimize the engine for both low RPM Torque and High RPM horse power... when one quits making boost, the other is picking it up. I do like the DB2 thought though, don't need to add to many more electronics if we don't have to, but how could we match the IP to both a supercharger and twin turbos? That could make things really interesting. And what about injectors? What are our options there? I guess that is going to depend on the intake and whether we decide on the supercharger or not, and what supercharger we decide on if we do.

I thought a supercharger and turbos would cancel out...idk. Don't quote me....

when you start talking "twins" and "supercharging" in the same sentence, you going beyond my experance.. lol i do know from when i built my 6.5 that you dont have much option when it comes to injectors.. you have stock NON-turbo, stock turbo, and marine "40hp" injectors.. if you use a twin setup, with a smaller, and a larger turbo, i wouldnt see where a supercharger would add anything to the mix.. the smaller turbo would boost at, and off idle, and the larger turbo would come in mid-range..

also, from the specs you listed for the P400, you would need to add a crank girdle, and ARP makes head studs for the 6.2 (same as 6.5) they are metric (M12) and rated at 220,000 PSI tensile strength

Danger Ranger said:

I thought a supercharger and turbos would cancel out...idk. Don't quote me....

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a lot of detroits use turbo over superchargers.. it needs the boost from the supercharger at idle and low RPM's just to run, then the turbo kicks in about mid-range when the supercharger "falls off"

Danger Ranger said:

I thought a supercharger and turbos would cancel out...idk. Don't quote me....

Click to expand...

One is belt or gear driven, and the other is exhaust driven. The turbos are easier to play with when it comes to choosing your ideal boost range. You need to synchronize them so that they compliment each other instead of fighting against each other. Each of them will make boost at specific points. We did this out in So. Cal. with a custom buggy. We took a 4.3L GM V-6, strapped on the heads and supercharger from a Buick 3.8L V-6, built a set of headers and put a small turbo on each bank. Someone else figured out the boost and all the synchronization between the two...when the supercharger stopped making power, the turbos were starting to come in and make boost... and yes, when they were out of sync, it was crap... but once the boost was made to be continuous/near continuous, that buggy would scream like nothing I have ever seen! It was one of those "Hey, we have a bunch of junk laying around, let's see what we can do with it this weekend" type situations.

It can be done, but it can be a PITA and I haven't worked with them enough to know HOW to do it, but have witnessed first hand that it CAN be done... and it was cool!

jdknech said:

a lot of detroits use turbo over superchargers.. it needs the boost from the supercharger at idle and low RPM's just to run, then the turbo kicks in about mid-range when the supercharger "falls off"

Click to expand...

Tplane37 said:

One is belt or gear driven, and the other is exhaust driven. The turbos are easier to play with when it comes to choosing your ideal boost range. You need to synchronize them so that they compliment each other instead of fighting against each other. Each of them will make boost at specific points. We did this out in So. Cal. with a custom buggy. We took a 4.3L GM V-6, strapped on the heads and supercharger from a Buick 3.8L V-6, built a set of headers and put a small turbo on each bank. Someone else figured out the boost and all the synchronization between the two...when the supercharger stopped making power, the turbos were starting to come in and make boost... and yes, when they were out of sync, it was crap... but once the boost was made to be continuous/near continuous, that buggy would scream like nothing I have ever seen! It was one of those "Hey, we have a bunch of junk laying around, let's see what we can do with it this weekend" type situations.

It can be done, but it can be a PITA and I haven't worked with them enough to know HOW to do it, but have witnessed first hand that it CAN be done... and it was cool!

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Ok, but you don't see them together very often. I was just skeptical...thanks for the info.

I know a bit about turbos, and how they work, and I know a bit about how superchargers work, just not together. Syncing them correctly would make sense. But this is why I asked...

jdknech said:

... if you use a twin setup, with a smaller, and a larger turbo, i wouldnt see where a supercharger would add anything to the mix.. the smaller turbo would boost at, and off idle, and the larger turbo would come in mid-range..

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The twin setup with a smaller turbo, then a larger turbo is something more along the lines of a tandem/series set up. And you are right, in that case, there would be no point of having a turbo over supercharger setup. The series turbo setup works out pretty good on an inline engine like the Cummins because the exhaust dumps all on one side of the engine. A single series set up does work on a "V" configuration engine as well, but requires a crossover pipe since the turbos inevitably end up crammed on one side of the engine bay, which adds heat to the engine bay near the fuel lines and engine, plus the right and left banks are out of balance, requiring one side of the engine to work harder than the other.

What I am looking at is to equalize the exhaust by having identical turbos on each bank, keeping the exhaust piping as equal on each side as possible. Now, depending on what supercharger options there are, it may be beneficial to run turbos as a parallel series (small+large on each bank, matched to each bank). It all depends on where the supercharger starts making boost, and where it stops, and if the added gains from the turbos can outweigh the added resistance from them.

also, from the specs you listed for the P400, you would need to add a crank girdle, and ARP makes head studs for the 6.2 (same as 6.5) they are metric (M12) and rated at 220,000 PSI tensile strength

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I forgot, these are metric engines. I was thinking about other builds I have done using fire rings (Cummins)... I instinctively wanted to add 7/16" studs with the fire rings! Good save, M12 studs would be what we should be after.

as i said, anything over 1 turbo is out of my knowage area.. lol (other then detroits, then i know alittle, but not much) everything i know is from months, and months of reading, and research... then by experameanting.. i turboed my M1009 and ran 10psi on a stock engine.. then i got my 1995 Z71 with the 6.5, and desided to play with it.. here is the list so far

4" exhaust
40hp injectors
6.2 J-code heads (blew the stock heads with 22psi boost)
lots of other upgrades for the electronics

(its for sale btw)