6.2L Dream Build

Skinny · Mar 22, 2013

I don't want to sound like a 6.2 hater. They are fairly easy to work on in the CUCV application, parts are cheap, and pretty reliable when serviced/upgraded correctly.

Having said that, unless you are getting a 6.5 turbo setup cheap from a JY or Ebay, I do not understand why anyone would spend any money on upgrading a 6.2 to make power or performance. I would replace it with another 6.2 if mine died, I would consider an Optimizer if I had lots of money and didn't feel like doing a lot of fabricating for an engine swap. I just do not understand why someone would build a spared no expense 6.2 engine. You can be time/money/performance/mpg/reliability/etc. ahead by using something better to start with like a BT engine. There is a reason why many people like them. If a DT466 fit I'd be looking at that too. Even look at something a little less conventional like a bigger Isuzu or something. I would hate to see someone spend $10k of building a 6.2 because in the end you still have a 6.2

BrushMaster Builder · Mar 22, 2013

I disagree with most on the 6.2 Liter engine. I say this becuase I purchased one of the first 6.2 litre applications built by GM in 1981 in a GMC 1500 4x4 application. After 586k on the truck, I passed it to my brother who is still driving it today. I did replace pump and injectors twice in the 500 plusk life when I had it but no MAJOR engine components replacement. Sure, the water pump, alternator, and other items but the top and lower end of the engine were untouched. As well, I spent a vast majority of my military career dealing with issues on 6.2 and 6.5 engines. The problems inherent to these engines are the problem with most diesel engines (less Cummins). They just are not very forgiving for lack of maintenance and driver stupidity (like shooting ether in them).
If the cooling systems are maintained correctly, the oil and filters changed when needed, and the engine operated and maintained correctly overall (no blowing broken glow plugs out the exhaust) then the 6.2 and 6.5 are reliable.
Cylinder head issues and cracking and lower end issues are a direct result of poor maintenance. Concerning performance, I've built a number of 6.2 and 6.5 applications that I would put up against any "PowerChoke" for power and longevity and did it very simply and economically. Here's an overview how to on the 6.2:

1. Have to use a known good block-not a military block that's been subjected to who knows what
2. Get rid of the timing chain and put in a gear drive set (this is huge in regards to performance although engine does get louder)
3. Gale Banks Turbo with Sidewinder single 3" exhaust (the Turbo retrofit will come with Stanadyne Pump Fuel adjustment Instructions)
4. Put in a Intercooler. Alot of folks would probably disagree based on turbo and temperatures but the fact is, the cooler the air in and out the more power you build. 1 degree means alot to me even though it wouldnt to most rookies
4. Run a 4 Core Aluminum radiator
5. KEEP THE PROPANE AWAY...
6. Finally, run only Shell Rotella 15/40 and Donaldson/Fleetgaurd filtration as well as a good extended life coolant (I recommend adding a remote coolant filter)

There is more you can do in regards to perfromance (head and block configurations due to pre-combustion chambers) but the above will give you an engine that performs speed wise like a gas 350/400 and pulls like a PowerChoke.....gauranteed.

Tplane37 · Mar 22, 2013

Skinny said:
I don't want to sound like a 6.2 hater. They are fairly easy to work on in the CUCV application, parts are cheap, and pretty reliable when serviced/upgraded correctly.

Having said that, unless you are getting a 6.5 turbo setup cheap from a JY or Ebay, I do not understand why anyone would spend any money on upgrading a 6.2 to make power or performance. I would replace it with another 6.2 if mine died, I would consider an Optimizer if I had lots of money and didn't feel like doing a lot of fabricating for an engine swap. I just do not understand why someone would build a spared no expense 6.2 engine. You can be time/money/performance/mpg/reliability/etc. ahead by using something better to start with like a BT engine. There is a reason why many people like them. If a DT466 fit I'd be looking at that too. Even look at something a little less conventional like a bigger Isuzu or something. I would hate to see someone spend $10k of building a 6.2 because in the end you still have a 6.2

I to am a fan of the Cummins BT's, but this thread is about what CAN be done to the 6.2L GM Diesels to improve on their design. Most people, instead, do as you suggested, keep the 6.2L stock, or pitch it to the curb for a transplant. That reasoning alone is one of the main reasons I started this thread. Please stay on track, or don't post in this thread.

Additionally, the money issue was intentionally taken out of the equation to open the door for all possibilities, this does not mean that any of us here are actually going to "spend $10k building a 6.2." In fact, $10k is only a drop in the bucket for a decent performance build for any engine out there. I have more than $10k in my Chevy 383 Stroker, and well over $10k in my 454 Chevy... and that was at 1990's prices for parts and machine work, and these engines can still be beat. I have spent well over $10k of customer's money on Cummins, PowerStroke's, and CAT's, diesels are inherently more expensive to build than gas-burners, but they last longer in the end. So again, with the money issue removed from consideration, we allow for more input and information, and after we gather what is needed, we can let the Laws of Economics determine if anyone will actually build a 6.2L from the information in this thread.

Tplane37 · Mar 22, 2013

BrushMaster Builder said:
* * *
5. KEEP THE PROPANE AWAY...
* * *

I thought Propane Injection had cleaning, mileage, and performance benefits, as well as being necessary on any diesel if Nitrous Oxide was intended to be used? Could you elaborate on your reasoning for staying away from the Propane?

BrushMaster Builder said:
* * *
There is more you can do in regards to perfromance (head and block configurations due to pre-combustion chambers) but the above will give you an engine that performs speed wise like a gas 350/400 and pulls like a PowerChoke.....gauranteed.
* * *

I am interested on this too, particularly some of the block/head configurations, and some of the pros and cons of the different configurations, particularly the combinations to absolutely avoid, and why?

BrushMaster Builder · Mar 22, 2013

It can't be debated that propane, on top of any mechanical diesel engine will of course significantly increase power. I don't beleive any of the folks that states it helps fuel mileage. The inherent problem with dumping propane on top of any diesel engine is the extremely high combustion temperatures we run. The direct or indirect injection of propane does nothing more than create a "violent" reaction and dramatically increases combustion temperature. Also, as for the "clean" aspect, propane is VERY dry and very hard on fuel systems. Zero lubricity in propane.
As a kid grwoing up in West Texas, I was around alot of propane and natural gas powered pickups (gas motors) and irrigation platforms. Don Hardy is best know for racing engines and perfromace propane engines and even he would tell you that without sold stainless crankshafts and ceramic seals, even gas motors can't handle propane long term. As well, talk to any engineer at Gale Banks, everyone will tell you to stay the heck away from propane. Oh, it's great if you don't mind doing an engine or head swap at 30-50k.

BrushMaster Builder · Mar 22, 2013

On the configuration, were I going to build one today, along with the other items I've stated, I would run a 6.2 block (pistons are better contrary to popular belief) with 6.5 heads using 6.2 precombusiton chambers (they are bigger).

Tplane37 · May 5, 2013

I was having a conversation elsewhere on this site and came up with another question. The 6.2L intake manifolds on the HMMWV's are lower profile, correct? How do the diesels react to the profile of the intake manifold? I recall on my Chevy 350's and 400's in the past that I always swapped out the intakes for high rise intakes for more HP/Torque (I think it was low end torque, but can't remember now).

So the question would be, with the Banks Sidewinder, or even the 6.5L Turbo setup, what would be more benificial? The HMMWV low profile intake, the factory 6.2L intake, or the factory 6.5L intake? Why?

HETvet · Dec 9, 2013

Here is my run down for insanity;

Starting with an optimizer 6500 block with Kennedy Diesel splayed main caps, 18.1:1 compression ratio and H beam connecting rods, all forged steel including the crank shaft. A Fluidampr will be mounted as well. ARP main and rod studs installed. The pistons should have the faces ceramic coated and the side skirts getting moly dry film coated. The piston skirts "clipped" to Lighten things up. All these parts should be individually balanced and assembly balanced. A SS Diesel Supply high volume oil pump installed and the oil pan to button up the bottom end. SS Diesel Supply roller cam shaft Kit SS Diesel Supply push rods. a Kennedy Diesel dual idler gear drive set also installed. Moving up to the top end, The bare heads needs to have the exhaust ports aggressively ported out and de-burred for maximum flow. The intake ports also need to be aggressively ported out, de-burred, and completely polished. The valves need to be Titanium and actuated by a set of shaft mounted roller rockers, titanium locks, and have a set of 320lb springs. The head and block needs to be fire ringed and sealed together with ARP 13mm head studs. Kennedy diesel DSG oil cooler and line kit installed and SS Diesel Supply cooling upgrade kit installed.

The exhaust manifold flange should match the exhaust ports and made of stainless steel. Equal length runners made from DOM wall stainless steel and smooth radius angles need to be made. Each manifold having a GTX3076R turbo mounted to it. Each turbo has a .61A/R divided turbine housing. The rest of the exhaust system is all 3.5" stainless steel tubing, H pipe as close as possible to the turbos, and is straight piped, of course. The manifolds to the turbos are exhaust wrapped and turbo blankest installed.

Dual air cleaners are mounted in an empty tool box in the bed. the tool box has various holes cut in to it for air flow and water drainage, but the top of the box is sealed. Aluminum intake tubing is run to the inducer of the turbos. Then Aluminum Charge pipes are run to the front of the truck, with a dual in/single out intercooler. The discharge from the intercooler going right in to the intake manifold. The intake manifold is a single plain HMMWV unit. Port matching to the head and continued through the runners, and the whole intake is completely de-burred and smoothed for maximum flow.

The fuel side of the matter starts with an Air Dog II 100GPH Lift pump. A complete Walking J Designs Feed The Beast Kit will all fittings installed. A Stanadyne DB4831 injection pump and marine injectors.

A Mishimoto aluminum radiator mounted. The coolant used will be Evans NPG+ coolant. mounted to the radiator will be a Flex-a-light dual 15 inch s blade fan with variable speed controller.

I think this set up would be capable of 450-475 horse power to the ground. As far as fuel economy goes, I really have no clue. I would assume it would be 20-30% better than the stock 6.5 due to a higher air volume, greatly improved heat rejection, and lighter internal moving parts with less resistance plus no power robbing clutch fan.

nattieleather · Dec 11, 2013

BrushMaster Builder said:
2. Get rid of the timing chain and put in a gear drive set (this is huge in regards to performance although engine does get louder)

Are these gear sets still available? I've done web searches with no luck on finding vendors selling them? I want to do this to my 6.2 but have not found anyone selling them. And if someone does have a set they think they are made of gold and silver.

350TacoZilla · Dec 11, 2013

http://www.kennedydiesel.com/detail.cfm?ID=45 thats little higher than I have seen but not far off going price.

skysix · Dec 21, 2013

DieselFreak88M said:
Here is my run down for insanity;

Starting with an optimizer 6500 block with Kennedy Diesel splayed main caps, 18.1:1 compression ratio and H beam connecting rods, all forged steel including the crank shaft. A Fluidampr will be mounted as well. ARP main and rod studs installed. The pistons should have the faces ceramic coated and the side skirts getting moly dry film coated. The piston skirts "clipped" to Lighten things up. All these parts should be individually balanced and assembly balanced. A SS Diesel Supply high volume oil pump installed and the oil pan to button up the bottom end. SS Diesel Supply roller cam shaft Kit SS Diesel Supply push rods. a Kennedy Diesel dual idler gear drive set also installed. Moving up to the top end, The bare heads needs to have the exhaust ports aggressively ported out and de-burred for maximum flow. The intake ports also need to be aggressively ported out, de-burred, and completely polished. The valves need to be Titanium and actuated by a set of shaft mounted roller rockers, titanium locks, and have a set of 320lb springs. The head and block needs to be fire ringed and sealed together with ARP 13mm head studs. Kennedy diesel DSG oil cooler and line kit installed and SS Diesel Supply cooling upgrade kit installed.

The exhaust manifold flange should match the exhaust ports and made of stainless steel. Equal length runners made from DOM wall stainless steel and smooth radius angles need to be made. Each manifold having a GTX3076R turbo mounted to it. Each turbo has a .61A/R divided turbine housing. The rest of the exhaust system is all 3.5" stainless steel tubing, H pipe as close as possible to the turbos, and is straight piped, of course. The manifolds to the turbos are exhaust wrapped and turbo blankest installed.

Dual air cleaners are mounted in an empty tool box in the bed. the tool box has various holes cut in to it for air flow and water drainage, but the top of the box is sealed. Aluminum intake tubing is run to the inducer of the turbos. Then Aluminum Charge pipes are run to the front of the truck, with a dual in/single out intercooler. The discharge from the intercooler going right in to the intake manifold. The intake manifold is a single plain HMMWV unit. Port matching to the head and continued through the runners, and the whole intake is completely de-burred and smoothed for maximum flow.

The fuel side of the matter starts with an Air Dog II 100GPH Lift pump. A complete Walking J Designs Feed The Beast Kit will all fittings installed. A Stanadyne DB4831 injection pump and marine injectors.

A Mishimoto aluminum radiator mounted. The coolant used will be Evans NPG+ coolant. mounted to the radiator will be a Flex-a-light dual 15 inch s blade fan with variable speed controller.

I think this set up would be capable of 450-475 horse power to the ground. As far as fuel economy goes, I really have no clue. I would assume it would be 20-30% better than the stock 6.5 due to a higher air volume, greatly improved heat rejection, and lighter internal moving parts with less resistance plus no power robbing clutch fan.

And the parts only cost would be.....

HETvet · Dec 21, 2013

I haven't added it up. it wouldn't be cheep though.

nattieleather · Dec 30, 2013

DieselFreak88M said:
I haven't added it up. it wouldn't be cheep though.

That's why it's called a "Dream Build" One can only build it in thier dreams... :lol:

6.2L Dream Build

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