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6.5 direct injected heads

D

drillgod

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Im looking into developing direct injected heads for the 6.5/6.2 platform that could be used with the same injecter pumps they use now. I think fuel mileage and power could increase. A new piston style would obviously needed to be developed as well.
 
This has been tried before.

IIRC AMG built a couple prototypes and tested them extensively.

I think there was a common rail setup as well tried.

The reason the design did not go too far was that sales numbers were not there to support it.

GM had already bailed on the 6.5 design due to several factors (Reliability and reputation had been torpedoed in 94 with the electronics) plus the emission standards were going to kill the thing in its current incarnation.

AMG has the resources to make it happen, but the Hummer is basically dead, and there in lies the sales, or in this case, lack of.


The P400 from AMG is about as far as your likely to see the 6.5 go.

These engines are making great boat power, as well as a good plant for many re-powers.

If you decide to do this, what are you planning for castings???


Have fun, sounds like a great project
 
GM made them, it is called a DURAMAX. In all seriousness, the 6.2/6.5 platform will never hold up to the added stress of direct injection, and the STANADYNE pumps will never supply the needed pressure to make a direct injection engine work properly. In contrast, the 6.5 can be set up for say 2500 PSI pop on the injectors, a direct injection engine needs almost twice that at idle just to keep from hazing. Without a precup to help burn and atomize the fuel, inejction pressures MUST go up. So GM DID go to a direct inejction setup for the 6.5 when it went to the 6.6L DURAMAX as it HAS all the needed upgrades to make a direct injection engine work and live at 200+HP power levels.
 
One time I cut the precups so they just became headgasket holders. The injectors sprayed directly on to the piston tops. I drove it for a few days ,but it had very little power.
 
I had them at 3800 psi. The pump was just a turned up .290 plunger.
 
All you were missing is an additional 285 psi of boost?

Somewhere out there is an actual calculation... If someone really wants to search for it.

Maybe lots of propane?
 
6.2 turbo said:
One time I cut the precups so they just became headgasket holders. The injectors sprayed directly on to the piston tops. I drove it for a few days ,but it had very little power.
Click to expand...


It did no damage to piston whatsoever? Like burning holes in them if you were to drive a long distance like that?
 
Don't recall it starting hard, but lacked power ,and smoked pitch black. It had a soft hollow knocking sound ,instead of the normal clatter . Was running an unmodified ip at the time ,just turned up. Might have worked better with one of my modified pumps .
 
To run a DI engine on our low pressure injection system... Well lets just say this is why our injection system is found on a IDI engine.

The expense to go DI on a 6.5 when better engines are around is not worth it and, as said above, is re-inventing the Duramax.
There is no reason to spend this kind of money on a 6.5 as someone with pockets this deep will simply go with a proven conversion to another engine. Modern fuels are limiting the life of these old injections systems and good parts are getting very hard to find. Cheaper than common rail stuff, but, hard to find.

A good read of the IDI and DI compromises is here:
http://www.thetruckstop.us/forum/showthread.php?27096-IDI-tecchie-info-courtesy-of-Great-White

I would encourage you to improve the IDI 6.5 in ways tried by others in the above link. Ceramic coating the prechamber for example. Others are working on different precups.
 
I would love to get a duramax, but it is electronically controlled by a smart a$$ computer when a sensor fails, it goes into limb mode and the cost of a engine plus electronics. Where I live,the duramax is not available, but the 6.2 and 6.5 are rare but once in a while one of them makes an appearance.

The other thing about a mechanical engine, it's plug and play. Less wires that can rot and fail.

Have a good day.
 
I've puttered with a few 3208 projects. Use 3 ring pistons and roller cams, they run good, pop pressure is 1600 I believe, 17.1 compression, they are all direct injected, NA and turbos, lots of marine applications back in the day. Emission issues took them out same as the 2 stroke Detroits.
For some unexplained reason Caterpillar hung onto the 2 ring piston for way too long, did not help the 3208 case for clean air.
Pondered direct injection for the 6.5 myself.
 
IDI engines are great workhorses, will run on just about anything, and are pretty simple. The amount of mixing they provide is great and makes it possible to run a low pressure injector with good results. Seen plenty of em burn really clean. The shrouding in the head that makes up the prechamber is a great heat sink though and sucks away efficiency. Ceramic coating is a great idea and a heck of a lot cheaper. Won't get you many more revs as we still suffer from a pretty slow flame front, but should bump up economy and available power and reduce likelihood of cracking heads and precups. Sure would be an interesting experiment if the marginal bottom end holds up. At least put splayed mains in it....


Sent from my iPhone using Tapatalk
 
WarWagon said:
I would encourage you to improve the IDI 6.5 in ways tried by others in the above link. Ceramic coating the prechamber for example. Others are working on different precups.
Click to expand...

Interesting, if you look at Heath's land racer, he coated everything EXCEPT the precup, wonder why?
 
Splayed mains? um, what block, and why? Not trying to come across rough but I think your missing something here. When pushing a gasser to 650 hp or so, and 800 torque, turning a 2 bolt main AND STRONG BLOCK, will help strengthen an over stressed crankshaft from to much movement. The 6.5 is already a 4 bolt main, that is a very weak block. Taking more meat out of the block to change the angle of the main cap bolts are not going to keep the block from cracking. Show me 2 crankshafts that came apart that had good harmonic balancers on them and the block is still perfect. Find 1- I call it a fluke. Find 2 and you could have something.

In the fleets I ran, I am very willing to bet I dealt with more broken cranks and blown out bottom ends than just about anyone out there. Hundreds of trucks in a couple of fleets. Some of the trucks ticked off over 27,000 miles a month. Engines shut off only for oil changes done at 10,000 mile intervals while the driver sat in the seat. 3 mechanics on the truck like a friggin nascar pit crew. All PMs done in less than 10 minutes and back on the road. Dozens of crankshafts into pieces. Wore out and killed well over 100 6.5s. The balancers go and it kills the crank and block. The lower end assemblies are horribly out of balance from the factory compared to modern stuff.
How do some guys get high mileage on 1 balancer and no block damage? Easy- when the rings and cylinders wear out too much to run, pull the lower rotating assy and have it balance checked. It will be in amazing tolerance numbers. BTDT.

I don't want to stop anyone from experimenting and having fun. Tear into it, you never know what you'll learn and the memories you'll create. But reinventing the wagon wheel because it's 44" tall to give you more ground clearance, and skinnier for less drag is what this reminds me of. Yeah you could do it, and you making a change that sorta sounds like a good idea at first. But the problems you are introducing is going to amplify other outstanding issues that are already known, addressed, and moved on from. I turned a sbc into a 2 stroke just because it was fun. Full roller bearing crank and all. Completely impractical and when it came apart people were ducking from parts 100 flippin miles around! But I had $35,000 to waste on the project and more importantly, I did my research before hand to know that it was all a waste of money before I started.


Back to the op- Anything yet? If you gave up on it have you thought of going another route like nitrogen depleted chambers to make up for a slow flame front (Hmm, where has Will pumped a few more $ into experimenting) or maybe some injected isobutene into the chamber to offset the draws of idi diesel fuel while not causing quite as much havoc as propane? Ever figure out how hot you can get diesel under 2,000 psi to accelerate the burn rate once it dumps into the prechamber? Lots to play with out there.:D
 
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