CP3 in a 6.5?

[Kmehr]

Just thinking out loud here and its not like i am even very knowledgeable on the subject, but it seems like to me that one of the largest obstacles to making big power with the 6.5 is the limited capability of the db2 and ds4 to give enough fuel. So my question is this: what is the feasability of putting a CP3 on a 6.5? I know lots of newer gen dodges use a p-pump, not that it is at all similar, and not that i am even thinking about trying this.

[john8662]

CP3 is just a very high pressure fuel pump, to supply fuel rails, which feed electronically actuated injectors.

So, if you had a CP3, high pressure rails, electronic injectors for 23,000 PSI, a computer, then it could be done. I don't know off hand what engines and parts are available that might be adaptable...

Many later (common rail) cummins feature the CP3 as well, the earlier 94-97 Cummins had the P-Pump, which can be modified to supply fuel like a fire hydrant. late 98's had the VP44, which is much like our DS4 (flawed too).

J

[Kmehr]

Excuse my ignorance here, but so the CP-3 being a common rail is sort of like EFI on a gasser where it gives fuel to a rail that connects all of the injectors, and the injectors, being electronically actuated determine the injection sequence though there is sort of a constant supply of fuel to the entire rail...?? ANd the 6.5 is IDI where the pump sends it to each injector?? if thats the case then it does not sound very likely it could be adapted. Are there any other big time injection pumps like say off another Detroit diesel that could be more readily used? I have heard of cummins guys using pumps off an 8.3 cummins.....

[Kmehr]

Also isnt there a pre-combustion chamber in the 6.5 head? would this be different than the duramax?

[JohnC]

It is my understanding that the marine pumps can deliver more fuel than the stock ones. Also, some folks have mixed and matched parts from different pumps, specifically the HD '94 pump which had a more agressive cam ring, to get higher fuel rates. Someone even set up 2 pumps in parallel on a tractor. All that said, there is emperical evidence that suggests the stock DS4 pump can produce enough power to tear the crankshaft out of the bottom end...


Yes, 6.5s have precombustion chambers in the heads. The duramax doesn't have precombustion chambers. Fuel is injected directly into the recess in the piston.

[6.5 Detroit Diesel]

I have been wondering about something like this too. Don't know if the CP3 makes much sense and you would really be changing all fuel delivery around. Whereas twin DB2 pumps could in theory put out more fuel. But then you need to increase PSI and get injectors that will handle that, being "pop" injectors. Just rambling, as I have really been thinking about how to turn of the fuel further on a 6.5

[Kmehr]

i am interested in hearing how the DS4's can be linked in parrallel......

[john8662]

i am interested in hearing how the DS4's can be linked in parrallel......

I don't know about DS4's, due to the computer's individual control over the unit, so two, dunno. Ideally, setup a test engine stand with a DS4 running on an engine, then progress from there. I'm working on a DS4 engine testing stand to let me test-run engines, and I want an electronic one. But, not solely for testing, to help me weed out a harness to help me convert an older 6.2L Diesel to 6.5L EFI, been done before (GMCTD did it well already).

The Dual-Pump engine that was created was done with two mechanical DB2 6.2L Pumps, which are similar to the early mechanical 6.5L pump (no computer), and yes, in parallel.

As for earlier, yeah the common rail idea is like that of a gasser rail...

[Kmehr]

Well i guess my question is how can a pump for an IDI diesel be setup in parrallel when there is an out put for each injector. I see now how a dual CP-3 setup works cause all the fuel essentially goes to one place.....

[Kmehr]

just to add, i just saw that tractor with the 6.2, man that thing is nasty!!! Saw the pics with the big ol inline pump on it, what is that off of? Are there any 8 cyl diesels with big pumps that could work on our little 6.5's?? that tractor gives me goose bumps!

[Robyn]

Exisitng components can take a 6.5 deep into the place called "MELTVILLE"

The issue with the 6.5 is not getting enough fuel to it to make huge power, but instead cooling it.

A marine application using the water from the Pond allows water cooled charge coolers to keep inlet air temps down as well as engine temps.

A pickup chassis application is limited in its ability to cool the engine under even the best of conditions.

You can get to about 300HP and still keep things together and operating within reason as far as temps go.

Under a full power hard pull with a load the cooling system is marginal.

The marine DB2 or even a DB4 will supply enough fuel to send one of these little creatures up in smoke or flying into pieces.

The basic design of the 6.2/6.5 has limits as to what it can do and live a reasonable life span.

250 HP is a good place if you like your little critter 300 tops.

Beyond this it gets sketchy real quick.

The block is not near strong enough as well as the crank being .

The heads can't reject near enough heat and so the list goes on.

Robyn

[6.5 Detroit Diesel]

I am guessing the aluminum incorporated into the heads of modern diesels is one reason for good heat exchange?

[stroh]

What About The Amg P400 With All The Improvements In This Engine Would Not The Cooling Problem Be Corrected?

[Robyn]

Some issues were helped some but the issue is the size a room available for the radiator in the truck chassis.

The new P400 had a lot of changes made to improve the block, crank and other areas but the basic design is still the same.

The P400 used in the HMMWV by AMG still rates the engine at 190 HP


best

Robyn

[stroh]

so if a bigger radiator could be put in the cooling problem would be solved? Would the 90 and older trucks have more room?

[DaveBr]

If cooling is the main drawback to more HP wouldn't it be possible to run a second rad with electric fans in another location on the truck. Have them hooked in series so coolant back to engine has to go through both rads first.

[6.5 Detroit Diesel]

one of the biggest problems with our typical V-8 engines was explained by the guys building the Buck diesels. We have a writeup here on the site. Coolant enters as one end, and by time it has made it's way to the last cylinders, it's much hotter than when it entered. But yea, bigger rad, bigger pump, dual t-stats, extra fans and air holes, and maybe a second rad would almost do the trick, eh? What do you say Robyn?

[Kmehr]

how about some hood scoops and no fenders and some more trimming? haha

But seriously, lets take a look at that tractor, what kind of pump from a bigger motor work on our 6.5? his looks to be a totally one off, but I am sure there has to be some IDI pump that could work......also looks like he has a hell of a lot more than 300 hp!! though i am sure he pretty much machined that motor from the ground up.....

[DmaxMaverick]

The dual pumps on that tractor were DB2 pumps. Mechanical. You could use dual DS4 pumps, but Bill Gates may have to get involved.

A single higher delivery pump can be had. The DB4 is available, but as rare as hen's teeth.

There are a BUNCH of 8 cylinder distributor-type pumps available. Problem is, getting one with the IDENTICAL timing/firing order as the GM Diesels. I'm sure they could be modified, but at what cost? And what gain? I can tell you how to grenade a 6.2 or 6.5 for free (just do all the don'ts you read here about). Any DS or DB pump can be fueled high enough to deliver more than enough fuel to overfuel. There's more to this equation than just the pump.

And remember....
Fuel pressure is determined by the injectors. Fuel volume and timing is determined by the pump.

[Kmehr]

alright, guess that answers the fuel question. Any idea how that guy with the tractor is keeping the block together to hold all that fuel, and i guess how he is keeping it cool like Robyn raised concern over? really looks like he is making some major power!!

[kojo]

Any DS or DB pump can be fueled high enough to deliver more than enough fuel to overfuel. There's more to this equation than just the pump.

This is intresting, i have done lot of mods to my burb, and need more fuel :D I already have bigger lift pump (original couldn't deliver enough), chip whic asks for 80mm3 from pump and really big optic bump, what i should do to get more fuel to engine? If it blows it my problem so dont worry about it..
is there any other things to do then change pump to 5068 and get right chip for that or change cam ring from that 5068 to my 5521?

[kojo]

Ok, so does anyone really know how squueze more fuel from ds4 or was that speak from overfueling just BS?