Common rail conversion using duramax parts

[smokinstroker92]

We did a 12v head here that flows right at 300cfm at 600ish lift.....

200 cfm is no better than a 6.4 head and it is feeding a lot less cubes.. remember on a turbo limited, fuel only class, feeding big displacement is not an advantage...

Been proven time and time again in 2.6 that big displacement cummins and stroker duramax's do not make hardly anymore power than their smaller displacement original versions. Without larger turbos and more air, your just wasting efficiency and money.

A big bore de-stroked 7.3 with 300 cfm heads @ about 6.0-6.5 liters displacement would be an animal. But then your right back at just using a 6.4 to begin with being cheaper and easier.

The whole "no-replacement for displacement" is a foolish thing to say when your running a turbo. Especially in an inducer limited fuel only class. It's all about efficiency of the engine for the size/flow of the turbo your allowed to run.

The cfm numbers are going to be entirely dependent on the flow bench that is being used and the calibration on said flow bench. The bench used to flow these 7.3 heads will flow about 210 cfms while fully ported 12v heads around 220-230 at .600 lift and the hamilton 12v big valve fully ported heads flow high 200s. I have seen variations of 40-50 cfms on the same head on other flow benches.
At the same time with a 12v head having intake ports feeding 5.9l or displacement and the 7.3s having 8 intake ports feeding 7.3ls. Each 12v port feeds .983L of displacement while the 7.3 ports are feeding .913L of displacement. So for instance on the same bench we have a fully ported 12v head flowing 230 and the fully ported 7.3 head flowing 210.
7.3l: 210cfms*8ports= 1680cfms total flow/7.3l= 230.14cfm/L
5.9l: 230cfms*6ports= 1380cfms total flow/5.9l= 233.89cfm/L
To me this shows that the efficiency of each head is pretty close to the same per displacement and the # of cylinders. Now would the 7.3l still be limited by a 2.6 charger? I could agree with that because the flow from a 2.6 charger is not enough to reach the peak of the potential for the larger displacement motor that a 3.0 or twins in a superstock application may have.

Now i may be off here on my thinking here whats your thoughts?

And why the decreased stroke? yes that would bring displacement back down but it would also decrease the time @ tdc which i would also agree is critical to overall engine efficiency

 

[Morgan@Midwest Diesel & Auto]

Ported Hamilton
295cfm x6 = 1770/5.9=300
Race ported 6.4
250cfm x8 = 2000/6.4=312
Billet 6.4
300cfm x8 =2400/6.4=375
Brodix d-max
350 cfm...... Need I say more?

I'm not gonna argue theories, big bore-shorter stroke>small-bore long stroke all day in a limited class.

Larger combustion area, less valve shroud.... Less wall wear, less crank stress, less rotating assembly stress.....

 

[Stroked777]

Shorter stroke for more Rpms and larger bore for the torque? Correct

 

[Morgan@Midwest Diesel & Auto]

The cfm numbers are going to be entirely dependent on the flow bench that is being used and the calibration on said flow bench. The bench used to flow these 7.3 heads will flow about 210 cfms while fully ported 12v heads around 220-230 at .600 lift and the hamilton 12v big valve fully ported heads flow high 200s. I have seen variations of 40-50 cfms on the same head on other flow benches.

I don't use fairy tale flow bench numbers. I would put the 12v head we had with the latest zzfab intake on it against anything in the country on the same bench.

At the same time with a 12v head having intake ports feeding 5.9l or displacement and the 7.3s having 8 intake ports feeding 7.3ls. Each 12v port feeds .983L of displacement while the 7.3 ports are feeding .913L of displacement. So for instance on the same bench we have a fully ported 12v head flowing 230 and the fully ported 7.3 head flowing 210.

7.3l: 210cfms*8ports= 1680cfms total flow/7.3l= 230.14cfm/L

5.9l: 230cfms*6ports= 1380cfms total flow/5.9l= 233.89cfm/L

To me this shows that the efficiency of each head is pretty close to the same per displacement and the # of cylinders.

The problem is if he wants to compete with the big players, he will not be running against ported "stock" heads.

Now would the 7.3l still be limited by a 2.6 charger? I could agree with that because the flow from a 2.6 charger is not enough to reach the peak of the potential for the larger displacement motor that a 3.0 or twins in a superstock application may have.



Now i may be off here on my thinking here whats your thoughts?

It's been proven in 3.0 that the turbo still limits overall. Superstock, yeah cubes and fuel rule!!

And why the decreased stroke? yes that would bring displacement back down but it would also decrease the time @ tdc which i would also agree is critical to overall engine efficiency

Hit on it earlier. But dwell, is about the only positive of a longer stroke. There are a lot more negatives. Bigger bore has a plethora of positive affects that by far out weighs the dwell theory.

 

[smokinstroker92]

Ported Hamilton
295cfm x6 = 1770/5.9=300
Race ported 6.4
250cfm x8 = 2000/6.4=312
Billet 6.4
300cfm x8 =2400/6.4=375
Brodix d-max
350 cfm...... Need I say more?

I'm not gonna argue theories, big bore-shorter stroke>small-bore long stroke all day in a limited class.

Larger combustion area, less valve shroud.... Less wall wear, less crank stress, less rotating assembly stress.....

Just for the record I'm not trying to argue with you, just presenting what I thought I knew and trying to learn and have a constructive and informative conversation. They seem to be few and far between these days on the forums

 

[Morgan@Midwest Diesel & Auto]

Just for the record I'm not trying to argue with you, just presenting what I thought I knew and trying to learn and have a constructive and informative conversation. They seem to be few and far between these days on the forums

Oh I know. And idk how you took it. But I'm kinda of blunt. Not trying to be un-constructive. I just don't sugar coat things. But yes you were correct with what you said. Just lacked some of the real players in the game.

 

[lincolnlocker]

Yea only reason I'm thinking of something like this is the fact I already have a forged piston, bed plated full built 7.3 sitting here that will never be competitive in a 2.6 class with heui injection as it stands now. Originally built the engine for a p pumped pro stock truck but they have since dropped the class here in western New York and I don't have the time to head to the mid west to pull.


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where do you live in new york?

live life full throttle

 

[smokinstroker92]

I don't use fairy tale flow bench numbers. I would put the 12v head we had with the latest zzfab intake on it against anything in the country on the same bench.

Im not talking about a fairy tale flow bench either my head guy uses a superflow flow bench that he also uses for all the billet heads he builds for alcohol tractors.


The problem is if he wants to compete with the big players, he will not be running against ported "stock" heads.

You are completely right stock heads are a thing of the past for all out competition but some designs for billet 7.3 heads are in the works also.



Hit on it earlier. But dwell, is about the only positive of a longer stroke. There are a lot more negatives. Bigger bore has a plethora of positive affects that by far out weighs the dwell theory.

Well that enlightens me on the benefits of a shorter stroke and makes sense and i would assume on a mechanical application the fueling rate would not be a problem

Assuming you are still running standard or close to standard bore in your 6.4? The 7.3s still have a larger bore diameter to work with. When you say big bore how big are you talking? Would it not be sufficient to shorten the stroke on a 7.3 while leaving the bore alone? You would have all the benefits of shorter stroke while still retaining the larger bore. Shortening the stroke would not be to expensive; offset grind the crank with a longer rod.

The stock 7.3 heads still have some gains to be had with bigger valves, machining the intake runners off and using different style intakes but all that could be changed with a billet head.

 

[NyCowboy87]

where do you live in new york?

live life full throttle

Arkport, bout 50 miles south of Rochester.



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[lincolnlocker]

Arkport, bout 50 miles south of Rochester.



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oh cool. im working in western NY now.. from syracuse to buffalo so far...

live life full throttle

 

[NyCowboy87]

Well that enlightens me on the benefits of a shorter stroke and makes sense and i would assume on a mechanical application the fueling rate would not be a problem



Assuming you are still running standard or close to standard bore in your 6.4? The 7.3s still have a larger bore diameter to work with. When you say big bore how big are you talking? Would it not be sufficient to shorten the stroke on a 7.3 while leaving the bore alone? You would have all the benefits of shorter stroke while still retaining the larger bore. Shortening the stroke would not be to expensive; offset grind the crank with a longer rod.

.

The problem I see with still running the stock 7.3 bore is that without some extensive head work to move the valves away from the cylinder wall, they are still close to the wall and will put a damper on how big of a valve you can put in it.


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[NyCowboy87]

oh cool. im working in western NY now.. from syracuse to buffalo so far...

live life full throttle

Oh nice what kind of work do you do? I work in Rochester at the Komatsu dealer, sucks driving 100 miles a day just for work.


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[smokinstroker92]

The problem I see with still running the stock 7.3 bore is that without some extensive head work to move the valves away from the cylinder wall, they are still close to the wall and will put a damper on how big of a valve you can put in it.


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Yes the stock head will still be limiting but ported they do much better than stock. That will be where the billet head will shine with much better port designs and placing the valves in a better location to use bigger valves, better rocker arm designs, etc

 

[lincolnlocker]

build powerlines and right a ways for the powerlines...

live life full throttle

 

[NyCowboy87]

Yes the stock head will still be limiting but ported they do much better than stock. That will be where the billet head will shine with much better port designs and placing the valves in a better location to use bigger valves, better rocker arm designs, etc

100% agree with you.


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[Morgan@Midwest Diesel & Auto]

Well that enlightens me on the benefits of a shorter stroke and makes sense and i would assume on a mechanical application the fueling rate would not be a problem.

The problem with mechanical fueling is the application and timing of the fuel entry. The big advantage of mechanical is volume and repeat ability. Other than that there is none.

Assuming you are still running standard or close to standard bore in your 6.4? The 7.3s still have a larger bore diameter to work with. When you say big bore how big are you talking? Would it not be sufficient to shorten the stroke on a 7.3 while leaving the bore alone? You would have all the benefits of shorter stroke while still retaining the larger bore. Shortening the stroke would not be to expensive; offset grind the crank with a longer rod..

We are standard everything in our 6.4. Going larger bore in the new motor. Same stroke.

Yes exactly what I was saying. Leave the 7.3 bore alone and just de-stroke it with offset grinding and a custom rod. Deal, done, cheap and it will jet a more effective engine in a 2.6 class.

The stock 7.3 heads still have some gains to be had with bigger valves, machining the intake runners off and using different style intakes but all that could be changed with a billet head.

Yes there are lots of things that can be done. All you got to asks is, why has it not been done in the last 20 years of their existence and is the cost worth it for what your going to get in the end product.

 

[Meniacal_Mark]

The 6.4 and 6.7 show much more potential than the 7.3.

 

[jdsf350]

Not sure if still available for sale but I think Empire had a 7.3 powerstroke motor complete with LBZ duramax setup all done ready to go awhile back maybe contact Chad @empire I know they have there hands in a few good running duramaxs in the sled pull scene.

 

[cbf9703]

How much air can the 7.3 heads flow? Is it worthwhile to p pump one without running twins or an unlimited single?

The stock 7.3 heads still have some gains to be had with bigger valves, machining the intake runners off and using different style intakes but all that could be changed with a billet head.

Yes there are lots of things that can be done. All you got to asks is, why has it not been done in the last 20 years of their existence and is the cost worth it for what your going to get in the end product.

I've seen a lot more focus in the last couple years with 7.3 head porting. Swamps put out some results (sucks that the link to the blog doesn't work anymore) and from what I hear they haven't stopped testing. Talking at Scheids, they've got some big things lined up for the 7.3 head with larger valves, I'm waiting to see what they can put out beyond their current stage 2 ported heads.

 

[golfer]

I've seen a lot more focus in the last couple years with 7.3 head porting. Swamps put out some results (sucks that the link to the blog doesn't work anymore) and from what I hear they haven't stopped testing. Talking at Scheids, they've got some big things lined up for the 7.3 head with larger valves, I'm waiting to see what they can put out beyond their current stage 2 ported heads.

We've surpassed annnything (posted and lost) from the blog...

These heads will make the most of HEUI injection system, as well as benefit our CR conversion engines.

(need to get this and other videos on our website...) but for those on Facebook..

https://www.facebook.com/video.php?v=10152794089612400&set=vb.332685942399&type=2&theater