Planning a 6.7 engine bulid

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Vest_racing

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Hi,


Now my 5.9 engine is leaking oil and **** all over, and I have been planing to upgrade it even more.
But if I want to do anything more I have to pull the engine for a rebulid, so I think I will bulid a new engine.

So have some questions, and hope you guys can give me some awnsere to my stupid questions..:lolly:

I have played with the tought of making a twin turbo with 3 cylinders to each turbo. So will be making custom exhaust manifolds.
I would like to use a 5.9 head just have it ported and get bigger valves in it.
Then I can use my Ssr, as there are no one here in Norway that tune efi live.

I already have fuel to support 1k ++ hp on my 5.9 so will use this on the new engine, just need to get bigger injektors.

First question is how much can I borr the 6.7 block befor it gets alot weeker?
 
I would absolutely recommend MCCBYRYAN at Hardway Diesel Performance to tune whatever you build. He has tuned hundreds of trucks remotely and I am sure he can handle yours. All done with email, you data log, he sends a revision. And yes, he can do it with EFI Live, if you can buy it over there....

I wouldn't waste your time trying to do two turbos right off the head, it's been done, and requires really small turbos or it never spools, killing driveability. Save your money and just put on a quality t3 or t4 manifold on and go from there, I assume with compounds.

My two cents....good luck!
 
Goinbyyabig said:
I would absolutely recommend MCCBYRYAN at Hardway Diesel Performance to tune whatever you build. He has tuned hundreds of trucks remotely and I am sure he can handle yours. All done with email, you data log, he sends a revision. And yes, he can do it with EFI Live, if you can buy it over there....

I wouldn't waste your time trying to do two turbos right off the head, it's been done, and requires really small turbos or it never spools, killing driveability. Save your money and just put on a quality t3 or t4 manifold on and go from there, I assume with compounds.

My two cents....good luck!
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Thanx.

So your saying no one has hade any luck with 2 turbo's on the head?

I think I have to change more on the truck to get efi live, since it's an earlie 04.
I buy all all my part for the US, not many over here buliding and tuning there dodges.
So I guess I have the dodge with the highest hp in the contry..:rockwoot:
 
Well, if you do a 6.7, and use the whole engine, meaning head, injectors, computer, you can get tuning for it with a Mini Maxx, and therefore use the custom tuning with MCC and Ryan Milliken. Maybe I misunderstood what you intend to do....I wouldn't bore the engine unless it needs it as a rebuild....you will see very little power increase from a few cubic inches, as compared to more fuel and boost. The increase of airflow, (boost helps tremendously) is what allows you to burn more fuel and therefore make more power. I would invest in a ported head and good turbos before boring the cylinders of a healthy engine.....it's just not the same thing as naturally aspirated engines...
 
I don't have any experience running twins like you want but I'm assuming it would spool like a biggg single because you are cutting the volume of exhaust in half and it is being pushed through the exhaust turbine half as fast as a 3 cylinder engine would be. Say 1,2&3 are powering turbo #1, cylinder 1 goes through its exh. stroke then 5 is next I think?? But 5 is on turbo 2 so there is zero flow for turbo 1 for that period of time. And the same applies for the rest of the cylinders. So there is just a lot of dead air and poor flow. You would need really small manifolds and turbo. I just think it wouldn't be nearly as efficient as a big single on a 6.7

Sent from my DROID RAZR HD using Tapatalk 2
 
Well first of all the, the reason I was thinking about bore it was higher tourque and it would be more room for bigger valves.

The turbo setup is not yet set but I would guess it would spool a 66 turbo with no problems on 3 cylinders if you use the right exhaust housing.
 
On a cummins one of the only reasons that more than two chargers should be ran is to achieve higher manifold pressure, that's it. The other reason is to broaden the power band. Do you understand how the high manifold pressure effects the engine and why it's not a good idea to run parallel chargers? Running two chargers in parallel offers no benefit in my mind at all.
 
I really don't see why everone is so against running two smaller chargers on the manifold. Wouldnt you get much higher torque at lower rpm? Well all depends on the charger tough.

I've not been tuning diesels, thats why I'm on here asking..:)
But I would really like to see some number and fact, not just what everyone thinks or belive.
There are so many things that are been said but not proven.
I was also told my auto trans input shaft would break after a week on my current truck, but I have used it for 2 years without any problems. Exept when the oil pump broke..))

But have buildt a 800hp rotary race engine running a GT4202R turbo set up with Tial exhaust housing.

And the 4202 with a Tial 1.01 housing would manage the same amount of exhaust as the 1.15 garrett housing.
 
Vest_racing said:
I really don't see why everone is so against running two smaller chargers on the manifold. Wouldnt you get much higher torque at lower rpm? Well all depends on the charger tough.

I've not been tuning diesels, thats why I'm on here asking..:)
But I would really like to see some number and fact, not just what everyone thinks or belive.
There are so many things that are been said but not proven.
I was also told my auto trans input shaft would break after a week on my current truck, but I have used it for 2 years without any problems. Exept when the oil pump broke..))

But have buildt a 800hp rotary race engine running a GT4202R turbo set up with Tial exhaust housing.

And the 4202 with a Tial 1.01 housing would manage the same amount of exhaust as the 1.15 garrett housing.
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Where are you getting the idea of more torque? You need to understand engine consumption in CFM based on VE, CI, RPM, PR. You'll notice, when the PR goes up, the CFM consumption goes up, vice versa. You'll make more low end torque with smaller charger that you can get on top of quick, and run a high PR. Also, if you search, I believe it has been done and discussed a lot and proven not to be a great idea. You can do it though, and please post your results.
 
Ghostman said:
Where are you getting the idea of more torque? You need to understand engine consumption in CFM based on VE, CI, RPM, PR. You'll notice, when the PR goes up, the CFM consumption goes up, vice versa. You'll make more low end torque with smaller charger that you can get on top of quick, and run a high PR. Also, if you search, I believe it has been done and discussed a lot and proven not to be a great idea. You can do it though, and please post your results.
Click to expand...



There you have my point, you get more low end torque with smaller chargers.
If you look at the tripple turbo setup there are 2 small turbos just that they are on a split on the one manifold, and you have the bigger charger for high rpm gains under.

Would be just the same I was thinking of just i would put 2 chargers on the head.
Because I dont race the truck and dont pull it to 5k rpm, I stay in normal range maks 3.5k rpm.
This is a truck I use for work, so it's more of a daylie. Just like to have the power if I need it.:hehe:

I tried to search but probably didnt get the key wourds right.
 
The 6.7 already a torquey engine, trying to add more at low rpm's has been proven to be destructive.
 
First connecting rods, then seems to be the block.

I'm not saying you can't add more to them, just saying they're not the same as a 5.9, and your plan for more low end torque will be trying to exploit their weakness.
 
TheBigNasty said:
First connecting rods, then seems to be the block.

I'm not saying you can't add more to them, just saying they're not the same as a 5.9, and your plan for more low end torque will be trying to exploit their weakness.
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Ok, thanks..:)

But I was planing to build it from bottom, new billet rods and pistons. Get the crank polished and everything balanced.

I've allways tought it was the rpm killing those cummins engines..:)
 
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Vest_racing said:
There you have my point, you get more low end torque with smaller chargers.
If you look at the tripple turbo setup there are 2 small turbos just that they are on a split on the one manifold, and you have the bigger charger for high rpm gains under.

Would be just the same I was thinking of just i would put 2 chargers on the head.
Because I dont race the truck and dont pull it to 5k rpm, I stay in normal range maks 3.5k rpm.
This is a truck I use for work, so it's more of a daylie. Just like to have the power if I need it.:hehe:

I tried to search but probably didnt get the key wourds right.
Click to expand...

Triple turbo setups use two smaller turbos as the primaries, not the secondaries like your thinking. There really is no "big charger", the two smaller primaries take its place. Keep researching. Splitting the exhaust between two small turbos is not the same as running one small turbo. Plus you would have two W/G on two different banks, on two different chargers, feeding the same bank, just sounds like a tuning mess also.


I'm done.
 
Ghostman said:
Triple turbo setups use two smaller turbos as the primaries, not the secondaries like your thinking. There really is no "big charger", the two smaller primaries take its place. Keep researching. Splitting the exhaust between two small turbos is not the same as running one small turbo. Plus you would have two W/G on two different banks, on two different chargers, feeding the same bank, just sounds like a tuning mess also.


I'm done.
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I really think you have miss understod what I been thinking about..
My plan was 2 small chargers not 1!
Just that I would build new manifold that would run cylinder 1,2,3 to one charger and cylinder 4,5,6 to the second charger.

Not one small charger that would never work.
 
Vest_racing said:
I really think you have miss understod what I been thinking about..
My plan was 2 small chargers not 1!
Just that I would build new manifold that would run cylinder 1,2,3 to one charger and cylinder 4,5,6 to the second charger.

Not one small charger that would never work.
Click to expand...

One smaller turbo would make for a real torquey engine. You could be building boost just off of idle. With two manifold turbos, you'd have to go really small to make it responsive. Something in the 30 lbs/min range. Like a GT2860. If you try to run two HX35's in parallel, the combined mass flow would be similar to a S475 as a single. Keep in mind the amount of turbine flow necessary to spool the charger.
 
Tate said:
One smaller turbo would make for a real torquey engine. You could be building boost just off of idle. With two manifold turbos, you'd have to go really small to make it responsive. Something in the 30 lbs/min range. Like a GT2860. If you try to run two HX35's in parallel, the combined mass flow would be similar to a S475 as a single. Keep in mind the amount of turbine flow necessary to spool the charger.
Click to expand...

Been looking at gt3576r and gt3582r, might have to be even smaller.
I will be in contact with a guy who knows everthing there is to know about chargers next week.
He calculate everything and even makes custom turbos.

So will see what he has to say, befor I deside anything..

I wont start doing anything if it's no hope of getting it to work..
 
As has been said already, you can do it, yes. You can find out the mass flow desired for your performance level, say, 60 lbs./min. and split it in half, buy 2 tiny turbos, and it SHOULD act like the single you are attempting to replace...It will cost a LOT more, and be a huge pain in the a$$ to fabricate the manifolds and Y pipes, transitions, etc, for no benefit..... I would research it more as suggested...It has been done and abandoned because it is not any better. I think if you want more quick torque down low, a really small set of compound twins, say a 62 over a 72 or 75 with tight housings and an external gate to get the backpressure down is the best, simplest, cheapest way to go. Don't make a "header" for your daily driver, use a cast iron manifold, so it doesn't crack. Heat cycles will kill that tubing, along with the heat and pressure you will put it through. Do whatever you want, but it will be an expensive, disappointing lesson in the end.
 
Goinbyyabig said:
As has been said already, you can do it, yes. You can find out the mass flow desired for your performance level, say, 60 lbs./min. and split it in half, buy 2 tiny turbos, and it SHOULD act like the single you are attempting to replace...It will cost a LOT more, and be a huge pain in the a$$ to fabricate the manifolds and Y pipes, transitions, etc, for no benefit..... I would research it more as suggested...It has been done and abandoned because it is not any better. I think if you want more quick torque down low, a really small set of compound twins, say a 62 over a 72 or 75 with tight housings and an external gate to get the backpressure down is the best, simplest, cheapest way to go. Don't make a "header" for your daily driver, use a cast iron manifold, so it doesn't crack. Heat cycles will kill that tubing, along with the heat and pressure you will put it through. Do whatever you want, but it will be an expensive, disappointing lesson in the end.
Click to expand...



Ok so compound is the way to go..

The manifold i will build anyway, its pritty straight forward on the cummins.
And it's allways nice to make most of the parts yourself.
I allways use 321SS tubings on manifolds, don't think they will crack.
 
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