morkable

So, basically, dont worry about aftermarket pistons, but maybe spend the money on better rods?

Dieselbuilder

Like I said where do you want to draw the line? But back to pistons skirts molly coat ceramic top coat, shot peen and ground and balanced rods should be AND I SAID I THINK SHOULD BE good for at less 1200hp I was even looking at the idea about drilling the block an and pressing in some really strong liners I was looking what the boys do with funny cars.....nitro methane crowd !!!!!!!!!!!

Dieselbuilder

Remember this is just thinking ideas

Tate

Not to mention all the meltdowns on the 04.5-07 engines, which bowl design seems to be a contributing factor of.

morkable

well Im not made of money,, but I also want to make sure I do it right and not have to do it again real soon,,, but I also want to build it for over 1300 hp,, as I am quite sure I am there already.


I all for thinking ideas,, that is where the best real ideas are usually born

Dieselbuilder

1300Hp to live!! well open your pocket book, head work, porting,intake manifold, bigger valves, springs, cam, list go's on and on and even then no guarantees!

Mike Holmen

The stock piston are not a true forged piston. Kev, have you determine where did you motor intially failed at? I would just find a ways to build cheaper, so when they go boom, its not to hard on your pocket.

cLAYH

Sooner the better, we are putting the house up for sale this week and I'd rather not move it to the new place. Garage would show better too if it wasn't taking up floor space. I could live with a post dated check if $$$ is an issue.

Have the head coming back from the shop as well this week. Was all checked out and all new valves put in #6. It was brand new from Cummins and only had about 80km on it when #6 let go..... Was going to keep it for a spare but I'm not really sure what I need a spare head for and it takes up a fair bit of room as well.

dvst8r

I for one would still really like to see the pictures of the broken engine (sorry I am morbid when it comes to broken engines).

However my initial assumption, based on the approximate amount of power you were making, the holes in the block, and the handful of other engines I have seen fail like that (extreme amounts of peak cylinder pressure) My best educated guess without seeing the damage is that a rod failed. It is not often that a piston fails and it makes a hole in the block. That and it has been semi documented that you are on the edge of rod life above 1200hp even on just straight #2. Nitrous happens to create a lot more peak cylinder pressure, especially in the cummins engine's we all love, as we have the unfortunate cummins ecu as well.

In this unbroken ecu, we get things like 9 choices on fuel and 4 choices on timing. What is even more unfortunate then that is, we have 4 rather arbitrary numbers that represent: a little more timing then stock, some more timing then stock, lots more timing then stock, ect... Now lots of manufactures will tell you what the max total timing each of these settings will give you, but I have yet to see any one publish a timing curve.

Have you ever started a post only to get half way through and forget your point?

As I see it there are two ways about getting more power and the engine to live: Brute Stregth or improved VE. Both is the best of all worlds, also the most expensive.

Brute strength (in it's extreme) would be:
-Billet Block
-Woodruff or Crower or ect... Rods
-Mahle Monotherm pistons.

VE (also in it's extreme) would be:
-main girdle (if the block flex's lots of bad things happen), and windage tray (lots of people will argue this)

-balanced lightened crank

-12v rods (can't remember if it is the usa or the england made rods that are metallurgicaly the strongest), peened, polished, and balanced

-lightened balanced pistons, something with lots of quench area, but cut to clear the next item. (Pistons are always my hardest to grasp item so many variables)

-BIG cam (roller would be nice), if you don't have to cut the pistons to clear it, it is not even close to big enough

- Intake valves on both sides, or just bigger valves

- Cut deck, similar to Somender Singh's ideas but... Well there not my ideas so I don't feel I can share much more then that.

- Ported head... a vast subject on it's own.

- Cut off intake manifold, tubular intake manifold replacement. Now most people think this is for increased air flow, while it does do this, the biggest benefit it has is balancing the flow across the cylinders...

- Cromoly Pushrods (roller if you can get that roller cam)

- Finally some nice light weight roller tip rockers.

The VE thing obviously allows you to make more power, with less cylinder pressure. Now this becomes even more of a benefit as rpm's increase, but as we all know this is currently an issue with the CR's. I happen to know a couple people working on a stand alone solution to this problem, not ready yet, not even ready for alpha testing yet, but it is in the works...

If only I could remember what my original point was, instead I gave everyone a rambling novel to read.

rage_blue

Who makes a roller lifter for the cr?

Mike Holmen

Roller cams are out there, but aren't not for little pockets. Good write-up. So where do we start?

I still think that you can do some cheaper improvements, to improve the durabilty of the engine. Once you get thru the 4000 rpm barrier there will be other issues that will surface. A billet block, wow, thats gonna hurt the visa card.

I would build a decent motor that priced right, so if it goes boom, its not gonna hurt the pocket book. That would be more stock than custom. I have a few motors, so wrecking one or two isn't gonna send me to the poor house.

dvst8r

Mike I am with you on the building something that is cost effective to replace.

With that in mind, we are probably going to go down the VE route, as a lot of it can be done by who ever is building the motor.

Bottom end if I am building it with the above in mind would look like:
-Crank girdle/scraper/windage tray
-Mainstuds
-Balanced crank (I would put in lightened and balanced, but I have no idea of the cost on a lightened cummins crank)
-12V rods (the good ones... One day I will even remember what they are ) smoothed, balanced, peened, polished.
-Balanced wrist pins.
-Balanced pistons, probably just stock early CR, with enough valve relief for the cam.
-Cam, not roller budget in mind however, the nice thing about even an expensive cam is that it is very rare that anything will happen to it if a motor dies) As I think about the cam this morning, I realize that until the CR computer issue has been solved you can only go big to a point as really you only have to ~4000rpm to work with.
-Cromo push rods (non roller)

- Electric water pump With all the guys blowing out frost plugs and all the issues it is having, for ~$200 you can totally eliminate it, also you can run it even with the engine off between rounds to control temps. I wouldn't bother with an idler pulley, unless some one knows of a really cheap one. I would just take the stock water pump out, cut off the fins, and put it back in.

Now the great part about this style of bottom end build is, if you are willing to do some work, it is quite inexpensive to do.
-Balancing requires something like this :Scale
And some time.

The crank is the only thing that you will have to send in for balancing. You will have to send the rods as well, as the big end of the rod is rotating weight, and will have to be balanced with the crank. Before you send the crank and rods away, smooth and peen the rods, and balance match everything.

I am a firm believer in that stress risers kill rods, this is a very debatable subject, but for myself the few extra hrs is worth my piece of mind. One of the things I like to do with my rods is smooth them. It happens just like you would imagine, you take some sandpaper and sand all of the edges off of the rod, ONLY GO UP AND DOWN THE LENGTH OF THE ROD Typically once I get close to being happy with the smoothness of each rod, I start using the smoothing procedure to balance them. After they are balanced you take them to be peened. OPTIONS: If you don't want to to all that work with the rods, both woodruff and Sheid offer "Factory Cummins connecting rods that have been head treated, stress relieved and shot peened. Come with A 1 rod bolts and are re-sized with new wrist pin bushing.***Note: USA Cummins rods are the preferred choice*** ***Core Required***" That particular quoted sentence was borrowed from the Woodruff site.

For the balance matching of the pistons, rods, and wrist pins, you can pretty much sit down on the couch with the scale on your coffee table, and the tv on [this entirely depends on how understanding of a wife you have ]. All components should be sparkley clean at this point, Have a pad of paper weigh each component (have the rings just sitting loosely on top of the pistons, if they are not already assembled.) Write down the weights of each, and then start removing material till all the rods are exactly the same, all of the wrist pins are the same, and all of the pistons are the same, at which point you are done. I explained how I do rods above, for pistons you drill away excess material from around the pin boss, and the inside of the crown, just dimples of material. The wrist pins you do by taking material out of the inside of the pin. You can do this with sanding cartridges, or a mill.

Note: Many people balance pistons, rods, and wrist pins as an assembly, I don't think this is wrong, I just think that the above way is better.

dvst8r

With all of that being said. If I had the money I would take the easy route of:
-Crank girdle / scraper
-Main studs
-Woodruff rods
-Mahle Monotherm Pistons.

Guys run more then 2000hp with that setup, and blocks fail before those components do. However you are looking at ~$9000usd just for the rotating assembly parts.

Dr. Evil

Whoa....racing 8000 pound diesel trucks is NOT the cheapest hobby

dvst8r

That is for sure. I can build a mid 10sec honda civic, for less then it costs for a decent built 47re/48re transmission.