Best bowl design for p-pumped 6.7?

[RonA]

I had a set of stock pistons welded up and the bowl was recut but kept small and shallow. I am concerned about keeping the head down without o-rings, and want to keep the compression close to stock. The piston is larger in diameter so going a bit larger on the bowl diameter to run a bit more timing shouldn't be a problem. Was thinking I'd just scale up the diameter from the '02 24V(what i have now seems to work well) but go shallower to keep the bowl volume the same. Basicly increase the bowl diameter by the same amount as the diameter difference between the 5.9, and 6.7, but go shallower to keep the volume the same.
I'm flying blind here and would appreciate any help i could get.

 

[MADDOG]

Sorry Ron I couldn't help myself.

 

[Bone stock 99]

I guess a big part of it is in what timing your going to run at, and what injectors you plan on running. I'm in a bit of a pickle too with this mix and match parts dillema. Trying to find out if a 6.7 head will work on my 04 5.9. from what im told it will work, but than I come to the problem with injectors, do I run 6.7's or keep the 5.9's. Its a mess!

 

[fnschlaud4620]

I would think you would want to take a look at the max timing you would ever want to run and the spray angle and height of the injector. Do some trig and calculate the maximum outer diameter of the bowl for your needs. Then calculate the needed volume for your desired compression ratio. Then you can choose how to shape the volume in the piston, you can choose to have an open bowl like comps duramax piston thread, or one with a riser in the center to induce swirl. I would be talking to the person who is going to be building the injectors to get their opinion and then you could draw it up in solidworks and have it stress and thermally analyzed. Does that Help? Who needs a bowl anyhow, try flattops.

 

[RonA]

I'm going to run the same injectors and pump I have now. They are at the limit of the stock bowl now(25 degrees timing) so i figure just slightly larger should be ok. I don't think i will need to run higher than 25 degs. I made 880's with this setup and a 5.9. I am hoping to make 1k with the additional cu/in, a bit more top end fuel, more aggressive cam, and the zz fab head/manifold combo. It still has to be a daily driver though.

 

[JOESHTRDDSL]

I'm going to run the same injectors and pump I have now. They are at the limit of the stock bowl now(25 degrees timing) so i figure just slightly larger should be ok. I don't think i will need to run higher than 25 degs. I made 880's with this setup and a 5.9. I am hoping to make 1k with the additional cu/in, a bit more top end fuel, more aggressive cam, and the zz fab head/manifold combo. It still has to be a daily driver though.

Are you going to run the same turbo setup or are you going bigger?

Joe

 

[Smokem]

If re-entrant, why not open it up to 64/67mm, what is the dome design?

 

[RonA]

Sorry Ron I couldn't help myself.

Richard.
Crappy design.

Joe.
I talked to HTT yesterday and they said they were seeing drive pressure issues with a 66/71/16 on a 6.7 at modest power levels. I will wait and see how my setup acts. It may just need an additional wastegate. If it's too far off though, I think i will build a new set starting with a GT4294 and build the wastegate into the t4 manifold in the thick area under the flange. That will help keep it as low as possible.

Weston.
I should have the pistons any day. I'll know more when i have them in hand and can take some measurements on the granite.