Which are better? We have an 03 motor that is getting a full build up and wandering what the consensus is on pistons. Whats the best and strongest to use.

 

I guess I should ask something about mileage to get any replies.


Surely someone has messed with the bottom ends of these things. How bout Mahle pistons, a good thing? If so what year or style to get?

 

I'm just guessing here but a few thoughts. Think that the 04.5 has a different cooling system in the oil spray under the piston tops. Will they work in an 03 and if they will work is there any benefit to using them? I would look at after market pistons first depending on what you are trying to do. Give us a little more information. Whats your goal, more HP, more MPG (probably not relevent here), running much boost and looking for lower compression? And give the board a few hours for someone more knowledgable about building these engines to answer. Sometimes it takes a day or so for answers to appear.....JM02

 

The guys that know the answer to that question just take more time post...keep it up top...

 

This is going to be a 1000hp+ build trying to get there on fuel only but havnt decided for sure on that yet. He still wants to drive it on the street and it will have much better manners if we tune it for Nitrous but he wants to stay bottle free. It will be twined (large if fuel only) and heavily fueled. I need a direction to go on pistons and will probly drop cr to around 14:1 once I figure out what the best way to machine them is.

 

I would think 04.5 + pistons would be the best for what you are trying to do. the 04.5 + trucks have different valves, due to the extra heat.

I would definately do NO2 with that truck, if you are going to drive it on the street, you would need some BIG turbos to get to 1000 hp on fuel alone

 

64/14 and a S-400 with a larger wheel should do the trick...and spool fine.


;-)

I am not that sure the pistons are that much different...maybe looked at forged arias instead?

 

Neither is really better over the other.
Some may say the 04.5 bowl is better for making power.

If you changed to a 04.5 bowl you would have to change injectors to a the newer style spray pattern to match (keep that in mind).

 

What is different about the spray pattern, as far as I can tell both bowls are centered unless the 04.5+ is a wider spray angle.

Another question, from what I remeber of my 05's when I had them out the bowl seemed larger or bigger then the 03's. Wish I had both side by side but if the bowl is bigger cc then it would have to be a lower cr piston unless they shallowed it up some.

Lookin like a 03 Mahle piston set and machine the bowls for the 14:1.

 

Call me crazy...but wouldn't you want the bowl to stay EXACTLY the same shape that Don M designed his spray pattern for? I am assuming you will run those injectors if you are set about 1000 on fuel only (Flux 5's!).

I would drop him a line...and ask him about the compression ratio vs piston choice. Maybe thicker orings/gasket?

 

Yes 5's are in order for sure.

Dont really like the idea of thicker gaskets, will check around for some ideas from John at FI And DonM.

 

spray pattern is definitely different on the 555 vs 600 motors. As Justin said, in order to run the 600 pistons, you would have to run 600 nozzles, which in turn might need the 600 programming. I am not sure how much different the timing and such is between the different bowl designs in order to keep the fuel inside the bowl. .