Piston Bowls
- Thread starter Fingers
- Start date
LOL, ohhhhh yeah yeah that's correct sir, we have ummm tracks with on coming traffic just like the video games...:roflmao:
Love the spikes from 3 grand to 4500 Mark!
Thanks, I do too! It's roudy and I think the head work and valvetrain parts make a difference becuase it revs very fast without delay like a gas motor. It will be stupid with twins, probably not even streetable at that point, lol! That won't stop me though...:woott:
Seems interesting
Mark your truck sounds sick, watched your vid on Facebook
Twinned Lmm 120 over pump 100hp injectors
Mark your truck sounds sick, watched your vid on Facebook
Twinned Lmm 120 over pump 100hp injectors
If it's here I apoligize, I missed it. Can the bowls go any deeper & still be semi reliable? I don't mean over the pin
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I vary the depth in the long direction (major Axis) to provide various compression ratios to the customers. The short way (minor axis) is almost always the same depth. I am limited depth wise by the oil gallery in the cast pistons. There is no such limit on the forged.
The deeper bowls do reduce the strength, but they are still stronger than comparable designs of a similar compression ratio.
The deeper bowls do reduce the strength, but they are still stronger than comparable designs of a similar compression ratio.
Not sure how to explain this 
How much more can the bowl be deeper on the long ends? Could you get 18:1 with a deeper bowl & maybe not as long major axis? I've just always been under the impression that the deeper the bowl and higher compression would be good for a 2.6 charger motor.
How much more can the bowl be deeper on the long ends? Could you get 18:1 with a deeper bowl & maybe not as long major axis? I've just always been under the impression that the deeper the bowl and higher compression would be good for a 2.6 charger motor.
Not sure how to explain this
Wouldn't a deeper bowl be less compression
If they are 15.5:1 now i wouldn't see how you could make them 18:1 by making the bowl deeper maybe im missing something here?
Wouldn't a deeper bowl be less compression
Yes, technically you are correct. To get an 18:1 you are not going to have a big chamber in the piston. Mine are at 15.5:1 but you can get them in different ratios.
Wouldn't a deeper bowl be less compression
I asked above about making the major axis smaller to compensate for the loss of being deeper & Jon says his are 17.5:1 with valve reliefs. That is whay I asked
Reducing the major axis would require removal of material over the piston pin. Stretching the bowl is how I found room.
Did you up the CR or the same and just have to pull timing? Would seem like this would mean you have would be limited to a shorter uS but with the right size sticks would make for a cleaner more effective burn
onlything that was changed was the pistons.. and i went from 16.8 to 17
fueling is less then a stock 06 truck.. we are talking 1000uS at 180mpa which is stock for a 06 van, 06 truck is 1400uS @ 180mpa at WOT.. its currently running 137mpa at about 550uS and 6-9* vs 11-15* at part throttle.
the timing that was good for the stock pistons knocked like you had 20* at part throttle with these.... and trying to push the piston down the hole while its still in upstroke.
to fix it one of two things need to happen slow the fuel burn down by adding fuel or pull timing out..
increaseing then rail pressure will allow me to inject the complete fuel shot quicker effectively slowing the air/fuel burn then i could increase timing to optomise the burn..
Just thinking outloud, but if you have to pull timing out like that, these pistions are acting like they are higher CR than they are as far as flame propagation so in theory you could run a lower CR fot chamber PSI but not have the smoky hard ignition issues like traditional low CR pistions
The van tune runs quite a bit more timing than the LBZ truck tune does if you compare them. The last time I checked I believe it ran about 5 degrees higher in the same areas VS an LBZ truck.