Thanks for the tip on those. I suspect I've got some blowby on my motor currently and was looking for a good solution which might help with that without doing a full blown rebuild (more than I want to spend right now). Only looking for maybe 450-500HP max and as much fuel economy as I can get out of it.
Piston Bowls
- Thread starter Fingers
- Start date
Thanks for the tip on those. I suspect I've got some blowby on my motor currently and was looking for a good solution which might help with that without doing a full blown rebuild (more than I want to spend right now). Only looking for maybe 450-500HP max and as much fuel economy as I can get out of it.
Just read this whole thread. This was a huge accomplishment and I will be running these if I ever build my motor. I am stunned that no one has broken one. It would be nice to see some high horsepower runs on these to really test them. I mean there's really no way to tell how much abuse they can take without breaking them... We could only be touching their potential at 1000 hp and not even know it..
It would be interesting if you could get Dimitri Millard to throw a set in his duramax 
he isn't afraid to blow anything up. I watched his lb7 tow truck do 1799 hp on stock pistons. Granted his engine blew right then and he used 8 tanks of nos but it was sweet!
he isn't afraid to blow anything up. I watched his lb7 tow truck do 1799 hp on stock pistons. Granted his engine blew right then and he used 8 tanks of nos but it was sweet!
milage update ODO is just under 210,000 puts mileage on the pistons about 68,000
mpg is pretty steady about 10.5mpg, best i have seen is 11.8 empty getting out of chester NH heading to erie PA.. its still down from the 12.5 i was seeing loaded with stock.. and 14mpg with the empty trailer
i called up mahle to ask what stock PTW and mahle specs for their pistons. and what are some things that would allow the oil to soot up faster (now less then 1000 miles vs before clean for 3000).. IE ring gaps
talked to eric at mahle motorsports..
stock is .0018" -.002"
mahle recommends .002-.003" for their pistons.
when i asked him what he thought about .004" PTW he asked what type of competition i was doing...
stock ring gaps via all data
1st .0539
2nd .0531
according to eric for every .001" in crease in PTW it opens the ring gap up by .002" that would explain my ring gaps being .004" bigger than stock.. there is no aftermarket file to fit rings for the dmax according to mahle
mine was built with .004" PTW and ring gaps are .058", couple that with an extra .010" quench over stock, stock is .020".
i feel i can say that an engine setup like this is ~10% less efficient then stock. while purely using MPG avg since it is the most steady variable that i can track on a daily basis.
only way to tighten the PTW is new block, both ring gap and quench can be fixed/doctored with gap less rings and decked.. neither are going to happen anytime soon..
to me blow-by is energy that is not used/wasted in moving the truck down the road and $$$ out the exhaust pipe.. while one will never have 0 blowby.. but i can build an engine on the tighter side of the specs, especially at the almost/below stock power im putting out, put as much through the exhaust ports vs PCV tubes.
this was a general answer to a question while back about eficency between stock the finger bowl designs that was asked by someone in one of these thread i can remember who or where..
hope you guys find that info usefull :thumb:
normally these are thing i know before building or rebuilding..
given the circumstances around my build/rebuild as stated below.. my biggest complaint/regret is i wish i had more time to be more informed. i would have built a much tighter engine.
i broke at the end of the day on 11/21(thanksgiving eve) 300 miles from home hauled truck and loaded trailer home (two trips and a bus trip home),
11/24-25 pulled engine and striped it down
11/26 dropped it off at the machine shop monday
11/27 drove to Pittsburgh picked up the pistons and dropped of for final honing and balancing at the machine shop
11/30 evening had everything back ready to assemble ,
12/1-12/2 assembled and road tested
12/3 hooked to the load and rolled out with ~30 miles on the engine.
11.5 days roughly from start to finish through a 4 holiday weekend too..
merchant auto(parts), fingers and local machine shop, played vital roles in me being able to turn around that quick.
things are little different when you have a customer asking when their load is going to be delivered
New rings:
First Ring 0.0118-0.0177 in
Second 0.0197-0.0256 in
If your gap was that big, you had the wrong rings. Which would have been my fault for not checking.
Stock ring gaps are not at .053. You have the wrong rings if you have that much clearance on gaps. You can also use gapless rings to fix the blow by issue or get the right rings. Usually I see .018-.020 on top rings and .025-.027 on second rings.
It's not even that. The bore would be almost exactly .010" too big to get that gap. Ouch.
true the math would indicate that....i dont have a bore guage, so i couldnt do a quick check while assembly..
the rings where checked after being squared in the bore with a piston.
i will say there is no indication of piston slap regardless of what is out of spec..
I was curious why most people weren't just automatically putting in the gapless piston rings?
Are there any major drawbacks to using them at all?
outside additional cost, possible lead times and lack of knowledge that they exist, would be my guess..
i didnt find out that they existed till after i had mine assembled. i found them by happenstance clicking through MA site..
At least in the rare instance you might ever tear back into your motor, you could add a set of those in and gain some efficiency back that way.
the company we use has a pretty fast turn around time, i just dont think its something a lot of companies talk about.
that's a possibility but one is looking at 1000.00 in parts roughly and 3 days down time.. i'd really like to get it decked as well to bring me closer to stock quench..
who do you go through?
I have several trucks well over 1000hp with the cast oval pistons. Mine is at 1085hp and I have been driving it everyday on the big tune just to push it. I have a set of 200% injectors and triples about to go on it to increase the hp to over 1200hp! Should get really interesting...:happy2:
