For my needs, Fingers pistons are everything I would want but it would be interesting to hear prospective plans on improving the current design.
Which pistons?
- Thread starter sickdiesel
- Start date
Are you referring to running .014" on a diesel race engine or just a nitro/meth top fuel engine ? They are totally two different animals . A top fuel motor can run that clearance because of the extreme heat created in the cylinders between each pass and also is torn down and rebuilt after every pass. I'm not sure how you think I'm insane ? I know you want and try to have it out for me Tim , but I want to assure you I am not ignorant when it comes to building an engine. Believe the lies and he said/ she said bullish*t that " someone" fed you, but I was on that train for a while till the truth revealed itself . It may take you awhile, as it did for me, but eventually it happens 
I am saying exactly that Trey. It's not that I have it out for you at all. It's that you have been listening to the wrong people about "piston slap" in a duramax running 2618 alloy pistons at .014" ptw clearance
Oh okay lol so there is no slap what so ever with a piston rocking in the bore with .014" clearance ? Just asking ? And for the record , I'm not listening to anybody ? I'm listening and learning
so teach me ..........
I have heard it in Cummins running 2618 alloy pistons at .014", but not in a duramax....does that give you a hint?
Piston Slap
I'm not sure what Jay was running for pistons (I think Ross) or clearances, but I know in 07 at Merchant's Spring Fling, he was one of the first guys running forged and it had some SERIOUS piston slap when cold.
Granted that was 5+ years ago and may have been a "prototype" set (I'm sure material selection and clearances have changed), but they were noticeable (maybe this is where many have garnered their concerns from).
Drawing from memory (which isn't too good), I believe he had some issues and upon teardown noticed some issues with them (not sure if it was just the rings or if there was scuffing as well). The tear down information is second hand, and going from memory, so don't take it as gospel. As for the piston slap, I heard it first hand (so it is not a legend).
I'm not sure what Jay was running for pistons (I think Ross) or clearances, but I know in 07 at Merchant's Spring Fling, he was one of the first guys running forged and it had some SERIOUS piston slap when cold.
Granted that was 5+ years ago and may have been a "prototype" set (I'm sure material selection and clearances have changed), but they were noticeable (maybe this is where many have garnered their concerns from).
Drawing from memory (which isn't too good), I believe he had some issues and upon teardown noticed some issues with them (not sure if it was just the rings or if there was scuffing as well). The tear down information is second hand, and going from memory, so don't take it as gospel. As for the piston slap, I heard it first hand (so it is not a legend).
Lol so by that being said what would stop someone from running the 2618
Nothing ! I'm not saying that at all. I was simply asking because I would have bought those instead , had I done a little more research.
not all pistons are created equal
: I don't know if Ross used a tapered bore or not, but I have heard of a high profile build or two running into an issue with their machinists ASSuming a straight bore and running into some issues...a few years agoAlso, He burnt up every single piston in that set, there was something seriously wrong with them and/or the recommended clearances
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Are they gonna be "DTS pistons" ?
who cares as long as they work better than what we have now....mahle rings suck donkey d*ck
Off Topic, but:
Jay wants to sell his truck, he texted me a few weeks ago asking if i knew anyone interested in it....NEW Twins, NEW Stroker motor, and many many other new parts. Just putting in out there for those of you who know the truck.
Pistons
I have said it before and I will say it again, EVERYONE needs to look up the differance in a 4032 and 2618 pistons! 2618. I run a Arias and have the same rings in the motor I put in it in 2009! I said again 2009!!!! It will not last 100k miles driving it daily but it will last longer than most build will!!!!! The rings that is. Tim I have to ask what motor had burnt up pistons from a bore problem? I also want to understand a tappered bore vs a strait bore? You do know a piston is not round? BUt ir does change with heat. I'm not talking about the crown. This is some funny stuff.
I have said it before and I will say it again, EVERYONE needs to look up the differance in a 4032 and 2618 pistons! 2618. I run a Arias and have the same rings in the motor I put in it in 2009! I said again 2009!!!! It will not last 100k miles driving it daily but it will last longer than most build will!!!!! The rings that is. Tim I have to ask what motor had burnt up pistons from a bore problem? I also want to understand a tappered bore vs a strait bore? You do know a piston is not round? BUt ir does change with heat. I'm not talking about the crown. This is some funny stuff.
IIRC:
2618 was an aerospace alloy developed when Russia had all the titanium. As missiles and planes started to go supersonic, the aluminum components were heating up and losing strength.
It loses less strength than other alloys under high temperatures. It is crack resistant as well, however, and has less strength at lower temps than other alloys do, and a very high expansion rate.
It is not new technology, it was developed in the 1950's IIRC. I do not know if there are better alloys today. By the time I started working in aerospace, it's use was pretty limited.
I will say this, if you DO have a ring problem, things go south in a hurry. Our high combustion pressures and temps will destroy the piston wall far faster than gas engines do. Excessive blowby on a Dmax should be addressed quickly. Do not run the engine hard until you're up to temperature with forged pistons with low silicon content like 2618.
2618 was an aerospace alloy developed when Russia had all the titanium. As missiles and planes started to go supersonic, the aluminum components were heating up and losing strength.
It loses less strength than other alloys under high temperatures. It is crack resistant as well, however, and has less strength at lower temps than other alloys do, and a very high expansion rate.
It is not new technology, it was developed in the 1950's IIRC. I do not know if there are better alloys today. By the time I started working in aerospace, it's use was pretty limited.
I will say this, if you DO have a ring problem, things go south in a hurry. Our high combustion pressures and temps will destroy the piston wall far faster than gas engines do. Excessive blowby on a Dmax should be addressed quickly. Do not run the engine hard until you're up to temperature with forged pistons with low silicon content like 2618.
What i was referring to jeff was that not all forged pistons are tapered the same amount from skirt to crown. The rate of expansion in the crown area and skirt area are different and depends on the alloy and clearances used.
pistons
there is a differance in the two types of pistons and how they work or should be used. There is a place for both just like cast pistons. it's the end result and what you truely want your motor to do that defines what would be best.
there is a differance in the two types of pistons and how they work or should be used. There is a place for both just like cast pistons. it's the end result and what you truely want your motor to do that defines what would be best.
What's excessive? Lol
At DPC i noticed more and more blowby everyday...and when i first started that motor a year earlier it seemed excessive. I broke the crank, tore the motor down, and the machine shop called me saying the bores were .0015" out of round in some areas, and not from use...., the pistons looked great, rings werent worn oddly.
At DPC i noticed more and more blowby everyday...and when i first started that motor a year earlier it seemed excessive. I broke the crank, tore the motor down, and the machine shop called me saying the bores were .0015" out of round in some areas, and not from use...., the pistons looked great, rings werent worn oddly.