Info: What pistons For build

[slowlmm]

Ok well hopefully this dosent start to big of debate but i need to figure out wht pistons i should go with.

option 1 cut and delipped lmm pistons ?

2.?

3.?

4.?
5.?

and if you could a little data why one would be better then the other. hp goal for the truck is 800 max for now and will be daily driven. i drive alott as you can tell over 50,000 miles a year this truck will become full race or non daily driven in 2010 so needs to last untill then. also i will be using nicks rods if tht matters. Thannk every one

 

[LBZrcks]

Call Guy

2. Cut and delipped and coated LB7/LLY with valve reliefs

 

[IOWA LLY]

If your careful with your tuning de-compressed LMM pistons should be just fine.

 

[sweetdiesel]

Howards rods and mahle forged pistons JMHO
and a new truck for DD

 

[Mike L.]

Call Guy

2. Cut and delipped and coated LB7/LLY with valve reliefs

I agree.

 

[Trippin]

IMHO LBZ/LMM pistons cut or stock are a loser.

Go with delipped LB7/LLY or the Mahle forged.

As for rods, take your pick, I have them all.

 

[NWTDIESEL]

Call Guy

2. Cut and delipped and coated LB7/LLY with valve reliefs

x2

 

[JOHNBOY]

For a Street Truck.

LB7/LLY pistons deliped and radiused.

LMM/LBZ stock pistons. The most effort I would put in to them is pitching them in the scrap bin.

 

[codyn]

forged pistion will do fine. any cast pistion will crack no matter what you do to them. forged won't crack and last longer then a cast. and they are around $2000 or less

 

[Stingpuller]

Pistons

The pistons Cody is selling are very nice. Arias makes a very good product. I am sure if anyone purchased these they will be happy. I would like to say I will test these with the new motor but I wasn't able to break the LBZ pistons in the motor. Jeff

 

[JoshH]

I've heard a lot of bad press about forged pistons in a daily driver, mostly about the flat compression ring.

 

[Stingpuller]

Everything is bad for everyone.

Just ask someone and they will tell you something is bad for you! Im sure they will not last like a stock piston. But I also think stock pistons suck and many don't get any miles out of them. So I guess one would have to figure out what would be the best of two evels for them personaly. Josh, do you know anyone personaly that has had problems or is it a friend of a friend of a friend? Anything can and will break. Jeff

 

[JoshH]

I don't personally know anyone running them; I've just heard from several sources that the flat ring in a forged piston is no good for a daily driven application.

 

[codyn]

I don't personally know anyone running them; I've just heard from several sources that the flat ring in a forged piston is no good for a daily driven application.

well i have 15000 so far and no problems. they have been using forged pistions in cummins and dd them. so whats the difference between a cummins bore and a dmax bore? are you talking about gapless rings?

 

[slowlmm]

I don't personally know anyone running them; I've just heard from several sources that the flat ring in a forged piston is no good for a daily driven application.

what problems could arise ?

 

[codyn]

I don't personally know anyone running them; I've just heard from several sources that the flat ring in a forged piston is no good for a daily driven application.

what have these sources said? because i see alot of people bashing a forged pistons for daily driving and all they really say is not enough testing on them and have not been out there that long to have alot of miles. but we take a cast piston that been known to fail and hold them to a higher power. well the rings have been holding up fine under power that i have been putting to them and the piston. it has not been a easy time on them. i have had no problems out of them so far with stock heads putting down 722hp at 42 pounds of boost on the dyno and the truck will run up to 67 pounds of boost with efi live going down the road. so i think im close if not over 800 to the wheels and still no problem yet

 

[Leadfoot]

what have these sources said? because i see alot of people bashing a forged pistons for daily driving and all they really say is not enough testing on them and have not been out there that long to have alot of miles. but we take a cast piston that been known to fail and hold them to a higher power. well the rings have been holding up fine under power that i have been putting to them and the piston. it has not been a easy time on them. i have had no problems out of them so far with stock heads putting down 722hp at 42 pounds of boost on the dyno and the truck will run up to 67 pounds of boost with efi live going down the road. so i think im close if not over 800 to the wheels and still no problem yet

I don't think most people are holding cast pistons to a higher power, but there were some legitimate concerns with running a forged piston in a diesel without being able to have the ring lands made of a stronger material. The first motor with Ross pistons finally gave up the ghost http://www.duramaxdiesels.com/forum/showthread.php?t=5972&highlight=built+motor and Nasty was over 1000RWHP on cut stockers....?? I know yours are not Ross' or Mahle's, etc. but there have been concerns that haven't been debunked.....YET. I for one hope that we can get a forging to last high mileage in a DD as I would love to buy a set.

I guess the biggest issue is/was ring sealing over the life of a forged piston as it is unable to support a keystone ring. From my LIMITED understanding, the ring sealing on a flat ring will give up over time as it eats into the forged piston. Now if you don't drive many miles a year, it might not be an issue.....

I wonder if the pistons Guy sells are the same "EXACT" metallurgy as OEM or if he gets different castings. It seems like there is no issue (except for Nasty which was beyond a normal build) on his pistons and that says alot.

Guy, do you know of any failures of your cut stockers (LB7)? and if so what were/are the circumstances?

 

[codyn]

I don't think most people are holding cast pistons to a higher power, but there were some legitimate concerns with running a forged piston in a diesel without being able to have the ring lands made of a stronger material. The first motor with Ross pistons finally gave up the ghost http://www.duramaxdiesels.com/forum/showthread.php?t=5972&highlight=built+motor and Nasty was over 1000RWHP on cut stockers....?? I know yours are not Ross' or Mahle's, etc. but there have been concerns that haven't been debunked.....YET. I for one hope that we can get a forging to last high mileage in a DD as I would love to buy a set.

I guess the biggest issue is/was ring sealing over the life of a forged piston as it is unable to support a keystone ring. From my LIMITED understanding, the ring sealing on a flat ring will give up over time as it eats into the forged piston. Now if you don't drive many miles a year, it might not be an issue.....

I wonder if the pistons Guy sells are the same "EXACT" metallurgy as OEM or if he gets different castings. It seems like there is no issue (except for Nasty which was beyond a normal build) on his pistons and that says alot.

Guy, do you know of any failures of your cut stockers (LB7)? and if so what were/are the circumstances?

they say 10,000 miles of drag racing or sled pulling use only. they need to be checked for compression to make sure the rings are fine. but that does not include driving around and doing being a weekend warrior. they say that they will last a good bit of time before they need to be changed. . if i have to put a set of twins and push it over 1000 hp to prove the point and that they will hold. ill do it. i am not bashing no one by no means. it will be some time before we will see problem with cast pistons or forged. my cast pistons went with 88,000 miles. so it could be some time. but im in this to make a lasting deal on making parts better and going farther for the dollar. i just see we have use them in cummins. if you had some extra money to get them and seen no issue with them. but im hear to help find something that will hold so we can get past the issues.

 

[JoshH]

I read something about the flat top ring causing issues with soot building up and causing problems, but I would have to go back and find it again. I really have no idea where I read it, but from what I remember it was a reputable source or it would have been immediately forgotten.

Obviously you care about it more than I do, so just forget I ever said anything. I didn't mean to threaten any sales.

 

[codyn]

I read something about the flat top ring causing issues with soot building up and causing problems, but I would have to go back and find it again. I really have no idea where I read it, but from what I remember it was a reputable source or it would have been immediately forgotten.

Obviously you care about it more than I do, so just forget I ever said anything. I didn't mean to threaten any sales.

threaten sales :rofl: so who did it come from then if it was reputable source. i would like to know more info. the more info the better