jsworkstd

I've got a set of Mahle # LS1105000I32 pistons and I'm concerned about the top thickness.
Measuring above the wrist pin area checks .146". Seems kinda thin.
Wiseco's check .187 in the same area.
Anyone have experience with these?
Thanks,
Jeff

Inspector12

iTrader: (29)

Might just give W2W a call I have talked to Kurt on a number of occations and they use Mahle pistons in a lot of there applications and could probably tell you real fast if the ones you have are going to suit your needs etc... I am like you and think the thicker area would be better, but it also depends on what material the piston is made of. I know I didn't answer your question just thought I'd offer a little advice that I try to use myself and that is talking to the people that are using these products all the time. Good luck.
Jeff Williams

KJ@FriendlyChevy

How much boost do you plan to run? If you are going to be 15lbs or under you will be just fine with your Mahle pistons, just make sure your rings are filed correctly. As you know I'm sure, your tune will be a big deciding factor on the life of your pistons. Alot of the standard pistons on the shelf don't have a very thick crown. Most manufactures will build you a custom piston & that is what I would recomend you to get. Diamond is who I have worked with alot, and they know exactly how to build a piston that will last. The other good thing about Diamond is they can get them to you in a decent amount of time and they don't cost much more than there off the shelf stock. I hate to run on about Diamond to you but they also have a "Hell Fire" ring package that works with the std 1.5, 1.5, 3mm ring grove.

Just my two cents.

Nate_Taufer

iTrader: (1)

Diamond custom sets run about 400 bucks more than their off the shelf stuff. A lot of coin if you ask me. If you run an off the shelf JE you're already setup to run a lot of boost as their top ring height is well over .210" to the ring.

Maybe the JE stuf is an eaiser option.

Nate

jsworkstd

I already have 2 set of pistons, don't want to get a 3rd.
The top ring distance is .235" on the Mahle's the Wiseco's have slightly more.
I'm gonna run about 15lb. boost, maybe turn it up to 20 someday.
thanks
Jeff

Nate_Taufer

iTrader: (1)

You should be fine. Turn that **** up with .235" on the first ring.

Nate

briannutter

3 questions.

top land thickness

4032 to 2618 alloy

pin thickness

jsworkstd

4032 alloy, .235" top land thick

427

iTrader: (3)

I have a daily driver pick-up truck with a Mahle 4032 piston that we had made for driver turbo engines. I have run 15-20 PSI for the last two years(39,000 miles) on it.
Last night a Ford pick-up with a hot rod diesel wanted to run from a roll, I love when they pick on me. His Ford truck with the FASTDZL liscence plate thought my pistons were good!

Kurt

briannutter

As for the .235 top land thickness, what's the compression height on the piston? I need to see if there's any real-estate left for thicker lands.

As for 4032, I guess I'll just say that 4032 is a step up from Hypereutectic, but not what most manufacturers use for Turbo or nitrous applications. If you don't detonate, it will live ok. Even in some high end applications, 4032 can be a "ok" choice. NHRA Prostock is one exception in "pro level" racing where 4032 is preferred over 2618...but this is usually because of the perfect tuning and a "weight reduction at all costs" mentality....try a set of pistons every 60 runs. Guys that were the "first 3rd gen in the 6's at over 200" were running 2618 alloy when they did it..

4032 is 3% lighter, has better wear "appearance" when pulled out of a run engine due to it's high silicon content. 2618 gets shiny and gets vertical scratches if the oil isn't kept clean, but for the most part maintains it's "shape". Installed clearance on each can be the same if the 2618 piston is engineered correctly. Things like offset pins can overcome the generalization that forged pistons (especially low silicon 2618) are noisy.

If you've ever seen an engine, with a dropped valve for instance, and the forged piston is a bunch of nickle sized fragments in the oilpan....that's 4032. If you've seen the piston wrapped around the valve head like taffy, that's 2618.

Dune-LS1

^^^ Great post!^^^^

bg-sdpc

iTrader: (4)

Most piston manufactures claim that there standard duty piston line will still handle up to 200hp of power adder. Like the post above stated, you can't lean it out or you will pop the ring lands. Gap the rings right and run it a little rich and they should live.

Brian

427

iTrader: (3)

2618 is the better material for a race application because of its ability to bend and flex without breaking. 4032 is better for street or mild race engines that will be used for years between rebuilds. The high silicone content fights the ring land wear that is dominent in 2618 pieces. Every builder has a point when they would like to balance engine life with the ability to take tremendous cylinder pressures, on our crate engine we make the change to 2618 material above 1,000 flywheel hp.


Kurt

briannutter

427 has a good point, 4032 is good for street and mild racing applications. I personally don't think that 700 horsepower "street engines" should run "street" quality pistons. A wise LS1 engine builder told me...If a LS1 guy isn't running nitrous or supercharging when they first drop a new engine in, they will be soon enough, so just build it right the first time.

Many Many Many people with over 100K miles with 2618 alloy have had no ill effects. As long as the ring grooves are flat to begin with and the rings are good quality (flat themselves), vertical clearance in the land is not an issue. I've run between .0005 clearance up to .0025 vertical clearance with no changes in power...In fact, some of the latest o.e. race engines have begun to specifically open up the top groove clearance to allow the ring to twist more for better seal. The ring doesn't seal on the flat surface of the land anyway, it seals on the outer lower lip. As long as that stays "round", you're in good shape.

The original post is this...the engine may be run up to 20 lbs at some point. We ARE talking about an engine with 700 to 800hp potential EASILY. There is limited room for lands and .235 tops are well under the .300 that ANY piston maker would prefer for a boosted application given enough room. ONE tank of bad gas is enough to pop a thin .235 top land even with 2618 alloy, so why take the chance.

I guess my main point is at least 5 of the biggest and most respected players in aftermarket LS engine buildups ALWAYS use 2618. I'm taking the high road here and leaving the names of those companies out of this post. That's not what this post is about. You don't hear people whining about noisy engines from these respected engine builders. Every piston company in the U.S. (except one) uses 2618 alloy for boosted and nitrous applications. If you don't hear a lot of pissing and moaning over 2618 alloy pistons making noise (especially the offset wrist pin ones), why WOULDN'T a guy use 2618 alloy.

427

iTrader: (3)

That is a interesting opionion you have on piston material. I am just giving my opionion based on our testing and experience.
A 2618 piston will have enough wear in the ring land to lose hp in a 24hr race. I test them on the dyno before we send them, then re-dyno when they come back. The engine in a 24hr race has about 35 running hours(break-in, practice, race) on it when it gets back.
The "quality" of the pistons we use are very high, the material has nothing to do with the quality of the product. The material choice is done for many reasons, when we chose 4032 over 2618, cost and quality are not the reasons, the application of the engine and getting the best part is the only concern.
The piston in my truck is 4032 because we tested different materials and designs and this one is the best for my application. My engine in my truck does make over 800hp and 900ft lbs. It will flip 40,000 miles this weekend with the turbo on it. It has seen 15-20psi daily for its whole life. If JSWORKSTD's application is under 1,000hp, then the 4032 piston that he has will work for his application.


Kurt

MadGoat

Any ideas where I can find real specs on the LS2 to have some custom CP's made?
Like journal sizes, deck height, etc. I found bore and stroke but need more info than that for customs.

Race-Prep

I would have to agree, we use 2618 pistons in nearly everything we build and have had no problems with losing power. Many of them are in the 40-50,000 mile range and are still going strong. We pretty much do street engines exclusively, and this type of alloy is working VERY well for us. I also have to agree with Brian on the top ring land choice, that is VERY thin for a street driven engine making that much power, one thing to keep in mind here is the street is NOT the same as the track, there are lots of fuel problems and believe it or not, MUCH more abuse takes place. I would re-think the piston choice if it were my engine, its just not worth it to chance.

-Bryan

briannutter

I appreciate 427's input on this. It's nice to have someone that speaks from experience. Some people even are able to make hypereutectics run with blowers...but those people don't detonate...not even once.

To say that everyone on this forum has the same tuning ability and luck would be wrong though. I'd be remiss in recommending 4032 in this application. I've seen too many broken lands (every manufacturer and alloy) to "take a chance" on it when 2618 is available. It's just too destructive.

For the tech-heads here, the best of both worlds is 2618 with Boron Carbide groove treatment. It's a $350 option, but it's what the pro's run in endurance applicatons.

427

iTrader: (3)

I think the hypereutectics would have went to the happy hunting grounds during our testing!!! The last test we ran was a torture test: With 60 hours on our test engine(6.0 gen3 single turbo) I added timing 2 degrees at a time and monitored the engine for signs of trouble, boost was stable at 20psi and inlet air was between 100-120F. At 30 degrees of timing (higher than normal NA for us) the blow-by meter was showing trouble was found. Upon inspection the crown of the piston had started to deform from heat, curling up. The second ring was not pinched and the sealing edge of the top ring groove was not damaged. The skirts still had the cam shape and original shape with light scratches from debris.
On land thickness our testing supports the pistons second land thickness is more important than top when using a "hell fire" or equal ring in the top groove.

Brian/Bryan
When you are testing the 4032 pistons, what type of failure do you see? Is it catastophic or just cracking? How many hours do they run before they fail? Do you run full throttle NA or boosted to cause the failure(approx HP/rpm).

Brian Nutter- Which piston company do you work for? Wiseco(guessing because of Ohio!).


Kurt

racer7088

Yeah with all the guys we know through SAM and from SAM working in the racing arena I have never heard of 4032 in a serious stress or heat environment being a good thing. I'm not saying anything bad about the other Mahles and I definitely am a fan of Wiseco too as they both have been very solid on the NHRA and NASCAR here in the USA.

Mostly 99 percent of power adder stuff is 2618 that I have seen and in fact I didn't kow Mahle made a piston like that with 4032! I'm sure it will last and guys like Kurt at W2W are also pretty damn good tuners and much more experienced than most so I have no doubt whatsoever that his piston there is working for him but the leeway for any old tuner taking those pistons out with a crazy tune IS higher.

I also am not a fan of the thin Mahle top lands on the power adder stuff. It's great for lower power and NA but not so safe for big power adders and any tuning slipups!

We use and love the Wisecos because they are built like a tank with strong lands and good deck thickness and are still fairly light as well. They also have the inboard pin boss design that Mahle and some of the JEs use which uses a shorter and stiffer pin. You can opt up on the Wisecos also for a .170 wall tool steel pin if you want extra insurance for about another 100 or so.