lude98SH

Well ive heard a mixture of things i want to seperate fact from false info here. Doesnt seem like i can find a straight answer here. Have they corrected the problem with the valve relief's ?

I originally was going to go Prelude type s OS pistons but the guy at hmotorsonline said that honda has discontinued them and he cant get them anywhere. Thats why i am now looking at these.

Also i bought eagle rods for a prelude type s pistons supposedly will those still work with those pistons ?

my9thtry

i was also going to use type s pistons. my engine is being built by DFE. i wanted a little more compression and Don recomended those pistons. as he plainly put it if mahle says they work then they work. the valve relief problem have been fixed.

and yes your rods will work just fine.

UK_Luder

I can also confirm that the valve relief problem was sorted.
I'm running these pistons with Eagle Rods and Skunk2 Stage 2 Pro camshafts & valvetrain with no issues.

NirVTEC

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by UK_Luder &raquo;</TD></TR><TR><TD CLASS="quote">I can also confirm that the valve relief problem was sorted.
I'm running these pistons with Eagle Rods and Skunk2 Stage 2 Pro camshafts & valvetrain with no issues.</TD></TR></TABLE>

Any Dyno numbers???

When they did that build in Honda Tuning a couple years back they cited the relief problem. Knowing MAHLEs history I have confidence in them.
Cosworth made JUN pistons work in FRM so its not impossible. That was 10+yrs ago that JUN released their pistons, and their 4th gen Prelude kicks ***.
If you search around you will find people bashing MAHLE but I have yet to see any details other than the relief problem mentioned...
I don't have an personal experience with them so I am kind of neutral, leaning towards trusting them. Until I see long term reports from people that I trust, I wouldn't try them. Thats just me.....Internet bitching and complaining usually comes with little details.....Other than that; my friends sisters cousins neighbors best friends uncles shop had a problem.
There was a guy that tried Forged pistons in FRM and kept us updated on it. He had no issues with it at all and then BLAM!! Done....fried cylinder walls.
I would love to see someone take the time to do it with MAHLEs.
Finding a capable shop that knows FRM is going to be key.....my previous suggest was to talk to Porsche engine builders about a reputable shop.

my9thtry

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by :=:NirVTEC:=: &raquo;</TD></TR><TR><TD CLASS="quote">

Any Dyno numbers???

I would love to see someone take the time to do it with MAHLEs.
</TD></TR></TABLE>

I should be able to show you some dyno numbers soon. My setup is so far:

Ported H22 head
95mm crank and rods
Mahle 11.5 to 1 pistons
Pro2's
Flat faced valves
Euro R intake
69 mm TB
Hytech 4th gen header

NirVTEC

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by my9thtry &raquo;</TD></TR><TR><TD CLASS="quote">

I should be able to show you some dyno numbers soon. My setup is so far:

Ported H22 head
95mm crank and rods
Mahle 11.5 to 1 pistons
Pro2's
Flat faced valves
Euro R intake
69 mm TB
Hytech 4th gen header</TD></TR></TABLE>

Now thats what I'm talking about!!!
Just curious......did you order H22 11.5:1 pistons from Mahle? Youre talking some serious compression if thats the case. Is your bottom end assembled yet?
I am going to stay on you about numbers and longevity of the Mahles.
Good luck!

prelittlelude

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by :=:NirVTEC:=: &raquo;</TD></TR><TR><TD CLASS="quote">

Finding a capable shop that knows FRM is going to be key.....my previous suggest was to talk to Porsche engine builders about a reputable shop.</TD></TR></TABLE>

this is very important, and make sure that the builder pays close attention to what the require piston to wall clearence is.

most of the people who have been ******* there mahles are the ones who threw them in with no check of the piston to wall clearence. Every piston needs a specfic clearence, and just because these pistons are frm compantable people think they can just throw them in with no prep. WRONG. when you order you gold series pistons they willl come with a sheet that gives the specfic p-to-w clearence. follow it!

lude98SH

thanks guys. Anymore info anyone has to share ?

Missing Gears

here are the facts:

the reason people complain about these pistons is because they wont handle any kind of abuse. if you want an oem replacement, they will work fine. but if you want something stronger that you can beat on (which most people do and is why they go through the trouble of building their motor) these are not the pistons to go with.

on the other hand, some people just want a factory rebuild keeping close to stock power levels and that is where these pistons work well.

the true fact is they are a good product, they just arent designed for making or handling power. and they are not designed for boost or nos obviously.

believe what you want, those are the facts.

lude98SH

but why would they go through the trouble of making a forged piston that cant handle FI or work with big power ? Theres no real market if thats the case. Im not disagreeing with your point just looking further into it, trying to find out as much as i can.

96vtecI4

People have ran these for years at 15psi no problem. They can take abuse. It's a forged piston with a special coating. These pistons are used in porsche engines, and they work. I plan to use them in my H22 turbo when I find someone who can do the machine work. They work, and they work well. Theres an archived thread thats like 100 pages long about them on here, upwards of 90% have had great long term results.

md23vtec

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Missing Gears &raquo;</TD></TR><TR><TD CLASS="quote">here are the facts:

the reason people complain about these pistons is because they wont handle any kind of abuse. if you want an oem replacement, they will work fine. but if you want something stronger that you can beat on (which most people do and is why they go through the trouble of building their motor) these are not the pistons to go with.

on the other hand, some people just want a factory rebuild keeping close to stock power levels and that is where these pistons work well.

the true fact is they are a good product, they just arent designed for making or handling power. and they are not designed for boost or nos obviously.

believe what you want, those are the facts.</TD></TR></TABLE>

Don't bother talking about these pistons. I have done it countless times and it will get you nowhere.


To everyone else goodluck with your Mahle builds

117

So has anyone actually built an engine with the Mahle pistons and at least taken off the head after xx miles to see what the cylinder walls look like?

Has anyone actually ran them for a specified amount of mileage without any obvious issues?

I hear stories of people who knew someone or knew a shop that has install them, etc. etc., but I have yet to actually meet someone who has used their pistons in an H22 with good results.

96vtecI4

Read through the mahle gold series thread. People with 15k miles no issues what so ever and consistent compression.

my9thtry

like i said its going together right now i just found i have a broken innner valve spring so i will be replacing all the valve springs... i had some doubts about the pistons as well but if Don says they work then i have no doubts in him.

Missing Gears

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by md23vtec &raquo;</TD></TR><TR><TD CLASS="quote">

Don't bother talking about these pistons. I have done it countless times and it will get you nowhere.


To everyone else goodluck with your Mahle builds </TD></TR></TABLE>

you know it doesnt bother me the least bit if nobody listens. you and i probably have more h series experience than everyone else on this forum combined, but most of the time people choose to ignore taking the free advice that we have spent years and tons of $$ learning only to learn for themselves the hard way. but hey, thats how we learned wasnt it

lude98SH

prelittlelude

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Missing Gears &raquo;</TD></TR><TR><TD CLASS="quote">here are the facts:

the reason people complain about these pistons is because they wont handle any kind of abuse. if you want an oem replacement, they will work fine. but if you want something stronger that you can beat on (which most people do and is why they go through the trouble of building their motor) these are not the pistons to go with. </TD></TR></TABLE>

every single failure i have seen with the mahle gold is piston to wall contact. as a material is heated it expands, if people use the correct p-to-w clearence then when they "abuse" there motor there should be no problems. I am not super experienced with the gold series, so if you know of a failure other than the p-to-w problem or the old old valve reliefs then i would like to know.

vinuneuro

Jdogg used Mahle's in his NA engine without any problems. There was a guy in the FI forum with &gt;500whp without any problems as well. I believe Whipfactory built/tuned a 400whp engine without any problems too.

Mahle is the absolute number one piston maker in the world. They supply basically every German oem and many others around the world too. And yes, they are a Formula One supplier.

shutta

I've heard many **** talking stories about these pistons, but NEVER any pictures of damage. until I hear of someone properly adhering to a piston-wall clearance, and properly building their motor and then still seeing devastating results, i'm not going to chancge MY mind about using these pistons when I build my motor.

NirVTEC

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vinuneuro &raquo;</TD></TR><TR><TD CLASS="quote">Jdogg used Mahle's in his NA engine without any problems. There was a guy in the FI forum with &gt;500whp without any problems as well. I believe Whipfactory built/tuned a 400whp engine without any problems too.

Mahle is the absolute number one piston maker in the world. They supply basically every German oem and many others around the world too. And yes, they are a Formula One supplier.</TD></TR></TABLE>

JDogg? How many miles and at what power? Im sure special attention was paid to p/w clearance.
FI 500whp? How many miles? Is it just a dyno queen or has it made successful 1/4 passes?
WF 400whp....again, how many miles and is it just a Dyno Queen?
I'm am still in the major belief that other than the valve relief issue which was handled.........People who have run them with negative outcome are just blaming poor installs on a New and easy to blame product. Thats just my opinion and I have never used them myself. I have just been around long enough to know people like to blame bad installs on especially new products.
I've seen people blame blown motors on Nitrous before!

On a side note, I personally am just not a person who will skip sleeving to run forged pistons......If Im building a motor, Im doing it the right way the 1st time.
Whats cheaper? Sleeve block, install Forged pistons or Hone block, install Mahles, cause cyl wall damage, source new block, sleeve, install forged pistons and end up right where you would have been the RIGHT 1st Time?
Thats just the way my brain works though.......Besides, 87mm for an N/A setup is just silly!
I don't believe in Budget Builds.......again, just me.
Good luck to everyone that decides to use Mahles and I hope this time next year we have several detailed write-ups to back claims that they are A-OK!
Its all going to be a numbers game......there are always going to be a certain amount of failures as with any products....How often and how bad are the way they need to be looked at.

Missing Gears

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by prelittlelude &raquo;</TD></TR><TR><TD CLASS="quote">

every single failure i have seen with the mahle gold is piston to wall contact. as a material is heated it expands, if people use the correct p-to-w clearence then when they "abuse" there motor there should be no problems. I am not super experienced with the gold series, so if you know of a failure other than the p-to-w problem or the old old valve reliefs then i would like to know.
</TD></TR></TABLE>

yes, i know of several faliures and NONE of them include piston to wall clearance. they are all cases of the piston itself not standing up to abuse unlike other pistons can and wil do in the same situations. mahle pistons are weak and will melt down and or blow apart very easy. the ring lands are also very delicate. it doesnt take much to destroy a mahle piston. they do not tolerate any amount of detonation at all. im not here to start an argument, if you want to run mahle pistons go right ahead but keep in mind it may cost you a rebuild later.

like i said, if your going for a stock rebuild due to low compression from a worn bottom end, by all means use them. they will work well. but if your rebuilding to make more power, there is a right and wrong way to do it. these pistons are not meant for making or handling power, thats it, thats all there is to it. if you want to make enough power out of a rebuild to justify spending the $$ for the build, then do it right the first time and sleeve the block and overbore so you will gain some displacement because to be honest w/ you the little bump in compression you will gain from the type s and these mahle pistons isnt going to do much for you. you will end up rebuilding and going overbore in the future anyway after your unsatisfied w/ the results of adding a little compression by itself.

it is basically useless to build a block for the purpose of making more power w/o adding more displacement.

prelittlelude

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Missing Gears &raquo;</TD></TR><TR><TD CLASS="quote">

mahle pistons are weak and will melt down and or blow apart very easy. the ring lands are also very delicate. it doesnt take much to destroy a mahle piston. they do not tolerate any amount of detonation at all. </TD></TR></TABLE>

interesting, time should show as more poeple start to use them. I need to do some research and see if i can find what alloy the pistons are made of, for some reason 4032 sticks in my head. seems pretty stupid of mahle to sell a piston for forced induction setups if they will break under abuse..

Missing Gears

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by prelittlelude &raquo;</TD></TR><TR><TD CLASS="quote">

interesting, time should show as more poeple start to use them. I need to do some research and see if i can find what alloy the pistons are made of, for some reason 4032 sticks in my head. seems pretty stupid of mahle to sell a piston for forced induction setups if they will break under abuse.. </TD></TR></TABLE>

im not sure what theyre made of, of course its always possible for mahle to make improvements. who knows if theyve changed anything other than the valve reliefs. but from what ive seen in the past im not impressed.

jam89si

UK_luder!
I am currently building the same setup as your's! Do you have any numbers (how many Hp)!?! Do you have the 87mm piston or 87.25mm??
my9thtry keep us updated!!