Best Pistons Choice ?

[shanef]

they are a racing piston and only come with the shorter skirt

[rob82]

i dont want to star a new thread !!!! so i will ask here first

i just received my pistons (MAHLE) for my rb26 ... and there are not the same as the stock or the JE i had before my engine blew !!!

the side skirt of the piston on the MAHLE is shorter then the stock and JE ...

does some of you guys have them in your engine and do they have the same design ?!?!?!

here are some pics ...

What is the specified piston to bore clearance on those pistons - also what compression do they come up to on a standard head/gasket?

[Angus Smart]

Will just find my photos...

apparently they need notching to clear the oil squirters. but will have to see about that one you'd think that thay would be a straight fit.

i still have not had mine fitted yet. i've put a stop to my engine build for a few weeks...

Edited November 13, 2008 by Angus Smart

[NYTSKY]

I ditched my CPs for Mahles, awesome looking pistons and they are extremely light!

[N1GTR]

Another mahle user here

Here's a pic (note they're rb30 for 8.5CR)

[FineLine]

I used Os Gikens last time round. Since discovered they are actually a cosworth slug. Brilliant piston but just too pricey. After doing my homework I settled on the mahle this time round. They look the goods and are very well priced.

[EFI Performance]

What are those piston's worth?????

Couldnt be bothered reading.

[FineLine]

Depends on where you buy them I guess. Around 1100 bucks rings inclusive.

[Angus Smart]

i got mine for about 800 with rods which were about the same price.

but then i was raped by the import duty man.. 5 bucks over 1000 declaired dollars..

Edited November 13, 2008 by Angus Smart

[2rismo]

I ditched my CPs for Mahles, awesome looking pistons and they are extremely light!

I don't see why you'd 'ditch' pistons in favour of another brand just for the sake of it unless they were rooted or didn't fit the bore any more.

[Stan]

Another mahle user here

Here's a pic (note they're rb30 for 8.5CR)

Do you know the piston to bore clearance?

I have just fitted a rebuilt RB30/25 with Mahle pistons and the motor has very loud piston noise.

After 100klms with no change in the noise, I have pulled my motor out again and rechecked the clearances

and found them to be at .003" as my machinist had set them.

I have since heard that the pistons are race only pistons and not street suitable, that they are always noisy

and should have less clearance.

Do you know if this is correct?

[The Dan]

Do you know the piston to bore clearance?

I have just fitted a rebuilt RB30/25 with Mahle pistons and the motor has very loud piston noise.

After 100klms with no change in the noise, I have pulled my motor out again and rechecked the clearances

and found them to be at .003" as my machinist had set them.

I have since heard that the pistons are race only pistons and not street suitable, that they are always noisy

and should have less clearance.

Do you know if this is correct?

For your application, the piston to bore clearance should be 0.0025in - 0.003in including the coating so basically if you measure the skirt diameter inc the coating you should come up at 0.0025in piston to bore clearance measured half way down the skirt.

How are you measuring the clearance? How accurate is your equipment?

They are suitable for street use and will be slightly noisier than regular pistons but only very slightly. They shouldn't be extremely loud compared to stock but you will still hear them when the engine is cold. Mahle require tighter clearance compare to other manufacturers so possibly your machinist has set them half a thou over. But even then I wouldn't imagine it would be as loud as you are suggesting. (How loud exactly?)

[Stan]

For your application, the piston to bore clearance should be 0.0025in - 0.003in including the coating so basically if you measure the skirt diameter inc the coating you should come up at 0.0025in piston to bore clearance measured half way down the skirt.

How are you measuring the clearance? How accurate is your equipment?

They are suitable for street use and will be slightly noisier than regular pistons but only very slightly. They shouldn't be extremely loud compared to stock but you will still hear them when the engine is cold. Mahle require tighter clearance compare to other manufacturers so possibly your machinist has set them half a thou over. But even then I wouldn't imagine it would be as loud as you are suggesting. (How loud exactly?)

Pedestrians looking when you drive past Loud. My machinist has heard the noise and agrees that it is piston noise.

As loud as stuffed lifters. The noise is VERY loud when cold and only a bit quieter when fully warmed up.

The equipment is machine shop equipment.

Measurement taken 10mm from the bottom of the skirt. I will check the measurement half way up the skirt tomorrow.

I am trying to decide if I should fit new pistons with longer skirts or maybe get another RB block and rebore it with tighter clearances

[rbs14kouki]

thanks for your replys guys . it's appreciated !!!

i was 99 % positive that i had the good pistons .

and i need to say that there packaging is great !!! nothing compare to the JE i had in my last engine !!!

spec on the box

the were 650 US , ship to my place in montreal, canada ...

650 US convert to canadian money is 800,48 CAD and them UPS charge me 109 CAN for border fees (the value for the border fees was 300 US)

in total it cost me around 900 $$$ CAN

Edited November 13, 2008 by rbs14kouki

[NYTSKY]

I don't see why you'd 'ditch' pistons in favour of another brand just for the sake of it unless they were rooted or didn't fit the bore any more.

I was going to buy another set of CPs, however these Mahles came up and could not refuse them. Seeing how Mahles a lighter, have a thicker top ring and have Teflon skirts only a crazy man would pass them up over the CPs.

My old CPs i still might use in another engine as the damage was nowhere near as bad as i expected when they were cleaned.

[omega36]

Thanks for this info... exactly what I am also looking for

[omega36]

On this note.. is there somewhere in AU where I can order Mahle Pistons & Pauter rods?

Thanks!

[rbs14kouki]

OIL Squirter !!!

Are they realy important !?!?! cause i have Mahle piston in my engine and the dont clear my oil squirter !!! i could make them fit but it's a pita !!!

the nozzle of the squirter hit right there !!!

what do you guys think !!!

[PHT33]

Have had a friend just rip out his mahle's because the teflon delaminated. Arias FTW!

[s13_Skyline_inside]

bit unreallated, but what do you guys do when the ring gaps are to big, i cant find file back rings anywhere

my engine was on hold for 6 fkn months cause my engine builder couldnt find file back rings, these guys are pretty pedantic though, I work in the industry and email/called je/acl etc and the wholesalers and was told by all to just use the rings that were made for the 86.5 bore size that came with the pistons as i could find file back rings anywhere, as i was sick of waiting for over 1.5 yrs in total for this engine to be put together i told them to use the acl rings that came with the pistons

just wanted to know what your guys take on it would be

Edited May 16, 2009 by s13_Skyline_inside