Mi16 Different Piston Type Question

[Rapiddave 3 1 Cars]

Hi guys

 

kinda new to this site so be nice - lol

 

just recently stripped my 205 mi to change the liner seals as i had a trickle of water running into the sump, i took the liners and pistons out and whilst out decided to give the pistons a bit of a clean up only to notice i had 3x pistons which were stamped with an ''x'' and 1x piston which was flat on the top which had a ''z'' on the top - question is - is this normal to had 3 of one piston and 1 of another ?

[Anthony 1,003]

No. My guess would be that someone's replaced one at some point, probably a complete rod/piston due to spinning a shell.

 

The Z and X stamped pistons differ in compression and are from the non-CAT (D6C) and CAT (DFW) engines, with 10.4:1 and 9.7:1 respectively.

 

I'd strongly suggest fitting a matching set, ideally all Z marked from the non-CAT 160hp engine.

[Rapiddave 3 1 Cars]

any ideas as to where i'd pick up some of these ? or maybe an upgrade ? i have seen a set of 85mm pistons for sale but would i need to change the rods and liners ?

[petert 586]

Wow, that's a balls up. Three cylinders running at 9.7:1 and one at 10.4:1.

[Rapiddave 3 1 Cars]

not had the car that long - had no idea till i stripped it down

[allanallen 528 2 Cars]

http://www.ebay.co.uk/itm/Mi16-PISTONS-CON-RODS-205-gti-309-peugeot-s16-race-rally-track-dimma-xs-rallye-/261228096231?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item3cd2686ae7

[Rapiddave 3 1 Cars]

A mate of mine seems to think I might start getting running issues if I change the pistons , is this correct ? He also said that although mine seems to have different pistons it did run perfectly fine so why change them ?

Edited June 14, 2013 by Rapiddave

[allanallen 528 2 Cars]

Is that a serious question? Your mate knows f*** all clearly, change the pistons.

[Rapiddave 3 1 Cars]

Will do , Cheers for the help , another question I need to ask is that when fitting the new liner seals do I need any other sealant as well or are the seals good enough on the own ?

[Anthony 1,003]

They should be OK on their own, although something like Wellseal doesn't hurt. However, that's assuming that the liner seats haven't corroded...

[Rapiddave 3 1 Cars]

Sorry should have said , I got new seals to go in , also just incase this crossed your mind , it is the 1st time I have ever stripped and rebuilt an engine so anymore rebuild tips would be handy , cheers for all you help so far mate

Edited June 14, 2013 by Rapiddave

[Rapiddave 3 1 Cars]

Also if I change the x pistons to z pistons will I need to do/change anything else ?

[welshpug 1,657]

Other than new rings, nothing.

[Rapiddave 3 1 Cars]

And what piston rings would I need ? Standard ? Sorry I'm a newbi

Edited June 14, 2013 by Rapiddave

[Rapiddave 3 1 Cars]

just been looking through all the pics i took whilst stripping and cleaning it and think i have actually got all ''Z'' on the pistons - not to sure where i've got the ''x'' form tho so gonna have to check in the morn and determine which pistons i have actually got - wow - feeling pretty thick right now - specially if they are all the same