bassboy

hi there, i was having a chat with a few people and was wondering what you recommend...

i am building a zetec turbo engine and was wondering what pistons to use...they will DEF be connected to steel rods which i can sort out without a problem...however, the pistons is whats rising some questions...

I was originally going to go for pistons along the lines of CP, JE, Arias etc however after speaking to someone, they recommended me using Calibra Turbo pistons...

he recommended me these as they are strong and made by a very good known company - MAHLE...he said they can be skimmed to whatever CR necessary and i can get them for a fraction of the cost of the above named companies...

However, i have read people say in the past that the pistons are only ok up to certain HP levels...IIRC Calibra pistons were rated at about 300hp...

what is it that makes the piston give up at this point or is there not a HP figure given on them and people have mislead me? I would have thought its more down to the fuelling, management, MAP etc that will determine the end life of a piston through whether or not the engine is detting or not?

I have thought of going for the Focus Central pistons and Eagle rods however after having a number of emails from the manufacturer, they told me that the pistons can not be machined down...hence me not being able to get the correct CR that i require (they come as 8.x:1 cant remember exact figure)

So is it worth me using the Calibra turbo pistons (MAHLE), or shud i go for a different make like Arias etc which gonna cost quite a bit more money?

thanx

bassboy

Alps Pacino

i put accralite pistons in mine, they can be skimmed to suit to. only about £500 aswell but dont know what there like cause it aint running yet

bassboy

i heard u get alot of piston slap (or something like that lol) with accralites? especially from cold

bassboy

Alps Pacino

i aint heard out bad abvout them till now, hopefully they will do the job

bassboy

lol they shud do the job fine...oh and i forgot to mention in my original post - im aiming for well over 300hp!

bassboy

Alps Pacino

wont 300+ be a tad tricky to drive or get of the mark. Wont 250 t0 300hp be a more reasonable hp to aim for, for driveability. only my opinion by the way

bassboy

alps...yep it wud very difficult however i have spent alot of money on suspension, and will be spending alot of money on the gearbox/diff/management etc to help put the power down as smooth as possible...will also use mappable boost to help get off the line cleanly...and help save the gearbox and clutch

neone else know an answer?????

bassboy

Garage19

That tends to be a feature of alot of forged pistons in general.

I would go for something like a JE/arias piston. Rather than just skimming the tops off and loosing your squish these companies will custom machine a dish in the head to your spec to give you more chamber cc.

Its worth contacting AustenWesty on this board. I believe he uses custom Arias pistons in his ZT.

PhilM

If the FC's 8.2:1 is too high a CR for you, look into Arias/JE pistons for the Focus, still use Eagle rods then, and the exchange rate is very favaourable

DONT use Calibra ones imo

bassboy

phil...we'll talk on messenger

bassboy

PhilM

turbomondy

use the cavalier/calibra pistons and bore it out to a 2.1 that will be ok for over 300bhp

bassboy

turbomondy...are they what you are using? (if you have a ZT lol)

bassboy

turbomondy

i will be using 2ltr redtop cavalier pistons which i havnt put together yet. the pistons will fit straight onto the zetec conrods but you will need to get the engine bored to a 2.1 if this is done you should be capable of 3-350bhp and a cr of 8.2:1 which is what im after. just make sure you replace the conrod bolts as tha standard bolts are crap and wont last.

PhilM

Do they? These are the NA XE pistons? Ie, flat dish, very shallow?

They wont fit straight on Zetec rods......Zetec rods are pressfit pin, you youll need someone to heat the rod to remove the original piston (destroying it in the process), and then bore the rod's small end out, and again heat it, to interferienace fit the Vauxhall pin into the rod.....

Not what id call a straight fit!

turbomondy

like i said i havnt actually done this yet everything i have is in boxes at the minute im just going on what i have been told when i brought the pistons.

bassboy

engine is going to be bored to 2.1 regardless as 86mm pistons will be used...however, i am unsure how the calibra turbo pistons will run at 300-350hp as i dont know anyone who has tried them at this level...and i dont really fancy being the first

I will be speaking to IH about Arias pistons and see if he can sort me a set of them out and prehaps go for the eagle rods (as discussed with PhilM )

oh and turbomondy, as PhilM said...they are not a straight forward fit and require a fair bit of machining work to fit correctly...hes done all the fancy technical talk ive just kinda simplified it

bassboy

Jasesapphy

iTrader: (1)

calibra and cavalier are 86mm pistons, thats what they suggested for the 2.0 14 engines but the calibra turbo pistons dropped the CR too much

PhilM

Rudey, bit early for me m8

As for testing, well, several engines ive been involved with have got various combinations of rods and pistons. As for R&D/testing CRs have been measured. You can of course test various things, such as ultimate limits, however thats very costly, everyone wants proven R&D, however, noone wants to pay for it on forums, yet they expect definitive answers .

Myself and B19 TRB run the NA XE piston in 2.1 zetecs.
Ian runs the Calibra piston in his 2.1. (I believe Lee @ Fusion does also now)
Matt M and Josh run the FC pistons with Eagle rods in their 2.0Ts.

All run fine and have no issues I have heard about yet. All I can say is in my opinion at wht point id use which pistons/rods......without ultimate testing we wont know the "failure point".

At the end of the day, go with what your engine builder or mapper says.

bassboy

rudey...still waiting for the suspension been 7-8months now!!! started to get a bit impatient now!

regarding the r+d about the pistons....no one i know has done the necessary testing needed for the results i/we need however just wondering through everyone's experiences, what they are using and achieved...only person i know who might know more about the testing side is Sunny...but hes kinda unavailable at the time being

that IH bottom end...is that including steel crank or just the rods and forged pistons?...all i need are pistons...maybe rods if he can sort out a good deal or ill get those else where

jasesaphy - what did the calibra pistons drop the CR down to?

phil what make are the NA XE pistons?

bassboy

PhilM

Mahle. Id not recommend them for your engine mate. Too high CR and id use them much above 280-300bhp.

bassboy

no probs phil anyone got IH's number?

bassboy