Quick ques about Forge Pistons

[gtirx2]

Imo if you are going to build a road car with forged pistons you are proberly best of using a 4032 alloy forged piston due to the tighter clearences.
HKS pistons are proberly a safe bet as they have been used on many pulsar engines with no problems even 500+bhp engines,they are just more expensive.
The trouble with 2618 alloy pistons is they run large clearences and on cold starts normally slap about and wear the bores.
If you are using it as a daily driver and doing a lot of cold starts or short jouneys it will wear your bores out a hell of a lot faster than a normal cast piston engine.
I am also still unsure on how long a 2618 pistoned engine should really last before you start loseing performance due to excessive bore wear,i have read that in some cases the most you should expect is about 20-30 thousand miles?
You can also get forged pistons with offset pin holes like the standard pistons which help reduce piston slap and bore wear, but are proberly weaker than a piston with a pin hole in the middle.
There are loads of pistons out there so the more you read up on them the better of you will be when deciding on which pistons are best suited for you car.
Then there are loads of other options from anti det/contact reduction grooves,Accumulator Grooves,uprated stronger wrist pins,different ring designs,different squish band designs on top of the pistons,different skirt lengths/thickness and proberly many other options aswell!

 

[BabyGodzillaGTi-R]

Same sentiments as i'm worried of the large piston to bore clearance.
Whole reason i really wanted to go forge is i'm not trying to extract the last bhp out of the car.
i just want the security of a bulletproof engine as i am a hard driver and intend to do track days and the motor is prepared to take hard knockings when the occasion demands for high boost (yes i understand ecu management will be considered too)

End of the day it's a street car but will be driven hard and more of a weekend car.
I wonder what' pistons are Tomei, Jun, Toda, Greddy?
Are they 4032 alloy or likely to be 2618 as i heard they generally require less clearance.
Not much write up i noticed on them.

As for "Caucasian Pistons" lol the brands i can think of that are 4032 are Supertech (i think its from Argentina -USA) and Mahle (Germany)..... Only issues is u don't know if these pistons can clear the squirters.

GTrix2 what pistons did u go for?
I'm still bending towards the CP for the good value. Japs unfortunately coz a bomb with the yen getting stronger.

 

[gtirx2]

I went for wiseco in the end.
Wiseco have the cut out for the oil squirters and also have the offset pin holes plus they are a pretty well speced piston.
Anti det/contact reduction grooves,accumulator Grooves and coated skirts,plus they where in the compression ratio i wanted 9.1:1.
I also went for wiseco as i had heared reports that they are a very quiet piston on cold start which they are,plus they were a good price and in stock in this country.
There is also a wiseco main dealer in this country so replacement parts are easy to get.
I would of sworn by wiseco pistons as one of the best, but recentaly i have stripped down my engine and i have some suspect marks on the tops of the bores.
I have still not got to the bottom of this yet so i am unable to be sure what has caused this yet,but i have had people say it maybe because i did not use a stress plate on the block when it was bored/honed to i am not running the engine hot enuff with these pistons,which i think could be the reason.
The engine had done 6000-7000mile and was running perfect before with 160psi on all cylinders low oil useage and not that much blow by,it just had some suspect marks in the bores so i have had it lightly rehoned and going to put new rings in as everything else is fine, bores still within specs etc so i am still not sure just yet.

If/when i build another engine i was thinking about CP but once again i have seen pics of bore wear in a honda motor and they looked like they had been slapping about quite abit,shiney marks up both sides of the bore but tbh thats what you expect with 2618 pistons.
Are CP's noisey on cold start?

Then there is JE i have heared gtirs with these pistons sound like a diesel on cold start before so i have never really had any intrest in these pistons, but saying that it could of just been a bad build with to larger clearences used?

As for HKS i have never really heared a bad thing about them really,except maybe the price.
Plus if you breck a ring putting them in or want to re-ring it at some point you would proberly have a long wait for the parts to arrive in the country and at great cost.
You also know in the back of your mind that HKS pistons are proberly not as strong as 2618 pistons, but like i said there are gtir's running upto and over 500fwhp on these pistons, proberly more?

 

[GTIR-LOZ]

i broke a piston ring trying to fit the pistons (my compressor was old and worn) took 3 days from japan to get a new set

 

[gtirx2]

i broke a piston ring trying to fit the pistons (my compressor was old and worn) took 3 days from japan to get a new set

That don't sound to bad then,how much did a new ring set cost just out of intrest?

 

[sumo]

i hav Mahle in my car as for the squirters they do move a little bit so when putting in make sure they miss turn engine over slow and i mean slow.
best thing is to get one that are ment for the gtir

 

[GTIR-LOZ]

i really cant remember but it wasnt alot around the 20 quid mark if i recall correctly (which i prob dont lol)

 

[BabyGodzillaGTi-R]

i hav Mahle in my car as for the squirters they do move a little bit so when putting in make sure they miss turn engine over slow and i mean slow.
best thing is to get one that are ment for the gtir

I was thinking of the Mahle pistons too as they look pretty good and light looking at the specs. Also noticed they are coated too and don't require much piston to bore clearance.
But was kinda taken back after reading this article Sumo.
How did u sorted out your squirter clearance issues.
Here's the article again if u missed it.
http://forums.nicoclub.com/zerothrea...93975&postid=0

 

[BabyGodzillaGTi-R]

I was thinking of the Mahle pistons too as they look pretty good and light looking at the specs. Also noticed they are coated too and don't require much piston to bore clearance.
But was kinda taken back after reading this article Sumo.
How did u sorted out your squirter clearance issues.
Here's the article again if u missed it.
http://forums.nicoclub.com/zerothrea...93975&postid=0

Hey gtirx2,
how come u had to open up your engine after 10000KM?

 

[gtirx2]

Hey gtirx2,
how come u had to open up your engine after 10000KM?

Had to open it up a few times tbh:lol:
First i threw 5 rockers then took the head of to check for valve damage and while i was there i crack tested that head and it had some very small hair line cracks between the plug holes and valve seats so i changed the head.
Thats when it all started to go wrong:doh: :lol: the head i used had a rough skim job and being tight at the time i reused the metal headgasket again for about the 3rd time and it leeked:doh: :shock: :der:
Then i changed it again for a standard gasket thinking it would be alright and it leeked again:doh: :lol:
All my fault really cutting corrners but like i said earlyer i am saving all my best bits for another engine and was just trying to bang that one together for a runner.
But all has changed now as i putting a bit more time in on this engine again now.

 

[sumo]

lol i thought u would ask this. what that lad has dune i did to but i put in a copper washer in as well about a 2mm thick one to make sure it clears o u hav to watch the crank dont hit it as well i hav put two engines together this way so far so good o i used a file to do my ones the as the squirters are soft as hell tighten them up when u hav it all to gether as u can make sure they in the right spot hope this helps

 

[sumo]

o and i did not notch my piston