Piston Coatings Worth It?

Rishi

Still waiting on some shims!
Its down to the material of the piston. As Rob says some expand more than others. 4032 (low-silicon) or 2618 (zero-silicon) .

Rishi
 
O

Odin

Guest
CruiseGTi-R said:
...which for the non-material scientists amongst us translates as non-rattly or rattly :-D .

Nissan Pulsar GTDi-R

LMFAO :lol: :lol: :lol: :lol: .



Good one Toby :thumbsup: .




Rob
 

Rishi

Still waiting on some shims!
4032 - is a low silicon piston. These are more for street applications. Low silicon pistons expand less and so can run tight clearances as with the likes of HKS. However the 4032 piston can become brittle under extreme stress and crack. If the 4032 starts to crack it continues and causes mass failiure.

2618 - is a zero silicon piston. There are more for higher power/pressure applications. Zero silicon pistons expand more and so require greater piston to wall clearance like the JE and CP for example. This can make them a little more noisy on cold start up. However they will handle greater pressures. In the unlikely case where a 2618 piston were to develop a crack it would lead to a lower point of stress and stop. The piston would still work fine..


Rishi
 

gtirx2

Active Member
I also thought the slap had something to do with offset pin holes on the pistons aswell but i could be wrong?
Have the hks pistons got offset pin holes or are they like the je's with the pin hole in the middle of the piston?
 

CruiseGTi-R

Member
Interesting.

Did a bit of digging around on the net. It seems that 2618 pistons can wear rings slightly quicker and have higher oil consumption and blow-by. BUT, this is only during start up, once warm they are said to be a match for the 4032 alloys for those criteria.

It looks like 2618 alloys pistons are better suited for kicking the sh*t out of - higher rpms and ultimate temperature but the 4032 seem to be more stable with regard to controlling ring gaps and clearances.

The crack propogation thing is a good point, and it seems the 2618 have more chance of holding up against a full crack failure, but thats under very extreme conditions, which is why I guess they're suited to enormously tuned applications.

Wiesco, CP, Arias and JE all use 2618.
 

CruiseGTi-R

Member
Apart from coatings for the JE pistons, which options did you ignore when ordering:?

(from TopEnd site)
Options: Items with * are recommended for Turbo and NOS use
*Add $20 per piston for Total-Seal Gapless rings
*Add $40 per piston for High Heat Ceramic Coated crowns and Moly coated skirts
Add $15 Per piston for Lightweight Heavy Duty Wrist Pins
Add $18 Per piston for Lateral Gas Ports
*Add $8 per piston for Contact Reduction Grooves
Add $6 per piston for Accumulator grooves
 
N

newbie2

Guest
i have no idea what options come with my pistons i bought them second hand on ebay !!
i bought these
 

CruiseGTi-R

Member
That is one of the options they list elsewhere. Confusingly some say they'll clear, others say they won't, but who's to know what options were included at time of order.

i.e. if you order them off ebay they may or may not have had the clearance machined in.
 
N

newbie2

Guest
i made sure they had the oil squirters cut out before i bought them.
i can also live with them being noisy on start up (im used to diesels) ,i will be safe in the knowledge that i put the stronger pistons in and will have a very strong engine.
 
O

Odin

Guest
oap-r said:
£365 for 2nd hand pistons :shock: :der:

Almost as bad as the two people who paid £90 for a tow eye cover and £102 for a pulsar umbrella :shock: :doh: :der: .

Don't you just love ebay.





Rob
 
N

newbie2

Guest
oap-r said:
£365 for 2nd hand pistons :shock: :der:
i bought them as i wanted some asap and couldnt find any cheaper in this country at that time, im not 1 for waiting around.
i should be making close to 500bhp in the next few weeks ,not years!
 

stumo

Active Member
oap-r said:
£365 for 2nd hand pistons :shock: :der:
that's just fcukin stupid. you could have had NEW pistons from the states within a few days.

Jeeez, there's lots of mongs about and you don't have to look very far.:der:
 
O

Odin

Guest
newbie2 said:
.
I should be making close to 500bhp in the next few weeks ,not years!

And exactly what else have you done to you engine/car to make your 500bhp goals a reality ?.

Because I know what I've spent to get their and make the car reliable ish at the same time ;-) .



Rob
 
N

newbie2

Guest
going to get it mapped in the next few weeks looking for 500bhp.
beat that 1 bar boys.
torque is very low though, so going to see if i can get that sorted.
 
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