HKS 87mm Pistons wall clearance wanted

Thor

Member
Hello,

i must know how much the piston wall clearance is for the HKS 87mm forged pistons. can anybody help me?

cheers
Sascha
 

frit

Member
Here's what info i have:
On the underside of the piston you should find two numbers, this denotes the diameter of the piston at 20degC - for example, 75 means that the piston is 86.975mm diameter, 80 would mean 86.980 etc.
This is measured 10mm above the piston skirt.
The piston to bore clearance is set at 0.020-0.030mm, this should determine the size of your hone.
Hope that helps
 

Thor

Member
Thanks for the info! i mean that i have seen a long time ago 0.040mm in a manual but i don´t know if it was for the RNN14.
 

Thor

Member
I have take a look under the pistons but there is mark only on 2 pistons 74 42 and on the other 2 pistons 74 43.
 

GTIR-LOZ

New Member
are you sure they are hks does it say hks under the piston, mine said hks under the piston then 87.213 for example
 

frit

Member
That info came from that that e-mail you gave me from HKS loz :-D.
it only says '13' under your ones loz? what size does that mean they are?
 

Thor

Member
yes HKS and 13 is under mine too but i had thought the other value tells something about the measure!
 

GTIR-LOZ

New Member
it def did not just say that under mine take a photo and post it up


the hks instrutions i gave you were right frit, i rang up hks and they sent them to me and the engineering shop used them to bore the block
 

Thor

Member
can i see a pic where i can see the 75 or 80? So at mine only HKS and 13 i can see. My engeneer must know how much the size is of the pistons when they are new.
 

Thor

Member
yeah you have right but when i add the 76 from my pic the piston must have 86.976 or not? how is it possible that my bore where i take off the pistons only had 86.90mm??
 

Thor

Member
Or is it possible that it is the bore size of the cylinders with clearance or only the measure of the pistons?
 
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