Anyone use Nippon FRM pistons?
04-04-2018, 02:36 PM
#21
Lets look at things with logic, an unmolested bore is 87mm the FRM liner is .5mm his piston is .5mm over. When the cylinder is bored out .5 over there won't be .2mm which is the boring service limit, but rather you will have ended up removing the FRM sleeve entirely. If the bores are that messed up, you might as well sleeve the block, at that point FRM pistons become a moot point unless you can find FRM sleeves.
04-04-2018, 04:29 PM
#23
A carbon fiber preform is filled with moltem aluminum under controlled pressure and speed to create the casting. Afterwards, it is heat treated and machined to final bore size. As far as I know, this can only happen when making an entirely new block, but please correct me if I'm wrong.
04-04-2018, 07:03 PM
#25
I think what he is saying is that having 0.50mm thickness all around the cylinder would leave 0.25mm total after overboring (0.25mm each side)... not sure if that makes sense lol
04-05-2018, 03:08 AM
#27
The amount of misinformation here is tremendous.
FRM is NOT the same as Nikisil. FRM is a composite, the block is cast around it. I've cut up several blocks, the frm is between 2 and 2.5mm thick. Boring them out is no problem.
The main problem here is the oversize pistons may hit the head. The 87.25 look like they have the stock chamfer on them, but unless they made the chamfer a little more aggressive on the 87.5 and 88mm pisotns they will probably hit the head.. They come 0.040 out of the block, headgasket is 0.030, they come 0.010 over the gasket. The diameter of the chamber is 86.5mm give or take some core shift..
These pistons will work fine. I've been using nippon pistons in h22's since they started selling them.
Nippon racing pistons are typically made right where the factory pistons were with the same materials and everything.
FRM is NOT the same as Nikisil. FRM is a composite, the block is cast around it. I've cut up several blocks, the frm is between 2 and 2.5mm thick. Boring them out is no problem.
The main problem here is the oversize pistons may hit the head. The 87.25 look like they have the stock chamfer on them, but unless they made the chamfer a little more aggressive on the 87.5 and 88mm pisotns they will probably hit the head.. They come 0.040 out of the block, headgasket is 0.030, they come 0.010 over the gasket. The diameter of the chamber is 86.5mm give or take some core shift..
These pistons will work fine. I've been using nippon pistons in h22's since they started selling them.
Nippon racing pistons are typically made right where the factory pistons were with the same materials and everything.
04-07-2018, 12:02 AM
#30
I believe they used diamond stones. Also learned that the Nippon piston pins are not DLC coated, so they are not compatible with the OEM rods. Fortunately, the OEM pins fit the Nippon pistons. Another option is to simply apply the needed coating to the pins.