172-200 engine bottom end.

[gez 172]

Hi all,

just a quick question. Are all F4R Pistons/Rods the same? Or are they different?

As in would a 172 Conrod or Piston be the same as the 197/200 Pistons/Rods?

Im 99.9% sure I know the answer is no, but I thought I'd ask to be 100%

I know the engine code itself is different, the 197/200 is the F4R830 and the 172 is F4R730??

Can someone clarify.

Seen some parts listed as 'F4R' but nothing else.

 

[Carbonraider]

I know the pistons are different although I'm not 100% on the rods they may be longer.

 

[Dan@SJM]

Rods are the same

 

[Chip-mk1]

Rods are the same length, but some pictures laine I think it was put up showed the later ones to be a little heavier.

Pistons are much higher comp on the later engines, they are raised up in the middle to poke right into the chamber, later head is a bigger volume to drop the cr back down a bit, if you put the late pistons with an early head it ends up at about 12:1 iirc

 

[gez 172]

Thanks for the input guys

so that clarifys that the rods are the same

with regards to the pistons, would Wosner high comp pistons be the same compression in a 172 or 200. Or would the 1*2 high comp ones need to be a different compression?

 

[Chip-mk1]

Different CR mate as the 197 is a slightly larger chamber volume as per my previous reply.

 

[gez 172]

Cheers for clearing that up Chip I thought I'd just clarify

i won't bother in that case then. They are just listed as 'F4R' so chances are they'll be for a 1*2 rather than a 197/200

cheers guys