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Would Hks rb28 rods fit in rb25?

Frozengrip
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Piggaz Grand Master

Piggaz

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Posted
1 hour ago, hardsteppa said:

You would need the crank too...so no longer a budget build.

Incorrect.

 

RB25, RB26 and the HKS 2.8 use 121.5 mm rods. From memory the RB25 NEO ran  RB26 rods from the factory. HKS get away with using a factory length rod while using the 77.7 mm crank by moving the pin in the piston.

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BK Grand Master

BK

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No, all 2.8 rods are not the same as stock length. There are Tomei, Spool ect. that have 119.5mm conrods for 2.8 strokers with 77.7mm cranks that use standard pin height, so be careful. All we're saying is the HKS ones specifically are 121.5mm standard length, like the Nitto rods for strokers. Most strokers actually will have different length to standard.

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Frozengrip Contributor

Frozengrip

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Thank you for clarifying that for me BK, now I done a bit of research on the rods and seems they come from the Hks 2.8 step zero kit. So pretty stout rods. Now another question, maybe an arrogant one but would I be able to use these rods paired with other pistons other than the Hks ones ?  

Piggaz Grand Master

Piggaz

Posted
Posted
37 minutes ago, Frozengrip said:

Thank you for clarifying that for me BK, now I done a bit of research on the rods and seems they come from the Hks 2.8 step zero kit. So pretty stout rods. Now another question, maybe an arrogant one but would I be able to use these rods paired with other pistons other than the Hks ones ?  

All depends on pin height. 

Piggaz Grand Master

Piggaz

Posted
Posted
15 minutes ago, Frozengrip said:

on the rods the pin bore is 21.0 so need some pistons to align up with that specifically, yes?

That’s a seperate issue all together.

Wherr the pin sits in the piston itself. If the RB25, RB26 and some RB28 kits use the same 121.5 mm rod but have different stroke lengths then the difference must be where the pin sits in the piston considering they all go in the same height block.

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Frozengrip Contributor

Frozengrip

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Posted
7 hours ago, Piggaz said:

That’s a seperate issue all together.

Wherr the pin sits in the piston itself. If the RB25, RB26 and some RB28 kits use the same 121.5 mm rod but have different stroke lengths then the difference must be where the pin sits in the piston considering they all go in the same height block.

ok ok, think I get you. So considering the rods for all those different stroke lengths are the same Length then I assume they would just work with my choice of forged rb25 pistons ?

Piggaz Grand Master

Piggaz

Posted
Posted
1 hour ago, Frozengrip said:

ok ok, think I get you. So considering the rods for all those different stroke lengths are the same Length then I assume they would just work with my choice of forged rb25 pistons ?

Can’t see how it couldn’t if you get pistons for a RB25.

71.7 mm stroke

121.5mm rod

RB25 piston

its the same geometry as a factory RB25.

if you got a piston for a RB26 or a HKS 2.8 it wouldn’t be right.

You can use any length of rod, crank and piston pin height you want, just need to make it up or lose it in another area.

At the end of the day you have the same length rods as a factory RB25 even though they’re out of a 2.8 kit. Just so happens that it all works.

Have you considered sourcing a stock RB26 (73.7mm) crank and pistons? If you’re buying pistons anyway, get a crank for a cheap stroker kit. 

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Frozengrip Contributor

Frozengrip

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Thank you for the detailed response piggaz! Glad it’ll be able to work since it’s a great deal I found on those. Not needing a rebuild at the moment but can’t let these slip noe knowing they’ll be good for my application.

and for the rb26 crank and pistons , I have given the idea a go but since I’m in the states it’s a little more difficult to source one. But ill see as time goes. 

 

 

 

Thank you!

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