Benefits of using 6" long conrods and shorter pistons

[WNX700H]

I am considering building a 1380 eight port but using longer than standard S rods ( +1/4" ) and then shorter compression height pistons 1.248" as opposed to 1.498" compression height.

What experience do others have of this configuration and the benefits experienced?

[Tupers]

The idea is to reduce piston slap at high revs by putting the gudgeon pin higher in the piston and lengthening the rod. Personally I wouldn't worry about it for a road engine as you're unlikely to reach the kind of revs where slap would become an issue.

[Vegard]

THAT is not the main reason for doing it!

[WNX700H]

well one obvious benefit is to reduce the rotating mass in the engine , any others , am also of the theory the rod geometry improves also .....

researching the concept before I decide which approach I take.

[Spider]

I'm sure a few other will jump in with the pluses on this type of set up, however, be mindful that increasing the rod length also increases the Rod to stoke ratio. For a five port head, with Siamese inlet, like on our A series a reduced rod / stoke ratio will have HP benefits.