5 valve engines...

[quikcobra]

If I recall Yamaha started this in the R1. Then it took off.

 

[Kdawg532]

cool cool thank you very much

 

[blackbronc]

Yamaha has been using the 5 v heads on dirt bikes for 10 years and longer on street bikes. The 8v with oblong pistons was a honda roadrace design from the 70s. They were smooth, fast and very competitive. Machine work for the cylinders was considered too expensive for production.

 

[BlackBII]

Audi made a 5 valve as well:

They used one back in the 80's for the Group B rally cars, I believe.

 

[Ranger5.0]

I was watching the powerblock today and they were building up a 4.6 they had sleeved and bored to a 5.0. Stock block, stock crank, and stock CNC ported heads. I missed the dyno test though.

I think it was just under 450 hp

 

[jonsranger]

audi still uses a 5 valve engine, my brother has a a4 i think that has the v8 5 valve engine. its not incredible fast but itll get you where you're goin in a hurry.

 

[86ford]

wow, thats like over a .1" overbore

sounds like a piston going up and down inside a aluminum can!

86