Don Q

iTrader: (3)

Hello,

I would like to know the differences as well as the advantages and disadvantages of each.

Thanks in advance

C6C6CH3vo

iTrader: (9)

F1 - big rod/crank ratio

nascar - small rod/crank ratio

jouniu

big rod/crank ratio = high rpm, low tq at low rpm, piston speed relatively slower in TDC

small rod/crank ratio = more tq at low rpm, not suitable for very high rpm, piston speed very fast at TDC, ignition timing more tricky.

Don Q

iTrader: (3)

Thanks for the info guys.

So, when you mean slower piston speed on a long rod engine, does that mean it revs slower than a standard rod engine?

n2oiroc

iTrader: (33)

The differences are very minor in the grand scheme of things. Figure about 300 rpm gain in safe redline speed.

Trever007

iTrader: (1)

Would big rod be referring to long rod? and small rod be referring to short rod?

erald01

iTrader: (5)

Yes big rod=long rod. The difference between the rods is the torque they produce and the mean piston speed. longer rod has faster piston speed and the torque keeps increasing a lot longer than the short rod.

Trever007

iTrader: (1)

So which set-up produces more low end TQ? Short rod?

BLKCarbonEVO

iTrader: (2)

This is what I wrote for the guys asking questions when we were building my LR motor.

https://www.evolutionm.net/forums/8282453-post28.html

My engine build thread

https://www.evolutionm.net/forums/ev...tor-build.html

Mikey