Asked before but... whats needed for 4mm crank

[01bansheefox]

My cases are already split so i might as well replace the crank with something bigger if major work isnt required. Can i just put in the 4mm crank? i dont want to have to send my engine off to have it worked on for a bigger crank just looking for an easy way to increase hp.

[Oilsmoke]

You will need to have it ported to match the 2 mill increase in stroke to gain maximum

horsepower.

A spacer plate or custom domes are needed to do a 4mill right.

 

If you are looking for more Power Porting is KEY.

[01bansheefox]

Its already ported and polished but its on a stock crank right now. So pretty much to have the bigger crank you need to pay for porting to match and more $$ for a spacer plate, my head is already milled.

Edited January 16, 2005 by 01bansheefox

[bansheefreak]

if your head is milled that means it will be even closer to the piston.. so a 4mil plate won't help much....

[Wallrat]

You don't have to have it ported right now but without porting the gains will be minimal - basically the same as a mild port job. You do however, need to either run a spacer plate or have your head domes cut to accept the added stroke. I just rebuilt my bottom end and threw in a +4 but didn't have the money for porting. Taking the jugs off is easy so I'll be sending those out in a few months. It doesn't matter if your head is milled, they'll be cutting the domes deeper since the pistons will go higher than the cylinders. You'll also need to run wiseco 795 pistons which have the connecting point to the rod moved closer to the cylinder top. Basically your looking at about $425 for the crank, $100 to get the head cut, and then $150 or so for the pistons.