Port timing

[Nieskes]

Right now the motor is dune ported with stock stroke. Im getting 4mill crank this spring and I am wondering how much the port timing will be off, and how it will affect how it runs. I get a different answer with everone that I have tryed calling. Any input would be great.

[BigRed350x]

Right now the motor is dune ported with stock stroke. Im getting 4mill crank this spring and I am wondering how much the port timing will be off, and how it will affect how it runs. I get a different answer with everone that I have tryed calling. Any input would be great.

 

Generally once you're ported for a stock stroke you can't get them set up for a 4mil. Not very easily anyway. Give Kevin at Herr Jugs Racing a call and he will give you an honest, straight-forward answer. Most builders will want to see your cylinders and take some measurements before they will give you a definitive answer. I would give him a call. He won't steer you wrong, and won't try and sell you something you don't need.

[FASTOYS]

It really depends on how it is ported for stock stroke. Who did the porting on it before ? They would be the ones to ask as they did the porting. Generally all the ports will need changed to go to a 4mm and have it run optimal. The transfer height is usally alittle high on a stock stroke dune port to work correctly with the 4mm and you will need to lower the ports for a 4mm along with changing other porting. Will it work just bolted on ? Maybe, but prolly not effiently . : ( Need to get with a builder on that one. Get with Kevin, myself , or any of the HQ sponsors on here for help as a 4mm requires a bit more work and checking to make sure you get a great running combination !