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ValveSpring
08-23-2009, 10:38 AM
Im a little confused on how to degree the intake and transfer ports on my engine. I know with the exhaust port I start at the top of the port and move the piston down and count the degrees until the piston closes the port again. My question is, for the other ports do you start at the top of the port or the bottom of the port?

ValveSpring
Purenitro
08-23-2009, 11:18 AM
You should take all port measurements from the top side of the ports for the open duration.
ValveSpring
08-23-2009, 11:22 AM
Alright, thanks. So if I want to increase the timing of ANY port I need to move the port up right? If thats the case, what are the effects of moving the port down?

ValveSpring
Purenitro
08-23-2009, 11:29 AM
Not sure how you would move the ports down, unless your talking about cutting the bottom side in which case you will gain nothing. Don't touch the bottom of the exhaust port or it may open a window into the block at tdc which will have a negative effect on performance.
ValveSpring
08-23-2009, 11:31 AM
Thanks Pure for the help. I'm just learning how to do this stuff and from what I have read you are the best in the business to learn from. Thanks again.

ValveSpring
Purenitro
08-23-2009, 11:35 AM
No problem, what engine are you working on?
ValveSpring
08-23-2009, 11:40 AM
Its an Axial .28 spec 1. I really had no plans on modding it until the mid range needle fell out of the carb while running. Since I had to take the engine out any way to clean it, I thought what the heck lets try some modding.
Purenitro
08-23-2009, 11:54 AM
Just be very careful as it is extremely easy to mess up, I say if you can't walk to a garbage can and toss your mill in and walk away, don't mess with it. I have worked on previously modded engines that were ruined and needed new parts just to run right again. Take your time and just remember that clean up of your grinding is just as important as the grinding itself. Good luck.
ValveSpring
08-23-2009, 12:00 PM
Great advice!! I actually have a new piston and sleeve in my shopping cart at tower just in case I ruin it on my first try.

ValveSpring
ValveSpring
08-23-2009, 12:21 PM
Here are some pics of the sleeve.

http://i598.photobucket.com/albums/tt61/ValveSpring/IMG00043-20090820-1844.jpg

http://i598.photobucket.com/albums/tt61/ValveSpring/IMG00042-20090820-1843.jpg

http://i598.photobucket.com/albums/tt61/ValveSpring/IMG00039-20090820-1838.jpg
Purenitro
08-23-2009, 12:41 PM
Kinda looks like my K4.6 mods from SC, have you run this sleeve yet?
ValveSpring
08-23-2009, 12:45 PM
Thats where I got the ideas from. I have not run it yet, still waiting for the carb needle to come in. I have put the engine back together so I can run it before I make any timing changes. Should I make any porting changes next time I have it apart?

ValveSpring
Purenitro
08-23-2009, 01:13 PM
The porting looks like it's all done, no need to change anything. Did you try running the piston up and down in the sleeve before you put it together? If not I would take it apart and try it. It "looks" a little rough from the pictures but it's hard to tell for sure.
ValveSpring
08-23-2009, 01:17 PM
The pictures are before the full polish was done. I also very lightly debured the inside of all the ports. The piston moves nice and smooth.
Purenitro
08-23-2009, 01:55 PM
Good, should be ready to rip then.