I'm port and polishing my 97 blaster and was wondering do I port the intake and exhaust or what. I've already ported the exhaust but didn't know about the intake.
DIY port and polish??
- Thread starter blasterfinatic
- Start date
I wanted to know because I've studied up on the exhaust port and I'm done with that part and I did a pretty good job and polished it up real good.
Yes I've watched them I had no problem with the exhaust but was just wondering about the intake because I didn't want to go ahead and do it and then ruin it
You can take that cylinder and completely destroy the flow in seconds by going with what "looks best" so just be careful. On the intake you want a 60-80 grit finish or a carbide texture. There isn't much to improve on without getting into it pretty deeply.
Thanks for the info and I ported it then used 220 grit sand paper, then 400 something can't remember exactly what but then used 1000 grit that's what I saw on YouTube then I polished it off.
The polished finish isn't something I waste alot of time on. It gets covered in carbon in a matter of minutes anyways. Just take your time
Not true. A good polished exhaust port will not let the carbon stick to it. AWK posted a pic not to long ago of his exhaust port. After a year of hard riding it had virtually no carbon on it.
It is imperative that an exhaust port be highly polished to allow smooth passage of gases and to restrict carbon build up, that is the reason that ports are polished.
I have seen first hand some of my cylinders get enough carbon build up to cover the polish within 20 minutes of track time. Slow, fast and in between riding had our YZ125's polished exhaust port faintly covered in build up. Enough to rough up the polish. Not saying I didn't polish the exhaust ports properly, just saying it doesn't have to be a mirror to run well.
For example, copy pasted this. "Flow bench testing shows that the difference between a mirror finished intake port and a rough textured port is typically less than 1%. The difference between a smooth to the touch port and an optically mirrored surface is not measurable by ordinary means. Exhaust ports may be smooth finished because of the dry gas flow and in the interest of minimizing exhaust by-product build-up. A 300 - 400 Grit finish followed by a light buff is generally accepted to be representative of a near optimal finish for exhaust gas ports."
"Any time the surface finish is fine enough that the highest protrusions don't stick through the general boundary layer thickness, then improvements on the finish have little effect on air flow. Be careful about polishing surfaces that are likely to carry wet fuel flow. A rougher (like a quality cast finish) can actually be an advantage. The bottom line is that shape is 98 percent of the deal and a shiny finish, at best, 2 percent."
Another great part of an article. I can get these all day. If the research is done, the results will show it. A perfect mirror polish is not at all necessary.
Another great part of an article. I can get these all day. If the research is done, the results will show it. A perfect mirror polish is not at all necessary.
You are right, it is not necessary. BUT if you are already doing it why not do it to the best of your ability. A polished exhaust port with a mirror finish will pevent carbon build up.
The proof is in the pudding. Enjoy.
http://www.blasterforum.com/engine-13/exhaust-port-piston-pics-54989/
http://www.blasterforum.com/engine-13/exhaust-port-piston-pics-54989/
The best of your ability has nothing to do with spending 15 minutes or spending 2 hours going nuts on it to get it to a mirror polish. 400+ grit is just fine and will work well.
I know York is a member of the misfit connection and I am wondering if this is just a way of taking a shot at KOR or is he really trying to post what he beleave a to be real info ?
What I "bleave a" to be real info? This is information I have experienced first hand. If you don't like it because I am a member and site sponsor over there, oh well. Go ahead, pick me apart. I couldn't care any less about taking cracks at anyone. I don't do builder wars. I let my results show my knowledge.
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