Chamfering Ports properly how to 2 stroke.MOV
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- เผยแพร่เมื่อ 21 ส.ค. 2024
- How to Chamfer port windows on a 2 stroke correctly, also known a putting a bevel on the edge of the port. Specifications and dimensions on properly chamfering (bevel) a port window. How to radius and recess a bridged port window correctly. Instructional how to for 2 stroke porting and polishing, brought to you by CC Specialty Tools.
Thanks man! It is a step in porting and top end rebuilds that I feel tuners need to take their time and be sure to get right.
You're exactly right buddy! Especially on the part about leaving burrs at the 1:45 mark in the vid. I had a friend who did that and the burrs messed with his ring ans of course, ended up ina scored piston and a ruined engine. I tried to purseude him to watch your vid first! He didn't listen to me, I tried to warm him. Oh well, you cant fix stubbornness I suppose. Great vid my man!
Ya'll make great videos. Keep up the good work.
+TheClintmeister Thank you and thanks for watching.
Not too many places out there that can point out over 10 World Speed Records and World Championships that were won or set by customers specifically on their Users List!
Sir, you inspire me.. I ride Yamaha TZM 150..
Thank you and thank you for watching. Hope this helps if you decide to do a little porting and polishing work
+CC Specialty Tools I did.. Last week.. Changes a lot of things.. I used to tweak my bike, & now I hv to tweak another which is not mine & there are others waiting for their bikes.. Its a blessing & a curse.. Haaha~
oniyukiyasu ! how to increase the tzm speed tho
Look at the Tips and Techniques from ccspecialtytool and look at Tips from TJ
Hi, nice video.
I have a couple of questions. I just chamfered the edges on my 1989 yz125 with a spherical diamond bit and a straight shaft hand NSK hand piece and then used a tiny buffing wheel with polishing compound to finish them off and remove the burr. I do a finger test to feel for sharp edges and judge that way. I have not assembled the motor yet and can make changes if you recomend. I it would be good to see a photo or video of the actual idea chamfer up close.
I know the challenge to get grinder and burr at the correct angle, even, and steady (climb cut and vis versa). How is one to get the such acuracy to have the correct depth and lenght of chamfer? Are these numbers ideal and a goal? Better to error on more chamfer? and what are the pitfalls of a larger chamfer?
I am assuming the larger the chamfer the more the port timing and time area is changed. On chain saws I consider the start of the chamfer the opening of the port. Saws have smaller bores the the ring bulge is less so my chamfers are smaller. What do moto guys think?
The last question is with the intake bridges, when you bore and hone the cylinder, can you bore .003 deaper at the bridge to compensate for expansion or is the extra chamfer going to help componsate for the material swelling?
Thanks for watching and the great questions.
I do have some videos on this channel that show the three steps that insure a great chamfer or bevel to the port window. You don't have to go through all three steps though, you can combine them a bit, the way you did, and I think your process will work just fine.
As for the challenge of the correct angle, depth, and length of the bevel, I can give you a few tips. A Right Angle Porting Tool, used with a diamond bit, approached with a slight angle back and to the side, seems to work very well. However, if you can reach the areas and get the correct angle, in particular the Transfer ports, with a straight hand tool, then I think that would be OK too. If I am having a hard time telling just by sight or feel on a chamfer (or other measurements for that matter) , I will take Dykem, layout dye, or even marker, and mark up the edge of the port window again, so I can have some contrast to the metal to go by. I have also "engineered" a little measuring device out some scrap wire or metal to use as a gauge to run along the edge and make sure I am keeping all the bevels true and consistent. Of course, like I say in the other videos I mentioned, going by feel works pretty well too. The numbers I give you on here are not the "Law", by any means, but they have worked extremely well for many tuners over many years. I don;t feel that more chamfer is better, just because you might start throwing off some measurements and such, but I am sure there are people that will disagree with my opinion.
You could consider the edge of the chamfer to be the upper point of the port window in relation to timing, but that can depend on depth of the bevel. You see if the depth is only slight (less than the 0.5mm maximum mentioned since you said you are making the bevels smaller relative to the smaller size of the chainsaw cylinders) then the port may not be fully opened during the descent of the piston until after the maximum expansion of the piston ring into the port is reached. In other words for the first 0.5 mm or so of the chamfer,( in the y axis) the piston ring may be riding right up against the aluminum, depending on the depth into the port that is used.
I would also mention it is a good practice to work toward a slight "rounding" or a slight radius curve to the port edges, this provides better gas flow an a less abrupt transition for the piston rings. I point this out at 4:47, but I probably should have spent a bit more time in the video going over that fact.
As for the small recess to the intake bridge, I recommend the slight arc I show above. This will be more consistent with the minimal expansion of the the bridges. Hope this helps.
TJ @ CC Specialty Tools
Good video pity about the echo.. echo.. echo.... echo..... echo....... echo...
***** yeah part of the fun of doing a video in the work shop. Thanks for watching
CAN YOU DO A VIDEO ABOUT CASE PORTING?
Which tool do you use for chamfering, electric, air etc
+d1977j we use a flex shaft electric, simply because this set up gives you more rpm control for better precision. However I think you could use whatever setup works best for you.
you do have videos in spanish?
+Hipolito Lora Sorry, I wish we could do other languages.