2 stroke transfer ports information, along with porting and polishing tips
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- Опубліковано 28 сер 2024
- Information about the transfer ports on 2 stroke engines. An explanation of the how the transfer ports on a 2 stroke cylinder work, along with tips for porting 2 stroke transfer ports. 2 stroke transfer port timing and trajectory are critical to power production results.
brought to you by CC Specialty Tools, world leader in porting and polishing tools.
Thank you very much for your help in getting my porting skills up to speed. 2 stroke engines are the best. Light, simple and elegant design. The sheer fun and adventure of trying to get the most speed and torque out of a small displacement engine is awesome.
Thanks again. I need to get some more porting tools soon to continue some bike projects. Happy chamfering to you.
Totally agree! 👍
Simplistic, Beautiful Engine. I could have not said it better, mate. I am buying all my cylinder tools from you in the future. Thank you so much for informing the world of these hard to find tools, for civilians that tinker with the little cylinders. I tinker with 50cc only and the smaller the cylinder, the smaller , more compact the porting tools I need to get into every tiny transfer port. Great Video and Thank you thank you thank you. RH DSD
I really like your CC porting tools it makes life easy.
Glad to hear it!
WOW CC Specialty has a UA-cam channel?!!! SWEEEEET!!!! I absolutely love your porting tools and have been using them for years!
Awesome video, lots of great tips. I'm going to try my hand at porting a Honda CR 125 cylinder and this definitely helped a lot. I'm just planning on smoothing out the transfer ports and exhaust port to keep things simple, not planning to get very close to the actual combustion cylinder since I only have a regular grinder, not an angled one. Thanks for the tips!
Great video!! I need to check out those tools and buy some. Thanks again for a very informative vid. RH DSD
Thanks for watching. We are easy to find at ccspecialtytool.com . The biggest names in porting and polishing, all over the world use our tools daily.
👍🏽
Looks like a pre 88 KX500 jug, the later model comes factory with plenty of casting slag to clean up.
Great motor, I have a 97, the KIPS work well if it clean.
Great Info thanks , I want to have a go at porting our YZ144 Athena barrel for some more top end over rev , but have been hesitant for obvious reasons , haha
awesome video! love learning about these 2 stroke motors
First in Love ( 🇮🇩 INDONESIA )
Ok I see that this is possible by looking at your web page. Glad I found your youtube and web page.
love the explanation at 2:30
Very Informative video! well explained!
Thank you and thanks for watching
I was initially thinking gee thats dudes a proper black fella!
MotorClassics Lol exactly what I thought. Very dark one too
😂😂😂
Very helpful info with how the transfer works. One question about the water jackets. Can I open the water jackets some to help the engine run cooler by moving more coolant through the jackets? Doing this would probably mean I need a bigger coolant reservoir. The plumbing or delivery system would need to be able to deliver more coolant. My drag sled heats up more than I like. I may watch some of your other vids and try changing the transfer slightly on a older sled I have. Always looking for more torque.
I have used the CC tools to improve the cooling paths and water jackets on many of my 2 stroke projects. I have also used them to improve the oil inlets and paths on other projects. Just remember to consider the structural integrity of the cylinder you are working on. If the walls get too thin you might have some problems.
EXCELLENT INFO!! THANKS!
+Miguel L Thank you for watching.
More content like this would be awesome!
Yep, I figured I wouldn't mess with the top of the exhaust port too much since that is where the power valve slides, but thanks for the heads up. Mainly I will focus on getting rid of any casting imperfections and roughness. Hopefully all goes well!
Thanks for watching. Starting out simple is a great idea for your first go at porting and polishing, so great plan. Remember the crank case outlet, gasket, and transfer inlet are critical areas to get matched for smooth air/fuel flow. Also most CR 125 cylinders have a power valves so watch closely when you are working on the exhaust port.
That was a great video but Now I’m scratching my chin wondering where I can make improvements on my 2004 cr85r cylinder. Any tips for this cylinder?
Unfortunately there is less of a database for information about the little Austrian Puch, However engineering and physics still work the same for all cylinders. I believe the downward trajectory of the transfer windows to be a less ideal design, and like many things on early 2 strokes, there is room for improvement. My opinion is an upward and away from the exhaust port trajectory would be better. Better Schneurle loop scavenging, and better power production. But that is my opinion.
Yes you can get a lot of Power out of a puch maxi. We even got puch maxi races in Austria ^^
So it’s best to think more in terms of angle than volume
Yes sir increasing cross-sectional volume, after a certain point, would only come into play if you increase the displacement By Boring the cylinder or increasing the stroke.
Lets say you had an atv engine and wanted to repurpose it for a street bike... what engine characteristics would you aim for and how would you alter the ports ?
Excellent question and that all depends on your starting point, in other words what kind of cylinder are we starting with , like a 250 banshee, or like a kx500 . Then you need to decide if you want high RPM horsepower or low end torque. Either way you port your cylinder differently. Please go to our website and look at my tips and techniques section. This will probably help a lot
@@Ccspecialtytool i will definitely read up on your site. I have a 1998 blaster 200 engine in very good condition. I was hoping to get a dt200/wr200 top end so i could get the power valves which i assume would help alot in repurposing the engine for street, but it seems theyre hard to come by and now it looks like ill just have to stick to standard blaster engine and maybe some porting in the right direction. Since the blaster already has good low end and power band is relatively flat and broad, im hoping that changing the gearing ratios should be enough ?
Are there gains to be made on a modern 2 stroke motocross bike? Or has the factory tuned them to the max?
Thanks for watching and yes there are always gains to be made. Another aspect of it it's not just horsepower increase but tuning the cylinder for your preferences. Some people want high RPM horsepower oh, some people want low end torque oh, some people just want to go faster. Doing the hard work of measuring and blueprinting a cylinder, crankcase, piston, and carburetor can always be used to improve the engine efficiency
Hey man I enjoyed the video but I have a question, So I have a little Nic on the timing side of one of my ports but feels completely smooth when rubbing my finger over it. Will that have a major effect on how it runs? It's a cr85
Top roof I think you called it
Is that an 86 KX500 cylinder you're demonstrating with?
KX 250. Thanks for watching
*Im actually buying a couple 2stroke motors at a discounted price arriving w/top end unassembled so Im wondering if I should do port work to it before putting together if its worth it or not????* Maybe just cleaning it up a polish without taking any real meat off.
There is absolutely a lot but can be done. Casting flaws , gasket mismatch, and improving the texture of the intake to better optimize flow, just to name a few
Can something like a small flex hone , Brush Research BC9M32 FLEX-HONE®, 0.354" (9mm) Diameter, 320 Grit, Silicon Carbide Abrasive (Pack of 1) be handy for smoothing ports ? Cheers .
I have just finished rebuilding a 57 Puch RLA 125 bottom end, and after watching these videos (and doing a lot of reading - bell + jennings etc) I thought I'd take a look at the barrel from the RLA, the transfer ports have a lip that angles the charge down towards the crankcase (or down at the piston crown) not across the top of the crown or even up towards the head like I've seen written in the books) is this just sloppiness or some special design? did they machine the transfer tunnel too deep?
Hello I want to ask I have a 66 CC 2 stroke motor what I did was I not the piston itself with a boost ports are about 1/8th of an inch and angled them the best I could to angle the boost port . now when I did this I noticed that I lost compression but I have to say I did notice that it idles much better revs much higher and much faster and it does seem that I gain more horsepower now I didn't put a second gasket on the bottom where it meets the crankcase and I don't know if had to or not but I did not touch the skirt of the piston on either the intake or the exhaust side. basically my question is, is what I did bad? will I have trouble down the road? is it affecting anything as far as not exhausting correctly by doing this? technically it seems the same as raising the boost ports but I just lowered the edge of the piston instead I would love to hear your input on this thank you
Anthony P Thanks for watching. Not 100% on what you are asking, but I can give you a few facts that might help. If you modified the piston crown with bevels or "ramps" then yes you decreased compression, by increasing the volume or area at TDC, since now at TDC the potential "space" for the gasses has increased, thereby creating less compression of the same volume. That however may not be such a bad thing. The resulting effect would be similar to changing the port timing, and if the results are advantageous, then well done on your part. The other advantage is that swapping out a piston is often easier and more cost effective than swapping out cylinders. The gasses are now able to escape out the port openings at an earlier point in the combustion cycle, this changes port timing, while not exactly the same effect as increasing port size or raising the boost ports, very comparable none the less. Changing the gasket thickness at the base of the cylinder will also effect compression, thicker gaskets decrease, and thinner increase(but often not as much as people assume). The gasket thickness can also have a negative or positive effect on port timing. Hope this helps, and if you like the results of your changes I would recommend keeping them for a while.
CC Specialty Tools thank you so much for the reply I understand much better now thankyou
so if im going to put more top speed on My bike, ill need more top power band and increasing the engine rpm more, while doesnt let the engine lose its breath of air. so what do you recommend me to do with my block, any idea? sorry just a newbie here.
A better way to describe the change in power delivery caused by raising the exhaust port roof, is that it moves the powerband higher in the rpm range. This "can" allow for slightly greater top speed, but top speed is mainly determined by the final gear ratio. Any time you raise the exhaust port height, you will decrease trapped volume and therefore port trajectory and expansion chamber tuning of the exhaust become critical for scavenging the cylinder. Of course power valves can also help. Thanks for watching
+CC Specialty Tools my bike is yamaha y125zr. known more on Europe as yamaha z. if I cut the head block increasing the compression ratio from 6.5 to 9, is it true it will give more top speed? im actually dont want to port the porting as you said it will change the tuning. and its also decrease the velocity and the structure rigidity of the block decreases. any idea for that bike spec to increase the performance of it?
Thank`s
Love your handle.
Do you texture the transfer pathways and case ramps the same as intake or make them smooth?
Jared Ferra I texture the transfer pathways and case ramps to a much lesser degree, when compared to the texture on the intake surfaces. Some pros polish these areas, but I do not think that is required. The reasoning is that the air fuel mixture is pressurized during it's travel through these areas, thus fuel droplet formation due to surface tension, is less of an issue, and the air boundary layer would be less of a concern. Thanks for watching.
Ok thank you for the detailed answer!
Cheers!
Hey cc can you tell me the beneficiaries of doing this and if you have dyno results on a ported head compared to standard ? I've heard that if it has a carb the rough walls helps the fuel defuse better i understand two strokes are high revving and allways on the power stroke so gasket matching could be beneficial but as it's a two stroke the exhaust port is open at the same time so I wonder what sort of volume of air/fuel you can take in before it's pushed out the exhaust? I believe this is why two strokes are never forced induction because it would just be blowing it straight through the cylinder! Please help
Thanks for watching, and I will try to answer your questions one at a time, so there may be a few answers to read. 1. The benefits of Porting and Polishing are increased horsepower and increased efficiency. There are thousands and thousands of dyno results and flowbench test out there that prove this beyond and shadow of a doubt. For better proof, of this, I would turn to your User's list( www.ccspecialtytool.com/cc-has-better-way-porting-tools-pay). The long list of names ,legends, champions, world record holders, and major companies like Pro Circuit, Kawasaki, Yamaha, BRP, and Boyesen, proves it even more.
2. Naturally aspirated motors, as you say ones with a carb, benefit more from the textured finish approach to intake walls because the rely on the difference in atmospheric pressure, and yes the main purpose is for fuel droplet dissipation.
3. Gasket matching is important and beneficial to all engines, 2 and 4 stroke. Any protrusion or obstruction by a gasket will decrease the air flow and efficiency of any motor.
4. The exhaust port is only open during part of the 2 stroke cycle. Once the crown of the piston closes the port off, the rest of the volume is trapped. However, while the exhaust port is open the trajectory and flow of the various transfer and auxiliary ports, along with the returning pressure wave from a well tuned pipe, will determine how efficiently the combustion chamber fills and how little of the incoming fresh air fuel mixture escapes out the exhaust port. There are turbo and supercharged 2 stoke engines, just not common. ua-cam.com/video/Oxj_OAb5bqk/v-deo.html
Thanks I had no doubt that porting and polishing works I have A port and polish on mt engine but it's a four stroke and I have my own charts but my question was dose it work on a two stroke I have never seen a dyno on one and a 4 stroke shuts it's exhaust valves so no air escapes but a two stroke can only suck so much air in as the exhaust port is allways open do you have any dyno charts ?
Somebody liked cartman.
What was that sound?????????1:17
Dose anyone else watch the video on the UA-cam app on the tv then go on the same video on your phone just too look at comments.
is that a kawasaki tecate or kx cylinder?
Dragon800 that one at the front of the video is from a KX. Thanks for watching
what about metal block
so taper the ports?
+burntrubberballs yeah you can taper the ports slightly to improve velocity to some degree. Thanks for watching
Thanks for posting.
can u port my 87 kx 250 or u no some one that can?
Thanks for watching. Here is a whole list of pros and companies that do porting and polishing www.ccspecialtytool.com/cc-has-better-way-porting-tools-pay
Hard to hear? Just me?
10.11 There is no explosion !!. It is a fast burn, if explosion occurs you have detonation and a wrecked engine.
sigh... yeah and they never said "beam me up Scotty" on the original Star Trek and Sushi actually refers to the rice... thanks for being "that guy" LoL , and you are technically correct and thanks for watching ;)
Lol... you the man!!!
port a zenoah 320 no one has info
Wish we could do requests but it's just not possible. Porting smaller RC engines follows many of the same principles as porting larger displacement, adjust the ratios and they are proportional. Thanks for watching.
FUCK YA IM GONNA GO POLISH MY BIKE THANKSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS
MY KTM 150SX IS GONNA HAUL EVEN MORE ASS
VERTEX PISTON, FACTORY FATTY, SHORTY
JUST NEED A COMPRESSION HEAD NOW
:DDDD
+Landon Gervais sounds fun!
feels like this vid was made in a doctors office or some asslym
Jack F no it doesn't. I didn't try to kill myself multiple times just to make the video end.
Knife transfers not help, best shape it's round 💪🏻
Agreed
guy don't know his ads from a hole
Well there it is! Five DECADES of selling Porting Tools, hundreds of MILLIONS in sales, and some of the BIGGEST names in racing on our Users List www.ccspecialtytool.com/about-cc-specialty-tool-p/aboutccspecialties.htm , all wasted because Matt, a Troll that is unable to grasp basic spelling or grammar(or polite UA-cam etiquette of saying nothing if you have nothing useful to say), says so. Thanks for doubling down on the Trolling, and giving me a chance to mention our impressive Users List for CC Specialty Tools
the volume comes and goes. Sometimes you talk too fast and mumble your words. I am a bit hard of hearing, but there are plenty of videos on youtube that work for me.
what happened to that cylinder at 8:07 ??! lol
That is the one we take for customers to practice cutting techniques on and test out new burrs on.
That's funny, he doesn't sound like a black man.
Oh, gloves. Duh!
It is not an explosion!! If it was it would explode the cylinder. It is a controlled burn and push. Smh.
Stop rattling that damn tool through the whole video.
(rattles tool at him)
Did anybody learn something here? 🙈
Yuuuup so feel free to troll on out
AAR'KHLDZ'-- MOHYK' TECH'! Vektored - arr-- never air = Haitian!
KTM = Half intake - of Reactant! HRC motor - YZ- frame!