Leave a rough finish on areas where fuel / air mix is travelling and polish exhaust till it's shiny. Rough surfaces help with atomization of your mixture and you want the exhaust to have the least amount of friction you can deliver.

One thing to keep in mind, when you cut away from the crank case and increase volume, when the piston comes down to pressurize the crankcase, it can not create as much pressure to push into the cylinder with.

If you dont mind me making a suggestion. I actually recommend the double cut carbide/tungsten burrs WITH a soft wax instead of WD-40. It will unclog the flutes, and makes for a very smooth cutting process and prevents grabbing of your work piece. Just insert your cutting bit into the wax while still spinning your cutting tool. Repeat the process frequently. Youll notice the difference in ease of your cut, no vibration or turbulence.

I have a buddy who did this with with a 70cc 2fast cylinder and the power it makes is insane. The information in this video is invaluable.

A squirt of bluing into a 2 stroke spun externally can reveal the major patterns in flow. Testing the reeds to identify the relative crank position is possible with the tiny vision equipment and data acquisition available now plus a little ingenuity. 2 Stroke Stuffing has been very interesting to follow in his quest for the illusive 50cc holy grail. Peace.

Excellent video. Thank you for taking the time to explain everything and edit this!

When removing alloy from the cases, remember you will also be lowering the primary compression. Look up Tods tuning for BSA Bantams. Tod used to fit crankcase stuffers, to compensate for metal removed from ports. Also renew crankshaft oil seals.

Very interesting as always hoping for more uploads from you thnx for taking the time to share your ideas

This video was awesome! The amount of detail and information was far more then I expected. Now I don’t have butterflies in my stomach thinking about porting my own. There was a segment were you showed two casings where one had sharp edges with no lead in angle. The other had rounds and drafts as we call them in the biz. The one with sharp edges was done by someone who doesn’t understand or has a clue of production casting methods. While the casting with rounds was done by someone who did the design by industry standards and understands the added benefits when designed into the part.

Pretty sure this is the best porting video available !

Wish i had youtube with this content back in 1998 when i was tuning my piaggio typhoon 70cc. Well me and my friends were selflearning back then with all the pros and cons hahaha. Nice video!

Perfect. Nice to see You back for real :D

Nice work ! Have been using this technic in snowmobile application to. Works very well.

It's like porting heads, only with the head cut in half! Haha. Great video, you got me looking for a deal on a 2T!

When you use JB Weld or Devcon on cases or heads, heat the item in the oven to about 90degC before you put the glue in, it will dry in a matter of minutes, but more importantly this is done to give the strongest adhesion to the aluminium.

WOW that's gotta be the best porting DIY guide I've ever seen for bottom ends on the Internet 😮

It sure is both a helpful and interesting video that gives out an accurate picture of what needs to be done and how when porting and trenching 2-stroke engine block👌🏻.Being an organized/structured guy myself, it's pretty clear that all the steps of the process have been really well layed out and explained since these are all delicate operations that offer little to no room for mistakes. Enjoyed a lot watching this as I feel I've learned immensely without having had the opportunity to do it in real life so far,👍🏻🙋🏻‍♂️.

excellent tips and camerawork, thanks for a great video.

I see you porting very meticulously and accurately😊👍👍👍

On aluminum I used 60 or 80 grit sanding cones. They're fast enough for me and slow enough to keep me from destroying case's or ports. They work really good on 4 stroke ports

i dont even have a 2T but man i love watching your videos. they're very educational. thanks.

2:59 brilliant, I've had a hallway chair problem for a long time. Got my dremel out, 3 days later it's ground away to only a tiny piece of wood with enough clear through way and direct path down my hallway. Thanks so much!

I always screwed in some small screws under the porthole filling If if comes loose, wel you know Cilinder skirts needs some work too If they interrupt flow They don’t need to be that big Same for the piston Lots of weight and skirts can be removed 5 gram removal on a piston is huge increase in move up and down The lighter the piston the better The best vid on porting Top

When workshop work actually becomes a work of art.

Great video, had some hard to hear places when grinding but other then that, great vid and much appreciated

I found this video well made. Narration was articulate with definitive terms and thought out before presentation. Lighting and video shot well. Overall, the topic was addressed and explained in terms that explained the objective. Good examples were shown and solutions addressing theory. Good Job. * I got something out of it. Confirming some ideas and building new ones.

I think the cut cases for the larger crank balance the volume of material removed by the trenching. Nice maticulous work.

Thankyou very much! After looking at my 1e40qmb case and Minerelli Zuma, it’s clear there is more meat on the case for porting on the 1e40qmb. The port maps thread on your forum I plan on using in the near future!

Nice video buddy!

Hey man, great video! Iv just ordered myself a gasket kit and im going to split my bock and take the pathways out a touch and clean them up. Iv been messing with a 40cc poulan chainsaw. Did some clean up on both intake and exhaust ports, opened the muffler a bit and dialed the carb in. BIG gains. 18 inches of green poplar in 18 seconds. *video on my channel* Again thanks a million!

Great video !

Good video👌🏼

Great video.... Thanks for the info.

Very informative, thank you.

One way to minimize the risk of cracking the case is to saturate the epoxy with fiberglass strands. It's dirt cheap, and will massively increase the strength of the filler. It shouldn't be any harder to shape with burrs or sanding either.

Very good video!

Impressive amount of work for possibly little gain. Still worth doing and the video is presented in an instructive manner, thumbs up!

Ahhhhh I have the 5BM engine so looks like most of the work will be done for me.. S6 street race 70cc kit.. Thanks for linking this its great info.

Disposable ear plugs are great for sealing holes for filling, painting and even general penetrations in house floors for speaker wire etc. Especially good for small holes and pretty easy to remove even when painted.

thank you master for inspieation...

Amazing video, thanks a lot!!!

I had a honda elite 49cc that I just cleaned up all the transfer ports, mostly with emery wheels. Put back togethe, the scooter would rev quicker and pulled much harder. Yes it does help "stock" motors, mostly in breathing.

Trenching is usually used to make room for a longing stroked crank without knowing exactly what you are trying to achieve you can open ports and cases so large that you begin to lose velocity and fuel Atomization also the crank gets its lubrication from the fuel/oil mixture so trying to redirect the flow of the mixture strait to the exchange ports via the intake is not always going to be beneficial if u lock up the crank bearing or bearings knocking down edges does increase flow but most importantly it reduces cracking.jb weld does not hold up to gas or oil well or vibration! Aluminum should be tigged

Great video. Clear and to the point. Just so the kids know, "polishing" the ports is a BAD thing. The air fuel mixture will form droplets on the smooth surface due to surface tension. It should be no more than around 220 grit with a random scratch pattern.

Nice upload 👍👍👍

great job !

Thanks for sharing

4:34 I think I have those same exact pockets! LoL

This is good, i dont like the chemical metal though, i found out after testing that oktan 110 disolves these kinds of metals like acid. My headache is over after Malossi released their C-ONE / RC ONE cartridges however, no need for chemical metal in those for flow optimisation.

I port the heads of my 4 strokes if they need it as well, some castings are shit and have horrible ports so a bit of time and a rotary sorts that out! Some bikes you dont notice any change and others are like you've summoned and saddled Lucifer himself! But as of yet no dyno proof! Great all round video on porting, got a Peugeot 49cc I'm thinking of boring to take the 100cc cylinder and using the 125cc BB kit! Will have to check some of your other videos out!

Just found your channel n I subscribed very cool thank you.

I'm impressed. I imagine a bit of a lost art form. Goodonyou and thanks

Thanks for the incredibly well explained video - your voice is pleasant to listen to and everything you explain and show is easy to understand even for beginners (or at least I think it should be). Do you have a dyno or access to one, or do you check your work for efficacy with the "butt dyno" only? How much power would you say you gained from all this porting and flow optimization, or was it more in service of making the cases able to handle the much larger pumping capacity of the 103cc bigbore/stroker kit?

If I need to do fill work in cases I try to orient the case in a fashion that allows the filler to fill the low spot intended to built up if another coat is required I will just reorient the part if necessary and you get a smooth filled are with minimal filler to achieve the desired result.

I really appreciate your time and experience. I am thinking about matching a 1987 Minarelli V1 engine. Not because of power or anything, I just want to do it for the experience, and maybe a bit smoother running, and this video explains all the critic points of that. Thank very much.

Color the entire gasket surface, with the marker, then use a scribe-all or pick to make a fine, very accurate line to follow.

Good jobs

Do a piston mod and sleeve porting video too please. Love the port filling.

The inner corner is where you’ll see most gains , boundary layer thickness is very higher there. Want the curve to be as gradual as possible

Nice vid bet it took some time to edit all that - thanks for doing it. Started off with puch cases, ruined 2 got a little too happy on the burrs. And oh yeah jb weld is your friend. Puch cases are thin and easy to trash, but i got one with a good 70 cc kit to work well. Hard to say if anything i did made anything better - wishful thinking is best used. A bit more than twice the power, maybe 10 hp ? a reed kit with a higher compression head made it run hot. Trade off fuel ratio to keep temps down, it ran well but a fuel pig that fouled plugs a lot - better than seizing the cylinder. I had big plans for my piaggio scoot hyper 2 engine. Found some very interesting cylinders on UK scoot sites, 90 cc bolt right up kits. But past dirt bike crashes caught up with me as i knew they would, need 2 disks fused lower back and c5 neck. Pain is hellish 24/7 so riding is not gonna happen this year, i'll be lucky if i heal by new years. Took my old ke 175 out last week all done in half an hour, just hurt too much. But i can still get info and make plans - that will not pan out. Anyway, good video thanks for putting it up. Have a good

Very very good

man thank you for the video, best video on porting 2 stroke on youtube, had the cases splited about month ago and now i feel sorry because i havent cut into them, i guess you gave me confidence to cut into cases from now on what about cylinder porting?

Awesome👍👍👍👍

Thanks for the video. I think I would try an HDPE screw for through holes. It's tough getting anything to stick to that except more hdpe.

I've been at this for a lifetime and watched everything and read everything long after being an established top shelf Master Mechanic and I have to say that all your videos are great but this one is by far the best one out there. Everything you said is true whether the so-called ASE idiots agree or not. Polishing is a joke, see I went further because I love to punish the idiots, now steam is building up and must be released while you and I just relax, smile and enjoy life which if you have not noticed is not polished either. So as the number one lover of JB Weld I want to share a little knowledge with you. If you will mix your batch 10% light in hardener and very warm and runny and then you dump it into the place it goes letting it run over and bond and then pool and then stick your part in the freezer. When you get it really cold the curing times change exponentially. So check on it often until it is like play-doh and then rub a little oil on a sandwich baggy and put it over your jbweld and mold it with your fingers to the exact shape you want it putting it back in the freezer if it starts to thaw. Once you have it as your want it then just keep it in the freezer for at least 6 hours and at that point it will have cured to the regular 5 minute mark in which is has a hard skin. Once the skin is developed the stuff won't move any more and you can pull it out and put it in the oven to accelerate the curing time, just treat it like bread or cheese toast at about 300 degrees or whateer you want as the more heat the shorter the cure time. If you try this I promise you will grow to love it and you will soon be able to do it and actually get it cured in a much shorter time than normal. The greatest part about doing it this way is once it becomes like play-doh it won't stick to your fingers anymore and you can actually use tools on it before it is cured and soft and using the oiled plastic will leave you with a perfect plastic smooth finish. You can even assemble your stuff together and let the parts push everything out of the way with the plastic in between and when it is at the perfect consistensy you can simply use a blade to cut it and just play with this method and I promise you will love the stuff even more. Once you become expert with the frozen method you can then add extra hardener and essentially make your own quick cure so that it has a skin in about 1 1/2 hours in the freezer while the stuff underneath is still moldable and moveable. The most important part is cleaning the surface and making sure the hot mixture is runny and gets sure contact without air to the surface. You will find that it becomes as hard as steel when you get the mixtures right and I hope you get something from this rant friend. I really appreciate your work and your patience and keep it up man. The kids need to hear the truth's you speak and if they doubt or have doubts they need only look at the finished product to know you know your stuff from experience not from books or videos and that should be enough. I repeat polishing ports does not benefit anything people. Peace Sizzlean

Very interesting..!

Nice.... Thanks

good video

I would like to try on my kids CR 80 go kart engine,I appreciate your sharing your knowledge. Anyone have any advice on the CR 80 engine?

Hi i watched you video on porting What I've done in the past is When you have gone to far strip the coating of 1mm wire and with a sharp knife cut it up 1mm 2mm Lengths Before you put JB on the case stick the wire sleeve in your casing with Super Glue then put JB over the case on the smoothing out you will see the tops that you glued in if you go to far then once finished you can touch each one you see with drill bit and refill over job done ✔ HOPE this helps you 👍 😊 then put heat and oil resistance Spray paint over the work to protect it 👍

Use a scribe as permanent marker rubs off when near oil . NEVER dig through cases unless you can wield it and NEVER use appoxy ,it's crap .people often forget it's in direct contact with petroleum vapourised fuel and heat .before anyone says go read up from pro's of tuning ,non use epoxy ,they weld cases ,the reason there isn't a definite book to tuning is cause all motors are different, that's why they called guides . There are port maps however and that's a top tuner producing a guide and a cutting guide to know exactly where to open up ports to

❤ Happy to subscribe.

Lut ! Hi ! Nice job :)

When using jb weld to get it into spaces that are tight if you mix it on card and fold it into a v you can heat underneath with a lighter and it will pour. To flatten it out and steer it wet you finger with gob grease and you will be able to push it about without It sticking to your finger

i wanna know what kind of dremel bit was used in the beginning, and how fast you were running it. it it cut perfectly

Good work! All understand without words 👏

Thanks for sharing all you have done and know. Have you or have you come across any data that would isolate the effect/gains of this wkrk by itself? Obviously the effect of enlarging the case area as part of the porting and trenching is hard to remove. Thx!

ciao............sempre lavori molto belli

Awesome video ,thanks for info , keep up the great work everyone ☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆

Very good video thanks wanna know more

привет !) ты крут !) видео получилось очень познавательным !) много чего подчеркнул из него !)

Cold welding can be use for the exhaust port ? I have a hole on one of my cylinder, meeting the studs hole...

great, nice to know you, I'm a mechanic from Indonesia 👍👍🙏🖐

Great video. Was just wondering if that black stuff works as good or better than blie locktight

just now trying to port a 700cc 2 stroke from your video :D

Can you do a video on how yamaha l2gf more powerful

Good video but with a lot of material removable at the base of the cylinder I wonder what kind of reliability the engine will exhibit especially with the continued enhanced vibration.

Mantap kaleee

Digging the graphics in this video. Note to self: I need to remove the chair from my hallway.

This could be great if you had made an engine without modifications with your TP 86cc mounted and measured on dyno field and measured HP. and after that made an engine with the changes you make in videos here mounted TP 86cc and looked at dyno field and measured HP so we could see with our own eyes what it would actually give of effect when we adapt our cylinder to the Engine Block These are some great videos you make.

Trenching can only help if the motor is at such a tune that a combination of the transfer momentum and the exhaust draw can draw intake air through the intake when the piston is at bdc

Nice I have the 5bm big bored

One and simple way to masure anything on engine at home is to count RPM's. Formula is simple. Any gaine in RPM's and how quickly it will hapen indicats that it works. Just switching to Iridium sparkplug is automatic 500RPM's gaine. My Vino 5BM with 68CC Malossi Alu. Cylinder made 12hp at 15K RPM's. I did dyno my scooter if you asking.

Two stroke Tuner,s Handbook and ask lots of Questions from people that have already been there .

nice

Permetex gasket maker never dries. How tgats worked well for you is a miracle. Fuel eats it/washes it away

Very nice 👍🏻

Can someone put some link of good dremel head?

JB WELD Rocks !!!!

Are you available to do case machining? I am planning to do what I think is the same build and will need this work done.