Basic scooter engine case and cylinder porting blog. Simple twostroke cylinder porting tutorial youtube. If you want to try to port your own blaster cylinder, ill be the first one to tell you to go for it. Lower the head for more compression or shave metal off the bottom of the cylinder. Geoff batticks notes on 2 stroke engine modification. I wouldnt mind having a go myself but what i am asking is. Use my formulas to determine if the ports need to be widened or changed in their height. There is no 2stroke displacement limit for our software, for example you can have a 125, 250, 500, 700 single cylinder and our modules will work flawlessly. Cylinder heads, as manufactured, are usually suboptimal for racing applications due to design and are made for maximum durability hence the thickness of the walls. However, the egt reading changes quickly with rpm, so for a scooter its use is limited. Please allow an extra week turnaround time for this. If you feel up to the task of porting your own cylinder, be sure.
Part 1 introduction to tuning a lambretta engine part 2 introduction to tuning cylinders the mb way part 3 explaining advanced tuning part 4 explaining advanced port timings this is the start of explaining lambretta tuning, ive. Cylinder head porting is an automotive machining processes that the average mechanic can do at home. Our model was a unit with an aftermarket 62mm stroke crankshaft with a 120mm con rod, and a stock ts1225 cylinder, not a good match without remedial porting work but fine for the exercise planned. Tips on how to port a two stroke cylinder, what to donot do and how to do it right. Heres a link below for a parts kits, dont be mislead by ported cylinder if the price is way high, not sure who you plan to buy from, but i can clean the ports up in about 1015 or less on a jug if that is all that has been done to it, just knock the burs off and hit. Minarelli style horizontal cylinder 50cc air cooled.
I just got a lambretta due50 adly panther 50 2t knock off with the minarelli style 50cc horizontal cylinder ac engine. I feel i am lucky to find it in such an easy to use. It also cuts down on the amount of charge that can in some cases simply blow right out the. Buy a good carburetor that will atomize the fuel better for better combustion. Cylinder head porting refers to the process of modifying the intake and exhaust ports of an internal combustion engine to improve quantity of the air flow. This is an important process to understand and is the reason why not only the cylinder decides the tuning degree but also the exhaust pipe. This short blog is a basic guide to matching the cylinder ports to the engine casings when tuning or fitting a new. So much myth and misinformation is associated with this complex machining and metal finishing process. You should measure precise on a tenth of a millimeter. Those of us who have grown up in the japanese twostroke. The computer allows us to compare the variables with existing. Rating is available when the video has been rented. One millimeter equals about 5 degrees with a 39,239,3 stroke in timing and will become even larger with a bigger stroke.
Calculates port heights from durations, or durations from port heights. Today were going to take an air cooled 70cc piaggio polini sports cylinder kit fitted to a piaggio zip and modify it to squeeze a bit more power from it. Basic scooter engine case and cylinder porting blog pedparts uk. From a 49cc racing engine, to a gp 125 engine, or a 1500 mercurial triple engine, or a 250 kart engine, racingsm software suits all. Ive got special computer programs that ive looked at and it just goes over my head. If you are aiming for these qualities, modifying your 2stroke engine is a great strategy. With a very versatile selection of tools, the 1082sr kit can also be used to modify 2 strokes above 150 cc and 2 strokes as small as 30 cc of displacement. If youre looking for a little more power, and your purchasing a cylinder, we now offer inhouse porting. By carefully selecting your cylinder it can for example be possible to duplicate the porting of a much more expensive cylinder. I weight 229 pounds and can only get to about 37mph on a flat surface. My porting setup affordable and functional 2 stroke tuning. The gauge above has a egt exhaust gas temp, this may be very valuable for a mircolight aircraft where the engine runs at a constant rpm. Porting your cylinder according to the old french magazine specs motobecane porting will get you a quick, easy boost without any thinking, but it is suboptimal because it usually kills your low end, and even if you start with a fast cylinder, there are a still lot of different variations in port geometry that motobecane put out stock. The first job was for us to set up the cylinder on the case to obtain a zero piston height at top dead centre, so the outer edge of the piston crown.
Porting involves using an assortment of grinding and cutting bits to reshape or polish the cylinder heads intake and exhaust ports, and combustion chamber. Porting your cylinder head is a great way to increase power. The process of cylinder porting is a funny paradox. A head can be engineered for maximum power, or for minimum fuel usage and. This simple ebar tool makes accurate, failsafe porting of the pushrod pinch point a breeze. For the twostroke engines used in scooters, motorcycles, and mopeds, edge chamfering and port work are important cylinder restoration tasks. Following these instructions here, you can achieve a much. Why dont you just get the upper cylinder kit from dax. Measuring the distance between top port and cylinder deck is done on the cylinder itself and not from a portmap. Relation of port timing to peak rpm, and port timing for. And if you are after a lot more power then there is hundreds of other things to do than porting as well. Two stroke cylinder porting tips watch this before you start cutting. Scooter cylinder moped cylinder gas scooter cylinder. This short blog is a basic guide to matching the cylinder ports to the engine casings when tuning or fitting a new cylinder kit.
In that case the egt will quickly tell you if the engine is in trouble. To get the engine running good, slight porting and crank balancing, crankcase and cylinder matching, exhaust and intake modifications, setting up the carb precisely etc helps a lot if done correctly. Two stroke cylinder porting tips watch this before you. I couldnt get the cylinder boring engineers to port the barrel as they wouldnt have a clue how to. All porting and polishing kits to purchase porting kits specially designed for 2 stroke cylinders, 2t cylinders, 2c cylinders use the link below. Scooter parts and riding gear superstore and defenders of the universe.
Cylinder porting, a related technique, is designed to improve flow characteristics and promote optimum engine performance. Each part of the 2stroke cycle can be evaluated and designed with computer software programs. Whether its a simple clean up job, or something more aggressive, we can handle the task. It pretty much stays in place as the porting is done, allowing for fast and frequent checks of the remaining metal thickness. On page 51 gordon uses the term onepercenter, the term refers to an american motorcyclist association quote that 99% of motorcyclists were lawabiding. Typically when a new engine is designed the port characteristics are one. My very first successful porting job was achieved because i actually took over a week just studying the piston and cylinder, and the flow through the engine. We sell only the highest quality chinese kids atvs, quads, go karts, and pit bikes available, including a full parts inventory for everything we sell. Cc specialty tools 2 stroke kits include 90 degree rotary tools for 2 stroke transfer ports and working from the inside of the cylinder combustion chamber. When attempting to tune up a motorcycle, consider these main points. Cylinders with port edges so sharp that the side of the piston and rings. There is really not a restriction that can just be pulled out except a washer in the cvt. Sometimes simple is best, a standard 4 ported lambretta cylinder can.
Cylinder porting tools artco american rotary tools company. These modern vespa performance cylinder kits and heads are designed with the latest advanced technology and can make a huge increase in power with a quick. Lets see some glamour shots of everyones porting tools. Assign fixed relationships between transfers and exhaust port.
There is one or more forwardlocated exhaust ports, two or more side transfer ports, and one rear intake port. Edge chamfering is a surface finishing technique that smoothes the edges of cylinder ports so that piston rings seat properly. Porting polini sport 70cc scooter shack scooter forum. The combination of cnc and cam software give the porter full control over the port shape and surface finish. I dont know that i would consider this information the indisputable truth and it is fairly specific to these particular smaller cc cylinders, but it can be a very enlightening as to observable relations in altering 2 stroke port timing, enjoy. This is a 2 stroke porting and polishing kit designed for 2 stroke cylinders in the 150 cc to 35 cc range.
Dont have any good questions or any decent advice to anyone at the moment, so thought this might be a decent idea for a post. I made this video long ago, but forgot to upload it. I used a sharpie marker to make reference marks, measured the port windows, the port timing, etc. It will include gaskets and everything you need to build the engine. Two stroke performance tuning chapter 3 porting and cylinder scavenging today, when we take a look down the cylinder of a twostroke engine, we find its walls literally filled with ports to handle the induction, transfer and exhaust phases of gas flow through the engine. You should only rely on the experience of the very best. However, you shouldnt just pick any business that you can find anywhere. You should read about how the two stroke enigne works before you attempt this. Port shape and size play huge roles in power on engines. Make sure this fits by entering your model number a set of performance parts for gy6 125150cc 152qmi 157qmj chinese scooter technical specifications. I am finishing up my porting job, then i will assemble the engine in full race configuration.
Mikes racing heads is a full service machine shop that specializes in the high performance motorsports market. Be very very careful when porting and polishing or you could ruin the head. Artco tools carries a great selection of cylinder porting tools including porting tools, porting abrasives, carbide burs, and more. An engine port is an open window in the cylinder wall for the intake or exhaust of fuel mixture airgas. With over 30 years of experience, we have the knowledge and technology to ensure that you dominate at the racetrack. Fully ported cylinder piston for gt5 2stroke motorized bicycle and lots of extras. You dont need fancy expensive stuff to port two stroke cylinders, you can get by with cheap tools and a little creative engineering. The new shortened intake track on the boost port cylinder has a major increase of cranking pressure. Everything you need to know about the twostroke cylinder. I think that workspacesgaragestoolboxes etc might be.
A lesser work would have surely passed into nostalgia heaven long ago. This new think simply fills the cylinder from the bottom up with a colliding swirl of gas that purges the cylinder of spent gasses as it rises with the piston. You can get by with a dremel and a few tools for it. Because so much confusion exists in the motorcycle industry relating to. For port work, one company that will help you is 2stroke porting. This article uses a piaggio zip engine and a stage6 sport pro mkii cylinder kit but applies equally to minarelli aerox etc. Really cool two stroke cylinder porting software youtube. The people in the market to buy it are looking for information and the people in the market of selling it are hiding information on porting. I ended up burning a valve in this head because i knicked the valve seat slightly. The gap between the two bar components arrow indicates twice the thickness of.
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