I got a hold of one of those Zenoah G320 engines about a month before they came out on the market, a "pre-production" engine. My goal was to be the first to come out with a ported G320 engine. So I get the engine, (same as the production engines), make the fixtures to port them on the CNC mill, develop the first phase of porting and get it on the dyno. Since we can get close to 7hp with the G290 platform, my goal to start was 7hp. I get 6.25hp. (the stock engine with the exhaust can makes 3.5hp. A stock G260 with can makes 2.3hp for comparison) with a DDM Baja side mount pipe is 5.5hp on the stock G320, (Not many fully modded G260/G270s will do better). I try a couple other things to make more power,---still, 6.25, and the curve looks the same, (pretty much). Now my plan has failed. I was not going to be the first out with a ported G320. I did more and more things, spent more time on this engine than any other by far, and every damn time, 6.25 and the curve hardly changed. So, since nothing else I did to it made any difference, all I did was what got me to 6.25hp. I wanted to see 7hp, but this engine did not respond to porting changes like the smaller engines do, at least not for me. I ended up being the last to come out with a ported G320. Now, I did not go for higher RPM because this larger crank does not like RPM higher than 17,000 rpm. So there can be more power up there that I did not look for, but I still doubt it would beat a good G290 above 13,000rpm, and the great low end power that engine has would suffer,---so why? This is the best RC engine for 8000-12,500 rpm, (tight tracks and heavy 4 wheel drives, still love the stock clutch), and my porting still keeps that great low rpm grunt. Nice vid sir. Thanks for mentioning that you started with an ESP cylinder. But I pulled a lot of hair working on that new engine, so I bet you didn't get anymore power from it, under 17,000rpm. :) Keep an eye on the lower end of the rod if you are getting more rpm. At 19,000, I turned the bottom of the rod brown in under 30 seconds on my dyno. If it goes blue,---change it. By the way, the rod is not longer, (it is 50mm cent to cent), but the stroke is for the stroked cranks, (the rod end pin is 1mm further from the center of the crank, and the 320 cases need a bit of clearance milled in them for the 2mm crank). If the rod was longer, (and they are sold longer), you would then put a spacer under the cylinder to get the same squish, (a 3mm longer rod, a 3mm more spacer), and your port timing will barely change. Thanks for using my stuff. I appreciate it. Happy roosting while surfing the earth. Doug @ ESP
Well, I did it! I took your advice and modified an engine for the first time! I just started it up, it idles a lot lower and smoother now, I will see how it runs at the field! Thank you for the awesome video!
Bro is the best video I found on porting heads on a 2-stroke I'm sure aupplies to the zenoah G260-G320 plum Marine engines I am subscribed and I have your alert on thanks
I did race 1/8 scale nitro for a while and I was porting the Nova rossi Roma25. My son was young at the time and just learning. One of the top drivers asked me to talk to him about taking him out at the end of the main strait. You see each time he went to lap my boy would pin it and pass him on the straight and often take him out. Not very cool. Kids lol and dads who port for fun, not a good mix. I'd say you would be looking for more top end but if you chase that and run out of midrange torque you will end up running flat which is what I suspect the guy I watched before your video did. If I were to start out I'd go for ex 100. It's a good compromise and you can make decent torque at say 10-12,000 rpm. It will give you a solid pull off the bottom to exit corners. With a pipe scavenging trans with 24-25 blow down and an intake at 80. In other words not very different from a stock motor. But if the motor had more than enough cc to pull the bottom I'd port higher, maybe 95 on the Ex. Particularly if its quite over square motor. Let it scream. But port timing is only half of the story and transfer direction and balance is arguably more important. If you want them to make power on top they must flow! I do a lot of flow work. I wish we raced these things here I absolutely get into it. Shit you guys have gear ratios too so you can play with that also, the list of possibilities goes on. I'd shoot for an 18,000 rpm screamer lol. I had the 1/8 scale wheel standing out of corners. I'd want that. Actually I had car this scale years ago with a Zenoha G23 in it and a box muffler and it screamed pretty good. I wasn't porting back then so I never did anything with it but you motors are possibly already running high rpm.
Hey man so I'm doing my poring job in quick question when you say taking off a little bit Of the bottom of the intake inside the cylinder do you go all the way through or Do you just take off a little bit on the inside and then taper it off off as it goes towards the carburetor. Do you get what I mean
Hey man yes i know what you are trying to say. All you need is to take off just a tiny bit and taper it and smooth it out toward the carb to get that smooth air flow! If you remove too much your motor will lose power and sputter a lot of fuel. On this prossidure any minimal removal of material is a big big change on how your motor can perform. If done right your motor will be way way stronger.
Where is the piston ring end gap on that motor, on the intake side? If you had an rc reed valve, could you cylinder reed port it for a 5th or 6th port?
Mount half of the crankcase to the cylinder. Drop in the crank with rod and piston. slowly rotate, noticing the ports on the cylinder in relation to the sides of the piston skirt. You can see where to modify piston for better intake flow from the crankcase up to the combustion chamber. Its all about freer flow, just dont get too crazy.
Absolutely correct my friend! This video is part of my previous video ahow that when im actually doing my porting. But, there were a few viewers that needed more explaining on how to and where to remove material on the ex and in ports
So I tried this just exactly what he said to do and now I get nothing but gas and oil dripping out of my exhaust. The engine runs but I've never seen this amount of oil and gas coming out the exhaust. It's like the fuel is unburned. Anyone have any suggestions??
And also addjustmenton your carb is needed. Its getting more air in so the carb needs tuning on the high needle give that a try. The needle setting is to high. Start by turning my small increments of 1/16 of a turn at a time in to lean it out just a bit. But if it doesnt stop the exesive oil than you might of removed material too much. But how is the power on your motor?
@@raulofalltrades5023 the power seems amazing. Very responsive runs amazing I just don't like all this unburned gas and oil dripping out. I did Lean the carb in a bit but it's still doing the same thing.
@@noahriedel801 if you have an extra cylinder gasket add it to the first one overlap it and see if that helps bro. Adding a second gasket will compensate for the material removed on your intake timing. That should help with the extra oil and fuel you are getting
Not true. BUT less is always more. Follow a 1mm rule and the cylinder will perform well. I have not measured once or used a degree wheel and ALWAYS had high positive results.
@@bdrgarage7039 I've never ported ones of these engines but I'd be willing to beat that your Ex is about 100 your transfer is 122 and your intake is 73-75. The intake is a little high and needs to go down to 80 yes about 1mm maybe. Now you have 22 blow down and your ex and intake are about balanced. Actually not bad for timing. If you raise your ex to say 95 at most you will have a higher revving engine with less torque. You will also need about 83-85 intake. The transfer can change how wide the power band is so if you raise your transfer you will broaden your powerband and weaken the top end a little ( I probably shouldn't get into this too much as there is far more going on than that but....anyway). Personally I'd go with the 100/122/80 timing and raise the compression to 10:1 or in my hotter builds 10.5:1 this will give you torque. Also the squish in that motor will be about 1-1.3mm bloody awful in other words. You will gain 5% power just fixing that and nothing else. You got lucky is all mate, I feel bad for all those poor buggers out there killing there engines. Making a 2 strokes go a bit better is easy. Making them haul arss is actually quite hard. The only thing I have really learnt stumbling across these videos this morning is this is a bigger market than the one I am in. Those engines are rip for some wicked mods. I could CNC those cylinders and make a real monster out of them. Its got me thinking.
@@foardhook Measuring is definitely the way to go. I have never done that, learned from guys that ported (unmeasured) old chainsaw engines and had them doing 80+mph on a gokart. On these small engines, less is always more. Yeah you can get scientific and get better results but great results can be had with a little porting and blueprinting. I have double acceleration and top speed on plenty of 23cc 2 strokes. Now the RC already have good porting but can still be improved. I have never raised transfer ports. I always raise compression, that's the easiest way to make power. I should learn to measure and port properly BUT what I do on my engines works beautifully and I have probably 30+ small bore 2 strokes here. Case reed, piston port, pocket bikes, gopeds, etc
@@bdrgarage7039 I understand what you are doing and how you are getting your results. For several years I did exactly the same thing. Just as I predict the port numbers for a motor I have never touched or seen most of these engines have pretty typical port timing. You have done so many now you have kinda worked out what to do and where. In all truth if you started using a wheel and crunching the numbers you will probably find you end up where you are. I do get that. I just finished a chainsaw last night, it is a pretty hot build I'm working on for myself. Every port is very carefully dialed in. I know before I even run it today how it will run, where the power will be etc although I'm experimenting with a higher than usual intake timing for this first run because I'm running a CNC head I made for it. The thing is I can guarantee you are leaving power on the table. I port so much differently now that I understand it than I did say 5y ago. It no longer matters to me if I have ported that saw before I can port it and the first one will haul arss. If you start porting to a map and planning your engine builds before you even start you will make more power. You are dead right about little bits make big differences. The work you are doing looks great. I'll go and find a video of your cars running. The last guy I watched was fair to average. These things have pipes and all they should be hauling arss. Why the manufacturers don't build a proper hot motor for these things has me beat. From a design perspective there id so much more they could do.
![2 Stroke Tips & Tricks [Blowdown]](http://i.ytimg.com/vi/0-DJP04BLRg/mqdefault.jpg)
I got a hold of one of those Zenoah G320 engines about a month before they came out on the market, a "pre-production" engine. My goal was to be the first to come out with a ported G320 engine. So I get the engine, (same as the production engines), make the fixtures to port them on the CNC mill, develop the first phase of porting and get it on the dyno. Since we can get close to 7hp with the G290 platform, my goal to start was 7hp. I get 6.25hp. (the stock engine with the exhaust can makes 3.5hp. A stock G260 with can makes 2.3hp for comparison) with a DDM Baja side mount pipe is 5.5hp on the stock G320, (Not many fully modded G260/G270s will do better). I try a couple other things to make more power,---still, 6.25, and the curve looks the same, (pretty much). Now my plan has failed. I was not going to be the first out with a ported G320. I did more and more things, spent more time on this engine than any other by far, and every damn time, 6.25 and the curve hardly changed. So, since nothing else I did to it made any difference, all I did was what got me to 6.25hp. I wanted to see 7hp, but this engine did not respond to porting changes like the smaller engines do, at least not for me. I ended up being the last to come out with a ported G320. Now, I did not go for higher RPM because this larger crank does not like RPM higher than 17,000 rpm. So there can be more power up there that I did not look for, but I still doubt it would beat a good G290 above 13,000rpm, and the great low end power that engine has would suffer,---so why?
This is the best RC engine for 8000-12,500 rpm, (tight tracks and heavy 4 wheel drives, still love the stock clutch), and my porting still keeps that great low rpm grunt.
Nice vid sir. Thanks for mentioning that you started with an ESP cylinder. But I pulled a lot of hair working on that new engine, so I bet you didn't get anymore power from it, under 17,000rpm. :) Keep an eye on the lower end of the rod if you are getting more rpm. At 19,000, I turned the bottom of the rod brown in under 30 seconds on my dyno. If it goes blue,---change it. By the way, the rod is not longer, (it is 50mm cent to cent), but the stroke is for the stroked cranks, (the rod end pin is 1mm further from the center of the crank, and the 320 cases need a bit of clearance milled in them for the 2mm crank). If the rod was longer, (and they are sold longer), you would then put a spacer under the cylinder to get the same squish, (a 3mm longer rod, a 3mm more spacer), and your port timing will barely change.
Thanks for using my stuff. I appreciate it. Happy roosting while surfing the earth.
Doug @ ESP
I hope you see this, how much improvement does your advertised 5.5 degree scalloped piston make for the g320?
I read this entire comment just so you not it's not wasted time writing it
Well, I did it! I took your advice and modified an engine for the first time! I just started it up, it idles a lot lower and smoother now, I will see how it runs at the field! Thank you for the awesome video!
Bro is the best video I found on porting heads on a 2-stroke I'm sure aupplies to the zenoah G260-G320 plum Marine engines I am subscribed and I have your alert on thanks
Thank you for this video man!
You are welcome i hope the info was helpfull! Let me know later how you did on your motor
@@raulofalltrades5023 will do! I’m currently at about 46 hours on it, gonna tear it apart when it hits 50
You should get a degree wheel, it will allow you to map your port timing events and make them repeatable.
Thanks for the info my RC friend I’ll be trying that 👍🏼 Now can it be done on a Zenoah g290 engine? Will be doing it on my g320 though 👍🏼
I would suggest a degree wheel so your adjustments are repeatable.
So what timing do you suggest? I assume you do use a timing/degree wheel?
I did race 1/8 scale nitro for a while and I was porting the Nova rossi Roma25. My son was young at the time and just learning. One of the top drivers asked me to talk to him about taking him out at the end of the main strait. You see each time he went to lap my boy would pin it and pass him on the straight and often take him out. Not very cool. Kids lol and dads who port for fun, not a good mix.
I'd say you would be looking for more top end but if you chase that and run out of midrange torque you will end up running flat which is what I suspect the guy I watched before your video did. If I were to start out I'd go for ex 100. It's a good compromise and you can make decent torque at say 10-12,000 rpm. It will give you a solid pull off the bottom to exit corners. With a pipe scavenging trans with 24-25 blow down and an intake at 80. In other words not very different from a stock motor. But if the motor had more than enough cc to pull the bottom I'd port higher, maybe 95 on the Ex. Particularly if its quite over square motor. Let it scream. But port timing is only half of the story and transfer direction and balance is arguably more important. If you want them to make power on top they must flow! I do a lot of flow work.
I wish we raced these things here I absolutely get into it. Shit you guys have gear ratios too so you can play with that also, the list of possibilities goes on. I'd shoot for an 18,000 rpm screamer lol. I had the 1/8 scale wheel standing out of corners. I'd want that. Actually I had car this scale years ago with a Zenoha G23 in it and a box muffler and it screamed pretty good. I wasn't porting back then so I never did anything with it but you motors are possibly already running high rpm.
Can you compare Bartolone and ESP ported top end?
Hey man so I'm doing my poring job in quick question when you say taking off a little bit Of the bottom of the intake inside the cylinder do you go all the way through or Do you just take off a little bit on the inside and then taper it off off as it goes towards the carburetor. Do you get what I mean
Hey man yes i know what you are trying to say. All you need is to take off just a tiny bit and taper it and smooth it out toward the carb to get that smooth air flow! If you remove too much your motor will lose power and sputter a lot of fuel. On this prossidure any minimal removal of material is a big big change on how your motor can perform. If done right your motor will be way way stronger.
Where is the piston ring end gap on that motor, on the intake side? If you had an rc reed valve, could you cylinder reed port it for a 5th or 6th port?
Great info my bro just sub
Hello sir. Jusy want to ask? How about transfer port? Need to porting?
Transfer ports dont need porting. The only thing you do to them is smooth out the rough edges to improve better air flow
What about the amount of mm taken away? And the piston, did something to it?
Hey man! I take off about 0.7 to 1mm of material on both exhaust and intake. If you do more than 2mm the motor becomes less torque and less RPM
@@raulofalltrades5023 ok. Thank you for the info. Nice video.
Sir i have two stroke cylinder i want to increase its rpm power please help me how i can increase the speed from its ports. Please help me tell me sir
Did you even use a degree wheel to see what the numbers were on the engine? And what squish are you running?
Mount half of the crankcase to the cylinder. Drop in the crank with rod and piston. slowly rotate, noticing the ports on the cylinder in relation to the sides of the piston skirt. You can see where to modify piston for better intake flow from the crankcase up to the combustion chamber. Its all about freer flow, just dont get too crazy.
Absolutely correct my friend! This video is part of my previous video ahow that when im actually doing my porting. But, there were a few viewers that needed more explaining on how to and where to remove material on the ex and in ports
Did you really say “the inside dremeled in” ?? And I’m trusting you to explain porting to me🤣
Yup! I trust my hands for sure!!! I Dremel the inside to round off the sharp edges so that the piston ring dont get caught.
So I tried this just exactly what he said to do and now I get nothing but gas and oil dripping out of my exhaust. The engine runs but I've never seen this amount of oil and gas coming out the exhaust. It's like the fuel is unburned. Anyone have any suggestions??
How much material did you remove from the cylinder?. Mine isn’t doing that. If you remove too much it does that
And also addjustmenton your carb is needed. Its getting more air in so the carb needs tuning on the high needle give that a try. The needle setting is to high. Start by turning my small increments of 1/16 of a turn at a time in to lean it out just a bit. But if it doesnt stop the exesive oil than you might of removed material too much. But how is the power on your motor?
@@raulofalltrades5023I removed just a little bit. Barley anything.
@@raulofalltrades5023 the power seems amazing. Very responsive runs amazing I just don't like all this unburned gas and oil dripping out. I did Lean the carb in a bit but it's still doing the same thing.
@@noahriedel801 if you have an extra cylinder gasket add it to the first one overlap it and see if that helps bro. Adding a second gasket will compensate for the material removed on your intake timing. That should help with the extra oil and fuel you are getting
If you just start grinding the ports with no measurements or calculations the best you can hope for is to get lucky and not FU your engine.
Not true. BUT less is always more. Follow a 1mm rule and the cylinder will perform well. I have not measured once or used a degree wheel and ALWAYS had high positive results.
All these car guys are the same it seems. I agree with you 100%. Yes guys are getting results but I bet a lot have stuffed there engines as well.
@@bdrgarage7039 I've never ported ones of these engines but I'd be willing to beat that your Ex is about 100 your transfer is 122 and your intake is 73-75. The intake is a little high and needs to go down to 80 yes about 1mm maybe. Now you have 22 blow down and your ex and intake are about balanced. Actually not bad for timing. If you raise your ex to say 95 at most you will have a higher revving engine with less torque. You will also need about 83-85 intake. The transfer can change how wide the power band is so if you raise your transfer you will broaden your powerband and weaken the top end a little ( I probably shouldn't get into this too much as there is far more going on than that but....anyway). Personally I'd go with the 100/122/80 timing and raise the compression to 10:1 or in my hotter builds 10.5:1 this will give you torque. Also the squish in that motor will be about 1-1.3mm bloody awful in other words. You will gain 5% power just fixing that and nothing else. You got lucky is all mate, I feel bad for all those poor buggers out there killing there engines. Making a 2 strokes go a bit better is easy. Making them haul arss is actually quite hard.
The only thing I have really learnt stumbling across these videos this morning is this is a bigger market than the one I am in. Those engines are rip for some wicked mods. I could CNC those cylinders and make a real monster out of them. Its got me thinking.
@@foardhook Measuring is definitely the way to go. I have never done that, learned from guys that ported (unmeasured) old chainsaw engines and had them doing 80+mph on a gokart. On these small engines, less is always more. Yeah you can get scientific and get better results but great results can be had with a little porting and blueprinting. I have double acceleration and top speed on plenty of 23cc 2 strokes. Now the RC already have good porting but can still be improved.
I have never raised transfer ports. I always raise compression, that's the easiest way to make power.
I should learn to measure and port properly BUT what I do on my engines works beautifully and I have probably 30+ small bore 2 strokes here. Case reed, piston port, pocket bikes, gopeds, etc
@@bdrgarage7039 I understand what you are doing and how you are getting your results. For several years I did exactly the same thing. Just as I predict the port numbers for a motor I have never touched or seen most of these engines have pretty typical port timing. You have done so many now you have kinda worked out what to do and where. In all truth if you started using a wheel and crunching the numbers you will probably find you end up where you are. I do get that.
I just finished a chainsaw last night, it is a pretty hot build I'm working on for myself. Every port is very carefully dialed in. I know before I even run it today how it will run, where the power will be etc although I'm experimenting with a higher than usual intake timing for this first run because I'm running a CNC head I made for it. The thing is I can guarantee you are leaving power on the table. I port so much differently now that I understand it than I did say 5y ago. It no longer matters to me if I have ported that saw before I can port it and the first one will haul arss. If you start porting to a map and planning your engine builds before you even start you will make more power. You are dead right about little bits make big differences. The work you are doing looks great. I'll go and find a video of your cars running. The last guy I watched was fair to average. These things have pipes and all they should be hauling arss. Why the manufacturers don't build a proper hot motor for these things has me beat. From a design perspective there id so much more they could do.