Index the degree wheel with the 0.015 wire at TDC. Then, when you use the wire to measure the ports, you have an "exact" number. My grandpa used to shine his flashlight up the port - my job was to switch the garage lights on and off, LOL! Great content, cheers!
yea just take the sleeve out and the piston goes to top, lines up with the lip the sleeve sits on. [for cmb and most engines if i recall correct] or just rock it at the top regardless whether sleeve moves and set the wheel. then like u say doesnt have to be critical. then u make final adjustment by bending the pointer. this method seems waaay to overly complicated . nice to see videos of people doing their own stuff and internal combustion too. refreshing
I understand what you're saying, but the piston dwells briefly at the top and the bottom making far greater room for error there. When I can easily set my pointer to perfect zero, why wouldn't I do it?
@@M5PerfHydros well its easy (for me...also im not THAT anal about 1 or 2 deg. plus im not selling engines so it wont matter to me) to "feel" the dwell and mark max right and left on the flywheel and break it in half an BANG u got center for zero. in fact i used just the flywheel to time engines for years . in recent years since i started using all the "proper" tools i started loosing interest in everything. it just got kinda boring. i blame it most on the local lack of competition. i can do an inconsistent 80mph with a 20 year old engine modded on a drill press. only literally 1 other person on the island (bermuda) that can hang .if everything is perfect i loose interest lol
Ive have degreed V8 Racing engine for years. All the camshafts come with a spec sheet and install centerline. I always installed the camshafts 1/2 to 1 degree advanced to allow for timing chain stretch. I guess my question is, as i am sure everyone else watching the video is what is the purpose and goal for all this effort and how to change the timing for what purpose?. In the early 80's we changed the port timing on a Honda ATC 250 2 stroke 3 wheeler. We "ramped" the piston top with a file at the appropriate port(s) to change the port timing, then polish the piston top (Open Sooner or Close later). If you wanted to change the "dwell" timing you would have to start grinding on the cylinder ports. It was a chrome lined cylinder so I did not touch the cylinder. On this small of an engine what is the goal for low end or top end power? If I remember correctly, all you could add was top end power by porting a 2 stroke. So I guess the overall question is why do all this on such a small engine, you tell how to check timing but not for what reason and how to change for a given result? Im not at all knocking the video, I fly RC planes and if I can be sure that my engine is degreed for the performance I want that would be awesome. I have never seen timing spec for a glow engine. Nice video with a twist of humor..I like it.
Thanks for your thoughtful comments. I made this video at the request of another racer who wanted to know how to check port timing, and hadn't really intended to share it publicly. I only did so afterward because I thought maybe it could help others as well. The video, as you've noticed, describes how to check timing only.... What you decide to do with that information is up to you! As with any production engine, engines intended for r/c use are designed to be simple to manufacture and operate in a wide range of applications, with fairly "simple" and safe valve timing. Careful modifications can improve airflow and efficiency (power!) without changing timing at all. Going further the timing can also be changed to raise or lower the rpm range and peak power, but only to a point. Go too far and you've got an expensive paperweight. So... It's up to you and the width of your wallet. With some engines (like the CMB shown) I have found certain changes to the timing makes a noticeable improvement in my application (r/c hydroplanes), where others (Nova Rossi for example) have ideal timing as manufactured. With these I only work within the ports to improve airflow making them as efficient as I can. Again... Your call, your risk! But am I going to show my competition exactly what modifications I do? Nope!
Fun stuff. Great input. The most accepted formulas for tuned 2 stroke exhaust all use duration of exhaust port open in the equation to determine the critical tuned length and a degree wheel would be mandatory. The practice of changing exhaust port timing by ramping the piston has really become common practice. I only wish I could have have all the hours back I spent grinding ports. Going backwards to original port timing is a little easier and cheaper too especially with chrome cylinders.
@@M5PerfHydros Thanks Steve, Where did you buy the degree kit? . I have studied a little on how to change the port timing on these type of engines. It really does make a difference on performance. My CMB's and Novarossi's have been sent off and modified by the previous owner. I would like to know what the port timing is as they run now compared to the original timing.
@@chaley9093 - I purchased the degree wheel from Stock Drive Products. Here is a link to the one I have, but they have other sizes also; shop.sdp-si.com/catalog/product/?id=S1228Y-GA-28 Or you could use one from McMaster-Carr; www.mcmaster.com/#20045a32/=1aui1rb The pointer is just a piece of flat stock 1/2" aluminum that I drilled to fit. Happy port timing!
Rather than chopping sleeve or piston, many times I'll put shims under the sleeve or machine the case to drop the sleeve in the case to run a shorter rod. Beyond proper fit and break-in, 90% of the battle is fuel/head/pipe and not timing.
You know what's frustrating? I can't remember where I got it! Anyway, you can get a printed version here and stick it on a piece of aluminum plate; McMaster-Carr Page: www.mcmaster.com/Degree-Wheels/adhesive-back-protractor-dials
What's "too soon" in a demonstration video Erwin? For that matter, what's too soon on any engine? That's exactly what everyone is trying to figure out! I only recorded this video for a friend who wanted to know how to do it. The specific numbers for the junk-parts engine in the video are not important. Thanks for watching!
@@M5PerfHydros So when do we get to learn about that aspect of it? I would like to know more. What makes low end torque, what makes high RPMs. How to understand what's happening there and make a decision.
I like your attitude! There's no way to cover it all here, and maybe I'll do a video with more detail one of these days, but if you're serious about learning some of the theory you'll love Gordon Jennings work from many years ago... Check it out; www.google.com/url?sa=t&source=web&rct=j&url=www.amrca.com/tech/tuners.pdf&ved=2ahUKEwjDtd7h2_LqAhWhGDQIHfnBDzYQFjAJegQICBAB&usg=AOvVaw1cGXdJ6egg3gqCxILowdeH
Ya I just got my first pico 65 marine engine and could certainly follow along but I guess I’m lost as to why I would want to do all this? It’s not like you can change the timing or anything or am I wrong? Ps your my new favorite channel since I got into boats, I’m loving every video and I can’t wait for the 2021 race season videos when u walk the pits and show everybody’s little secret setups! Keep em coming Scott Thanks Scott
Some guys like to change port timing by grinding or shimming the liner, but modern engines are already pretty darn good so I don't recommend it. I'm glad you like my channel Scott. Watch for a bunch of new videos coming soon!
Great info, will have a look at mine now, what is your mobile number so I can call you tonight ? I forgot which way to tighten the pointer nuts.... With our 100cc kart motors I would insert three lots of solder wire at once (at 120 degrees) to avoid piston rock upsetting the measurements. We were running one tooth gearing off touching the head though, which was about 0.05mm actual squish clearance at 17K revs :)
Marwen Martina - Hello, I purchased the degree wheel from Stock Drive Products. Here is a link to the one I have, but they have other sizes also; shop.sdp-si.com/catalog/product/?id=S1228Y-GA-28 Or you could use one from McMaster-Carr; www.mcmaster.com/#20045a32/=1aui1rb The pointer is just a piece of flat stock 1/2" aluminum that I drilled to fit. Happy port timing!
Nothing whatsoever except to show some folks who might care, one possible method by which to measure port timing. If you are not one such person, please just move along with my thanks for giving it a look.
+Salim Os - Hello, I purchased the degree wheel from Stock Drive Products. Here is a link to the one I have, but they have other sizes also; shop.sdp-si.com/catalog/product/?id=S1228Y-GA-28 Or you could use one from McMaster-Carr; www.mcmaster.com/#20045a32/=1aui1rb The pointer is just a piece of flat stock 1/2" aluminum that I drilled to fit. Happy port timing!
Index the degree wheel with the 0.015 wire at TDC. Then, when you use the wire to measure the ports, you have an "exact" number. My grandpa used to shine his flashlight up the port - my job was to switch the garage lights on and off, LOL! Great content, cheers!
The indexing idea is nice, but I like the light switch method even better!
"Do you want me to wait while you write that down?" lol, good one.
And if you knew the guy I made this video for it'd be even more funny!
Great video thanks. Strait to the point, with some humor. "I want that boat motor".
yea just take the sleeve out and the piston goes to top, lines up with the lip the sleeve sits on. [for cmb and most engines if i recall correct] or just rock it at the top regardless whether sleeve moves and set the wheel. then like u say doesnt have to be critical. then u make final adjustment by bending the pointer. this method seems waaay to overly complicated . nice to see videos of people doing their own stuff and internal combustion too. refreshing
I understand what you're saying, but the piston dwells briefly at the top and the bottom making far greater room for error there. When I can easily set my pointer to perfect zero, why wouldn't I do it?
@@M5PerfHydros well its easy (for me...also im not THAT anal about 1 or 2 deg. plus im not selling engines so it wont matter to me) to "feel" the dwell and mark max right and left on the flywheel and break it in half an BANG u got center for zero. in fact i used just the flywheel to time engines for years . in recent years since i started using all the "proper" tools i started loosing interest in everything. it just got kinda boring. i blame it most on the local lack of competition. i can do an inconsistent 80mph with a 20 year old engine modded on a drill press. only literally 1 other person on the island (bermuda) that can hang .if everything is perfect i loose interest lol
a small powerful flashlight is ur best fren doing this shine through top or without the drum ,through the drumhole
Great video bud really enjoyed it must invest in one of them myself thanks for sharing big like from me bud 🤝
Ive have degreed V8 Racing engine for years. All the camshafts come with a spec sheet and install centerline. I always installed the camshafts 1/2 to 1 degree advanced to allow for timing chain stretch. I guess my question is, as i am sure everyone else watching the video is what is the purpose and goal for all this effort and how to change the timing for what purpose?. In the early 80's we changed the port timing on a Honda ATC 250 2 stroke 3 wheeler. We "ramped" the piston top with a file at the appropriate port(s) to change the port timing, then polish the piston top (Open Sooner or Close later). If you wanted to change the "dwell" timing you would have to start grinding on the cylinder ports. It was a chrome lined cylinder so I did not touch the cylinder. On this small of an engine what is the goal for low end or top end power? If I remember correctly, all you could add was top end power by porting a 2 stroke. So I guess the overall question is why do all this on such a small engine, you tell how to check timing but not for what reason and how to change for a given result? Im not at all knocking the video, I fly RC planes and if I can be sure that my engine is degreed for the performance I want that would be awesome. I have never seen timing spec for a glow engine. Nice video with a twist of humor..I like it.
Thanks for your thoughtful comments.
I made this video at the request of another racer who wanted to know how to check port timing, and hadn't really intended to share it publicly. I only did so afterward because I thought maybe it could help others as well.
The video, as you've noticed, describes how to check timing only.... What you decide to do with that information is up to you!
As with any production engine, engines intended for r/c use are designed to be simple to manufacture and operate in a wide range of applications, with fairly "simple" and safe valve timing. Careful modifications can improve airflow and efficiency (power!) without changing timing at all. Going further the timing can also be changed to raise or lower the rpm range and peak power, but only to a point. Go too far and you've got an expensive paperweight. So... It's up to you and the width of your wallet.
With some engines (like the CMB shown) I have found certain changes to the timing makes a noticeable improvement in my application (r/c hydroplanes), where others (Nova Rossi for example) have ideal timing as manufactured. With these I only work within the ports to improve airflow making them as efficient as I can.
Again... Your call, your risk! But am I going to show my competition exactly what modifications I do? Nope!
Fun stuff. Great input. The most accepted formulas for tuned 2 stroke exhaust all use duration of exhaust port open in the equation to determine the critical tuned length and a degree wheel would be mandatory. The practice of changing exhaust port timing by ramping the piston has really become common practice. I only wish I could have have all the hours back I spent grinding ports. Going backwards to original port timing is a little easier and cheaper too especially with chrome cylinders.
@@M5PerfHydros Thanks Steve, Where did you buy the degree kit? . I have studied a little on how to change the port timing on these type of engines. It really does make a difference on performance. My CMB's and Novarossi's have been sent off and modified by the previous owner. I would like to know what the port timing is as they run now compared to the original timing.
@@chaley9093 - I purchased the degree wheel from Stock Drive Products. Here is a link to the one I have, but they have other sizes also; shop.sdp-si.com/catalog/product/?id=S1228Y-GA-28
Or you could use one from McMaster-Carr;
www.mcmaster.com/#20045a32/=1aui1rb
The pointer is just a piece of flat stock 1/2" aluminum that I drilled to fit.
Happy port timing!
Rather than chopping sleeve or piston, many times I'll put shims under the sleeve or machine the case to drop the sleeve in the case to run a shorter rod. Beyond proper fit and break-in, 90% of the battle is fuel/head/pipe and not timing.
Those cmb's are bad mofos. I've been trying to get my hands on one of their land engines for years.
Ok, I’m back. What’d I miss? .....Nevermind, my wife just showed me how to rewind the video. 😜
Someone suggested watching my videos at 2x speed... Maybe I drone on too long?
😂cool want me to wait while you write that down
Looking at your head edge and piston top, you have LOTS of detonation in your engine.... :)
You think?
Ha ha.... I know. This is just a mocked-up engine from old parts!
Another good one
where do i get a tiny degree wheel? thats awesome.
You know what's frustrating? I can't remember where I got it!
Anyway, you can get a printed version here and stick it on a piece of aluminum plate; McMaster-Carr Page: www.mcmaster.com/Degree-Wheels/adhesive-back-protractor-dials
So how do you take a nut off a bolt?
Air hammer. Or torch, that works too!
Hey they sell a piston stop now
Dear boater ,I am praud to sea your videos.
Thank you!
did you do it right !? looks like the port is opening to soon
What's "too soon" in a demonstration video Erwin? For that matter, what's too soon on any engine? That's exactly what everyone is trying to figure out!
I only recorded this video for a friend who wanted to know how to do it. The specific numbers for the junk-parts engine in the video are not important. Thanks for watching!
@@M5PerfHydros i wish i noticed it sooner that you was wasting my time....
Ditto Erwin
@@erwinmaes3105 what a useless Tool you are...
So ok you record the timing. What for? To modify the engine? Or in case something changes?
Many racers like to change the timing by grinding the ports, and you'd better know how to check it before you start moving metal!
@@M5PerfHydros
So when do we get to learn about that aspect of it? I would like to know more. What makes low end torque, what makes high RPMs.
How to understand what's happening there and make a decision.
I like your attitude! There's no way to cover it all here, and maybe I'll do a video with more detail one of these days, but if you're serious about learning some of the theory you'll love Gordon Jennings work from many years ago... Check it out; www.google.com/url?sa=t&source=web&rct=j&url=www.amrca.com/tech/tuners.pdf&ved=2ahUKEwjDtd7h2_LqAhWhGDQIHfnBDzYQFjAJegQICBAB&usg=AOvVaw1cGXdJ6egg3gqCxILowdeH
Ya I just got my first pico 65 marine engine and could certainly follow along but I guess I’m lost as to why I would want to do all this? It’s not like you can change the timing or anything or am I wrong?
Ps your my new favorite channel since I got into boats, I’m loving every video and I can’t wait for the 2021 race season videos when u walk the pits and show everybody’s little secret setups! Keep em coming Scott
Thanks Scott
Some guys like to change port timing by grinding or shimming the liner, but modern engines are already pretty darn good so I don't recommend it. I'm glad you like my channel Scott. Watch for a bunch of new videos coming soon!
Great info, will have a look at mine now, what is your mobile number so I can call you tonight ?
I forgot which way to tighten the pointer nuts....
With our 100cc kart motors I would insert three lots of solder wire at once (at 120 degrees) to avoid piston rock upsetting the measurements.
We were running one tooth gearing off touching the head though, which was about 0.05mm actual squish clearance at 17K revs :)
thanks
Hi where can i find the time tool?
Marwen Martina - Hello, I purchased the degree wheel from Stock Drive Products. Here is a link to the one I have, but they have other sizes also; shop.sdp-si.com/catalog/product/?id=S1228Y-GA-28
Or you could use one from McMaster-Carr;
www.mcmaster.com/#20045a32/=1aui1rb
The pointer is just a piece of flat stock 1/2" aluminum that I drilled to fit.
Happy port timing!
Can you do this with novarossi .67 as well?
Of course! The process is exactly the same for any two stroke engine
what did this accomplish?
Nothing whatsoever except to show some folks who might care, one possible method by which to measure port timing. If you are not one such person, please just move along with my thanks for giving it a look.
You must have went to school in Pasco.
Say whaaa?! Richland!
hello sir,where you buy you tools for measured the engine please,and very good video. tky
+Salim Os - Hello, I purchased the degree wheel from Stock Drive Products. Here is a link to the one I have, but they have other sizes also; shop.sdp-si.com/catalog/product/?id=S1228Y-GA-28
Or you could use one from McMaster-Carr;
www.mcmaster.com/#20045a32/=1aui1rb
The pointer is just a piece of flat stock 1/2" aluminum that I drilled to fit.
Happy port timing!
tky very much sir
Avnt a clu Wat iam watching timing Wat kind of engine is it
CMB RC boat engine, 11cc nitro powered
Lost our conection text me i have some guestions. Tim