[quote="Kels"][quote="Larry S"]
To hear how 95% of all burn downs are due to lean jetting.. REALLY!! (where are the facts to support this statistic?)
Ed, it appears he did. I guess I didn't read the S.A.E. paper. Actually it's 90% which he somehow always gets wrong. (I think your opinion was "most") It was my research by the way not some paper.
Max
Probably done with this one--things to do.
oil migration
Re: oil migration
WOW!!hodakamax wrote:Kels wrote:Larry S wrote:
To hear how 95% of all burn downs are due to lean jetting.. REALLY!! (where are the facts to support this statistic?)
Ed, it appears he did. I guess I didn't read the S.A.E. paper. Actually it's 90% which he somehow always gets wrong. (I think your opinion was "most") It was my research by the way not some paper.
Max
Probably done with this one--things to do.
Last edited by Kels on Sat Apr 30, 2016 4:21 pm, edited 1 time in total.
Re: oil migration
Okay, cooling is the functional opposite of burning, and you suggested mockingly that burning was not the result of lean jetting. Since you posed your remark in the negative, all Max is doing is inverting what you wrote to express the idea as you meant it. I don't think he got it wrong. Doesn't matter if you used the word "cooling." You are simply parsing your own statements hoping to duck the result of what it is you actually said.
For the record:
Two-stroke High Performance Engine Design and Tuning
Cesare Bossaglia (not Bossoglia)
1968
Two-stroke Performance Tuning
A. Graham Bell
1999
Two-stroke Tuners Handbook
Gordon Jennings
1973
Design and Simulation of Two-stroke Engines
Gordon P. Blair
2014
At first blush, only one of these works was written recently, 2014. However, Professor Blair died in 2010. The book was compiled and published posthumously far as I can tell, from research and development done by Blair between 1964 and 1984 while Professor of Mechanical Engineering at Queens University in Belfast.
I am not certain when Bell did his research before publishing but presumably it wasn't just in 1999, and even then, that was 17 years ago.
All of the references you offer, as legitimate as they are, do not represent modern technological advances. Instead, they reflect knowledge from the era in which Hodaka was built, and during which many of us here were working in the industry or at least riding the starch out of our Hodakas. I don't see any of these works as standing for the proposition that there is new advanced technology out there that was not available in the 1970's or within that era. Instead, all or most of the work you reference is contemporary to our older era of experience.
Still, feel free to cite specifically to work they did or theories they developed which you employ in the modern sense but which us older curmudgeons don't. There is bound to be one or two.
By the way, I have had Jennings book since (I am guessing here) before you were born. Bells ideas, to the extent I have become exposed to them, parallel what we already know. I attribute this to the fact that his work was contemporaneous with the engines we are most familiar with. Not being an expert in his work, however, feel free to point out those of his theories or findings that we are not incorporating in our engine building but should. No doubt it will help us all and save us the time of reading what you already have incorporated into your lexicon. Bossaglia I have never heard of, but if I come across his book, I will be sure to buy it.
And let me cherry pick one of your stated facts, that modern two strokes make two to three times the power versus those from the 70's. First, there is very little dynamometer data available for bikes in the 70's, and manufacturers claims were often quite optimistic. That makes reference to the power of the 70's vague at best. But still, let's say for sake of argument that the odd stock Super Combat MX bike made, oh I don't know, 15 or 16 hp. Today, I can go out and buy a two stroke 125 MX bike that makes 30 to 48hp? That's great. Which one is it? There are some 650's running around out there that make no more power than that. Or maybe you were just being emphatic. I can appreciate that, but I would not call it being factual.
More than one of us has now asked that you back up your assertions with actual information we can use to correct issues we have or build better machines. You say you are here to help. Dropping authors names isn't helping. Naming a half dozen internal combustion engine micro-phenomenon that occur as a result of rising exhaust back pressure isn't helping, it just suggests you remember what you have read. Offer something helpful. Pretty sure Danny and others will be grateful. The rest of us have tried and, apparently, have failed. I concede the field of battle to you.
For the record:
Two-stroke High Performance Engine Design and Tuning
Cesare Bossaglia (not Bossoglia)
1968
Two-stroke Performance Tuning
A. Graham Bell
1999
Two-stroke Tuners Handbook
Gordon Jennings
1973
Design and Simulation of Two-stroke Engines
Gordon P. Blair
2014
At first blush, only one of these works was written recently, 2014. However, Professor Blair died in 2010. The book was compiled and published posthumously far as I can tell, from research and development done by Blair between 1964 and 1984 while Professor of Mechanical Engineering at Queens University in Belfast.
I am not certain when Bell did his research before publishing but presumably it wasn't just in 1999, and even then, that was 17 years ago.
All of the references you offer, as legitimate as they are, do not represent modern technological advances. Instead, they reflect knowledge from the era in which Hodaka was built, and during which many of us here were working in the industry or at least riding the starch out of our Hodakas. I don't see any of these works as standing for the proposition that there is new advanced technology out there that was not available in the 1970's or within that era. Instead, all or most of the work you reference is contemporary to our older era of experience.
Still, feel free to cite specifically to work they did or theories they developed which you employ in the modern sense but which us older curmudgeons don't. There is bound to be one or two.
By the way, I have had Jennings book since (I am guessing here) before you were born. Bells ideas, to the extent I have become exposed to them, parallel what we already know. I attribute this to the fact that his work was contemporaneous with the engines we are most familiar with. Not being an expert in his work, however, feel free to point out those of his theories or findings that we are not incorporating in our engine building but should. No doubt it will help us all and save us the time of reading what you already have incorporated into your lexicon. Bossaglia I have never heard of, but if I come across his book, I will be sure to buy it.
And let me cherry pick one of your stated facts, that modern two strokes make two to three times the power versus those from the 70's. First, there is very little dynamometer data available for bikes in the 70's, and manufacturers claims were often quite optimistic. That makes reference to the power of the 70's vague at best. But still, let's say for sake of argument that the odd stock Super Combat MX bike made, oh I don't know, 15 or 16 hp. Today, I can go out and buy a two stroke 125 MX bike that makes 30 to 48hp? That's great. Which one is it? There are some 650's running around out there that make no more power than that. Or maybe you were just being emphatic. I can appreciate that, but I would not call it being factual.
More than one of us has now asked that you back up your assertions with actual information we can use to correct issues we have or build better machines. You say you are here to help. Dropping authors names isn't helping. Naming a half dozen internal combustion engine micro-phenomenon that occur as a result of rising exhaust back pressure isn't helping, it just suggests you remember what you have read. Offer something helpful. Pretty sure Danny and others will be grateful. The rest of us have tried and, apparently, have failed. I concede the field of battle to you.
Last edited by --- on Sun May 01, 2016 7:33 am, edited 1 time in total.
GMc
Re: oil migration
Let me summarize for the last time. Lean mixtures cause overheating which causes oil failure resulting in piston seizure. Lean jetting causes 90% of piston seizures in air cooled two strokes. They seize because they get too hot. "Burn down" as you say means too hot thus related to cooling. Pretty basic. It appears that you don't believe this is happening but I see no rebuttals. To deny this is saying jetting is not related to cooling.
Thanks Greg for your valued opinion, I too have other things to do but don't really concede but resign in frustration.
Max
Thanks Greg for your valued opinion, I too have other things to do but don't really concede but resign in frustration.
Max
Re: oil migration
Greg! I'm in! Where do I find one of these 45 hp 125's in a new bike? I'd jump all over that! I just need to know how they are achieving such a phenominal horsepower rate and why they aren't making 2 Stroke 250 cruisers which would have around 80-90 hp?!?!? Damn! I've been missing out riding a big bore 4 stroke 1500 that only puts out 67 hp stock and maybe 25-30% more with the mods I've made. Seems like Honda/Suzuki/Yamaha & especially Kawasaki missed out on not sticking with those 3 cylinder H series 2 strokes and making those superlative hp increases from the 1970's up to now! And Danny must be wasting his time restoring his Kaw H2 triple?!?!? ; Victor 
1978 175SL
1976 03 Wombat
1975 99 Road Toad (2)
1973 96 Dirt Squirt (2)
1973 “Wombat Combat”
1973 Combat Wombat
1972 94 Wombat (2)
1972 Super Squirt
1971 92B+ Ace
1970 92B Ace 100B (2)
1968 92 Ace 100
1966 Ace 90
; D Victor
Re: oil migration
- Einstein-Cory-220x300.jpg (21.06 KiB) Viewed 8024 times
Re: oil migration
You know, I have received some good info on this forum and posted same for others. I joined in on this subject as it appeared to apply, at least to some extent. That being oil quality / quantity as the thread originally intended. It was my opinion initially, poor oil quality / quantity for the intended purpose was a contributing factor to the repeat engine failure....still is to some degree. As I have mentioned before, I think getting the engine to perform and live is going to require a combination of tweaks. I do not try to pull any punches or prove any preconceived ideas. I simply allow my careful inspection, observation, measurements and butt-ometer, along with logic, to indicate the proper course of action. On this second failure the first order of business was to assure the top end was set up properly to live at sustained high rpms. First tweak ended up being additional piston to bore clearance more suited to high rpm use with forged piston. I have no scientific support to offer for this opinion other than the experience of an old gear head / mechanic and other generally situated individuals. Fuel tank vent was checked and found to be operating properly. Timing verified correctly set to desired spec. Second tweak involved jetting with larger needle jet installed to improve mid range response and assure no bottle neck that limited main jet flow. Third tweak involved rechecking main jet and reducing main jet from 310 to 270....reduction is, to some degree, related to temperature changes and on going. Forth tweak is restricted exhaust flow and is in process for correction. With out Kel's input on this issue I would have spent a good bit of time searching out this issue. Again, no flow meters, transducers, temp gages, or flux capacitors...just good old fashion common sense. Remove spark arrestor and runs better......hum...how about that. It is not difficult for me to imagine exhaust restriction can contribute to engine over heating and seizing. Last tweak will involve oil and oil ratio.
Regarding any opinions expressed on this forum, dis-agreements are going to happen. For me, if you dis-agree with me that is ok. I appreciate input, although most of the time I am not posting looking for solutions. What is not ok with me is feeling like I have to include so much detail that my posts are unassailable. That atmosphere discourages input and participation....not a good thing.
Danny
Regarding any opinions expressed on this forum, dis-agreements are going to happen. For me, if you dis-agree with me that is ok. I appreciate input, although most of the time I am not posting looking for solutions. What is not ok with me is feeling like I have to include so much detail that my posts are unassailable. That atmosphere discourages input and participation....not a good thing.
Danny
Re: oil migration
The first thing I see on the Forum is my hero Albert Einstein being prophetic. Really funny Kels, Thanks! Again, life should be funny. And Danny, you are my favorite post on the Forum in that you really do study problems and do good work, plus your mind is open and you make me laugh, keep it up!
My two positive statements for the day--
Max
Re: oil migration
Arizona Shorty wrote:
And let me cherry pick one of your stated facts, that modern two strokes make two to three times the power versus those from the 70's. First, there is very little dynamometer data available for bikes in the 70's, and manufacturers claims were often quite optimistic. That makes reference to the power of the 70's vague at best. But still, let's say for sake of argument that the odd stock Super Combat MX bike made, oh I don't know, 15 or 16 hp. Today, I can go out and buy a two stroke 125 MX bike that makes 30 to 48hp? That's great. Which one is it? There are some 650's running around out there that make no more power than that. Or maybe you were just being emphatic. I can appreciate that, but I would not call it being factual
A 2016 KTM 125SX makes 37 horsepower on the dyno. At 2 to 3 times the horsepower, that would have the Hodaka at 12 to 18.5 HP. That sounds about right. For reference (AZ and Max) I got the HP rating from Motocross Action Magazine, Feb 21, 2016. I'm sure you will just discredit that source....viclioce wrote:Greg! I'm in! Where do I find one of these 45 hp 125's in a new bike? I'd jump all over that! I just need to know how they are achieving such a phenominal horsepower rate and why they aren't making 2 Stroke 250 cruisers which would have around 80-90 hp?!?!? Damn! I've been missing out riding a big bore 4 stroke 1500 that only puts out 67 hp stock and maybe 25-30% more with the mods I've made. Seems like Honda/Suzuki/Yamaha & especially Kawasaki missed out on not sticking with those 3 cylinder H series 2 strokes and making those superlative hp increases from the 1970's up to now! And Danny must be wasting his time restoring his Kaw H2 triple?!?!? ; Victor
Keep up the good work Kels. I appreciate your input here.
Mike
Re: oil migration
A lot of the topics in this forum stray way off the original subject. This one initiated with the principles of oil migration and morphed into what we have here.
For the benefit of future archivist and researchers trying to look up specific issues new threads should be started when the subject matter changes.
This topic should have debuted as "The Grumpy Old Men of Hodaka Discourses" a couple or so pages back
For the benefit of future archivist and researchers trying to look up specific issues new threads should be started when the subject matter changes.
This topic should have debuted as "The Grumpy Old Men of Hodaka Discourses" a couple or so pages back
Re: oil migration
Hey Mike, don't be mean, this all sounds reasonable. The point everyone is missing here is that the KTM 125 does have 40+ years technology which IS curing the problems that we had in our career. The big one is liquid cooling which allows jetting for power rather than cooling. Add computer timed fuel injection and ignition and you can achieve these gains. Our limit on air cooled engines with fixed timing prevented us from reaching the proper jetting with what we had. You could only adjust jetting down to to the point where the engine was cool enough to prevent seizure. If we had liquid cooling circulating around the head and cylinder we too could have reached optimum jetting. To put it another way our racers were jetted too rich for optimum jetting, we were limited by engine temperatures. Also with fuel injection you can provide optimum jetting at any RPM which carburetors do somewhat poorly. The KTM might even have a variable computer controlled exhaust valve which even adjusts the exhaust pressure along with its computer assisted ignition which is also searching for the optimum timing related to conditions.
The engines we are talking about are from the past and the engine builders of the day did quite well with what they had to work with. We saw the problems, they were not old or new problems, they were the same problems we have today in engines. The technology just didn't exist at time to produce optimum conditions. It's just a different time.
One more point Mike, I'm not questioning sources of information but the information from them should be in context and relevant which it wasn't. Classes on such subjects (reading, quoting) should be balanced with Lab (hands on stuff) which shows you the real world and keeps you from mis-interpeting all the information available.
Max
The engines we are talking about are from the past and the engine builders of the day did quite well with what they had to work with. We saw the problems, they were not old or new problems, they were the same problems we have today in engines. The technology just didn't exist at time to produce optimum conditions. It's just a different time.
One more point Mike, I'm not questioning sources of information but the information from them should be in context and relevant which it wasn't. Classes on such subjects (reading, quoting) should be balanced with Lab (hands on stuff) which shows you the real world and keeps you from mis-interpeting all the information available.
Max
Re: oil migration
Max, you missed the point. I responded to AZ question. This pissing match can go on forever.....
Re: oil migration
Max... You believe that you can not apply new technology to an old design... This is where we differ and a main reason why we keep having this sort of dialogue.
The advancement in OIL alone is staggering..(remember this is an oil thread) and this BETTER and MORE ADVANCED OIL will help bring MORE consistency AND Protection to your air cooled engine.
Now how about piston technology? If you are running OEM 1972 pistons then you are missing out on BETTER Pistons that will IMPROVE your engine.
Cranks.. Nice advancements in this critical area of your engine that can be applied to your engine.
Carburetor... Are you running a Bing, Amal, or Keihin or Mikuni? Again.. there have been advancements that HELP your engine..
Reeds.. Early engines ran steel reeds.. I had the great fortune of working with Eyvind Boyesen for a week at his facility.. CRAZY information obtained from a genius in this area. Anyway.. Reed design is one of the biggest areas of advancement. You running stock reeds in your engine?
Exhaust systems... MUCH better now due to a MUCH better understanding of the engine and how to HELP it stay consistent.
Air Filters.. Seems trivial.. but IMO, it is not.. Nice improvement in this area.. YUP... you guessed it.. It will HELP your engine.
OK.. those are just some of the "engine areas" (there are more).. Think about chassis and suspension.
Point being.. applying some modern technology to ANY Air Cooled engine allows the Air Cooled engine to function BETTER..
I will agree with you that IF you are still running the same era components as you were in the '70's.. then there is much less to be gained and your engine will probably run about the same as it did in the '70's.
I think EVERYBODY would prefer a better running 70's bike over a poorer running '70's bike.
Beauty of it is.. that you can do it and still keep the bike looking "era correct"
Can anybody spot the differences with this bike (see attachment)
The advancement in OIL alone is staggering..(remember this is an oil thread) and this BETTER and MORE ADVANCED OIL will help bring MORE consistency AND Protection to your air cooled engine.
Now how about piston technology? If you are running OEM 1972 pistons then you are missing out on BETTER Pistons that will IMPROVE your engine.
Cranks.. Nice advancements in this critical area of your engine that can be applied to your engine.
Carburetor... Are you running a Bing, Amal, or Keihin or Mikuni? Again.. there have been advancements that HELP your engine..
Reeds.. Early engines ran steel reeds.. I had the great fortune of working with Eyvind Boyesen for a week at his facility.. CRAZY information obtained from a genius in this area. Anyway.. Reed design is one of the biggest areas of advancement. You running stock reeds in your engine?
Exhaust systems... MUCH better now due to a MUCH better understanding of the engine and how to HELP it stay consistent.
Air Filters.. Seems trivial.. but IMO, it is not.. Nice improvement in this area.. YUP... you guessed it.. It will HELP your engine.
OK.. those are just some of the "engine areas" (there are more).. Think about chassis and suspension.
Point being.. applying some modern technology to ANY Air Cooled engine allows the Air Cooled engine to function BETTER..
I will agree with you that IF you are still running the same era components as you were in the '70's.. then there is much less to be gained and your engine will probably run about the same as it did in the '70's.
I think EVERYBODY would prefer a better running 70's bike over a poorer running '70's bike.
Beauty of it is.. that you can do it and still keep the bike looking "era correct"
Can anybody spot the differences with this bike (see attachment)
- Attachments
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Re: oil migration
Sorry Mike, being a grumpy old man I'm starting to take things personally. Just trying to help with some basic science. Cheers for the day.MWL wrote:Max, you missed the point. I responded to AZ question. This pissing match can go on forever.....
Max
Re: oil migration
No doubt this will piss off someone, but one more try at making a point about useless generalities...
Kels wrote:Max... You believe that you can not apply new technology to an old design... This is where we differ and a main reason why we keep having this sort of dialogue.
Didn't say we couldn't. I am asking you to do it, since it is your position.
The advancement in OIL alone is staggering..(remember this is an oil thread) and this BETTER and MORE ADVANCED OIL will help bring MORE consistency AND Protection to your air cooled engine.
Agreed in the general, but need specifics..
Now how about piston technology? If you are running OEM 1972 pistons then you are missing out on BETTER Pistons that will IMPROVE your engine.
Which ones? Not Wiseco surely, so who else is making pistons for Hodaka?
Cranks.. Nice advancements in this critical area of your engine that can be applied to your engine.
Such as......? Short of custom construction or changing the stroke, what do you have in mind?
Carburetor... Are you running a Bing, Amal, or Keihin or Mikuni? Again.. there have been advancements that HELP your engine..
Already running a modified Mikuni, dividers and UFO. Anything we missed here?
Reeds.. Early engines ran steel reeds.. I had the great fortune of working with Eyvind Boyesen for a week at his facility.. CRAZY information obtained from a genius in this area. Anyway.. Reed design is one of the biggest areas of advancement. You running stock reeds in your engine?
Nope. Nor Boyeson either. And far as I know, Hodaka never used steel reeds. My RD did, but there is nothing actually wrong with the stock steel RD reeds, either. Dyno runs show you can boost from 39hp stock to about 70 hp using stock reeds and stock reed block. Yes, there are others, but the most popular (TRD) are stiff and only usable for high rpm, road race specific applications. They tend to suck on the street. For the Hodaka, choices are limited, unless you change to a different system entirely, manifold and all.
Exhaust systems... MUCH better now due to a MUCH better understanding of the engine and how to HELP it stay consistent.
Such as...? Who is making exhaust systems for Hodaka? Already have the Harry Taylor design in place. Who else is building Hodaka pipes these days?
Air Filters.. Seems trivial.. but IMO, it is not.. Nice improvement in this area.. YUP... you guessed it.. It will HELP your engine.
Specifically....? Uni and K&N, or something else? No one building a competition Hodaka uses a stock filter, and I haven't used one since 1972?
OK.. those are just some of the "engine areas" (there are more).. Think about chassis and suspension.
Already did that 40 years ago. Lengthened and reinforced the swingarm, aftermarket shocks laid down...something else we missed short of one off aluminum parts?
Point being.. applying some modern technology to ANY Air Cooled engine allows the Air Cooled engine to function BETTER..
So here we are again, you with generalities, and the rest of us with questions. Are you getting a feel for the situation yet, or is Einstien still confused?
I will agree with you that IF you are still running the same era components as you were in the '70's.. then there is much less to be gained and your engine will probably run about the same as it did in the '70's.
Actually, a great deal can be gained using largely stock or vintage era parts. You just have to apply what you know.
I think EVERYBODY would prefer a better running 70's bike over a poorer running '70's bike.
Beauty of it is.. that you can do it and still keep the bike looking "era correct"
Can anybody spot the differences with this bike (see attachment)
Uh, no, unless you mean the vibration isolators on the fins.
GMc
Re: oil migration
Sorry Shorty.. I am no longer in the 5th grade.. YUP.. made all the way up to 10th now....
Let me know when you get there...
Let me know when you get there...
Re: oil migration
Greg, Nice response. Sadly you are talking to a tree. Not calling anyone a tree but its a metaphor for wasting your time. A tree is deaf and set in its ways. I too talk to trees in that there is a positive side that makes you think or rethink your position and research your position. When you are satisfied with your position its time to stop talking to a tree.
While being philosophic I should mention another interesting piece of thinking in the saying, "The hottest places in Hell are reserved for those who in time of crisis maintain their neutrality."
I'm not neutral nor do I talk to trees.
Maxie
While being philosophic I should mention another interesting piece of thinking in the saying, "The hottest places in Hell are reserved for those who in time of crisis maintain their neutrality."
I'm not neutral nor do I talk to trees.
Maxie
Re: oil migration
- Tree.jpg (12.65 KiB) Viewed 5220 times
Re: oil migration
Kels
I'm extending an olive branch.
You seem to be very knowledgeable about modern liquid cooled two stroke engines. I'm sure some of that technology could be used on our fifty year old air cooled engines. The problem of course is heat. Double the horse power- double the heat.(I just made that up,but I think I'm on solid ground).
There are many engine builders on this forum that are capable of building a thirty HP 125cc engine. The problem is, because of the heat, the engine won't survive the first moto.
You could become a valuable member of the forum by bringing modern technology to fifty year old air cooled two strokes.We have forum members that have been building these engines since the late 60's and early 70's. Don't discount them.
Larry S
I'm extending an olive branch.
You seem to be very knowledgeable about modern liquid cooled two stroke engines. I'm sure some of that technology could be used on our fifty year old air cooled engines. The problem of course is heat. Double the horse power- double the heat.(I just made that up,but I think I'm on solid ground).
There are many engine builders on this forum that are capable of building a thirty HP 125cc engine. The problem is, because of the heat, the engine won't survive the first moto.
You could become a valuable member of the forum by bringing modern technology to fifty year old air cooled two strokes.We have forum members that have been building these engines since the late 60's and early 70's. Don't discount them.
Larry S
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