Unsaid info about high compression heads

[Stoneman]

I cant agree with something that's not true,AS big of a contributor to this community as he is,He should be on here reading more and at least keep up with what's going on.Saying that squish is not what is making power rather the increased C/R really is a contradiction in that using a squish allows the higher compression to be used safely and there fore make more power and controlled burn.We are not all sheep and we have to question those who know to learn aswell as point out when those we learn from are wrong that's how the world advances we all learn from each other!

I wouldn't look at myself as a sheep as I have gotten some great tips from all of you

I think its good to see both sides of a debate and by the end of it most of us can make our own mind up from what we read.
We all tend to see and think of things differently doesn't mean its not valuable information to anyone.
Sometimes someone will say something a different way and than it twigs in mind what its all about, this could just be me though

my main point is i don't like to see these threads disappear and no one get anything from it.

There is a few good helpful blokes here

 

[gary55]

I wouldn't look at myself as a sheep as I have gotten some great tips from all of you

I think its good to see both sides of a debate and by the end of it most of us can make our own mind up from what we read.
We all tend to see and think of things differently doesn't mean its not valuable information to anyone.
Sometimes someone will say something a different way and than it twigs in mind what its all about, this could just be me though

my main point is i don't like to see these threads disappear and no one get anything from it.

There is a few good helpful blokes here

I know I've learned a lot from these guys. Jag was one of the first guys I ever asked for help, and he gave me good accurate info that solved a early problem when I was even dumber than I am now. We bumped heads on some things. Mostly on products that I had been using for some time and new what they really were while he was only going on what they were advertised as. I should try harder to leave my ego in the real world and use this for what it was meant. Learning, helping and a little jab here and there.

 

[Steve Best]

John William Dawson was born here in the wilds of Nova Scotia in 1820. He loved geology and fossils, collected and traded them as a boy and learned all he could about them from his teachers. He went to Scotland for a serious education and came back to Nova Scotia as geologist mainly tasked with finding coal, iron, copper, and phosphate deposits in eastern Canada. He didn't stop there. He surveyed and mapped and took samples from every area he visited, and even took the time to teach at small schools and the local universities along the way. This was the age of Charles Darwin, who Dawson knew personally through his close friend Charles Lyell. While Dawson had diametrically opposite views from Lyell and Darwin, he read all their work and held them in great esteem. You see, while conclusions may differ, it is the work that is important, the thousands of miles of surveying wild blackfly country, the body of study and documentation that others can share and grow from. Personal attack has no place in professional disagreement.

John Dawson's greatest contribution was in the field of coal fossils and how they related to ancient life. As it turns out, he was mostly wrong, but his work and his samples and his efforts lead others in the right directions. The effort and work and documentation is the important thing. So is argument, to test theories.

 

[6blueoval9]

I'm getting an old cylinder and piston sent to me so I can widen the squish band of the stock head from 44 to 47mm.

My hopes are a cooler piston with improved efficiency...rather it makes more power I won't really know because I'm not running the stock squish first...lol

 

[gary55]

John William Dawson was born here in the wilds of Nova Scotia in 1820. He loved geology and fossils, collected and traded them as a boy and learned all he could about them from his teachers. He went to Scotland for a serious education and came back to Nova Scotia as geologist mainly tasked with finding coal, iron, copper, and phosphate deposits in eastern Canada. He didn't stop there. He surveyed and mapped and took samples from every area he visited, and even took the time to teach at small schools and the local universities along the way. This was the age of Charles Darwin, who Dawson knew personally through his close friend Charles Lyell. While Dawson had diametrically opposite views from Lyell and Darwin, he read all their work and held them in great esteem. You see, while conclusions may differ, it is the work that is important, the thousands of miles of surveying wild blackfly country, the body of study and documentation that others can share and grow from. Personal attack has no place in professional disagreement.

John Dawson's greatest contribution was in the field of coal fossils and how they related to ancient life. As it turns out, he was mostly wrong, but his work and his samples and his efforts lead others in the right directions. The effort and work and documentation is the important thing. So is argument, to test theories.

It's funny how Darwin and Dawson had opposing views, but their studies seem to eventually compliment one another's.

 

[Steve Best]

It's funny how Darwin and Dawson had opposing views, but their studies seem to eventually compliment one another's.

And that they had the greatest respect for each other.

 

[JAM Power]

Who's research showed such b/s?.Why is it then that all the engines YOU list on your site as having ideal timming ALL have a squish band?Why is it then that ALL small displacement performance 2t's have a squish band, Are you saying all these manufacture's are wrong and that you know better than they do!You can say that I'm part of the wolf pack that pounces on you,But what do you expect when you constantly contridict yourself.

Street Ryder, an ingeneer I also double about it, but I have tested improvements Jaguar have concluded after a huge research and I can tell you, the Industry of motor kits is making a lot of things wrong conscientiously in order to sell you stuff that doesn't gives you the power and that makes your cilinders, pistons and bearings run faster... China is an production oriented country, not a marketing oriented one, that means that don't give a damn about it some improvement gives to someone value over their investment.

Said that, as engineer I am, I have to research if what Jaguar says is right, in another places, scientific papers and research from professionals like Jennings.

And also I have to make my own calculations to test if the theory fits 48cc 50cc and 66-69cc. Done that then I do modifications and measurements to test the results, and confirm not only Jaguar's ones but also, Jennings, my own and other people researchs to be sure stuff will not crack, brake, burn, explode, or run out quickly.

After oil mixture and carburacion, Timming is everything in 2 strokes... Spark energy, spark maximum gap, exposure of the spark to the mixture, spark duration, are all electrical stuff that comes second but will give you a lot of power if you have the know-how.

Next are porting, bearings change, mufflers modifications, intakes elongations.

By last reed valves, and piston modifications, together with a few more sofisticated stuff that will give you a plus and will gove you a smoothly run.

I can tell you also that bike Motor kits have a lot of flaws, because I corrected 2 factory defects in the muffler and the intake, and gained 58% more, also corrected the spark plugs and gained 200% power output in high and low revs.

BTW: best spark plug gap so far is 0.093" or 2.362mm. bit biu need a powerful CDI to acccieve it, imposible with the stock one.

I have tested compression heads and I'm getting more from a standard off-set cilinder head, due to technical improvements than in my twin (control for the tests) motorbike without improvements (except for cilinder head, that is supposed to give me high compression).

The point is, a lot of stuff is being sold, and a lot of stuff is made wrongly on porpouse ofof y having to buy the "enhancements" they sale, and ending with a Frankenstein, bigger than the necessary to get the same.power from more elegant and refined modifications.

Cilinder heads are not the exception, because stock ones are easy to brake and gets deformed by the pression from the head bolts. So grind them 0.05mm from the base before installing and seal them.

Squish bands are not the exception, also; for our engines poorly fabricated, a squish clearance must have at least 0.015" or 0.381mm, but how will you have that with a deformed dilinder head with variations of .03mm between the cilinder front, rear, and sides?

Practically impossible with the stock ones, but with the CNC ones.

In our stock motors with our stock cilinder heads, squish bands seems to be merely for cooling (very necessary if you get higher RPMs).

 

[Street Ryderz]

Street Ryder, an ingeneer I also double about it, but I have tested improvements Jaguar have concluded after a huge research and I can tell you, the Industry of motor kits is making a lot of things wrong conscientiously in order to sell you stuff that doesn't gives you the power and that makes your cilinders, pistons and bearings run faster... China is an production oriented country, not a marketing oriented one, that means that don't give a damn about it some improvement gives to someone value over their investment.

Said that, as engineer I am, I have to research if what Jaguar says is right, in another places, scientific papers and research from professionals like Jennings.

And also I have to make my own calculations to test if the theory fits 48cc 50cc and 66-69cc. Done that then I do modifications and measurements to test the results, and confirm not only Jaguar's ones but also, Jennings, my own and other people researchs to be sure stuff will not crack, brake, burn, explode, or run out quickly.

After oil mixture and carburacion, Timming is everything in 2 strokes... Spark energy, spark maximum gap, exposure of the spark to the mixture, spark duration, are all electrical stuff that comes second but will give you a lot of power if you have the know-how.

Next are porting, bearings change, mufflers modifications, intakes elongations.

By last reed valves, and piston modifications, together with a few more sofisticated stuff that will give you a plus and will gove you a smoothly run.

I can tell you also that bike Motor kits have a lot of flaws, because I corrected 2 factory defects in the muffler and the intake, and gained 58% more, also corrected the spark plugs and gained 200% power output in high and low revs.

BTW: best spark plug gap so far is 0.093" or 2.362mm. bit biu need a powerful CDI to acccieve it, imposible with the stock one.

I have tested compression heads and I'm getting more from a standard off-set cilinder head, due to technical improvements than in my twin (control for the tests) motorbike without improvements (except for cilinder head, that is supposed to give me high compression).

The point is, a lot of stuff is being sold, and a lot of stuff is made wrongly on porpouse ofof y having to buy the "enhancements" they sale, and ending with a Frankenstein, bigger than the necessary to get the same.power from more elegant and refined modifications.

Cilinder heads are not the exception, because stock ones are easy to brake and gets deformed by the pression from the head bolts. So grind them 0.05mm from the base before installing and seal them.

Squish bands are not the exception, also; for our engines poorly fabricated, a squish clearance must have at least 0.015" or 0.381mm, but how will you have that with a deformed dilinder head with variations of .03mm between the cilinder front, rear, and sides?

Practically impossible with the stock ones, but with the CNC ones.

In our stock motors with our stock cilinder heads, squish bands seems to be merely for cooling (very necessary if you get higher RPMs).

I have been building these engines for over a decade now and Im sure when it comes to testing and logging the findings and seeing what works Ive done alot more than most! I have also been building engines for over 40 years now and though I still lean things all the time I have a very good working knowlage of something so basic as a two stroke and this is what I do for a living.The squish band in a stock head is almost non existant and has to be reworked if you want it to work.Shaving anything of the stock head just yeilds higher comp due to reducing the volume and that raises cylinder pressure well above 130 p.s.i that Jag says will ruin the cylinder and then deffinatly needs proper squish to reduce heat and control detonation.I have run cylinders from 165-185 p.s.i for years with no issue using proper squish with both the stock and cnc heads.Most all the cnc heads are lower comp than stock I would think that an enginneer would know this since its not hard to measure. Any one can achive gains in output from these engines,getting them to last with the increased output is and has always been my goal,and to get way more out of them compared to most of the current user base.My personal current engine is made up of half breed case halfs that are at least 10 years old and have seen various stages of mods over time,the cylinder has been ported twice before its current mapping,my crank has seen two rod changes (with bearing)its over ten years old and used constanly because its balenced to a factor of 40% and trued so I use it in all my highest performing builds because I know it works from all the real world testing I put them through.

 

[Deleted member 12676]

JAM, you should use an original Honda CR high voltage coil which might be able to spark that 2.4mm gap that you want. It does on my tester but that is cheating since the spark plug is not inside an engine and subjected to high pressure. The compression inside the engine fights against the ability of the electricity to spark the gap. More compression means you need more voltage to spark the same gap. But its worth a try.

 

[Bufu racing#1]

I have to disagree. I run 220 psi in my 66cc china motor.