Do aftermarket cylinder jugs exhist?

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exokinetic

New Member
Mar 18, 2016
108
4
0
Lake Forest, CA
My dream component is a knock sensor, a high definition crank position sensor, and a computer controlled ignition system that keeps the spark advance at the absolute maximum, and takes timing out when it needs too as it senses knock.

So you ride the maximum spark advance curve no matter what the conditions are.

Colder outside? Hotter? Elevation Change? Humidity Change?

Knock sensor loop compensates.

Change Fuel? Raise Compression? New Pipe?

Knock sensor loop compensates.

Jetting not quite right? Yea, you will be slightly down on power, but the knock sensor loop will be giving you the maximum available power from the current jetting.

It's what makes today's turbo cars -gas and diesel- so much more efficient than their pre-knock sensor brethren.

Apollo Moto Racing is currently in the R&D phase researching the necessary components, and how to engineer a system of incorporating them into the "China Girl" type 2 stroke engine.
 

sbest

Member
Nov 3, 2015
343
2
18
Nova Scotia
I have some experience with knock sensors from work I did on my 84 and 85 SVOs and and 94 Supercoupe. The 84 dropped the timing back 3 degrees when it picked up a hit, the 86 dropped it back 1 degree at a time up to 5 or 6 IIRC and the 94 was almost totally ineffective as far as I could tell. It is simply a tuned crystal microphone.

My Grubee GT5A had an odd rattle under heavy load, like popcorn popping sound. It is detonation. It bent the head and blew the gasket and would have eventually taken out the bearings. What was the answer? Cylinder head chamber design.

Evolved machine design goes from simple machine to add on features to incorporated features and mature designs that simplify again by incorporating the features into the basic design. Add-ons like knock sensors are a band-aid.

Steve
 
Aug 26, 2015
472
6
18
Overgaard AZ
I didn't want to be the one to point that out... EFI systems are a bit more complex, but would address more of the issues, again only a band aid. The chainsaws I refered to run like sexually assaulted primates to begin with, adding EFI just eliminates tuning and makes starting a little easier. In the real world, the difference isn't as noticeable as you would think, at least not in my experience, in fact, the carbureted MS 290 has noticeably more poop than it's EFI counterpart, again in my experience.

Again any thing that can be bolted to a ChinaGirl to make it run better, and actually works, gets my vote. Especially if it will out last the 3000 mile lifespan of these cylinders, so I can use it on the next one.
 

sbest

Member
Nov 3, 2015
343
2
18
Nova Scotia
I`m on over 10 tanks of gas now, losing count.
Cylinder got scratched up bad from running the original aircleaner.
Running a better air cleaner now and still the scratchy cylinder with some porting.
Making good power and runs all day at around 50-60 kph. Love these things.

Steve

 
Aug 26, 2015
472
6
18
Overgaard AZ
Nice bike Steve! Needs more maple leaf than that itty bitty one, and don't you hate the cable mess? I don't pedal much, only to start, needless to say, things simplified after paint...

I was at 2,756 miles, before my CDI took a dirt nap, the first part failure. I've never had the head off, no clue what nastiness is going on in there. Going to pull the head soon though, around 3000 maybe, probably the jug too, as I think I heard the needle bearing the other day...

Oh and I see that tank dimple from the handlebars, were you on it when it fell over, or am I way off the mark? I only bring it up cuz ise gots one too! It almost hurt, nearly ate an Avalon.
 

exokinetic

New Member
Mar 18, 2016
108
4
0
Lake Forest, CA
I have some experience with knock sensors from work I did on my 84 and 85 SVOs and and 94 Supercoupe. The 84 dropped the timing back 3 degrees when it picked up a hit, the 86 dropped it back 1 degree at a time up to 5 or 6 IIRC and the 94 was almost totally ineffective as far as I could tell. It is simply a tuned crystal microphone.

My Grubee GT5A had an odd rattle under heavy load, like popcorn popping sound. It is detonation. It bent the head and blew the gasket and would have eventually taken out the bearings. What was the answer? Cylinder head chamber design.

Evolved machine design goes from simple machine to add on features to incorporated features and mature designs that simplify again by incorporating the features into the basic design. Add-ons like knock sensors are a band-aid.

Steve

So why then would modern turbo cars still have knock sensors, with much more advance logic.

Like for instance the new Ford Ecoboost, that has basically become a legend of efficiency and performance.

Yea, it uses a knock sensor...
 

mobike91

Member
Sep 14, 2010
111
2
18
lebanon, oregon
Have any of you guys seen the GT80 engine that costs $200 from kings? Its pretty neat for what it is. I did a piston skirt job on my piston tonight. Let me know what you guys think. Also check out the porting job they did on the jug.



Doing this from my cellular device. Gotta post one pic at a time lol
 

sbest

Member
Nov 3, 2015
343
2
18
Nova Scotia
Nice bike Steve! Needs more maple leaf <SOME SNIPPED>
Are you old enough to remember Chevy Chase: "Needs more Cowbell!" ?

Pretty sharp eyes on the tank handlebar dimple.
Yup I took a header right in my own driveway reached down to open the choke and BANG! Landed on my head.
Thanks for the helmet, even in the driveway, no serious injury.

So why then would modern turbo cars still have knock sensors, with much more advance logic.
Like for instance the new Ford Ecoboost, that has basically become a legend of efficiency and performance.
Yea, it uses a knock sensor...
Not yet mature designs.
These are design evolution theories, not mine. Just spreading the thought.
The goal for the design engineer is to build without the add-ons.

My SVO runs quicker 1/4 miles with the knock sensor disconnected, as do most cars.


Mobike91, I just bought a RSE Reed Valve but darned if I didn't buy a 32mm one when I am running a 40mm cylinder right now.
I am not impressed how stiff the pedals are. It takes a lot of draw to open them.

Steve
 

mobike91

Member
Sep 14, 2010
111
2
18
lebanon, oregon
I completely agree on the pedals, they're like as stiff as yamaha blaster stock reed pedals. Might have to buy some V force reeds from a bike kit and Cut them down to size, either that or maybe loosen them up some. They seem kinda thick for the size of engine.
 

exokinetic

New Member
Mar 18, 2016
108
4
0
Lake Forest, CA
The goal for the design engineer is to build without the add-ons.
Totally agree.

Something still has to tell the spark plug when to fire.

This thing also has to know at what crank angle (in degrees) will result in the most efficient extraction of energy from the filled cylinder.

Untill someone discovers some ubiquitous method of firing the plug without "add-ons" we will have to live with some form of external spark control.

Or we could all drive diesels?

....or jet engines?
 

a.graham52

New Member
Nov 22, 2013
232
1
0
island of misfit toys, maine
Knock sensing system is a bit different depending on the manufacturer but all pretty similar. There is a target timing curve that is programmed into the module by the engineers. When knock is heard timing is then cut back a set amount of degrees. Some vehicles will go to a complete different curve or map for a duration of time and then swith back. And repete if knock is heard.

Knock sensing system alone does not give you best or maximum timming. That's all in the programming for target timming. A feather of your ignition module. The added knock sensing system is more of a failsafe In the event of bad gas, over heating, ect.

And to top it all off. I suspect the engines "internals" would be too noisy to properly detect the difference between knock, piston slap, and normal firing.