60 MPH...achieveable? Who cares?!? Let blueprint an engine!

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BarelyAWake

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Jul 21, 2009
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o_O

Angst?

The way I see it - this thread holds the potential of illustrating a fully "blueprinted" 2 smoker with speed as a secondary effect...

If it does turn into a buncha mindless "mine's faster than yers" bladebla - we'll just hafta lock it... again.



So just chill and wait fer Jim to get a mo'
 

rockhopper

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Mar 20, 2010
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o_O

Angst?

The way I see it - this thread holds the potential of illustrating a fully "blueprinted" 2 smoker with speed as a secondary effect...

If it does turn into a buncha mindless "mine's faster than yers" bladebla - we'll just hafta lock it... again.



So just chill and wait fer Jim to get a mo'
Shame that this is probably the end of the two strokes for all practical purposes. I really would like to see an exceptional result from this experiment. I'm rooting for the original poster.
 

stuartracing

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I finally got a tach on my motor and just got back from a test to see what my motor was turning....At 32 mph it was running at 7600 rpm`s, as steady as I could hold it that is....And that mph was read on a Wallymart speedo that seems to be fairly accurate by riding next to a car....Give or take a mph or so.....Idle is about 3600 rpm`s....Much lower than that it wants to die out....
So to go 60mph I`m guessing these/or Jims motor would have to be turning some pretty high rpm`s....
 

foureasy

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Jul 9, 2009
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sounds like you need to do some low speed tuning stuart.
i love how the title of this thread changes with the latest posts/moods.
bike speedos are extremely accurate if the circumference of the tire is accurately measured, like rolling through some oil for a few tire revolutions, (with you on the bike) and taking the average distance. the only problem i had was the vibrations would destroy the screen. i just installed one of these yesterday.
https://www.1977mopeds.com/product/2018 it has a thermocouple that goes under the plug washer for head temp and a quality speedo
 

stuartracing

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Yes I agree about the tuning,I`ll get if I have to do a tank full of testing to get it right....But for the mid range port job on int. and exh. it`s not too bad....Plenty of bottom end torque...
I have my screen mounted on some foam for that vibration problem...
 

happycheapskate

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Nov 26, 2009
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Re: title changes / 60 MPH...achieveable? Who cares?!? Let blueprint an engine!

Venice Motor, the title probably changes because people type in the box above the normal text space when replying, or because several threads were merged by moderators.

If you could do 85 on a motorised bicycle people would kill themselves to pass you just because you hurt their egos. America needs to be educated majorly about alternative transportation. PS I don't want to go 85 on a bicycle, even a real Moped. But if you can do it on the drag strip, someone will have to do 86 just to beat you. xct2

60 doesn't sound so earth shattering.... 70+ now that's a treat. You could keep up on the interstate, lol. Dead Man Biking.
 

happycheapskate

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RE: fairing bike. Now THERE's an idea. Maybe if you look more like a cager, they will respect you more.



I'm sure DVBikes can do it. The top land speed for a bike with no motor on flat ground is 80ish mphI think lol. He can either spend thousands on one of those bikes:



Or just get a Morini with a 34T sprocket (;) @ EZRider).

He never said what size engine. It could be a 250cc V-Twin for all we know (or a V-12) lol

My point is it's certainly possible.

Especially with a bad speedometer...
 

happycheapskate

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Go for it and good luck (truly)

Since NASA is out of business, maybe motor bicycles will be the next technology to have trickle down effects for the average consumer. :)

re: Trinidad. It must suck to live in second rate countries, but at least in Cuba etc, you can pretty much drive anything.

I really like the idea of a motor bicycle street race like you mentioned. That is awesome! Is there any video footage?


YouTube - Hicktown (Lyrics) - Jason Aldean

"Let it rip/ when we got the money/ let it roll/ if we got the gas/ it gets wild/ but thats the way we get down, in a hick town!" Jason Aldean

There are those who have years of experience with engines...and there are those who don't.

This is not a pissing contest.

Just calm down, and let things unfold as they will. The reason for making a speed bike has already been stated. It will go to Trinidad when finished. We just figured that forum members would like to see the progress...If not, I will ask the mods to delete this thread, and we will not discuss this build any further. Simple enough! The matter is of a complete indifference to me!

Foureasy...it is possible, using the China engine, to go 60mph+

No...they don't hold NHRA events at Sunshine speedway. It's just a small, hick, track. But they do have the standard traps. I'm sure the customer in Trinidad could care less. We are going to go to Sunshine speedway for the safety aspect. No traffic...and yes they will let us run it down the track!

Jim
 

Venice Motor Bikes

Custom Builder / Dealer/Los Angeles
Mar 20, 2008
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Re: title changes / 60 MPH...achieveable? Who cares?!? Let blueprint an engine!

Venice Motor, the title probably changes because people type in the box above the normal text space when replying, or because several threads were merged by moderators.

If you could do 85 on a motorised bicycle people would kill themselves to pass you just because you hurt their egos. America needs to be educated majorly about alternative transportation. PS I don't want to go 85 on a bicycle, even a real Moped. But if you can do it on the drag strip, someone will have to do 86 just to beat you. xct2

The Mods have changed it a few times... I'm wondering why?
 
Sep 20, 2008
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web.tampabay.rr.com
And the final name change will read...

HOLY CRAP HE DID IT!!! laff

Seriously,

I've got other obligations that have to be filled first. Running production is boring and I would much rather be dickin' around with this project...but that's not life in a shop that has overhead to pay.

Jim
 

meowy84

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Jul 18, 2009
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I'm kind of late in posting this but being a bit anal.....here it goes....I'm a newb here, just on my first build but I can't resist and have to mention a few things and make a couple of observations. I'm not trying to step on any toes, hurt anyone's ego and mean no disrespect whatsoever. The point is that there is almost never a black or white scenario. The truth and reality is almost always in the grey.

First, the title of the thread when first posted mentioned trying to achieve 60mph but the real emphasis in the title seemed to be on blueprinting. Yet so many got hung up on the 60mph part and that it couldn't be done before even hearing what 'mods' CreativeEngineering had planned. Reminds me of all those engineers/physicists/scientists saying that an object heavier than air can never fly. Then came the Wright brothers and the rest is history. If his aim was 120mph+ then the negatives would have been more warranted and even then you could say that sure 120mph is possible from the HT engine if you threw it off a high enough cliff to achieve terminal velocity.

I guess it all depends how scientific you want to be about this challenge.



Armchair engineers abound, the speed claims have always been a touchy issue, newbs whom think a sprocket swap will achieve mach 2.567 exactly 'cause "they did the math"...

Let's not even get started on those that think a $10 wallyworld speedometer is even vaguely calibrated - even if they know enough to switch it from KPH to MPH lol, so many obsessed with speed alone - they have no idea what it takes to get there, one-upmanship the primary interest they'll happily tack on another 2-5-10 even 20mph to impress. Yet so terribly few will provide any substantiation, posting all sorts of pics of their shiny bike, even vids on youtube - yet somehow they jus' can't seem to find the time to hand the cam to a buddy, to film the car's speedometer whilst they ride...
I agree here that selective censorship is necessary on here to keep the quality of the information accurate and free of the 'oh yeah, well my dad can beat up your dad' immaturity, especially for the newer members such as myself. While quite familiar with 4 strokers I must say I'm a relative newb when it comes to 2 strokers and my only real 2 stroke experience is with 2 stroke model glow engines. :) Coincidentally can these HT spark ignition 2 strokers benefit from exhaust throttling in addition to the carb throttling as is often done on glow engines which increases the throttle response?

As to the car speedometer, I hope you weren't being entirely serious. :) I know I may be splitting hairs here but I don't think that that particular method of measuring speed is entirely precise either. Sure, it can give a rough hobby level idea of the speed but it is not at all uncommon for car speedos to have an error margin of +/- 5mph or more. Then there's other factors too on top of that. Heck, just changing from bald worn tires to brand new ones will change your speed at a given engine rpm by the difference in the circumference between the bald and new tires. I do agree with you on the wallyworld speedo thing however. Heck even the most expensive speedo you can get from the "house of Spandex" with spot on calibration is no good since all the ones I've seen you yourself enter the diameter of your wheels/tires but without taking into consideration the weight of the rider and how much that rider will compress the tires reducing their circumference and so skewing the actual speed reading. So the only accurate and precise way of measuring speed would be through the traps like CreativeEng wants to do. IMO anyways. :)



Crank bearings?

What about the crank bearings & the seals?

They must be bad...right?

Not so fast there skippy...let's have a look at reality for a moment.

There are very few bearing manufacturers on the the planet. In order to stay competitive in a global market certain ISO, (Interntional Standards Organization), standards must be adhered to. The fact that this is a cheap Chinese Bicycle engine does not mean that there is a cheap Chinese bicycle engine bearing manufacturer. Given the capital outlay for a bearing plant, and the fact that a high volume is critical to success...there's not even the slightest chance that the crank bearings in these engines are sub-par!
I do have a bit of an engineering background let's just say but I am not a machinist per se yet I can appreciate the quality of your work and believe your project is not only feasable but very doable indeed. However I must disagree on the bearing issue. There are bearings and then there are bearings. ISO provides certain, essentially minimum standards, that manufacturers in a particular sector should adhere to. Some meet these standards while others exceed them. Others fall somewhat short yet their goods are in circulation nevertheless. I haven't enough experience with the HT engines to pass judgement on bearings in them but quality-wise these engines leave much to be desired and if bearing failures in these engines are common I seriously doubt the bearings are top of the line. To illustrate, install the same quality bearings in a properly machined engine (like the one you're working on for instance) versus an off-the-shelf HT engine with misaligned cases and guess where the bearings will last longer? It's a combination of soundness of original design and final execution.

ANYWAYS, thank you all for listening to my rant. And please I'll give you my milk money just don't give me a wedgie. :)
 

BarelyAWake

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Jul 21, 2009
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As to the car speedometer, I hope you weren't being entirely serious. :) I know I may be splitting hairs here but I don't think that that particular method of measuring speed is entirely precise either. Sure, it can give a rough hobby level idea of the speed but it is not at all uncommon for car speedos to have an error margin of +/- 5mph or more. Then there's other factors too on top of that...
Ofc you're right - but the filmed chase car's speedometer is a compromise for those that don't have a GPS or access to a track and it helps to reduce the potential for "clever" bicycle speedometer shenanigans. While a car's speedometer is most definitely NOT a precision instrument, it's not as prone to such easy abuse as switching the MPH to KPH and then sayin' "ZOMG I did 47" or whatever lol

Here's a previous lil rant on the subject of car speedometers ;)

It's commonly accepted that even the factory speedometer in a car has a comparatively large margin of error: Speedometer error, Wikipedia whereas even the basic modern GPS has only about a 0.1 knot (about 0.1 mph) variance if tracking four satellites: Global Positioning System, Wikipedia.

Throw in the problem that it's simply impossible to have a "correctly calibrated" bicycle speedometer with the fact that when discussing MBs we're often bickering over even 5mph increments - such speedometers are really only good for "ballparking" speed estimates at best. Even the "radar trap" signs aren't nearly as accurate as we've been lead to believe (target size and vibration have huge effects): Radar gun, Wikipedia, to the point where speeding tickets have been contested successfully with GPS data: GPS Data Used To Disprove Radar Gun In Speeding Trial

For just $10-20, sure a digital bicycle speedometer is a fun toy to give ya an idea of your speed - IF you can manage to get it set even vaguely correctly, but remember the faster you go - the larger the error, whereas the opposite is true with a GPS as it'll get more and more distinct tracking information beyond say a slow walking speed (about 3mph).
 

meowy84

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Jul 18, 2009
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BarelyAWake, yup you're right. Even GPS is not 100%.

Someone else also made a comment not to ask if you can do this 'blueprinting' with a Dremel. I say NEVER say NEVER. If you're like McGyver you can go to the Moon with a couple CO2 canisters for propulsion, a coathanger, some bubble gum and an old tent. I swear on the workmanship of my HT I've seen it done! laff

The basic premise of blueprinting is to try to compensate for the often mass volume manufacturing techniques and to get every engine component to the dimension as it was originally indended by the designer in his 'blueprints'. Without a machine shop and lots of skill you can't do all that CreativeEngineering is doing. However, you CAN do quite a bit of basic blueprinting with very simple tools, including a Dremel. :) At least on multicylinder engines and if not for all-out performance than at least for longevity which also does transalate to free performance gains. I have some hours logged playing around with American V8's and VW air cooled flat fours. The VW is probably most similar to our engines in that it is also air cooled and the crankcase consists of 2 halves. Anyhow, you will find that when buying new rods and pistons their weight varies. You may find that the weight spread between the lightest piston and the heaviest one in a group of quality pistons might still be say 5 or 10 grams. Well even 5 grams spun at say 5000rpm is a huge deal and will over time pound out your bearings more. So we used to grind the pistons with the handy Dremel to make sure they're all the same weight. That's very basic blueprinting. Same goes for the rods. You just need to be very selective and mindful where to take material off. Then there's cc'ing the combustion chambers which can also be done with the Dremel to ensure same combustion volume in each cylinder which reduces engine vibration and makes for a smoother idle and throttle response. Then there's intake and exhaust matching so the mixture goes in smoother with less obstructions and exhaust comes out easier as well. The easier that mixture can enter the engine the more of it will enter per cycle increasing performance. Same with exhaust gasses. You want to get them out of there as fast as possible. You don't get this as much in the HT engines but in the VW jugs the fins are relatively close together and in new rebuild kits you will often find quite a lot of casting flash between the fins which you can remove with a hacksaw and a small file. This way cooling air has a better path around the fins providing better heat dissipation and so better performance. Now I've never tested the power gains with this simple blueprinting on a dyno but I'm sure that on an stock VW engine rated at 60bhp it probably does free up a horse or two but more importantly it does lead to smoother idle and throttle response, less vibration, cooler temperatures and ultimately longer engine life. Then of course you get into more advanced blueptinting where you need the machine shop and lots of expertise and then you can you align hone the cam and crank bearing saddles, match and dowel the case halves as Creative Eng is doing, and the list goes on and on.

With the 1 jug HT engines you obviously can't do much cc'ing or piston or rod matching but you can still match the intake and exhaust and if you know anything about port timing and such on 2 strokes do some port smoothing. There are also ways to statically balance you con rod without many tools which might also increase the longevity of these 'cheapie' engines. Since personally I have little experience with 2 strokes I'll just smooth the intake and exhaust ports and deburr here and there. And all with your Dremel and a couple of jewellers files. The bubble gum is optional. :)
 
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