Goniometer ???

[acidburn_2001]

What exactly would you use a GONIOMETER for when tuning a 2st engine and how would it work?

I assume it would be used for finding port timing and that it would attach to the crankshaft....but you know what assume means :nod:

Please excuse me if this needs to be moved for any reason
Thanks Joe

 

[digifox]

A goniometer is an instrument that either measures angle or allows an object to be rotated to a precise angular position.....

So i would guess that...lol

 

[inotocracy]

^ Wikipedia to the rescue? :p

 

[dirt bike dave]

Well, I'm familiar with the goniometer after I destroyed my knee, but never used one on a motor.

My guess is it would be used to measure the angle of the rod at certain points of the stroke. With some math, it could be used to determine the optimum connecting rod length for the application, or to compare the angles of various known rod lenghts.

 

[Rich Rohrich]

I've been around a little bit and I've never heard (or used) the word goniometer in a conversation regarding a two-stroke. :)

Degree wheels are used all the time, to verify port timing and ignition advance. There are times where the angle of the transfer port roof, or the angle of a rear boost port might need to be measured, but I've always found it easier and much more accurate to make a port mold and measure the mold slug. With a mold slug pulled from a port you could use a goniometer to measure the port angle.

A lot of tuners make aluminum templates set at specific angles and use them as Go / No-Go guages to verify port roof angles.

Anything that can measure an angle is a potentially useful tool, but given the limited working space most commercially made goniometers (i.e. protractors, angle finders) are not very practical for our use in the engine.

 

[IndyMX]

After reading this thread this morning, I found it odd that I saw a device with that name on it at Physical Therapy.

 

[XRpredator]

and here I thought we were talking about groinometers and what they measure . . .

 

[Rich Rohrich]

and here I thought we were talking about groinometers and what they measure . . .

Dangle angle ? :whoa:

 

[IndyMX]

Dangle angle ? :whoa:

What's this dangle you speak of? :yikes:

 

[julien_d]

lol, he said dangle....

 

[jsantapau]

the angle of the dangle is directly proportional to the mass of the :moon:

 

[acidburn_2001]

thanks Rich the goniometer that I saw wasn't as technical as that one. The one I saw was a red plastic disc that was marked 0-360 degrees. Do they normally just bolt on to a crank or something?

I believe the correct formula is as follows:

Heat of the meat X
Angle of the dangle=
The mass of the A$$

However I could stand corrected as I haven't been in need these calculations for some time now. And could someone please explain how the mass seems to growing exponentially for the past 8 yrs :laugh:

 

[whenfoxforks-ruled]

Acid, that is correct, they are for reference for the crank or cam. Jsantapau, it does correlate with gravity and old age also! Gravity sucks!

 

[Rich Rohrich]

thanks Rich the goniometer that I saw wasn't as technical as that one. The one I saw was a red plastic disc that was marked 0-360 degrees. Do they normally just bolt on to a crank or something?

If it's full circle and marked in degrees, you are looking at a "degree wheel". Old school two-stroke tuners use it to determine port height versus port timing in degrees. Since about 1983 I've been using a computer do do this far more accurately. I think a lot of tuners go the computer route these days.

The common use of a degree wheel is by four-stroke engine builders to determine cam timing. No computerized way to do this job. :)

Here's a picture of a degree wheel mounted on Okie's YZF262 while I was doing final assembly and checking cam timing.

 

[IndyMX]

If it's full circle and marked in degrees, you are looking at a "degree wheel". Old school two-stroke tuners use it to determine port height versus port timing in degrees. Since about 1983 I've been using a computer do do this far more accurately. I think a lot of tuners go the computer route these days.

The common use of a degree wheel is by four-stroke engine builders to determine cam timing. No computerized way to do this job. :)

Here's a picture of a degree wheel mounted on Okie's YZF262 while I was doing final assembly and checking cam timing.

I've never had occasion to use a degree wheel.. How do you read it to set the cam timing in the pictured situation?

And could someone please explain how the mass seems to growing exponentially for the past 8 yrs

Food & Beer.. ;)

 

[acidburn_2001]

That's the one....and that's used by old school tuner's to find port timing and such? I promise I'm nowhere near ready to break out a die grinder or dremel, however if I had a cylinder in an engine and wanted to copy the port timing I could go the poor man's way and use a degree wheel?

While I'm not ready to have at it yet this is something I would like to consider (just to prove to myself and have fun) doing on an old cylinder I have lying around. The engine I would want to copy from is an Italian made BZM 50cc 2st liquid cooled 6 port intake single port exhuast 40mm piston, 39.2mm stroke anything that I should be aware of(besides the risk of an engine not running when I'm done)

 

[whenfoxforks-ruled]

Wait till you see the price for porting clay. Eric is really cheap!

 

[acidburn_2001]

I'm only looking to have some fun, and it would be on an old (near useless) cylinder. While I'm a Sandblaster/Painter by trade, I get a lot of enjoyment messing around with bike engines. I think the unknown result, wether good or bad is what draws me to wanting to tear an engine down

Thanks to rich for clarifing it's actually a degree wheel, and to those who responded with humour

 

[High Lord Gomer]

I always thought it was:

The angle of the dangle is directly proportional to the heat of the meat and inversely proportional to the stench of the wench.

BTW, a goin'ometer is used when you don't have a speedometer, but you want to be able to tell people how fast you was goin'.

I wuz goin' at least a hunnert!

 

[acidburn_2001]

:laugh:

 

[Ol'89r]

I always thought it was:
:yikes:

BTW, a goin'ometer is used when you don't have a speedometer, but you want to be able to tell people how fast you was goin'.

OH GAWD! This thread is goin' down hill. :whoa: Don't need no meter to tell you that. :nener: :moon: :rotfl:

 

[Ol'89r]

I've never had occasion to use a degree wheel.. How do you read it to set the cam timing in the pictured situation?

Indy. All a degree wheels does is tell you the postition of the crankshaft. You have to set top dead center and use a pointer to tell you at what degree the crank is. If you will notice, Rich has a little pointer pointing at the 34 degree mark. Once you determing tdc, you rotate the engine until you come up to the degree that the cam should open and then rotate it until the cam closes. When you buy a cam it will come with a cam card or spec card. It will tell you that, for instance, the intake cam should open at 45 degrees before top dead center and close at 75 degrees after bottom dead center.

By using a degree wheel and a dial indicator on the lifter, it will tell you exactly where your cam is opening and closing. Of course, there is a lot more to it than that, but those are the basics.

 

[IndyMX]

Indy. All a degree wheels does is tell you the postition of the crankshaft. You have to set top dead center and use a pointer to tell you at what degree the crank is. If you will notice, Rich has a little pointer pointing at the 34 degree mark. Once you determing tdc, you rotate the engine until you come up to the degree that the cam should open and then rotate it until the cam closes. When you buy a cam it will come with a cam card or spec card. It will tell you that, for instance, the intake cam should open at 45 degrees before top dead center and close at 75 degrees after bottom dead center.

By using a degree wheel and a dial indicator on the lifter, it will tell you exactly where your cam is opening and closing. Of course, there is a lot more to it than that, but those are the basics.

Cool. Thanks. Good explanation.

 

[High Lord Gomer]

Cool. Thanks. Good explanation.

Good explanation my a$$! He didn't include any nude supermodels or pictures of Abe Vigoda...basically worthless.

 

[Ol'89r]

Good explanation my a$$! He didn't include any nude supermodels or pictures of Abe Vigoda...basically worthless.

You never sent the nude picture of Abe Vigoda back. :nener: :moon: