GTC 340

joshua. c.

joshua. c.

Well-Known Member
#21
#21
one of the major advantages of the original 340 was it was near perfectly balanced and didn't vibrate much. and the jr drag unit coold handle some serious power. If these copy's cant do that than I'm just lost all interest. hopefully these issues are just from these being new to the market and needing a good shakedown.. I'll wait on purchasing any until they are addressed by the manufacturer. it almost seems like these were rushed to market in response to the juggernaut. this seems like a rather poor copy for a company that has been sitting on this products development for so long. you would have thought after listing them as ion development for years that this would come out as a flawless well tested improved version of the original. god knows they had the time to do it right.
 
delray

delray

Well-Known Member
#22
#22
have you thought maybe making it out of a piece of billet aluminum round stock. you have all the equipment? you would need a index table to make the shaft end. cast steel got to be just dead weight to spin. specially for a performance application setup.
DSC02098ole4 new gtc.JPG
 
ole4

ole4

#24
#24
no been working on heads. I machined the webs and it is still out of balance. I will have to make a steel weight and tig it on to the heavy side. It is still on the bench just like the picture above. Here is a picture on the back where I machined off the ribs. I am having a issue with my M head bridgeport where I cant use the boring head to make a clean hole. It sets up a harmonic chatter that leaves a pattern when boring. An old machinist once told me the pulley hub had too much play on the splines of the quill and that was why when I went from a climbing mill and then switched directions it would jump but back then it bored just fine. I think from doing some reading on the practical machinest forum it may be the spindle bearings loosing the preload from me banging on the drawbar trying to get one of the tapers out. I found a new spindle with the hub top NOS (my M head is from 1943) and I found all 6 bearings including the annular groove spindle bearings.
 

Attachments

delray

delray

Well-Known Member
#25
#25
ole4 said:
no been working on heads. I machined the webs and it is still out of balance. I will have to make a steel weight and tig it on to the heavy side. It is still on the bench just like the picture above. Here is a picture on the back where I machined off the ribs. I am having a issue with my M head bridgeport where I cant use the boring head to make a clean hole. It sets up a harmonic chatter that leaves a pattern when boring. An old machinist once told me the pulley hub had too much play on the splines of the quill and that was why when I went from a climbing mill and then switched directions it would jump but back then it bored just fine. I think from doing some reading on the practical machinest forum it may be the spindle bearings loosing the preload from me banging on the drawbar trying to get one of the tapers out. I found a new spindle with the hub top NOS (my M head is from 1943) and I found all 6 bearings including the annular groove spindle bearings.
Click to expand...
interesting when you take it apart and see what was jumping around on you.
 
ole4

ole4

#26
#26
that is the problem, If I put an indicator on it its rock steady no lateral or up and down play.. I have read that the spindle bearings which have a inner and outer spacer between them have a preload measured in microns and if you lose that it can cause symptoms like I am having. I don't know why I cant measure it but I joined practical machinist forum and will ask there. I had already found a lot of useful info there on the bearings.
 
delray

delray

Well-Known Member
#27
#27
ole4 said:
that is the problem, If I put an indicator on it its rock steady no lateral or up and down play.. I have read that the spindle bearings which have a inner and outer spacer between them have a preload measured in microns and if you lose that it can cause symptoms like I am having. I don't know why I cant measure it but I joined practical machinist forum and will ask there. I had already found a lot of useful info there on the bearings.
Click to expand...
hard to say until you pull it apart. maybe without a real load on it the indicator will read fine,but under a load it whats to move around?
goodluck on it ole. sounds like alot of fun work.
you'll figure it out.
 
BenWeatherley

BenWeatherley

Member
#28
#28
My harrison wildcat I'm restoring had a salsbury 330 driver and driven. The driver is long gone. Could I use one of these gtc340 units? Does the 340 use a wider belt than the 330 did? Cheers
 
J

jayJams

Active Member
#37
#37
ik this isnt the right area to talk about this but my mini bike is acting weird its hard to start so ole4 told me to tighten valve lash etc it worked but the more i run the engine, the harder it is to start plzz help me
 
mustangfrank

mustangfrank

Well-Known Member
#38
#38
jayJams said:
ik this isnt the right area to talk about this but my mini bike is acting weird its hard to start so ole4 told me to tighten valve lash etc it worked but the more i run the engine, the harder it is to start plzz help me
Click to expand...
You really won't get noticed posting under an old unrelated post. Click on the sub forum, like "Engines and Modifications" and look for the "Post Thread" button there, I believe it is usually in the top right corner area of the page.

@ole4

He'll see he's been mentioned now.
 
joshua. c.

joshua. c.

Well-Known Member
#40
#40
any new updates on these clutches? has the company solved the production issues? and did oli4 manage to balance his driven clutch yet?

hay oli4 idea for you, if you find a repeatable fix for these clutches you could buy and fix them then re sell them as a better balanced clutch for a profit.
 
You must log in or register to reply here.
Top