big_wasa
|
| posted on 16/11/08 at 08:38 PM |
|
|
Help on re-spacing Tb's
I am cheesed of with the locost so I am playing with my other hobby, engines 
I am respacing a set of 5vy Tb's to go on a zetec.
Any ideas on extending just one throttle linkage 34mm.
I dont think extending the finger 34mm is the answer.
Reading PPC the other month its the main gripe that Dave Walker has with them.
cheers all
 
|
|
|
|
|
David Jenkins
|
| posted on 16/11/08 at 08:47 PM |
|
|
This is what I did with my bike carb linkages:-
I first tried silver-soldering an extension onto the tab, but it proved to be almost impossible to keep everything in line. This idea was eventually
scrapped, and I resorted to MIG-welding the extension pieces on. Each piece was clamped to a steel block to keep everything aligned, then the weld
made and a grinder used to tidy things up. I made a groove under the two pieces where they were to be welded, to ensure that they didn't end
up fixed to the block! Finally the pieces were tidied up and oil-blacked to improve their rust-resistance.
I then rough-shaped it (as in the picture), tried it for size and function, then tidied it up.
|
|
|
omega 24 v6
|
| posted on 16/11/08 at 08:47 PM |
|
|
why not?? if your worried about deflection/bending then us a small anle and taper it up to the fixed lug and tig it on.
If it looks wrong it probably is wrong.
|
|
|
MikeRJ
|
| posted on 16/11/08 at 09:28 PM |
|
|
Extending the fingers out a few mm isn't a problem, but 34mm isn't really going to be viable if you want a rigid, repeatable throttle
linkage.
Ideally you want an extension that long to be supported at both ends, which adds a bit of complexity but is entirely possible. If you start with the
linkage shown in Daves picture, one possibility would be to cut the tab off and solder/weld a tube off appropriate length to the remains, making sure
you get the flat sided hole well centred. By choosing a large enough diameter you can get a nut down to tube to fix it on the end of the spindle. At
the other end machine a small piece of bar to have the correct thread for the spindle, and an outer diameter that fits snugly into the tube mentioned
above. You can then weld a tab onto the tube in the required location and you have a perfectly rigid assembly.
A bit like this:
 
Throttle spindle extension
|
|
|
David Jenkins
|
| posted on 16/11/08 at 10:05 PM |
|
|
quote:
Originally posted by MikeRJ
Extending the fingers out a few mm isn't a problem, but 34mm isn't really going to be viable if you want a rigid, repeatable throttle
linkage.
Fair comment - my longest extension is only around 20mm long after welding.
|
|
|
scutter
|
| posted on 17/11/08 at 07:43 AM |
|
|
Not giving an answer, but this is the reason people use seperable throttle bodies not paired, It makes each extension only 12-14mm.
That said, i do like the answer above, if a little fiddly.
ATB Dan.
The less I worked, the more i liked it.
|
|
|
flak monkey
|
| posted on 17/11/08 at 08:27 AM |
|
|
Just done mine this weekend, but my longest extension was 25mm. Seems rigid enough, just TIG weleded the extensions on.
Time will tell though....
Perhaps weld some ribs on either side as well? This will stiffen it up no end.
David
Sera
http://www.motosera.com
|
|
|
bbwales
|
| posted on 17/11/08 at 09:58 AM |
|
|
Hi,
When I put the R1 carbs on my Ford DOHC I had to respace the carbs by 40 and 45 mm and found that the plates did twist and gave me different throttle
reactions (found by having a seporate vacuum gauge on each inlet). I resolved the problem by welding on a second strip of steel under the control
arm.
HTH
Bob
|
|
|
Rob Lane
|
| posted on 17/11/08 at 10:17 AM |
|
|
Dave Walkers just a moaning old bugger If it doesn't suit him he doesn't want to play.
Why not even out the linkage if you are concerned about distance.
i.e. Cut off the tab and the adjustable 'u' and weld on a small flat extention to each and reweld to cut point. That would extend each and
make the adjustment point central. Use slightly thicker material for stiffness.
|
|
|
MikeRJ
|
| posted on 17/11/08 at 12:31 PM |
|
|
quote:
Originally posted by Rob Lane
Dave Walkers just a moaning old bugger
Possibly, but he's also got a lot of experience and knows his stuff. He's always been very polite and helpful when I've spoken to
him, but I think people turning up for a mapping session with half baked bodges that he has to spend time rectifying does tend to annoy him!
|
|
|
big_wasa
|
| posted on 18/11/08 at 09:29 PM |
|
|
cheers for the help, It was going really well,
Untill the wife started, nag nag nag that is then Fu**ck it as I ran the lathe tool in to the spindal and bent it 
|
|
|
David Jenkins
|
| posted on 18/11/08 at 10:09 PM |
|
|
You wouldn't bend it on my lathe... if I ran the 1" square tool into the chuck something's going to break with a BIG bang!
|
|
|
MikeRJ
|
| posted on 18/11/08 at 11:03 PM |
|
|
quote:
Originally posted by big_wasa
cheers for the help, It was going really well,
Untill the wife started, nag nag nag that is then Fu**ck it as I ran the lathe tool in to the spindal and bent it
Bugger
|
|
|
big_wasa
|
| posted on 21/11/08 at 09:56 PM |
|
|
Not to worry, I will have another go when I pic some more up .
|
|
|
