So, maxcichon and I were talking last night, and the subject of the old 68mm TB I have came up.
Max says he can bore it to 74mm in his shop, no problem, but neither one of us can figure out how to pull the butterfly shaft out without breaking something.
Anyone have any advise / experience in this area ?

 

Or a dead/broken/inoperable TB that I can dissect to figure it out? I'll pay shipping.

 

Seemed possible when I looked into it, and Beaner gave me one to study. I did not have the bal!s to try in the end as I did not want to screw his one up. I ended up buying the larger one and it worked straight out the box when the sensor was changed.

THE RUDY said he ended up with a box of broken parts for his efforts.

The question remains though, why bother?

Of course if the challenge is 'because it's there', then it's a different ball game.

How hard can it be?

 

I looked at one time and decided that I didnt want to destroy my TB.... but I recall reading somewhere that there is a retainer on the rod, under the cap on the side opposite the electronics.... I think...

Pics would be great if you find a scrap one the play with....

 

You nailed it, Dave. It's "because it's there", and "how hard can it be" too ........
Mainly, it's because when I want to do something, I don't want to be told I can't.

 

about the best you can machine is 4mm you wont get a 74mm t/b but a 72mm. the stock srt6 t/b is 74 so why not just use that? they are all over the scrapyards as they were used on slk 32 srt6 c32 e55 pre 21 and clk430
if you must bore it send it to maxbore.com. 125$ with a new butterfly

 

You know, I'm just about done here.

FI.

 

I measured it and I think you can get to 74mm. I never had the bottle to do it though. The warnings from Rudy were ringing in my ears as I contemplated putting it on a face plate in my lathe and making chips. So with only one TB to screw up I got a 74mm one from Potomac. Call me chicken if you like. CLUCK CLUCK.

To do it as an exercise I say go for it.

 

If you have to tooling and a spare laying around why not go for it? I wouldnt buy a new TB if I had access to the machinery necessary to bore out my TB and make a new butterfly. Some things are just more satisfying when you do it yourself. If Maxbore can do it why cant anybody else?
Go for it!