Exhaust thread replacement

[comnoz]

I have uploaded a new video showing how I do exhaust thread replacement. Jim

[video]http://youtu.be/ZPQc-mHtkiA[/video]

 

[Peter R]

Good video Jim, thanks for posting.
You make a complex job look very easy..

 

[comnoz]

Good video Jim, thanks for posting.
You make a complex job look very easy..

Yeah, they get easier after about the first 500 of them....

 

[boz]

In my mind the question is how long did it take to do the first one? The set up, programing, measuring must have been quite the project to get to this point. Very impressed. Wish I could do things like that.

 

[dennisgb]

Awesome!

That Aluminum Bronze makes an interesting sound when it's cutting...

Your giving away all your secrets Jim

Dennis

 

[comnoz]

In my mind the question is how long did it take to do the first one? The set up, programing, measuring must have been quite the project to get to this point. Very impressed. Wish I could do things like that.

Well I started out doing them 25 years ago on a manual Bridgport with a boring head and a big tap. I made the inserts in a lathe. It has slowly progressed to this.
I can now turn them around much quicker but the care and feeding of a CNC machine is considerable. jim

 

[xbacksideslider]

Wow.

Makes me want to have you do it to my head, even though it doesn't need it! . . . . . at least for now.

 

[comnoz]

Wow.

Makes me want to have you do it to my head, even though it doesn't need it! . . . . . at least for now.

I would estimate 25% of the inserts I install are on heads that are not stripped-yet. Including new Fullauto heads.

Another 25% is on heads that have been repaired before with aluminum inserts. I keep a supply of oversized inserts that will repair all but the worst of them without welding.

The remaining 50% is on heads like in the video. It was a nice original 7000 mile head with pulled threads. Jim

 

[motoalchemist]

Thankyou Jim, great seeing that. craftmanship and skills.

 

[Torontonian]

Nice to watch Jim. My wife did a Xmas gig for Magna auto-parts corp. recently where on the factory floor a technician had created a program for the one evening , for entertainment purposes for the crowd. One of the Robots was fed a program to pick up from a row of colored markers to draw Hello Kitty drawings on paper for people to take home. It would reach over to grab , hold ,draw and put back markers and pick up new colors as required. She said the robot was 2 storys tall. Many of them work 24 hours round the clock.

 

[worntorn]

I think Jim only works about 12 hours a day, but then he is also less than a storey tall.

Love watching that CNC mill go.

Glen

 

[texasSlick]

Makes me want a thread repair, even tho I don't need one....yet....

Slick

 

[cjandme]

Outstanding ! :mrgreen:

 

[ashman]

Its great having a miller that has auto feed and computer program, I have just brought a milling machine and lathe but its only a cheap one with out auto feed, the lathe has but not the miller, but things still can be done on my miller and its going to be great getting into machining again as I was T/A to a fitter and turned for over 15 years and have learned a lot, but its been about 10 years since I have used a milling machine but it will all come back to me I am just getting some tooling for what I need, its great watching a true craftman at work, but the trades man I worked with just set the machine up for me and showed what was needed and let me go for it, its a good way to learn and you learn by your mistakes .

Good work Jim.

Ashley

 

[Stephen Hill]

Jim, what kind of milling machine are you using? Did you convert it to a CNC machine or did it come that way?
I have never seen a mill do rotary machining like that. Makes me wonder how the program deals with backlash.
Stephen Hill

 

[comnoz]

Jim, what kind of milling machine are you using? Did you convert it to a CNC machine or did it come that way?
I have never seen a mill do rotary machining like that. Makes me wonder how the program deals with backlash.
Stephen Hill

It is a Bridgeport. It was originally built as a CNC machine. It uses ballscrews which eliminate most backlash. Even after years the backlast will be only a few tenths of a thou. Any wear in the ballscrews can be compensated for in the programming. It is capable of 4 axis machining. Jim

 

[737captain]

Jim,

Fascinating thank you for posting.

It was especially interesting as you currently have my 850 head that Matt (CNW) sent to you because the old threads are pulling out apparently. I'm keeping my fingers crossed you don't have to weld it.

Thanks for your expertise.

 

[comnoz]

Captain,
Your head is a good example of how NOT to do bronze thread inserts.
One side looks OK.

The other side is starting to pull out, You can see the crack at the retaining pin.

All that was holding it in was the threads on the three small pins.

It's going to take a bit of welding. Jim

 

[spelky]

Thanks for posting the video, looks superb quality. One of the old alloy inserts have started to pull so looks like it's time to go down the same route with a threaded bronze insert, I am in the UK and have found Seager engineering who look like they use the same technique, anybody had experience of using them?

 

[B+Bogus]

Thanks for posting the video, looks superb quality. One of the old alloy inserts have started to pull so looks like it's time to go down the same route with a threaded bronze insert, I am in the UK and have found Seager engineering who look like they use the same technique, anybody had experience of using them?

I haven't used them, but I use David Burton Engineering in Thornton near Blackpool - he's now done 4 Ducati heads and 3 Commando heads for me using the same process.
The last one took less than a week to turn around, and he's reasonable on cost too.