Exhaust Thread Repair Australia

[Connie73]

Hi Folks,

Putting some feelers out there to see if anyone can help me. I have a 73 750 head that needs some attention to the exhaust thread. Having trouble tracking down someone in Australia that can do that kind of work. Have tried the usual sources but most are now either retired or cant be bothered.

Please help.

Regards

 

[Davo]

Murray at Cycle Craft Engineering will sort you out, although he is in Welshpool, Perth WA.
He did a fine job on the mangled mess I dropped off.
Dave

 

[Connie73]

Davo,

Thanks, im on the East Coast but should it come to it i will send it over there.

Cheers

Ross

 

[MGB65B]

Rams Head Services in Windsor are outstanding. They repaired a Commando RH10 head for me with the same problem perfectly.
They are very competent at porting/flow work too if you're interested, and do a lot of work for the racing fraternity, and for dealers such as Frasers on their Harleys.
They currently have another RH10 head of mine for repair and flow work. They've also done two MG heads for me, and a BMW Alpina head and a vintage Rolls Royce head for a friend of mine.
The downside is that they are extraordinarily busy, even getting work from overseas, and despite I think four full time guys on the shop floor six days a week, their turn around time is slow. But they sure know their game, and I've never heard anything but positive reports about their work.

https://www.ramsheadservice.com.au

If you speak to Bernie, Tully or Darren, please give them my regards. (Tell them "Dr Tom" sent you)

 

[Tinsy]

http://www.mdamotorcycleengineering.com.au/index.html.


I just picked my MK III head up from Martyn Adams last week. It was a 2 week turn around. Quality work. He will want the exhaust nuts you intend to use and will make each port to suit a specific nut.

 

[Burgs]

Hi Connie73
I haven't done any Norton heads yet but have the machinery to do it, CNC Machining Centre, CNC/manual lathes etc.
I have a 72 Combat head myself that needs both threads repaired, just haven't had a need to do it yet, so maybe this is the time.
To do it I will need to make a jig to hold the head, not a big job, then away we go.
I am in the Hunter Valley 2321 by the way.

Burgs

 

[kommando]

My experience with bronze inserts was not good, unless pinned they will eventually work loose. To repair the loose insert it was removed and I had the port alloy welded and the thread recut back in the 90's and its still looking good.

 

[Connie73]

Wow,

Thanks guys for the info.
Dr Tom, How many dollars are we talking per thread and what was the approximate turn around?. They look very professional indeed. I think they may be up for the challenge of line boring my Dommi head and fitting inserts to the rocker spindle holes. Will have a chat to them.

Tinsy, Thanks for your comments. Will keep in mind if the lead time is long from the above workshop.

Burgs, Wish I could accommodate all that machinery. I have a couple of people interested in getting repairs done in the future so il keep ya in mind. I have played around on Mills and Lathes but that was a long time ago as a trainee. Let me know how you go on your Combat head....

Kommando,
Little worried about welding due to the heat possibly warping the head, correct me if im wrong. Sounds like it was the repair option from back then though.

Thanks again guys, just reminding me why I joined this site.

Regs
Ross

 

[acotrel]

The last time I did that, it was with a Triumph 650 head. I simply bought a large Helicoil and made a tap by turning a thread on a piece of pipe, then cutting a slot with a hacksaw. I Araldited the helicoil into the port. It worked OK, - however the motor was methanol fueled, so heat was less of a problem.
You simply wind the Helicoil onto the bit that normally screws into the port, then use the thread gauges and cut the thread for the tap slightly undersize. I inserted the Helicoil using pliers. - ALL LOW COST !

 

[ashman]

http://www.mdamotorcycleengineering.com.au/index.html.


I just picked my MK III head up from Martyn Adams last week. It was a 2 week turn around. Quality work. He will want the exhaust nuts you intend to use and will make each port to suit a specific nut.

This is the right way to do it, I am rebuilding my mate's Commando motor now and have to do his exhaust ports that are damaged, I was going to buy the right butt tap for the job but $300 for a tap, so now I am going to use my lathe to screw cut the right thread in the Bronze inserts then mill the head for the inserts, but its going to be a few more weeks before I do this as I have a few other things on the go at the moment.

Ashley

 

[madass140]

Ash, how will you retain the brass inserts in the head?

 

[gortnipper]

Look at this thread - exhaust-thread-replacement-t21055.html

Then buy some of comnoz's thread inserts and have them installed in AUS.

They should fit any nuts - are-there-exhaust-nut-thread-size-variances-t23564.html?hilit=rose

 

[ashman]

Ash, how will you retain the brass inserts in the head?

I am just in the planning side of things at the moment but thinking of grub screws and JB weld at this stage, but still got plenty of time to do some more home work, but was looking at the damaged ports yesterday and the damage is not that bad and might get away with cleaning the threads with a thread file, I have a good set of thread files and have used them to clean my port threads many years ago.

I am still going to machine and screw cut the bronze inserts on the lathe once I set it up for the right cuts, I am retired now so have plenty of time to muck around in my workshop, I might get hold of a old head that is beyond repair and do it first before I do it to a good head, I have watch Jim's video and how he does it, this probably be a one off job for me but you never know if it works out.

If I don't give it a go I will never know.

Ashley

 

[acotrel]

If you use grub screws, you will probably damage the thread on the insert. So if you have to screw the insert in and out, the problem becomes bigger.

 

[ashman]

Once the inserts are in no need to remove them unless they get damaged again, I have a bit of experience with grub screws through threads and if done properly there be no problems at all.

Ashley

 

[acotrel]

I used grub screws on a Triumph head for that purpose. Over a few race meetings the situation with the exhaust stub became disgusting. It's probably OK if your exhaust pipes don't shake around too much. On the Seeley my stubs are simply threaded sleeves and the pipes are held on with slip joints and springs. I get none of that damage you get when the pipes are mounted firmly to the head.

 

[ashman]

In 42 years of ownership and with the orginal port threads they have never been damaged, I only cleaned the threads with my thread files as one of my flages started to cross thread, my pipes where made for my motor to Featherbed frame with no balance pipe once done up I have never had one come undone in the 37 years of the conversion, my pipes are mounted at the flange and one bolt for the muffler mount and I have only lost one muffler mount bolt in all those years, I use no locking rings or anything for that matter, they are just screwed in and tighten with my large multi grips, it takes me less than one minute to pull each exhaust pipe off my bike in one piece.
If the head pipes where made for each bike I don't think there be any problem but then they are rubber mounted which does make them shake a bit more, my pipes aren't rubber mounted or my motor so no problems at all.

Ashley

 

[Foxy]

G'day Connie,the exhaust threads in my RH10 head were about 75%, in other words new bronze nuts felt loose in there.....having a hydraulic press I pushed through a.020 oversize die and swelled the nuts to a perfect tight fit all the way! Just a thought!? Also I can't recommend Martyn Adams highly enough to do any machine work, a bloody genius really! Being an avid longtime reader of Classic Bike Magazine years ago Martyn (ex Brit) was often featured doing one of intricate machine work! Speaks volumes I think.

 

[comnoz]

unless pinned they will eventually work loose.

I certainly hope this is not correct. I have done several hundred al/bronze exhaust thread inserts over the past 20 years with nothing but an interference self locking thread fit and JB weld -all with a lifetime guarantee.

I have redone 3 or 4 of them but not because they worked loose. They have been redone because of size issues when I did the job without a nut to check. Jim

 

[keso]

Hello, I have this exact problem with my 73 850...is there a way to fix on the bike?