New Exhaust Port Inserts

Just when I had run out of ideas of replacing worn exhaust rose threads!!!!
I found this head last weekend, a friend had it lurking in a parts box under a bench.
Vv's, spindles , rockers and other hardware is all in very good condition, not so the port threads.
Anyway just thought I would share the pics to see the members responses.
Regards Mike

That is pretty nasty looking. Looks like it could be restored with a little machining. If it was mine, and I wanted to use it, I'd send it to Jim Comstock and see if he could clean it up and do his bronze inserts for it.

I recall seeing something similar on a Norton race bike years ago, but don't recall whose bike it was.

Ken

What a mess!
I had an RH10 head with some very ugly welding around the exhaust ports done to it some years ago. It was beautifully repaired, and ported, by a cylinder head specialist I've used several times over many years for both car and motorbike cylinder heads, with outstanding results every time, Rams Head Services. They are located in Sydney's north western perimeter. My completed RH10 head really was a work of art.
I'm told they do a lot of Norton heads (but then I've seen everything at Rams in for work, from Harley Davidson to a set of Formula One Ferrari cylinder heads!)
I would imagine from the work I've seen them do, that they could salvage your head, but it looks like it would need a lot of labour, and the cost may not prove to be cost effective. It can't hurt to ask. They've got some incredibly experienced guys there, and a lot of hi-tech gear too, flow benches, CNC milling machines etc, but most of all, many decades of head work under their collective belts.
https://www.ramsheadservice.com.au
But then from what I've seen, you've got some pretty clever skilled people in NZ too.

If the inlet ports are still ok and not too much been skimmed off the mating face, then I may look at sorting the exhaust ports.
It was for "ugliness" value that I posted!!!

While I have not done as many as full time norton machinists (comnoz).... I have been doing aluminum exhaust port inserts for about 20 years and never had one come back or pull out. $75 single hole or $125/head. Cleaning your head is extra $ at shop rate. Only problem is, I only service local club members. Second problem is, that head may have been way oversize over bored in the port. Which would require a custom insert, which would cost more. :roll:

Brooking 850 said:

If the inlet ports are still ok and not too much been skimmed off the mating face, then I may look at sorting the exhaust ports.
It was for "ugliness" value that I posted!!!

Click to expand...

Just for the fun of it!

I used to own an ex works short stroke head machined to fit in the space frame. It had the exhaust port machined away down to the sealing ring seat. Then there were three threaded holes bored and a steel top hat style stub was attached and located with allen screws. The exhausts I used on mine were welded to the stubs, but no reason why a slide over pipe and spring retainer system couldn't be used.

There didn't seem to be much of an issue with heat dissipation.

most likely not bored out at all, but just smacked in and welded up. some one with the skill to do that ain't going to have the skill to set up and bore out the ports.
probably still stripped port threads under those stubs

I am building up a mates motor at the moment and have to repair the exhaust threads as PO had done a bodgy job on it, going to do bronze inserts and do the maching myself, been looking at a tap for it cost a bit but my friend will pay for half it and I get to keep the tap for the next one.

Ashley

Well Mike I just can't much see any problem with this exhaust "style". I like it a lot and would not hesitate to use it to create a night cruiser waker-upper bike. The sound would be awesome and the blasting flames on a night time sprint would be spectacular. Think of the fun and attention . Bolt it down and fire it up I say. At night of course. :wink:

It is an RH10.
If the ports haven't been butchered for racing it's worth fixing. The inserts would be an easy fix. Jim