Valve seat and throat cutters

[Smallfry]

Toying with the idea of modifying or repairing some old cast iron cylinder heads.

Recutting the 45 degree seats, and opening the throats for larger valves. 60 or so degrees. Needs to be concentric with the guides.

I have no idea what sort of machine tooling I would need for this, what would it be called ? Need carbide I guess, as old seats will be very hard. Any ideas ?

Dont want any hand tools, they dont work.

 

[addjunkie]

@northwest will give you the name of a firm who will make specific cutters for you!

 

[minimutly]

Serdi are the experts, but their machines cost fortunes. If you have a lightweight vertical mill you can buy the cutter holders, need an adaptor to hold in the quill. If you use a mill you must clamp both axes, ask me how I know...

 

[oldbikedavey]

Toying with the idea of modifying or repairing some old cast iron cylinder heads.

Recutting the 45 degree seats, and opening the throats for larger valves. 60 or so degrees. Needs to be concentric with the guides.

I have no idea what sort of machine tooling I would need for this, what would it be called ? Need carbide I guess, as old seats will be very hard. Any ideas ?

Dont want any hand tools, they dont work.

Neway .

 

[optima21]

I ended up making my own valve seat cutters using carbide planer blades to recut some hardened seat insterts

the planer blades do need replacing though after 1 head was done.

 

[Smallfry]

@northwest will give you the name of a firm who will make specific cutters for you!

Sounds like it might be expensive !

 

[Smallfry]

Likely they will need new guides, before recutting the seats truly concentric. How old? Diesels and post lead-free petrol will have hardened exhaust seats - the rest might be either inserts or cut directly in the casting.

Carbide cutters likely only need a hand operation unless new hardened seats. I have an old Wolf cutter set with stones for grinding only ‘soft’ seats. I doubt it will ever get used again by me. It served me well for the few seats I reground. I now use a limited selection of carbide cutters, mostly.

Its for a BMC B series petrol, so the seats are direct in the casting, at least I think they are !

Where I used to work, they had a set of those grindstone type cutters, but they were never used because the stones were worn and needed dressing. They also had a set of cutters that had lots of edges (can't remember what they were called) probably carbon or HSS. Wouldn't even touch the exhaust seats, no matter how much pressure was applied.

I am thinking of a Neway set, but will be too expensive for my limited use. Don't know yet.

 

[Smallfry]

I ended up making my own valve seat cutters using carbide planer blades to recut some hardened seat insterts

the planer blades do need replacing though after 1 head was done.

Thats interesting and might be worth a go.

How did you hold the blades in ? Looks like JB Weld or similar.

All in all though, might be just as well to put them into an engineering shop.

 

[8ob]

Its for a BMC B series petrol, so the seats are direct in the casting, at least I think they are !

Where I used to work, they had a set of those grindstone type cutters, but they were never used because the stones were worn and needed dressing. They also had a set of cutters that had lots of edges (can't remember what they were called) probably carbon or HSS. Wouldn't even touch the exhaust seats, no matter how much pressure was applied.

I am thinking of a Neway set, but will be too expensive for my limited use. Don't know yet.

Seats on a lot of these older cast iron heads were induction hardened, once through this hardening the seat will be chocolate. That said there are loads out there running like this , just dont expect much in the way of longevity. You are more than welcome to borrow my seat grinder, just let me know the guide diameter, valve size and seat angle.

Bob

 

[optima21]

Thats interesting and might be worth a go.

How did you hold the blades in ? Looks like JB Weld or similar.

All in all though, might be just as well to put them into an engineering shop.

yeah it was JB weld I though it might be a big tougher than normal epoxy adhesive

 

[Melvyn Best]

Where I used to work, they had a set of those grindstone type cutters, but they were never used because the stones were worn and needed dressing.

Probably a Black and Decker Vibrocentric valve seat cutter which should have had a diamond tipped tool to dress the stones

 

[Martin Hocking]

This might be a standard feature I don’t know much about it but I remember seeing a cutting tool holder on one of the proper machines that had a ball on the end with a clamp. The holder wiggles while you sort out alignment with the valve guide and then is tightened so you can cut.

Seemed to me that would be a good way to approach the job on a mill at home.