inlet valve seats

[tom horse]

 Hi, Has anyone had INLET valve seats installed in a GT6 MK1. Due to the  valves, inlet and exhaust, recessing into the head  the PO had put shims under the rocker pedestals, otherwise there was no adjustment possible. I've had the exhaust seats done to convert to unleaded, it was while reassembling the engine I realised why they had used these hand cut brass shims, the inlets had recessed as well or perhaps they'd been cut to match the worn exhausts. Either way, the engineering company reckons they can't put inlet  inserts in, as there isn't enough metal. If they try they'll have to cut into the water jacket. If anyone has had it done I can let them know it is possible.

 

 Thanks JMM

 

[glang]

I would get a second opinion on the options available from another shop, preferably a specialist Triumph place...

[Nick Jones]

I have seen a 6 cyl head with double inserts on one cylinder only, I think to address a crack between the valves.  It’s not an easy job for sure, but should be possible. If this is really what is needed I’d be considering another head.

Are you sure the inlets are recessed, not typically a problem on inlets. Got any pics? Where do the valve faces sit relative to the roof of the combustion chamber. Should be a couple of mm proud approximately.

Big skim making the pushrods too long, or just plain using the wrong pushrods could have the same effect. 
 

Nick

Edited October 21, 2021 by Nick Jones

[JohnD]

And, a hefty skim of the head to raise compression could make shimmed rocket shaft pedastles necessary.   Rather more probable than ALL the valves recessing!

John

[Gt6s]

Pre 73 TR & PI heads have inserts on the inlets as stock

[Nick Jones]

38 minutes ago, Gt6s said:

Pre 73 TR & PI heads have inserts on the inlets as stock

Eh??

None of the ones I’ve seen have had any inserts at all…..

Nick

[Gt6s]

Revington TR & Rimmers sell replacement inlet and unhardened or hardened exhaust seats for these heads. I have one it definitly has inserts in both inlet and exhaust. You can hang a fingernail on them all. Even the stock exhaust insert is pretty hard material anyway did a file test on it. Late PI TR Heads do not have these inserts.

Edited November 1, 2021 by Gt6s

[Gt6s]

On 26/10/2021 at 12:19, Nick Jones said:

Eh??

None of the ones I’ve seen have had any inserts at all…..

Nick

They are actually quite hard to identify, this is because they were installed before any head machining. meaning they sit completly flush in the chamber top, you cannot see them. The ony way to identify these seats is to run a finger nail inside the port  ( even after porting inlets ). Retro fitted exhaust seats are normally fairly easily seen because they are machined seperate to the head meaning not exactly perfectly level with the top surface of the chamber.