My alias won't change. My kids say I will look like a walrus no matter how much weight I lose.
The cylinder head is done. It is a double overhead cam engine with four valves per cylinder. There are no rocker arms. The cams push down on inverted buckets with adjustment shims on them. The valves tips, collets, keepers, and springs are inside the inverted buckets. It is similar to most all modern bike engines.
The standard Triumph valve springs were used with high lift cams. The springs buckled sideways at full compression and this pushed on the buckets and in turn, the buckets pushed sideways on the bores they slide in. Worn bucket bores = new cylinder head needed = major outlay of $. I was worried about this so I sent the head, cams, etc. to the best person I could find. That is Mike Perry at Kibblewhite in Pacifica, California. They know a lot about these modern Triumphs. Only one bore was scuffed from the sideways movement and they were able to salvage it. The guides were worn loose and the valve heads, too, from all of the lateral shoving at full compression. This hurt performance. Racing springs are installed as part of this rebuild. I prefer steel spring keepers. They are not available so they used the titanium ones that are. Lesson 1: always use racing springs with a racing cam.
Triumph does not make replacement valve guides. They say to buy a new cylinder head if the guides are worn. Kibblewhite pushed out my worn guides, miked the holes, made new ones, and honed them to fit the valve stems, exactly. Lesson two, don't toss a worn head when the guides are worn. It can be saved.
The guides and valves do not get much lubricant. There are oil seals to keep the oil from going down the guides. It is important that the valves and guides are compatible metals. I did not use Triumph exhaust valves for this reason and I used Kibblewhite valves instead. They developed their valves and guide metal to work together without a lot of wear.
The intake valves are 2mm oversize to give better flow for the 994 cc engine. Kibblewhite removed the old valve seats, made up some new oversize ones, installed them, made up some bigger intake valves, and installed them, too. They also did a multi angle valve job and matched the intake ports to the bigger seats.
A problem with these engines is the valves receding in the cylinder head as they wear and as valve jobs are done. Soon enough, the adjustment shims that are needed are thinner than they make. Kibblewhite shortened each valve as needed so I could use larger shims to start with and I would have the ability to use thinner shims later.
The bike continues to use shims on top of the buckets. This is OK for this street/race motor with an 8,400 rpm red line. Shim under bucket followers are needed for higher revving motors.
Incidentally, the Triumph valve shims are the same as some old Hondas, Yamahas, and Kakasakis. New shims are available from these dealers, too.
The only Triumph part of the valve train now is the cylinder head and exhaust valve seats. This is custom work with a lot of parts made to fit. It isn't cheap or fast. Budget 1K per cylinder for similar work and a month or two for turn around time.