TR6 (expensive) laugh

[6PAK72]

For those who might appreciate this:

Winter maintenance on the TR6 2.5L. It's been blowing some oil, (in addition to the normal Triumph 'marking the spot') so I ran a leakdown. No prob with the cylinders. Well, that's good news.

Take the valve cover off, take the roller rockers out, pull the really expensive titanium pushrods. Get ready to pull the head, thinking I've got a badly seating valve or an internal leak.

Valve guides are elliptical. Not a little, like .5mm!!!

Apparently, when the shop I worked with to build the engine dropped the head height, they failed to re-do the rocker geometry calculation - the pushrods are the same length as the OEM units, when they should have been geometrically corrected for the .030 head shave. And apparently, titanium is a lot harder than bronze.

Pushrods? you say?? Yea, I know.

Head job after 22,000 miles. Grrrr.

[breakaway500]

Pushrods never touch the valve guides,so it is not about hard vs. soft metals. What will accelerate guide wear is the valve train geometry being off as you mentioned(pushrods too long),and the rocker tip riding over center on the valve stem tip,creating side thrust on the valve stem,thus wearing the valve guide faster than normal.

[6PAK72]

Yes, I short cut the description. The valves are from PRI Race, titanium mix, the guides are actually bronze. I had a good chat with Jon there today and he had some interesting input on geometry, how it was pressing, and how the spring force had an affect.

Lots to learn.

[breakaway500]

A SBC will take care of everything.. Best of luck with the repair!

[6PAK72]

Mmm. While working on the head, discovered through-rust on the pass. front fender.

TR6 parts are scattered around the garage. You know, in 1972, they built cars with bolts, instead of plastic clips!