Great news that your block is ok, pretty ugly looking in there otherwise ...

 

Yeah, it'll give me something to do besides enjoying TWS in 3 weekends.

 

thats not a bad merge...

 

Ouch. Glad the damage isn't more than that. When I had TBF on my eagle talon it through a valve through the piston and trashed the head.

 

Well this looks familiar

I did have that happen on an aftermarket valve but am very surprised to see it on an original Porsche valve. The keeper design requires very close tolerances to keep this from happening and Porsche valves that I've seen are extremely well made.
Are you sure this head hasn't been apart during its life? There are things that can exasorbate the design weakness but an original Porsche engine should be immune from them.

In short, the "design weakness" is the 3 groove keeper that doesn't actually clamp the valve stem. Allowing rotation is the reason for that. A close fit is important so that a crappy aftermarket valve with even .001" additional clearance between the keeper and valve will allow significant rocking of the retainer which fatigues and breaks the valve.
I do have a quick fix that will likely prevent this from happening but hate to post it publically, it's very half-a**ed. I prefer to use quality valves with clamping type single groove retainers.

Are you really, really sure this head hasn't been apart before?

BTW, I have a healthy, complete 85 engine to sell.

 

Seeing how clean that head surface was, it's been apart recently.

 

Cleanliness cought my eye as well. Head gasket look like it was installed yesterday..

Edit. no wonder - "head recently R&R'd by me"

 

Yes the heads were "apart" to a degree by prior owner: the "valve job" he had done included replacement & possibly lapping in new or used valves, & that's it. Guides are on the margin, stem seals were original, seats barely had full contact.

In October I showed up at Third Coast on 7 cylinders: a valve spring had snapped. I pulled the head off because leakdown was 0 in 1 second: suspected bent valves but found a broken valve spring, so replaced the stem seals, lapped in all the valves & reinstalled on fresh HG (hate throwing away a 1 year old, 2-mile headgasket, but not worth the risk of failure for reusing). Got about 4 solid hours of test & tuning, well off full throttle. I did re-install the valve spring spacers as there was one for every valve, & with them they were all within 1/2mm of overall non-compressed length. I need to look closely at this valve vs others from my extra engine to determine if it was OE or not: that'd be good to know.

This whole incident makes me leary of using valves from engines that have come apart or popped t-belts: need to ask my machinest if there are tests he'd recommend to see if valves are solid or not.

& yes, my valve snapped at the lowest keeper ring: total bummer.

 

Go get em Mark. You're a bad dude and you can do this!
Dropped a valve, meh- gonna take more damage than this to put that ole dog down. !

 

JB Weld fixes anything!

 

I try to keep my garage clean, though the 2nd lift kinda blew my extra play area, glad the garage is extra deep. Old picture: garage now has a 42" replacing the wee 32" TV pictured, AC, two more red Porsche's, one less yellow 914.