Thread: OST-037: Under Pressure

https://drive.google.com/file/d/0ByPsC-cMs1-ATVlJUmNoZWNLOEU/view?usp=sharing

This one is pretty rough. I have some work to do before it will format everything correctly.

translated manual.

Thank you... my client, and I are quite grateful for your efforts


So, when I got up this morning the shop was a "balmy" 28 degrees , and with the holiday coming up fast... I was only able to finish up #1 exhaust port...


Top view was yesterday...



Bottom view is as finished.

The finished exhaust port....



.... in comparison to #2's exhaust port, and in comparison to the VE gasket


and in so doing #1 chamber, and ports are now complete, now that I'm happy with the results...



when I get back to work next week, the other 3 cylinders should go quickly...


so we end today with 1 down.... 3 to go





More to come....

these arrived Saturday.......

Nice! Def keep the old valves for us plz

long weekend.... and then it got COLD


Well, the temp rose a bit so I managed to get some work done. I took the head out to the race shop to consult their head specialist, the guides are @ about .0015" clearance, right about at the limit... good thing we are using new valves, the old valves might have been a bit outside the tolerance .

About - Most of the intake valve to guide clearances measured .0015" to .0016", the exhausts measured a bit larger - closer to .0018" to .0020"

Quick little quiz.... Why would I want to keep the valve to guide clearances a bit loose??



Half the port work now complete....





2 down... 2 to go....





More to come......

The specifications for the guide to valve clearance




Specifications for the valves




The stem diameter of the new Inconel exhaust valves... 5.97mm

With the new valves... the spec is mid tolerance.... the old valves.... a wee bit loose

I'm sure the old valves will still come in handy in a pinch

nothing wrong with them.... there was some wear (to be expected)... the new exhaust valve just moves the tolerance back to the middle of the spec


Boy... I'm having a tough time communicating today.... glad I'm not a diplomat......

What all of these specs, and measurements mean in the end....... No replacement valve guides needed....

Forgot this until today..........



this head now carries an OST serial number


a slightly different view.... this time from the intake side...



3 down, 1 to go......



more to come......

3 down 1 to go on the exhaust...


The chambers are now all roughed out*, the sharp machining marks have all been blended into the chamber



This head goes into the race shop on Monday to get the seats cut, and to back cut the new valves if needed.


So since there will not be many updates for a week or so, I'll leave you with a few questions to ponder........

1) The chambers are now "roughed out", why didn't I finish them now before the valve job??

2) Why did I not mention having the surface machined, It'll get machined eventually, but why not now?





more to come......