Valve stem height

[sdibbers]

Hi all, getting new valves, valve seats and guides fitted to Beryl’s cylinder head.

The machinist has asked if there’s a specification for valve stem height above the guides or the head below the deck of the head. I’ve not found any in the manuals but thought someone here might have some guidance.

Thanks in advance!

 

[cobraboy]

Is it not posdible to measure current guide height and installed valve stem height above the head.
By setting to current specs it may make setting up clearances after easier.
On the four pot, is there a valve stem seal ?
I ask, as on the V8 there are proper seals now available to sit on the top of the guide, but this affects the installed height of the guide as there has to be clearance between the seal and spring retainer at full valve lift.
If there is an option to fit proper seals if there are none as stock I would do so, this will certainly help keeping the engine cleaner.

 

[sdibbers]

The existing seats were cut cut too deep by a previous machine shop in the 80’s, so we are a little worried about using those as a ref for stem height. But I guess we can use the least recessed valve as a starting point, maybe add 0.003” or so?

The four cyl engine uses o rings as stem seals. Each guide has an internal annular groove for them.

 

[sdibbers]

Quick update in case anyone else has a similar question in the future.

A friend had a low mileage head that was able to measure the valve head height relative to the deck of the head. All valves measured 0.080” with a tolerance of +/- 0.005” I’ve let the engine shop know and they’ll use that as a metric for cutting the new seats. I guess that will work as a starting point.