Brian_Heil Posted March 20, 2017 Share Posted March 20, 2017 (edited) There were several Tour posts from last year where I had burnt, leaking valves. First time I had the hood up on my '23 on a Tour (knock on wood) in 20 years. Thought I would start a new thread and cover what I did to solve the issue. Thanks to Dandy Dave and Larry Schramm for capturing the 'event' forever on digital camera, and for stopping and helping too. We did get back on the road and my Buick did finish the week. Issue is worn valve cage stem bores allowing the valve to wander around and not seat which leads to leaking which leads to burnt exhaust valves. The intakes stay lubed since they run cooler and were worn but not badly. The exhaust valves were burned to ~0.020 inch gap/burn path/missing head material. 1923 is the last year for the jugged head and the use of caged valves on Buicks. So, what to do? I have a set of NOS Buick valves I bought off eBay years ago for $3/valve. Still have them. Going this way would require having the worn cage bores further oversized and grey cast iron rod pressed in and then drilled, reamed and honed back to stock dia. to accept the NOS valves. The other option is to find 'modern' valves with stem diameters just a tad larger than stock, hone the cage stem bores out to fit and also machine the modern valves to correct length, head dia. and re-grind head, add the keeper slot hole to the end of the valve and grind the cage seats to match. Since going this way, saved the NOS valves for another day and left the cages capable of being sleeved in the future, I went this way. Turns out the larger diameter Buick intake valves are close to (very cheap cost wise) big block Chevy valves and the Chevy valve stem diameters were just a bit larger that we guessed correctly that the worn cages would clean up to fit them nicely and they did, so they were bought, cut and ground to correct length and keeper slot added. The head diameter had to be trimmed down too which caused the head seat surface to be re-ground to a smaller diameter. Note these valves are long enough to lop off the Chevy keeper groove end and still have enough length to put the Buick keeper slot in. Cage stem bores were honed to size and cage seat ground to match the new valve. I think we removed ~0.006 inch of cage stem bore dia. or 0.003 on the stem wall to remove the wear hour glass shape and fit the stock Chevy BB stem diameter with proper clearance. Again, the intakes were not that bad compared to the exhausts. The exhaust cages were really worn, so a 'large' stem diameter, small headed valve with enough length to allow for the keeper slot had to be found. A (not so cheap this time) Caterpillar exhaust valve was found to fit the bill for $20 each and given the same treatment as the intake valves and the cages honed (a bunch) to fit and the cage seat ground to match. Sounds easy since I didn't do any of the work. At this point I need to put a plug in for Denny Newman in Clio, Michigan and his machine shop. Most of Denny's work is on Brass cars and he does it all from paint to line boring an 4 cylinder EMF block to fit half shell bearings that are babbitted to his design which was todays project when I stopped at lunch. A huge Packard block was on its way out after being machined. My valve work was a 'fill-in' job. I almost have enough additional exhaust cages to go the second route with them and have these cages sleeved and use the NOS valves. Mark Shaw has been a big help finding used, rebuild-able cages. Thank you Brother Shaw! Now my issue is painting. Not the Buick, but a dining room, a back hall and a 1/2 bath. If Mamma aint happy, aint n-o-o-o-o-o body happy as the old saying goes. A reassembly project in the garage would not be in my best interest at this time. Edit/correction to the actual valves used, see 3/21/17 post below. Thx BTH. Edited January 5 by Brian_Heil (see edit history) 2 Link to comment Share on other sites More sharing options...
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