Matt (Centerville) said they offer 4 different valve sets, with intake weights of 139, 150, 125, and 118 grams. The 118g set is the same as the valves from TA.
Finally got my heads to the machine shop for finishing. My big issue is the intake-exhaust valve clearance with the oversize TA valves. One cylinder was only 0.010", others were 0.014-0.020" between the valve heads. I spoke to Mike @ TA, he said that was unusual. He prefers 0.025" clearance but would be ok with 'valves not touching when pressed together at 0.50" off seat'. My shop said they would turn the exhaust valve down 0.010" for a min clearance of 0.020" on that cyl, others will be 0.024"+. The cause for this is Buick machining the valve guide bores afterwards.... the hole in the guide is often off-center. I measured stem-stem distance on each cylinder (stock guides) and there was a variation of 0.020". Thanks Buick! I also inquired with SI valves. They offer stock size, undercut stem, swirl-polished SS valves. They sound comparable to the TA valves, just stock size. But I'd be concerned with the stock size when you're replacing valve guides.... offset the valve stem guide hole by 0.020" and you're going to grind the valve seat deeper. If you're not replacing guides, it's not an issue, just have the original guides sleeved. I replaced the guides since I did porting work and they were in the way, and I cut them shorter. The SI valves were a great price, $12.95 ea vs $18.75 for the oversize TA's. Lots of tough choices when building a Nail!
When you consider all the machining operating on an engine block, I guess it's no wonder that detentions are not that close. Just think, engine blocks have to be decked just to get all the pistions at the correct TDC detentions. When I was young, I always heard that blueprinting was the best single option you could do to get the best performance out of an engine. As a machinist, + & - .005 is pretty much standard detentions I had to hold and very precision parts are much closer tolerances. I can't imagine a casted part as large as an engine being held to + or - .005 detention. I guess that is one of the reasons why guys pay for align boring a long with all the other time consuming and expensive engine machining operations. Ordinary/Non car people have no clue. I have to wonder how close the the dimensions are on TA's all aluminum block. I would love to know. Vet
Please excuse my bad spelling, never been the best at it and the spell checker isn't fool proof either. Vet
No problem, I understand what you're saying! Buick got the important tolerances right, such as crankshaft. But when it came to the heads, I'm seeing quite a variance. The valve guide heights vary by 0.028" (bang em in and get em close?). Valve-valve spacing variance of 0.020". And inner valve spring seat depth variance of 0.022". (Thanks to Mike @ TA for pointing this out!) The guys that did NHRA blueprinting back in the day sure had some work to do! As well as those of us trying to get stuff 'right' this time around..... I just balanced my connecting rods. There was almost a 6 gram variance. I got it down to under 0.5 g. I might be anal about some of this stuff but I want it right. I'm a recently retired engineer, some habits are hard to break! Can always make stuff better....
I hear you, i'am a retired machinist that also worked as a Tool & Die Maker and also worked with lot of Mechanical & Electrical Engineers. I have always been a perfectionist. When I was 20, I was rebuilding my first high performance V8 Chevy 327. During the rebuild, I found the the block varies from front to back .045. Of course this means the pistons at TDC varied in CR. Of course I was in the Navy at the time making $32 bucks every two weeks so getting that machined to correct specs wasn't going to happen. Amazing, the 11.250 GM factory pistons still seemed to work fine. With all the power adders I installed, I got my 56 Belair to run 11.2 ET's. Always wondered how much lower I could have gotten the Belair ET's down if I had unlimited $$$$. Never had that option. But dreaming is free. Lol Vet
LOL, I was enjoying trying to figure out what word you meant It was a good brain teaser, I liked it! I’m weird tho
Ya Mark, I posted a little while back I have dyslexia, so when I get in a rush to text, it's no telling what the spelling will come out to be. Lol I had one of my friends said I write in Egyptian, I said what type of Egyptian? He says hieroglyphics, Lol. That was so funny . I'am cool with that. Vet
