Guest Will's Fiero Posted May 17, 2005 Share Posted May 17, 2005 This isn't Z related, but I have in the past seen enough deep technical expertise here that I think this is a good place to ask this question. I'm building a Cadillac Northstar for my Fiero. I have a time-serted block, stock crank (flawless after 100K miles), Eagle rods, custom Ross pistons, Clevite bearings, Total Seal rings, and CHRF ( www.chrfab.com ) valvesprings. The first time I tried it, the engine smoked terribly and went through a quart of oil in 50 miles. I pulled it back apart and started to research. I found that the shop I'd originally had do the hone did a worthless job. Not knowing any better at the time, I'd put it together this way. I found a better shop that did a good job honing the block. Since the block had now been honed twice, the bore was out of spec and I had Ross make a custom set of pistons for the new bore size. Here's where things get sticky. The Northstar uses 1.5mm top and 2nd ring grooves. Ross seems to have cut these exactly to SAE spec at 0.0605". The SAE spec calls for rings to be 0.0575 to 0.0595. The TS top rings are 0.0574 and 2nd rings are 0.0567. This puts the top rings just out of spec and the bottom rings well out of spec (Isn't it interesting that 0.0008" is "well out of spec"). This gives me 0.0031" side clearance on the top ring and 0.0038 on the 2nd ring. The Total Seal tech with whom I've been working to troubleshoot and improve thsi engine, and who hasn't led me wrong yet, has told me that it will work. However, other sources are MUCH less optimistic, especially considering that I want to wrap this engine to 8500 after I get a heads/cams package for it. A friend of my dad who knows a good bit about such things mentioned 5,000 RPM at that side clearance. I'm not terribly optimistic either, especially since Total Seal literature mentions 0.0015" top and 0.0020" 2nd side clearance. Please post your thoughts on this. Also, should I get Total Seal to make me a another set of rings the right thickness? Should I give up on them and go to another ring manufacturer? Should I use TS top and 2nd rings with Caddy oil rings? I've heard various things about TS oil rings. TIA Quote Link to comment Share on other sites More sharing options...
Guest Will's Fiero Posted May 18, 2005 Share Posted May 18, 2005 How did this post get in this forum? Would a moderator mind moving it to the Chevy V8 tech forum, which is where I thought I had put it... Quote Link to comment Share on other sites More sharing options...
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