DragBikeMike
Serious Thumper
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SuzukiSavage.com Rocks!
Posts: 4401
Honolulu
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I appreciate the condolences. I'm not bummed out over the failure, it comes with the territory. The nature of my project is experimentation and I expect failures. All part of learning.
Hotrod: I think 4500 fpm is a good number for a street engine in mild state of tune. If I set an arbitrary redline of 7500 rpm my average piston speed will be limited to 4625 fpm, just slightly above 4500. I think that should be fine as long as I maintain proper A/F ratio. My engine made max power at 6240 rpm. Shift point should be 110% of max power or 6865 rpm, well below the arbitrary limit of 7500. I just gotta be reasonable and stop burying the tach. One thing I might consider is changing my performance measurement criteria from 4K to 7K in 2nd to say 3.5K to 6.5K in 3rd, but that would make comparisons to the older setups impossible. I really need to take it just past 7K to do meaningful testing. I believe I can do it safely.
Dave: Good suggestion on the thermal coating. I think I will look into that. Do you think the forged piston will hold up better to the heat than the cast piston, or does it just handle more load better? Regarding the acid, I think I will mess around with my laps and the Gizmatic first. Problem with acid is I have to store it and ultimately get rid of it. If I have to resort to the acid I will see if I can find some in a small quantity, maybe I can get a small amount from someone who owns a swimming pool. Don't they use that stuff to clean pools?
Armen: Yes, I installed robust springs but the retainers and keepers are stock. BTW, they look great. I gotta take this statement back. The retainers looked great from 2 feet away peering through the valve cover, but closer visual inspection shows that the stock retainers ain't gonna cut it. Still have to test the springs. More later. Revision posted 2/14/20.Still have to load test them but visually they are in fine condition. I didn't use the pop-top to begin with because I wanted tight quench. Can't get that with the Wiseco because the compression height is only .025" taller than stock. I feel that high compression with tight quench is better than high compression with no quench. It definitely has promise on this LS engine. Considering how well it worked before the failure, I'm convinced the tight quench is the better way to go. Now I will be able to test that. The 97mm Wiseco is almost exactly the same weight as the stock cast piston. If I machine the top of the 97mm Wiseco so that it's a flat-top, I will reduce the weight by something less than 28 grams. Since folks are running the 94mm Wiseco (which is 52 grams lighter than stock) with no adverse vibration reports, I think a modified 97mm Wiseco will be OK. I would get a bump in displacement, a bump in compression, tight quench, and a thicker wall at the valve relief. What's not to like about all that? I'll keep my fingers crossed on the rest of the parts, main bearings, rod bearing, wrist pin, rod, etc. There will always be a weak link, that's the fun part.
DieselBob: Thanks, it's my pleasure. I simply love doing these tests and reports. I'm glad you find it beneficial.
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