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Old 11-08-2008, 11:17 AM
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CHANMADD CHANMADD is offline
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Join Date: Mar 2006
Location: San Marcos california, CA
Cobra Make, Engine: 1989 KCC from South Africa Right Hand Drive
Posts: 1,601
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I would be almost certain that the problem is the rod. Once you run a bearing in a rod ,and more so if you spin the bearings, the rod big end is not going to be "round".
Even if you now machine that Big end again and make it round ,the first time you really spank that motor the rod is going to let go. Replace the rods.and spend the extra and get "H" beams from Eagle, they are reasonable in price and the quality is ,to my mind ,great! A clearance of 0.002" is exactly what I use when building motors, and it has always seemed to work for me.
New crank and rods and no more worries!!!!
Oh and you might as well put the longest rod in there that you can,so that you you get the most favorable Rod/Stroke ratio.....close to 1.6 or above.Might require new pistons ,but if you are building a ""Strong"" motor you might as well spend the little extra..100's not 1000' to get reliability!!!
John
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