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210psi compression. wtf.need opinions


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Hard to say since they are big bore. What pistons are in it at the moment? Usually have a part numbers on the crown of the pistons. I see the crank is stock stroke and rod length. Probably have to run a blaster piston and have domes cut for them. Then of course the jugs need ported to match the stroke.

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You need to send the cylinders to someone competent to tell you what will work with them.  You don't just "bolt up" another crank.  Port timing will be radically affected.  That is what makes turd bikes.  You need to know what you have. 

 

If it was trenched, it might be setup for a 10mm, you don;t know. 

 

As far as compression, again, cranking compression does not mean a thing!!!!  I have some of my MX motors out there with 250psi of cranking compression!!

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I did alot of research today and was laughed at! I was told noone should be running a Banshee or actually his quote was a "twin" with 250 PSI and this is per Yamaha Motor, the efficiency is lost after 180 PSI, a banshee will stop making any more torque after 180 so why do it? I was also told Dynoedge I believe was the name used in Michigan did excessive tests and started actually raising the head at 200 PSI just because the 8mm studs could not hold that amount of pressure! now this was from a very knowledgeable individual that has a vast amount of information but he may be wrong,

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I did alot of research today and was laughed at! I was told noone should be running a Banshee or actually his quote was a "twin" with 250 PSI and this is per Yamaha Motor, the efficiency is lost after 180 PSI, a banshee will stop making any more torque after 180 so why do it? I was also told Dynoedge I believe was the name used in Michigan did excessive tests and started actually raising the head at 200 PSI just because the 8mm studs could not hold that amount of pressure! now this was from a very knowledgeable individual that has a vast amount of information but he may be wrong,

. And this is all based on CRANKING compression.....Who gives a shit about building a motor around the cranking compression, port timing can alter the compression and there are a lot of variables to total tourqe output. Edited by sstaton1983
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