454 rebuild with blower... Pistons and clearances.
01-23-2015, 10:09 AM
#81
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Ask any of the builders here and they will all tell you that in a blower application 8.7-8.8 is the ideal compression number and to stay 9:1 or under in a marine application. You are from maryland, call Tony at CMS or Dave Govatus, actually call Eddie Young too. This information was the same between all 3 of them for this application.
Last edited by Black Baja; 01-23-2015 at 03:24 PM.
01-23-2015, 10:52 AM
#82
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I know Tony and I wouldn't let Dave touch a weed eater. I've seen his work. And I'm sure anybody that knows anything told you to keep the boost down with the little p-shooter. I've built and ran all kinds of motors from a-z when you have a little tiny blower like I would put on my sons go-kart with a Briggs and Stratton you put the initial compression up higher in the motor so you don't have to spin the heck out of the blower make a lot of heat in the intake and melt the motor.
01-23-2015, 11:06 AM
#83
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Well let's have Mike weigh in, Mike why did you do your build at 8.5:1 and run stock pully ratio on the blower instead of more compression and lower boost?
Another factor is I didn't touch my lower end as it was just done, we used the cylinder head combustion chamber to bump the compression to where it is. I would imagine that Mike used a flat to piston in his build as 8.5:1 is about where a flat top with a 3cc relief would put you.
Another factor is I didn't touch my lower end as it was just done, we used the cylinder head combustion chamber to bump the compression to where it is. I would imagine that Mike used a flat to piston in his build as 8.5:1 is about where a flat top with a 3cc relief would put you.
01-23-2015, 11:07 AM
#84
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Well let's have Mike weigh in, Mike why did you do your build at 8.5:1 and run stock pully ratio on the blower instead of more compression and lower boost?
Another factor is I didn't touch my lower end as it was just done, we used the cylinder head combustion chamber to bump the compression to where it is. I would imagine that Mike used a flat to piston in his build as 8.5:1 is about where a flat top with a 3cc relief would put you.
Another factor is I didn't touch my lower end as it was just done, we used the cylinder head combustion chamber to bump the compression to where it is. I would imagine that Mike used a flat to piston in his build as 8.5:1 is about where a flat top with a 3cc relief would put you.
01-23-2015, 11:11 AM
#85
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Well let's have Mike weigh in, Mike why did you do your build at 8.5:1 and run stock pully ratio on the blower instead of more compression and lower boost?
Another factor is I didn't touch my lower end as it was just done, we used the cylinder head combustion chamber to bump the compression to where it is. I would imagine that Mike used a flat to piston in his build as 8.5:1 is about where a flat top with a 3cc relief would put you.
Another factor is I didn't touch my lower end as it was just done, we used the cylinder head combustion chamber to bump the compression to where it is. I would imagine that Mike used a flat to piston in his build as 8.5:1 is about where a flat top with a 3cc relief would put you.
01-23-2015, 11:19 AM
#86
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Ealeash you sent me pictures of your pistons. They were a dished piston from what I remember, not a flat top. So how are you getting 8.8 range with those pistons? How small are these chambers
01-23-2015, 11:25 AM
#87
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265 106cc chamber with .030 MLS gasket.
01-23-2015, 02:20 PM
#88
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Ok so what happens if you take that same motor that "you put more compression in to accommodate the small go kart blower" and you upgrade to a 250 blower? Oh you would have to change the heads or a piston swap in order to bring the compression back down. Ill be honest it was a blanket statement, with the harsh demand of the marine application and in a blower application, stay 9:1.
01-23-2015, 02:46 PM
#89
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Mine are just shy of 9:1 as well with 420 blowers. Worked great with the 177s and even better with the 420s. I do know however I'm not able to pound 10lbs of boost to it on 93 gas, but its still making more power with the same boost level with the larger blower so the upgrade was still worth it .
01-23-2015, 03:07 PM
#90
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Well let's have Mike weigh in, Mike why did you do your build at 8.5:1 and run stock pully ratio on the blower instead of more compression and lower boost?
Another factor is I didn't touch my lower end as it was just done, we used the cylinder head combustion chamber to bump the compression to where it is. I would imagine that Mike used a flat to piston in his build as 8.5:1 is about where a flat top with a 3cc relief would put you.
Another factor is I didn't touch my lower end as it was just done, we used the cylinder head combustion chamber to bump the compression to where it is. I would imagine that Mike used a flat to piston in his build as 8.5:1 is about where a flat top with a 3cc relief would put you.
