Jetting for Supercharged 502
#1
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Jetting for Supercharged 502
I have a 502 with a B&M 250 with dual Holley 750's. The carbs were set up by pro-systems, and are boost referenced. The jets are 74's all the way around with 5.5 power valves in both the primary and secondarys. The engine was a 500hp carb, but now has flat top pistons in it. I took the new engine out for a test ride yesterday, and the plugs were reading very lean. I have dual fuel pumps running to a manifold, and then to the carbs with 7.5lbs of pressure. Just wondering if anyone has an idea what I might jet these at? and do the power valves sound right? Was going to start with 78's all the way around to start with.
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I have a 502 with a B&M 250 with dual Holley 750's. The carbs were set up by pro-systems, and are boost referenced. The jets are 74's all the way around with 5.5 power valves in both the primary and secondarys. The engine was a 500hp carb, but now has flat top pistons in it. I took the new engine out for a test ride yesterday, and the plugs were reading very lean. I have dual fuel pumps running to a manifold, and then to the carbs with 7.5lbs of pressure. Just wondering if anyone has an idea what I might jet these at? and do the power valves sound right? Was going to start with 78's all the way around to start with.
PS Mine is a single 650.
Last edited by pachanga; 05-23-2011 at 04:49 PM.
#3
I have a 502 with a B&M 250 with dual Holley 750's. The carbs were set up by pro-systems, and are boost referenced. The jets are 74's all the way around with 5.5 power valves in both the primary and secondarys. The engine was a 500hp carb, but now has flat top pistons in it. I took the new engine out for a test ride yesterday, and the plugs were reading very lean. I have dual fuel pumps running to a manifold, and then to the carbs with 7.5lbs of pressure. Just wondering if anyone has an idea what I might jet these at? and do the power valves sound right? Was going to start with 78's all the way around to start with.
#4
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How much boost ??? When I had a similar setup, I ran 82 prim and 94 secondaries.
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#5
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Looks like we have a spammer !!!! ^^^^^^^^^
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Want your ECU tuned right?? Call Mark at Precision www.pmefi.com
Want your ECU tuned right?? Call Mark at Precision www.pmefi.com
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#9
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are you checking fuel pressure under hard run ? need to...if thats fine...read the plugs and tune from there..I have been running prosystems carbs for years(and still am) and they are usully real close out of the box...but close not always perfect...tune from there..