Carb opinions 540's 700 hp...
06-09-2015 | 09:01 PM
#342
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Joined: Aug 2011
Posts: 2,733
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From: bel air, md
Well..gotta say QFT "MISSED" it for this build! I expected to be fat outta the box...LEAN! Just got done on the Dyno...gotta call them tomorrow...Never used their product before...hopefully have "bigger" distribution blocks??? anyone know?? went UP 8 sizes to 100 jets a still WAY lean! BSFC was only ..400 at 5000 rpm and we still have the timing backed down! 8psi fuel pressure...Bakers best Marine Pump...1/2" fuel line....But we are going to be well over 700hp when we can get enough fuel to them! Torque was still climbing at 5000rpm!
06-09-2015 | 09:24 PM
#344
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Joined: Nov 2004
Posts: 14,097
Likes: 3,686
From: On A Dirt Floor
Well..gotta say QFT "MISSED" it for this build! I expected to be fat outta the box...LEAN! Just got done on the Dyno...gotta call them tomorrow...Never used their product before...hopefully have "bigger" distribution blocks??? anyone know?? went UP 8 sizes to 100 jets a still WAY lean! BSFC was only ..400 at 5000 rpm and we still have the timing backed down! 8psi fuel pressure...Bakers best Marine Pump...1/2" fuel line....But we are going to be well over 700hp when we can get enough fuel to them! Torque was still climbing at 5000rpm!
I hope you are actually tuning by plugs and WB02 and by what the motor is telling you ........
BTW: I can change your BSFC's without any tuning changes..or any motor changes for that matter.....pretty drastically too.
06-09-2015 | 09:37 PM
#345
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Joined: Jul 2004
Posts: 11,332
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From: chicago
I agree with SB. Bsfc is not a measurement of mixture and a carb should not be tuned to hit a target bsfc.
If a wideband is not available , I'd be looking at pluga and power numbers.
I'd also make sure that floats are adjusted properly as was stated,, and if everything is setup properly and the engine is liking the extra fuel, you may be better off adding fuel via larger power valve restrictors rather than the alcohol jets
If a wideband is not available , I'd be looking at pluga and power numbers.
I'd also make sure that floats are adjusted properly as was stated,, and if everything is setup properly and the engine is liking the extra fuel, you may be better off adding fuel via larger power valve restrictors rather than the alcohol jets
06-10-2015 | 06:42 AM
#349
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Joined: May 2014
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Tom doesn't have AFR on his old Dyno...Plugs looks like is close to melting! QF sent these with a PV in the front...none in the back...laying in bed last night..was thinking adding a PV to the back? Fuel Pressure is rock-steady 7.8 to 8 psi Float levels are perfect (love those big sight plugs) Going to call QF today...wondering if they have "different" metering blocks available?? I personally havnt touched a card in 25 years...But Tom and John does this ALL the time...some pretty sharp minds in that room. Engines are gonna be stout! And YES ...1050 Dom
06-10-2015 | 06:48 AM
#350
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Joined: Jul 2007
Posts: 2,640
Likes: 14
From: MI
Tom doesn't have AFR on his old Dyno...Plugs looks like is close to melting! QF sent these with a PV in the front...none in the back...laying in bed last night..was thinking adding a PV to the back? Fuel Pressure is rock-steady 7.8 to 8 psi Float levels are perfect (love those big sight plugs) Going to call QF today...wondering if they have "different" metering blocks available?? I personally havnt touched a card in 25 years...But Tom and John does this ALL the time...some pretty sharp minds in that room. Engines are gonna be stout! And YES ...1050 Dom
