No more power past 3/4 Throttle
06-30-2005, 03:50 PM
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Re: No more power past 3/4 Throttle
Originally Posted by Badtoon
Are the secondary jets to large??????????????
I did a plug reading at 4k which puts me just into the secondaries and the plugs were very lean. that was 80 front 82 back. So I upped to 82 front 84 back that worked good at 4k. I have not taken a reading at WOT yet I'm going to check that this weekend. Transom is clean though so I don't think I would be that rich.
06-30-2005, 03:56 PM
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Re: No more power past 3/4 Throttle
Originally Posted by Pure Energy
I agree with wet vette, make sure you are getting WOT at the carb, but also may be a fuel delivery problem. I replaced my fuel tanks and had the same problem, normal operation untill the last 1/4 throttle...and nothing. Turned out the pick-ups in the fuel tanks were too small. I had prochargers, but maybe something in your system is not allowing enough fuel.
A plug reading this weekend should tell me if I have a fuel problem. It does make sense. Especially the jet changes with no rpm or mph changes.
06-30-2005, 08:29 PM
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Re: No more power past 3/4 Throttle
Not sure if this will help but I had a 31 with 502's, hyd roller, dart int, stock heads with bowl blend, 800 carb, gill exh with a 4 1/2 tail pipe and ran 79 on GPS with 25 Mirage wheels at 5450. I figured the motors made 450hp or so. 27's ran 82 at 5200.
07-01-2005, 07:43 AM
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Re: No more power past 3/4 Throttle
Originally Posted by bob
Not sure if this will help but I had a 31 with 502's, hyd roller, dart int, stock heads with bowl blend, 800 carb, gill exh with a 4 1/2 tail pipe and ran 79 on GPS with 25 Mirage wheels at 5450. I figured the motors made 450hp or so. 27's ran 82 at 5200.
07-01-2005, 08:15 AM
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Re: No more power past 3/4 Throttle
Are the carbs in box stock configuration? An 850 on a 502 should be real close the way it comes from Holley. If it isn't in stock configuration I would put it back and start over from ground zero. Have you tried to run the motors without the flame arrestors just to see if it makes a difference? I also wonder what a single plane manifold would do compared to the air gap on this motor, particularly over 5000 RPM. The headers are still your biggest problem.
07-01-2005, 08:44 AM
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Re: No more power past 3/4 Throttle
Originally Posted by WETTE VETTE
Are the carbs in box stock configuration? An 850 on a 502 should be real close the way it comes from Holley. If it isn't in stock configuration I would put it back and start over from ground zero. Have you tried to run the motors without the flame arrestors just to see if it makes a difference? I also wonder what a single plane manifold would do compared to the air gap on this motor, particularly over 5000 RPM. The headers are still your biggest problem.
I agree manifolds are killing me but I think I still should see at least md 70's even with those manifolds.
As soon as I scrape up 5 grand I will replace them... Problem is they have to be custom made. so cost is crazy...
