Help miss on top end

[bbc540]

:confused: I have a 555 chevy with afr aluminom heads lunati solid roller cam and a 1050 Quick fuel carb with annular boosters the carb is on a 4150 style base on a tem g intake running 90 primary and 96 secondary jets plugs are a little black but I have played that game with it and fuel delivery is not the problem I also changed the distributor and coil. It actually started it on my last motor last year then this year I installed the new one with the only thing that stayed the same is the intake and carb. I dont have another carb to try so hears the problem in low gear it runs hard all the way to 7500 in high gear it starts out strong then about 6600 it starts a very slight miss and acts like its lugging down. could my fuel preasure be too high its set at 11 pounds. The distributor rides hard on one side of the intake hole? maybe I need even smaller jets? do I need to go to a 4500 style carb?The cam is a lunati 50226 >722 >722 272 280 like I say the motor is a beast in low and bottom of high I am runnig 1.18 and a 16 pitch prop please help

[bbc540]

I forgot to mention when it gets to 6600 it will actually fall back to about 6400 or so

[SmokinLowriderSS]

Strikes me as being just a tad too rich. Loading up some WFO once it is settled in. Doing OK as long as it is trying to wind up but once it is really pulling hard on teh mains being a bit too fat. Seems like the direction to me. I'd drop 2 main sizes on the seccondaries I see what happens.

[Moneypitt]

Lets go back to the dist riding hard on one side of the intake hole. What exactly do you mean by this statement? How much oil pressure does it carry? Is this what is side loading the dist.? Is the oil drive bottomed out against the oil pump? Dist. should contact intake without a gasket, then with the gasket you are assured that the oil drive shaft has some clearance. As far as the laying down goes, does it ever bang or pop in the exhaust?..MP

[bbc540]

the shaft does not bottom out it just rides hard to one side I actually had to slightly clearance the intake so it would not be a side load on it. It was weird to me I have never incountered it before and have built a few chevys. as for as popping in the exhaust it is not doing that that I can tell its more like a spitter than a hard miss. it runs about 60 psi at idle and 95 - 100 at wot

[Fiat48]

could my fuel preasure be too high its set at 11 pounds.
Too high...needles and seats can't handle it...which will make the motor rich. Get that fuel pressure down. 7 lbs is enough.

[SmokinLowriderSS]

I missed the 11 psi fuel pressure, yes, set down to 7, plenty. You are giving the floats nightmares trying to maintain a proper fuel level at that pressure. Level gets too high, you will be too rich, regardless of what jets you have in.

[steelcomp]

Ask Miss to remove shirt...be glad to help on top end. :D

[bbc540]

Thanks guys I am currently away from home but when I get back will back down the fuel preasure and try it again :cool: