BBC 454 with 10.2 static compression and 262/272 duration cam @ 0.050, iron oval heads

5/6 psi procharger boost, may try 10 later if this works without melting anything.

Propose 24 degrees total timing, jetting up 10 sizes from stock Holley 750 DP, blow through setup

94 octane pump gas (10% ethanol advertised), no intercooler, but air intake at grille

2 ranges colder than usual plugs with 0.025 gap

6 psi idle fuel pressure with boost referenced pressure regulator

race car only application, density altitude usually 3000-4000 ft.

have Innovate wide band O2 installed to log air fuel

Anyone run a similar setup? Do you think this tuneup will be safe with pump gas?

Do you think it would be safe to run a full pass?

Best normally aspirated 10.7 @ 125

Goal is 10.0 @ 135

Any info/advice appreciated.

 

More details on the carb and fuel system.

 

"AED" prepped 750 Holley DP carb was installed in an aluminum procharger carb box.

I have not pulled the carb from the box yet to check what is in it for floats, jets, PV's, etc. All I know is that it was installed on a low compression 454 previously and the guy ended up buying a high compression crate motor.

BG400 fuel pump (was in the car when I bought the roller), half inch fuel line from the trunk mounted cell to the engine compartment fuel pressure regulator. I have run this car for a couple of years normally aspirated and other than having to fix the leaky BG400 the fuel system is big enough for my purposes.

 

from what I have read and learned .... your setup is right in that "GRAY AREA" (comp ratio vs boost).... tune the carb on the rich side and watch your w/b like a hawk. If it shows safe numbers while at WOT then retune more aggressively in baby steps. Check every plug because I herd w/b arent always 100% accurate.

 

You should pull the carb apart just to be sure whats in it. Look at jet,floats,powervalves ect.

 

Pulled the carb apart tonight. was previously installed on 8.5 comp 454 with procharger marine carb box

primary jets 78 looks like stock type 6 inch vac PV
secondary jets 87 no PV

has the "black" floats

10561 and 10562 metering blocks

air horn machined off

choke rod hole plugged

primary air bleeds 3/4 turn out
secondary air bleeds 1/2 turn out

red cam on both pri and secondary accelerator pump #1 hole, small pump both ends

"U" tube on both both vents

Otherwise looks very clean and functional, could not detect any other obvious changes

According to the previous owner of the setup, he had taken out quite a bit of jet cause it was running so rich in normal driving. Would that have been caused by the stock type power valve leaking out a lot of fuel?