Good point I'll have to take a look at everything that's for sure thanks for the great advice everyone greatly appreciated I know a lot of guys would be blaming the webers but I've seen webers lay down good numbers on dynos and honestly if it was the difference of 20-30 hp difference I would still run them they are a fun carb I think my issues (yet to be found) is not in the carbs
I would not be overly concerned with comparing dyno figures, many supposed 500hp engines with dyno sheets have been shipped into the uk only to find they are nearer 350hp. I think they are referred to as happy dyno figures
Bob
Ron Earp
Admin
Absolutely if you're comparing an engine dyno with a chassis dyno. Most engine builders are using an engine dyno while most customers end up running the car on a chassis dyno. Engine dynos are great if you're set up to produce engines or want to play with eight different header configurations in your race shop. But they're going to read much higher than a chassis dyno due to parasitic losses being present with the chassis dyno.
After using both I prefer the chassis dyno as it's the motor in the "as raced" environment. And with modern ECUs it's a real pain to setup an EFI engine on the engine dyno anyhow.
I've built an honest 405 HP and 380 TQ with a SBC 305 punched to 310 using essentially the same camshaft along with a Performer RPM intake and a Holley 4776 (600 cfm double pumper) in my old SCCA American Sedan car. My heads were no where near what yours were either as we were limited at the time to 1.84 intake and 1.5 exhaust.
Your AF Ratio has a lot to do with the problems you're having. Frankly, she's running so lean, I am surprized you're not melting spark plugs.. My AF ratios are typically 12.5-12.7 on our racing engines.
The 110 lobe centers will produce reversion with IR manifolds and Webers. Reversion is a bad thing for any carb as it (the carb) simply stops working for a moment as air is forced upwards, into the booster venturis and makes a total mess of the fuel being drawn out of the emulsifier wells.. That's why webers run like total crap with narrow lobe centers at lower rpms.
Your AF Ratio has a lot to do with the problems you're having. Frankly, she's running so lean, I am surprized you're not melting spark plugs.. My AF ratios are typically 12.5-12.7 on our racing engines.
The 110 lobe centers will produce reversion with IR manifolds and Webers. Reversion is a bad thing for any carb as it (the carb) simply stops working for a moment as air is forced upwards, into the booster venturis and makes a total mess of the fuel being drawn out of the emulsifier wells.. That's why webers run like total crap with narrow lobe centers at lower rpms.