Dynoed my wore out old BBC

[80' 427]

I build quite a few dirt track engines so I was a the chassis dyno again on saturday while we were doing some head testing. While I was waiting decided to dyno my pos k30 454 to tune in the a/f and try and tweek a couple more hp out of it. This engine is a very low budget build starting with a peanut port 7.8 to 1 454 that was remaned by Marshall engines. I swapped cams (204 intake/214 exhaust, Valve Lift 476 intake/501 exhaust, Lobe C/L 112), Weiand Street Warrior intake, headers, and LS6 oil pan.

It make 241hp @ 3984 and 365ftlb @ 2401 at the wheels. This is about 335hp and 506ftlb at the flywheel. Not too bad.

 

[rcamacho]

I build quite a few dirt track engines so I was a the chassis dyno again on saturday while we were doing some head testing. While I was waiting decided to dyno my pos k30 454 to tune in the a/f and try and tweek a couple more hp out of it. This engine is a very low budget build starting with a peanut port 7.8 to 1 454 that was remaned by Marshall engines. I swapped cams (204 intake/214 exhaust, Valve Lift 476 intake/501 exhaust, Lobe C/L 112), Weiand Street Warrior intake, headers, and LS6 oil pan.

It make 241hp @ 3984 and 365ftlb @ 2401 at the wheels. This is about 335hp and 506ftlb at the flywheel. Not too bad.

Nice torque for a low end build

 

[badmix]

I think flywheel numbers are generous, is there really that big a loss thru driveline?

 

[rcamacho]

I think flywheel numbers are generous, is there really that big a loss thru driveline?

Typically 10-30% loss

 

[80' 427]

I was figuring 72% of rear wheel. We figure 68% on a loose convertered auto. With the high hypoid angle of the 14ff it may have a bit more loss. This is on a mustang dyno so it typically reads lower then a dynojet. You may not like my flywheel guestimate but we have proven it very close many times with engine dyno then wheel dyno. Still if you look at the where the peak rpm is and what it made I am super happy. Built it to pull racecar and lug up hills when rockcrawling.

 

[badmix]

I have seen more times than not ppl guessing on dynos , regardless of what type and their numbers are ALWAYS lower than what they GUESS. Your rear wheel hp / tq is the true numbers, nothing else really matters IMO. I was just suprised at your guestamates and still feel the TQ is being generous, if Im wrong so be it. until it hits a brake dyno, no way to be 100%. If your happy thats all that matters.

 

[80' 427]

I just like that it is low and will pull my bit undergeared k30. The thing was a grease ball I spent a few hours cleaning, swapped on a few parts and have been beating on ever since. My friends 12 to one 427 made less torque but more hp than mine but at a much higher rpm (his is a bit more peaky). The other thing we compared it to my k10 which I dynoed last year and it is about 150ftlbs to the wheels stronger so it should pull much better. Oh and something I just thought of is we did make the pulls in 3rd gear as to prevent the driveshaft from coming out at 5000rpm in high. Still even if you use much more conservative numbers it still is a improvement over the stock 454. Plus even the minor tweeks to fix a/f and timing and it is so much happier all the time now.