daniel92345z28

like it says dyno results for a 454 gen 6 stock vortec heads unported trought a t56 and the stock 10 bolt

i am having issues with the hie distributor and it was leaning out past 4 so the dyno pulls only made to 4250 i usually go 5500

Z28ricer

iTrader: (2)

Looks nice, would have liked to have seen if you kept the oem injection.

Kingtal0n

Something is up with the timing or spark because with smoothing set to 5 that graph should be far straighter.

As for it leaning out, perhaps the timing is so far retarded that excess fuel is entering the exhaust system (along with unburnt oxygen) and causing the O2 to read false lean. That would explain the wavy torque curve also.

An EGT would help tell. If the EGT is getting high during subsequent runs (Over 1480* perhaps?) that is also an indication that timing is too far retarded.

Was that on 93 pump gas? What is the compression of the engine? Any idea how much timing is max advance? Did you try to advance it some (mechanically)? What is the air fuel ratio? Engine coolant temp?

A supra will make the same sort of graph on 93 octane when you push 18psi and only run 10* or less of ignition timing. except of course it does this around 6k 7k rpm
I know apples : oranges but I am judging the graph with experience

daniel92345z28

well yeah that was just a base line dyno so i can see if the mods im gonna do improve the power.
im going to install a msd 6010 box for the coil per cylinder
it was open header .now im gonna do the dual 3' in a single 4'
850 double pumper with out a choke horn

daniel92345z28

as for the engine specs
7.4 chevy gen 6 compression is 9 to 1 stock heads and block
230/236 @50 510/520 lift
cloyes timming chain / melling oil pump
roller rockers
longtubes 2' primaries and 3 collecter
single plane team g intake manifold
holley 750 csu prepped for blowtrough
and a stock hei distributor
also has power steering and
fan of the water pump gonna change to electric duals

brando54009

wow those are pretty nice numbers for not doing too much

daniel92345z28

thats what i was thinking .remember this engine was rated at 290 hp and 410 tg from the factory to the crank.
next step is gonna be a set of Brodix race rite heads
or the f1r procharger

brando54009

i would go heads first. it just seems to make more sence to flow more rather than force it in

1gary

A big set of heads without a compression change and matched cam is going to take away from the bottom end.10.5 would be about the limit I would go on today's 92 octane gas and aluminum heads.Then a matched cam watching the DCR.54'a like a good exhaust flow.
Forced induction,I suggest should be apart of you game planning,but after your somewhat "there" so it compounds the mods done watching the compression ratio vs the amount of boost and a system to retard the timing on the top end.You don't want to increase compression ratios and end up not being able to really capitalize the blower having it ending up being a decoration on top of the engine.Cams for a blower engine are alot different than N/A engines.They are more conservative and don't have long durations generally.My point is if you want a blower engine,you have to plan for that now and I don't suggest you use that as a add-on later.I know they are sold that way,but a properly applied blower or for that matter any forced induction is a fast track to 100hp and more.