Assuming it has a flat tappet, non roller lifter, cam and lifters I'll guess a little over 700 HP, maybe 750 HP, at 6500 RPM and almost identical torque on 91 octane non ethanol rump swill What brand an part number is your EFI throttle body? I'm in the middle of planning a new race motor (551 C.I. B1-MC heads) with a crank driven centrifugal super charger with EFI running E85 pump swill Hoping for 2000 + HP depending on how much boost I limit it to planning on under 30 lbs. at 7500 RPM
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: The 541 is DONE! Headed to the dyno.
[Re: Cab_Burge]
#3060253 07/18/2202:40 PM07/18/2202:40 PM
My last pump gas 517 C.I. stroker 400 motor with a set of M.W. port size SR heads made 727 HP at 7000 RPM and around 680 Ft. lbs. at 5200 RPM with a single 1050 CFM Dominator carb on a DTS engine dyno in Klamath Falls OR, at 4300 Ft above sea level in the spring with decent air Same short block with a set of MCH ported 440-1 heads and same intake manifold and carb made 775 HP at 7300 RPM on Oregon 91 octane pump swill one week later on the same dyno Your motor is bigger with smaller heads so keeping that in mind with the time of year (weather conditions), dyno elevation and how stingy or generous the dyno is will make the numbers you see on your motor.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: The 541 is DONE! Headed to the dyno.
[Re: Cab_Burge]
#3060291 07/18/2204:58 PM07/18/2204:58 PM
My last pump gas 517 C.I. stroker 400 motor with a set of M.W. port size SR heads made 727 HP at 7000 RPM and around 680 Ft. lbs. at 5200 RPM with a single 1050 CFM Dominator carb on a DTS engine dyno in Klamath Falls OR, at 4300 Ft above sea level in the spring with decent air Same short block with a set of MCH ported 440-1 heads and same intake manifold and carb made 775 HP at 7300 RPM on Oregon 91 octane pump swill one week later on the same dyno Your motor is bigger with smaller heads so keeping that in mind with the time of year (weather conditions), dyno elevation and how stingy or generous the dyno is will make the numbers you see on your motor.
You neglect to mention cam specifications. I suspect it's a lot bigger than Feets'.
Re: The 541 is DONE! Headed to the dyno.
[Re: Sniper]
#3060342 07/18/2207:51 PM07/18/2207:51 PM
You neglect to mention cam specifications. I suspect it's a lot bigger than Feets'.
That's what some people haven't keyed in on. It's a comparatively small cam on purpose. I want a good vacuum signal, to cruise a 5300 lb car at 75 mph @ 1800 rpm, and enjoy good street manners. Then, it needs to have silly amounts of torque everywhere.
It's a very different kind of build. I didn't really care about hp. There was no focus on that at all. Think of a stock Ram 5.7 truck. Give me the same drivability and street manners but raise the power number by 200 everywhere.
We are brothers and sisters doing time on the planet for better or worse. I'll take the better, if you don't mind. - Stu Harmon
Re: The 541 is DONE! Headed to the dyno.
[Re: feets]
#3060347 07/18/2207:59 PM07/18/2207:59 PM
I did not have them flowed before porting so the after numbers mean nothing. I imagine that a cam and intake swap would run deep into the 600s. However, doing that would sacrifice the nice easy cruise of the Imperial.
We are brothers and sisters doing time on the planet for better or worse. I'll take the better, if you don't mind. - Stu Harmon
Re: The 541 is DONE! Headed to the dyno.
[Re: feets]
#3060745 07/19/2211:32 PM07/19/2211:32 PM
We struggled at first to get all the planets in alignment. After the issues were worked out we warmed it up to 180 degrees for some real world data.
And promptly ran into valve float around 5100-5200 rpm.
It's not likely to pick up much power with new springs but it would give me a little more RPM cushion.
Anyway, the Imperial is going to be a bit more frisky with this thing under the hood. I wanted torque and I got torque.
Me thinks you may have the wrong camshaft for the valve springs and not the wrong valve springs for the camshaft I'd try a different camshaft with a little more torque I had an engineer say "you DRIVE an engine on the TORQUE not on the horsepower" when asked "how much horsepower will the new engine make?" In my opinion if it's going to be your "DRIVER" I'd keep trying to get as much TORQUE out of that beautiful stroker of an engine. TORQUE is king IMO especially in that Imperial. NICE WORK feets
Mike
Re: The 541 is DONE! Headed to the dyno.
[Re: feets]
#3060815 07/20/2208:08 AM07/20/2208:08 AM
At what RPM does the geartrain of the Imperial do 70 mph?
I know there are Dyno challenges but wouldn’t it valuable to have Torque values at lower RPM typical of typical highway driving?
With the Dyno info you now have a relatively cheap program like Engine Analyzer from Performance Trends could give you a plus/minus 7% estimate of where “best” Brake Specific Fuel Consumption occurs, and how BSFC varies at part throttle opening and lower RPM.
What are the chances this is the all time Imperial “Torque Champion” ?
Re: The 541 is DONE! Headed to the dyno.
[Re: 360view]
#3060820 07/20/2208:28 AM07/20/2208:28 AM
Same short block with a set of MCH ported 440-1 heads and same intake manifold and carb made 775 HP at 7300 RPM on Oregon 91 octane pump swill one week later on the same dyno 
I'd try a different camshaft with a little more torque 
I had an engineer say "you DRIVE an engine on the TORQUE not on the horsepower" when asked "how much horsepower will the new engine make?" In my opinion if it's going to be your "DRIVER" I'd keep trying to get as much TORQUE out of that beautiful stroker of an engine. TORQUE is king IMO especially in that Imperial. NICE WORK feets 
