Is this believable HP out of a 572?
 

I read this on a site somewhere it could of even been on here:

"these 572's so far they make 780hp @5900 & 786ft pounds torque @4700 super flow #'s ....dart pro ones 336cnc heads,dart intake, big m block ,top dollar rotating assbly, and a .612, .612 valve lift with 256in & 258ex @.050 on a 114 CL hyd roller."

The reason I ask is Im in the middle of a 582 build and expecting 725hp with brodix bb-3 cnc'd 365 runners, flat top pistons, the cam will be .258int & 262 ex @.050 with .612 lift on both and 114 sep.
Where Im at is 1400ft elevation and around 70-80f temps on an average boating day.

Could be legit, could be a generous dyno. If its on the internet you never know.

Great point! The original question posed reminds me of a YouTube vid I saw about a ZZ502 GMPP crate motor that was "built-up" and installed in a vehicle. The owner claims to have made a 700HP ZZ502. Given my experience so far with that motor, that is a very tall claim (without forced induction). When question about his HP claim and where is the dyno information, he quickly :7160:

My reaction to this thread is, don't believe numbers unless they are backed up by realistic dyno numbers. And not some stepped on correction factor.

its all in correction factor

700 is about all you will get from that build with the proper intake and carb.We get 720+ HP (uncorrected #'s) from our 572's with custom intakes and carbs @5900 rpm's but run more lift and compression at 9.9 to 1.

Interesting...I have always wondered how NASCAR gets 800hp out of their small blocked 350s and runs them WFO for 2-3hrs.

That HP is attainable from a 572 at a slightly higher RPM but the torque is bogus. That's a BMEP of 207psi at peak torque.. Not likely with that combo.

ultra lite weight parts in the recipro, every trick coating/process you could imagine, dry sump oil system, short stroke/large bore, exotic valve train and camshafting and a very narrow , high rpm hp peak.

Simple answer. MONEY.

(smittys description too)

Uncle Dave

Spinning 8000rpms also makes a big difference.