HP increase
 

I have a 509 putting out 650 HP. It is a stock block, crank and rods. 10 to 1 JE pistons, 741 hyd cam, Jim Valakeo ported Dart 1 alum heads. Dart intake, Lightning dry headers and an HP 950 Holley.
My question is that I am thinking on stroking the engine to 540 and installing a Bob Madareas solid roller 110 CL cam. I figure the compression will go up to 10.5 to 1 from this. I plan on turning it at least 6500 RPM.
What increase in HP do you think this would do? 750 - 800 ish?

A 540 in the 6500 range has the potential to make over 750.

without knowing all the information on things like cam,heads,compression ratio etc it,s pretty hard to figure out what hp&torque the engine will make.after all this info is given to bob he can make a fairly close assessment of what the engine will do.

10.5 to 1 would scare me in a boat. Think 800hp would be hard to achieve unless the heads where killer. With a 540.

with the right setup i think it could work well.i believe he has a lite weight cat.

How much power you think .5 is worth?
Raising the compression in my 598 from 10. to 1 to 12 to 1. And running aviation 100ll Don't know what I will gain.

i think with a static of 10.5 to 1 vs 10. to 1 in itself will not do much but it will allow a cam more suited for the higher rpm&power.your increase of compression if everything else stays the same should give you a decent increase in power but im not going to take a guess as to how much.

I am changing everything so I will not no what did what. Cam, heads, and compression hoping for 150 more. but might be hoping to high.

sounds interesting,let us know the outcome.

Thanks for the info.
The engines as they are run great on mid grade without any spark knock. The pistons are zero decked, cylinders are valve notched and the intake is port matched to the heads. The heads are CC'd. Lots of other little things.
I intend to build a 598 with an M4 Procharger this spring / summer. But there is NO way it will get done before summer. The other engine that is still in the SCARAB needs to be rebuilt to be safe. ( it free reved when I blew a drive three years ago in the fall.)
It has been run for a few hours after that but to be safe I am going to rebuild it as a spare.
So if it needs to be rebuilt why not upgrade to 540 CI and up the HP to 750+ and use it as my main engine until I build the 598.
I intend to sell the engine that is now in the Daytona after the 598 is built. I don't need three engines.
I have 93 octane readily available to run on the new engines.