All Custom but all parts were known to work good. 540, AFR heads, running 10 lbs boost, CMI headers, FAST ecm, don't remember what cam was in it.

Awesome, thanks for the reply. Sounds if I go NA now, and think a little ahead, FI won't be written off. I like it.

Darn duplicate posts...

Build it with the good parts, Keep compression low. If you look almost all mercruiser supercharged engines are at 7.5 or close to that compression. I was told by an engine builder many years ago that you will build more HP with lower compression and more boost then with higher compression and less boost. If they are tuned correctly with the right AFR they will live a long life.

I do not think I will ever own a boat that does not have a supercharged engine of some sort, They last three were along with the current one.

Gotcha. Makes sense to build for a better tomorrow lol. The CR on the 500 is 8.75:1 stock, and with the minimally larger combustion chamber (121cc heads) it drops it a little bit. I suppose if I plan on going forced induction, a thicker head gasket could get it a little lower, but sub 9:1 should do the trick. And them there is cam choice. Could be a long day of research...

Cam choice is a big deal. The cam I had used was one that everyone was recommending back then. It was a hydraulic roller made by Crane. Not sure if it is still made or what the specs of it were.

Many years back when I was young I had a 1970 nova, I changed the cam out and turned the car into a dog. Went to another cam and I was kicking everyone's butt, so they can either make or break a motor.

Turbojack,
How is your Daytona running? It should be flying with that kind of HP.
I always thought the 30' has the best lines of the Daytonas.
I I looked at one for sale years ago with 525s. The recall said 112.
Seems pretty efficient to me.
Steve

Hey Jay, I'm not dead...LOL. I set up shop at my house. Still have the dyno and everything. I may be able to take on your project when you are ready. I'm just finishing a procharged 502 for my boat. I sold the 598. I've done quite a few 500 efi with whipples. They are really turn key and good for over 700 HP. Maybe my boat's slow, but it takes a lot more than 600 hp for me to hit 80. The 598 was making right at 800 and would run about 84. Sometimes barely 80 in really hot muggy conditions. I don't think you'd be happy with a naturally aspirated engine. Get the whipple, or I can tune for a procharger. Problem with the PC is low end torque. I fought that with the 598. You need a big enough prop for the top end, but was kind of slow to plane with a P5X. They just don't slip enough. The whipple solves that problem.

Bob Lloyd

BOB!!! You live! Cant send you a PM, drop me an email or something when you get a chance. [email protected] Unfortunately things have changed for me.

Bob, good to see you back on the board.
I hope you are doing well old Buddy!
Steve