redcorvetteman3

I was wondering what kind of hp tq numbers are obtainable from a N/A 496. with 9.5 comp dart alm pro 310 cc eagle crank and rods, srp pistons hyd roller. This is what im running now dynod 500 hp 600trq. Is this about right or am I a little short? Also what could I do next to make more with these or start over with 572, 598 short blocks and use the heads intake?

blownjet 468

would have to know more, like your cam specs- generally,
1 HP per cubic inch is very easy to achieve with a relatively
mild setup, personally, a 496 build -NA- I would expect to
see closer to 600 - also, where are you dyno testing? close
to sea level? what correction factor, etc.. lot of variables
here - with out alot of information......jmho

FIXX

iTrader: (2)

Sorry! i would say your about 100hp shy,which cam are you using?

Rookie

iTrader: (4)

With that setup and the right cam I have seen 1.25HP/Cu.In.
Need cam specs

redcorvetteman3

Ill get the cam specs. I didnt have Bob Mandera spec a cam but should have.. Better yet what are you guys useing .What RPM should I rev up to? I dynoed wet with stock manifolds I know I left a little there also . Just wondering what every one else iis getting from there's and where to go from here.

Rookie

iTrader: (4)

What were the performance gains (or non-gains) vs your stock power? I remember a while back about your dyno #'s and thought they were a little low, but we could have desktop raced dyno sheets all day and got nowhere.

blownjet 468

#1- Ditch the stock manifolds
#2- get ahold of Bob (RMBuilder) and have him grind you a
custom cam- he IS THE MAN for MARINE camshafts-

redcorvetteman3

Yea on the little low and peak tq was at 3800or so way low but thats what I had and buget didnt allow for a redo at that time so I ran it a few times and now looking to do it better this time. Cam and manifolds well thats the thought for sure but if Im only going to gain 60 to 75 hp I still might build something bigger and then the cam would be no good on a new combo. Of coarse manifolds would work on either I think if I get a set that will fit a tall deck side by side in case I go that route.Just dont want to keep double buying. How fast can I spin a 4.25 eagle crank or a 4.5

Rookie

iTrader: (4)

Here is my opinion, take it for what it's worth. If you build a 572 or 598 and put them in front of your TRS's with that torque and the weight of your 415 Stinger, you are on a path of destruction. I built my (High Strung) 600HP 468's knowing that I would have less torque, and I would have to spin my engines to 6000RPM to reach my max HP. My reasoning was that it would be a little easier on the drives. Granted I have a considerably lighter boat than you. I know you want torque in a boat, but I do not need as much as you. I think you can build a pair of great 496's for your application.

I also think you need to ditch the stock manifolds and let them babies breathe, BTW what are your performance goals.

I had a friend that use to have a HEAVY '86 Top Gun with 700+HP solid roller 540's and he was going through a TRS/month. He also drove it like he stole it. Money for drives were not an issue. Babying it was not an option.

FIXX

iTrader: (2)

a little story,a guy over at donzi.net had built a 496 and used round port heads, cam ?? and stock exhaust..

i gave him a cam grind to use (flat tappet) changes his cylinder heads to square port,changed his exhaust to stainless marine's and put a 850 cfm sea demon carb on..the boat picked up 10 mph,all this through a trs drive..then be put nos on it because he wanted to go faster then blew the phucker up

i think with the rite cam and exhaust your motor will pick up that 100 hp..
dont under estimate the 496 (stroked 454) they are a a$$ kickin motor.