coolcarwrench

I am going to install a comp roller in my 330 HP 454 part #01-451-8. The #'s are 230 int. 236 ex. @ .50 547 lift on 112 seperation. comp's tech line recommended this one for my application. Has anyone tried this cam? or have any idea what it will sound like? Tired of "stock Sounding motor". Will also be upgrading prop to 25" and will be watching rpm's, trying not to hurt motor.

blue thunder

The increase in cam duration should make a noticable change in the rumpety rump of the engine. I wouldn't get to overly optimistic on going to larger pitch prop until you run it with the new cam. Typically the heads on the 330hp are the biggest stopper to more power, doing just the cam may not deliver much, at least at WOT. The other thing to consider is will this cam cause more reversion in your exhaust.

BT

coolcarwrench

I'm trying to keep from going overboard (like everything else) I do, I want the cool sounding idle, but I want to keep my reliability also. I have a set of early Chevelle oval port heads I can install if I need to, but I've been told that I have to be careful because bottom end is weak in these engines (too much RPM) on cast parts, BAD DEAL!

blue thunder

You can easily spin cast assemblies to 5000rpm if balanced properly and upgrade to arp rod bolts. Even without those two things I did it for several years and never had a cast component fail. Put the better heads on, but make sure you install proper valves and seats and you may be suprised with the result. That is assuming the new heads are the better oval head design.

BT

JohnJan

Does Comp's tech line know that that's an 8:1 motor?

cooltoys61

Merc didn't use the Vortec heads around 97-2000 did they? I bulit a vortec 97 truck motor (2 actually) for my boat and used the ZZ502 cam which is close to what your specs are less int dur. Idle is not very Radical or Rumpy but low end torque is good and all around a strong runner. I picked up 8 MPH on my 29' Non-step Fountain with twins over what I had with 454 mags. Vortec heads are great on exhaust flow and much better than the peanut ports on intake flow esp if you install larger valve,,but I didn't. I raised the compression to 9/1 by decking as these small combustion chamber Vortec head have about 8.75/1. Used all stock bottom. I'm overpropped right now but seeing 80 at 4700rpm and slowly creeping up. I plan to go from 29hydros to my 27 mirage and spin em around 5100-5200 for short runs. I agree that the cast parts are under rated BUT I spent last summer replacing one blown Mag mtr then the other so I won't push them very hard for very long. See if you can find some Vortec BBC heads and you'll raise your compression enough to help overcome the bigger cam and make a better sound too. Don't run as much advance on the ign with these though, they are happy with 29 deg total and with blow up at the normal 36 deg.