95NovaSpyder

iTrader: (2)

I had a 454 mag that ran pretty good, but having to replace the bravo upper and pulling motor for coupler replacement, I decided to rebuild motor, so its done all at same time. I took it to a machine shop who does a lot of marine motors. I finished assembling the short block myself. I am looking for some input on the cam that was used (builder says he uses it a lot). I wasn't looking for anything excessive.

Gen 4 - 454 4 bolt main - 30 over
icon forged piston - 9.3 CR (calculated with head CC)
stock GM rods
fully balanced
stock 188 rectangle port heads - CC @ 119
GM alumn hi rise intake (the good one, I notched the center plenum about 3/4")
Gil exhaust manifolds with HP 500 arched risers (straight thru hull exhaust)
cam:
Erson hydraulic roller # RH-282-4 (it was degreed in and its @ 111* lobe separation)
.050" info:
intake 222*
lobe lift .320 valve lift .544
exhaust 226*
lobe lift .320 - valve lift .544
Elgin pro stock roller lifter
comp 1.7 ultra pro magnum roller rockers
Edelbrock marine 750 (If i can swing before summer - i am switching to a 800 or 850 quickfuel marine carb)
HEI distributor

I'm not worried about reversion - since I have the longer arched risers. and from research I think it should idle well with the lower duration, and mild lift. I plan on only spinning to 5400-5500 rpms

mike tkach

iTrader: (3)

i think you may be a little confused about the cam.it has a lobe seperation angle of 110 deg.the intake centerline is 110, if you mean it was degreed in at 111 instead of 110 that is fine,if you are + or - 1 degree you are golden.

95NovaSpyder

iTrader: (2)

sorry - yes degreed in at 111*

MILD THUNDER

iTrader: (3)

I think that cam is light on duration for 5500rpm propping.

95NovaSpyder

iTrader: (2)

I dont need to spin it that high - but i figured since the stock mag cam easily spun to 5200 - that this should spin a few more rpms - I'm not looking for a 500hp motor, i guess it to be near 400- 420ish. I wanted to keep the nice idle and low end. It spends most of the time at 3000-3500 rpm

MILD THUNDER

iTrader: (3)

That cam is pretty close to a stock 454/502 mag cam.

getrdunn

iTrader: (7)

Ya even close to the 454/420 cam. I always liked using that 502/465 hp cam in 454 installed about 3 deg advanced. With oval ports darts, torker 2 int it makes 480 hp but that's a flat tappet. Otherwise I'd run the 731 cam if your going hyd roller. Just my opinion but I honestly don't think the OP will be happy with his cam choice either.

getrdunn

iTrader: (7)

454/420hp cam is like 228/236 @ .050 530/551 I believe. That does work well with 454 however wouldn't expect much more than 2-3 mph top end. I did that build also with a back to back comparison in a 24 challenger.

95NovaSpyder

iTrader: (2)

I know the came isnt that large - i wasn't looking for huge HP increase. With the original 365 mag the little Nova would run 65-67. I wanted slightly more hp, but mainly better rebuild with reliability.

getrdunn

iTrader: (7)

You will have a nice reliable upgrade package for sure. Like we all say from time to time it's better to be on the water than in the shop on a 90 deg day!!! Sounds like you've got a nice rebuild that will work well for you. Better under size cam with a 454 than oversize. There's a fine line with where the edge is especially in boat app.