I posted last fall that I wiped out a cam lobe after it had more than 100 hrs of running time on it, and we had to limp back to the marina at idle about 15 miles away. obviously we had to tear the engine totally down, and took the oppertunity to make a few changes.

This engine started out as a 330 HP 454, and this was the third modification of that format. The last version ran good up until the time the cam lobe failed, but there was room for improvemnt, which we made and I am very pleased.

454 .060 overbore
9.0:1 compression
049 Chevy heads with 2.19 and 1.88 valves
Cam Motion flat tappet with Cam Motion Springs (selected by Bob aka rmbuilder)
800 CFM Holley
Edelbrock Air Gap
Thunderbolt IV Ignition
Competion Cams Magnum Roller Rockers

465 HP @ 4800 RPM
540 ft/lbs @ 3600
at 5000 RPM 462 HP, 483 ft/lbs
My son was the engine builder, rmbuilder was a great help and Katech Engine Development let me use there facility and one of there dyno's. I'm very pleased.

congrats now get out there and have some fun

No porting on the heads, and the cam is 224* .527 Intake
231* .544 exhaust on 114* lobe seperation. I think this engine has more left in it, but we ran out of dyno time and we were still fooling with a new carb.

Whiteknuckle----congrats on your engine, nice combination.

What carb did you use? Holley?
Mechanical or Vac secondary?
Bolt on out of the box?
Thanks
JIM

What carb did you use? Holley?
Mechanical or Vac secondary?
Bolt on out of the box?
Thanks
JIM

Nice mill.

Great, good news. Same cam and heads I use. They seem to like each other. Any work done on the heads? Ive upped my intakes to 2.25. Im surprised the HP peak was so low. Maybe I should prop mine down some.

Big Jim,
I used an 800 CFM 4150, mechanical secondaries right out of the box. That is where we ran into problems. If I had been smart, I would have had a pro set this carb up prior to the dyno pulls to at least get it close. Holley claims this carb is set up for " universal marine calibration" Maybe for tug boats for not for my engine. We could not feed this engine enough gas. I still think there is upper end horsepower to be found, as engine vacuum appears still high, but we had to clean up and get off this dyno, for some testing for some dumb race in France, LeMans I think they call it.

formula31
Yeah, the combustion chambers were just cleaned up a little otherwise stock. We did pay quite a bit of attention to the quench, and the lower end machine work was excellent. Keep in mind that we ran the engine on shop headers, not the EMI's that it will see in the boat, but we did run it with the flame arrestor on. Actually the dyno's at Katech are known to be a little on the conservative side.

Did you change anything in the carb while you had it on the dyno or was that still out of the box numbers?
Have you changed anything on the carb after the dyno runs?
JIM