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454 Rebuild. Aprox HP with Comp Cam

The first 11-12 hours were run using Joe Gibbs 5w-30 break in oil then change out to the 20w-50. The oil pressures with both oils read the same. Re: the camshaft. It is a flat tappet with a "mild" profile with the overlaps specifically designed to prevent reversion. The whole intent of the rebuild was to provide a 15-20% boost in HP and torque at a 3000-3200 rpm cruise. Not interested in what it does at 4400 rpm. The cam specs were written by Jim Reid based n his extensive marine engine experience and the specs were reviewed by 2 engineers at Com cam and they agreed with Jim Reid's specs. Looking forward to having the other motor done and changing the props next spring.
 
Update: The starboard engine is out of the bilge and will be lifted out of the boat when hauled in next 2 days. The engine will then be put through the same rebuild process as the port engine last spring. Should be done by Xmas and dyno run to get true HP and Torque specs. The port engine ran great all summer (60 running hours) and I always had to give starboard motor more throttle (above 200 rpm) than the port in order to keep in sync. Last run of the year at wot the starboard motor turned 4200 rpm and the port was at 4400 with one inch of throttle left. I guess it would have turned 4800 rpm with stock 19 X 18 three blades. Already acquired a set of 20 X 19 three blades to run next year and will fine tune them after the year is done. I expect 410-420hp on the dyno and 3 mph added to the cruise speed with the 20 X 19's.

Jeff

Ran the engine 12 hours at varying rpms with 5-30 break in oil and then switched to Valvoline 20-50 racing oil with zinc additive. Oil pressure was the same with both oils, 55 psi at idle and 70psi at 3000 rpm. I am not concerned about loss of crank hp as I have faith in the shop that is doing he work. I am stupid anal about maintaining all my toys and rarely have mechanical issues with them. I will talk to Jim Reid about the oil specs and will make a change if needed. Thanks for your input. Ray
 
Current cruise @3100 rpm with the 4 barrels still closed would get 17.5 knots. I expect 20 knots with then new props @ 3100 rpms. I would currently have to turn 3400-3500 rpm to get 20 knots. The top end on the last run was 25 knots but I suspect the bottom and some running gear is fouled also.
 
Update. Picked up the starboard motor yesterday after witnessing it being run on the dyno 2 days ago. The dyno results initially were not what I had hoped for but after some internet research I am actually encouraged. The engine produced 375 HP max @ 4800 rpm and 458 ft. lb. of torque @3500 rpm. I tried to find HP and torque specs on the internet for the stock 454 marine engines and it is not widely published. The best I can come up with is from Wikipedia under Chevrolet Big Block engine. They state that the 454 "truck" engine which I believe the marine version is based on produces 385-405 ft. lb. torque. If that is a valid engine to use as a comparison the my engine produces 13% more torque than the 454 truck engine. I have learned that the Mercruiser 330/340 hp. and the Crusader 350 hp. motors are the same but are rated at different rpms. The torque ratings in the cruise rpm range are as follows. 447@3000, 446@3100,450@3200,452@3300,455@3400,458@3500. So the torque curve in the cruise rpm range is decent which was the goal from the start. Time will tell what difference it will make after the boat repropped and running a couple of months from now.
 
End of season update: Started the season with the 20X19 three blade props with heavy cups. Loved the way the boat felt and responded while docking. Almost felt like the boat had diesels. Problem was I could only get 3800 rpm at about 26 knots. Didn't want to run all season with the engines "overloaded" so had a short haul and reinstalled the stock 19X18 light cup props for the rest of the season. Got 4800 rpm with those props and the Crusader spec is 4200-4400. Will have the 20X19's reworked to 20X18 and remove a small amount of the cup. Should put the engines right in the sweet spot and still work well around the docks. Engines sound really nice with a little more rumble at idle.
 
More time in that "sweet spot" has got to translate to fuel savings too. Glad to read the project has worked out well!
 
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