454 Mercruiser Inboard with Volvo Penta Duo Prop Outdrive

[bcbassin20]

My first thread guys so here it goes........I have just purchased a 1990 Mako 250 WA. It is setup with a freshly rebuilt 454 Mercruiser with a bigger cam and roller rockers and she is matched up with a Volvo Penta Duo Prop outdrive. Has anyone ever heard of this setup before and if so give me some tips, ideas, or opinions about it. She sounds like Dale Jr's nascar at Talladega when you fire it up. What kind of fuel consumption do you think I will get with it? What's probably the best RPM to run it at? I have owned numerous bass boats with 200's and 250's on them but never an inboard. Thanks for the help.

Brandon





1990 Mako 250 WA

 

[Bt Doctur]

Re: 454 Mercruiser Inboard with Volvo Penta Duo Prop Outdrive

does it have marine headers or the oem cast iron manifolds?
has it been run tested for exaust reversion issues?
28-38 gallons per hour or more.

 

[Mischief Managed]

Re: 454 Mercruiser Inboard with Volvo Penta Duo Prop Outdrive

Does it have oval port or square port heads? If oval port, the internals are built for 4600 RPM max and 3500 RPM or less cruise. If square port, the internals may be from a 454 MAG and should be good for 5200 RPM and 3800 RPM or less cruise, if memory serves.