As seen in Speedboat Magazine’s
March 2024 Issue.

OIL PRESSURE ISSUES

Dear Bob:
I have a 39 Cigarette Top Gun with Mercury Racing 700 SCIs. I recently had the engines completely refreshed. At idle on initial startup, both engines maintain 60 PSI on the oil pressure gauge with no fluctuation in pressure. One engine has an issue with oil pressure when it goes above 3,000 rpm. Above 3,000 rpm, the oil pressure drops down to around 15 psi. It takes about 1 minute for it to drop from 60 psi to 15 psi, and the drop is linear. It will stay at 15 psi until the engine goes under 3,000 rpm, and then returns almost instantly to 60 PSI. The water temp on this engine does not get over 180 degrees. In order to validate the electric oil pressure gauge, I placed a mechanical gauge on the engine and was able to replicate the problem. The engine does not use or leak oil. The engine runs smoothly and does not make any unusual noises or knocks. I have concerns about oil pressure being low on high rpms.

Any help would be greatly appreciated.

Bob Campbell
Houston, Texas

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As seen in Speedboat Magazine’s
Nov/Dec 2023 Issue.

High Horsepower
Carbureted Fuel System

Dear Bob:

I have a pair of older TCM 800 carbureted supercharged engines in my 382 Formula FasTech, which also has been converted from the original XR drives to Arneson Surface Drives.

I need to change the mechanical fuel pumps that are mounted on the engine blocks. The pumps have a label on them that says “Edelbrock.” Which Edelbrock pump should I use? Currently, the boat also has an electric Holley fuel pump as part of the system. What part numbers do I need for the mechanical and electric pumps? Can I do away with the electric fuel pump and just use a higher-volume mechanical fuel pump? Thank you!

Randy Davis
Stafford, VA

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As seen in Speedboat Magazine’s
Sept/Oct 2023 Issue.

CORRECT
Distributor Gear

Dear Bob:

I bought a Crane Cam in 2014. It is part number 139021 and has the iron gear. Do I need to use a melonized distributor gear
with this camshaft?

Thanks for your help.

Chad White
Campbell River, British Columbia, Canada

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As seen in Speedboat Magazine’s
August 2023 Issue.

AERATORS:
Pros and Cons

There have been quite a few discussions
on social media and the boards regarding the benefits, advantages, and downsides of using prop aerators on boats equipped with surface
drives. I have been personally involved in the development, design, and manufacturing of various aerator kits since surfacing prop sterndrives were introduced. In this article, I will provide the history of the development and evolution of the various aerators that are available. While aerators may not be indicated on some boats, they provide significant benefits on boats that have engines with lower bottom end power using higher pitch propellers and higher gear ratios (less reduction).

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