View Full Version : Motor Build

Magnum Ralph
01-10-2016, 09:36 AM
I have a 94 18 with dual ram hydraulic and ss drive. I am building a 406 ci dart block dart pro one heads 215 runner dart intake diamond aluminum pistons skat crank and rods. Should be 500 hp pump gas reliable. Any tips from you guys.

Magnum Ralph
01-10-2016, 09:37 AM
Also imco thunder exhaust

01-10-2016, 10:31 AM
----Ya, Ralph,,,,Keep it under 8000 RPM!!!!.......Bill S

Magnum Ralph
01-10-2016, 11:07 AM
We will good advice. Question I have a. 5 quart oil pan now but would like to go to an 8 quart. Will it fit in boat?

01-10-2016, 03:41 PM
while the motor is out I would beef up the mounts and stringers to handle the increased power and torque

Magnum Ralph
01-10-2016, 04:19 PM
Good idea to beef up but don't know how. Any threads to show me ?

01-10-2016, 06:15 PM
What ever you do...... Get a Canton marine oil pan. They have the best wet sump pans on the market.
Mark can help you beef up the stringers, otherwise he's just laying around drinking beer. That goes with Bill too.


01-10-2016, 06:36 PM
I was just at the Toronto Boat show. Merc had a display. Anybody put the new 500 series blue motor in a 22?

01-10-2016, 06:41 PM
If you can weld, an easy way to get a larger oil pan is to make your current one bigger by adding to the front section.

I've done this a couple times. I leave the original front part of the pan in place to act as a windage tray and just drill some holes in it for oil flow.

As far as beefing up the stringers, it's just a matter of adding another layer or two of glass

Bobby D
01-12-2016, 10:24 AM
Yep it will fit with a larger oil pan, my 406 went in with plenty of room to spare. I purchase a short block from a friend and the shop that built the motor also provided the modified oil pan. When I started bolting on parts to see how they fit up and what will require modification I also decided to install the dipstick tube on the new oil pan to match what came off the old SBC 350 motor. At the original drain plug hole I decided to install the mercury drain hose kit that fits thru the transom plug hole and it works well. Also since the bottom plug boss is about 3/8 thick the oil below the boss will never drain and contaminants will settle so I also have the option to use the tube to change oil occasionally. When I drained the old oil it measured 7 quarts not including the filter.
Good Luck with your project and keep us posted.


joseph m. hahnl
01-17-2016, 06:19 PM
Absolutely no reason what so ever to use a larger capacity oil pan. Dart blocks use priority main oiling and use standard pressure / standard volume oil pumps. I'm running a 4 quart aluminum oil pan with a main mount windage tray. I went with the 4.125 bore over the 4.155 bore to allow for a couple rebuilds if needed . I opted for the internal balance which makes it a piece of cake to match the flywheel and harmonic balancer. I also used a lighter circle track flywheel which significantly improves throttle and prop response when air born:kingme:

I'm very happy with the quality of the Dart block, all the mistakes that GM made, have been fixed:yes:

01-21-2016, 10:31 PM
Sounds like a killer mouse! With that kind of power goal I'd double-check to make sure the cam is gonna work in a marine application. Idle speed (low enough to save the drive), reversion potential (even with the Imco exhaust), powerband, etc.

The "more is better" oil capacity theory has always made me feel warm and fuzzy even if it's not strictly necessary. What's an extra couple of quarts of good oil cost? $20? I'll spend that for peace of mind all day long. How are you managing oil temps, both high and low? T-stat controlled oil cooler?

Let's see some pics!

Magnum Ralph
01-22-2016, 11:07 AM
Thanks for input got the cam covered. Oil cooler. Although this will have power won't use it much.