Copy pasted from Weldons FAQ page Weldon Racing FAQs page answer many commonly asked questionsWhat position can I mount my Weldon pump? Can I mount it upside down? Can I mount the pump above the top of the fuel cell?

"The preferred mounting position is with the motor up and the pump end down, but it can be mounted horizontally or vertically. It is okay to mount a Weldon pump above the fuel tank / cell – they can lift as well as push the fuel. Although, if the pump is placed above the tank, the use of a one way check valve on the outlet of the pump to prevent the back flow of fuel into the tank, is recommended. Avoid mounting a Weldon pump at a 45 degree angle – this will cause an added load on the motor and pump bearings."

Yours is an older unit but it appears to be the same as the DB2025-A . I just got off the phone with Jim Craig there as I need to send one of mine in for overhaul. He's super helpful and knows his $hit on these.

Dave,

You beat me to it.

Yup. I just got off the phone with Jim Baker at Weldon Pumps. His phrase to me was, "Our pumps suck," and he made the exact same recommendation.

I am preparing to start drilling holes and mounting fuel delivery hardware. I have to make a leveling block that will allow for the mounting of the fuel filter true vertically, so I won't spill AS MUCH when it comes time to change it. I wanted to mount it someplace where fuel wouldn't spill on carpet, but it is just not in the cards. I'll just have to be careful and take mitigative precautions.

Thanks. Brad.

Guys,

So, what do we think?



This is in no way dimensionally accurate, but you get the idea. We would cut the "trumpet" off the end of the inner tube, weld on an extension that actually telescopes over it, full seam welding at the base and spot welding through holes in the extension tube, toward the end of what is left of the existing inner tube, then weld on the new dam toward the end of the extension, then weld the outer tube, after proper length has been established on location, after the engine is back in the boat. The dam would have the same water exit parameters as the original elbow.

The idea is to get the water dump as far from the exhaust valves as possible and increase the slope back toward them. The elevation and tilt is provided by the riser blocks pictured above.

Thanks. Brad.

Are you running GIL manifolds? Wouldn't the HP500 risers work for you?

Liberator,

Nope. Stock Merc 496 manifolds. Which I’m told flow really well, due to them essentially being headers, cast as manifolds.

Thanks. Brad.

oh yeah forgot you were 496

Liberator,

Yup. The red-headed stepchild of the BBC family.

And it’s a 503 now. Get it right.

Thanks. Brad.

You're have to generate a manual for it now with all your changes...!!

Your riser extension plan sounds good. Those stock 496 risers are really short. Maybe just the CAD layout look as you mentioned.

The whole extension package looks amazing with the machined adapter blocks.

Tartilla,



The drawing probably is a bit off. It was just for illustrative purposes. I literally cobbed it together at (semi) random.

I’m going to assume that the little “trumpet” tip of the elbow is purely for the purpose of preventing water ingestion, and can be omitted for the modified version…..?

Thanks. Brad.

The bell opening likely pushes the raw water flow into the rubber hose. Maybe even speeding up the flow if the gap is small enough.

With the longer and taller riser system, you should be gtg.