ENGINE & TRIM PUMP SHIELD

I spent a ton of money this season finally going through the Cooling System on my D4-260 after 2000 Hours of run time and Benson told me it would be a lot worse if I didn't find a way to keep the large amounts of Deck Wash Down Salt Water which sometimes overflows my scuppers off the top of my engine. The 2 main victims are my Turbo and Aftercooler; they are both big ticket items when the casings become corroded & shot. After giving it some thought I came up with a couple of pieces of 24 gauge Aluminum Sheet Metal; one starting from the deck hatch scupper reaching forward about half the engine length to make the water run off to either side of the motor, and a second cover in rear of the port side deck storage box where my trim pump is mounted directly under the deck drain. Engine overhead clearances are tight with the D4 so I put a 1/2" 90 degree bend in the end of the cover to keep water from rolling over the front of the engine; I will probably caulk the joint between the shield and the hatch rear scupper to seal the joint I'm just not sure yet whether I should use Silicone or 4200 in case I need to remove it for maintenance. I picked 24 gauge as it is easy to bend up out of the way when necessary for oil filter changes, etc. The Trim Pump Shield has 1/2" 90 degree bends on each side to form a pressure fit against the port side hull and engine compartment bulkhead; I ran 2-#10X1/2" Stainless SMS screws into the bulkhead forcing the front of the shield to angle downward so the water overflowing from the scupper drain would drain in front of the pump down into the bilge. I made a second smaller fill in piece to go around the drain pipe cutout with a tighter fit around the hose to keep water out and I used an adhesive caulk to attach them together. I hope it works and I'll be checking its effectiveness often and come up with mods as needed and keep you informed.Attachment 236Attachment 235

Is there a way to put some weather striping around the engine hatch to help as well ? I had to do that on my skipjack and it helped keep water out . How does the boat handle with the d4 compare to the 41 ?

The only thing that might help would be a rubber flap screwed to the outside of the deck gutter with enough rubber above the gutter to contact the hatch and attempt to seal it but I don’t think the corners would seal very well and that’s where it usually overflows when you break out the wash down hose after a tuna stop.

The D4-260 is the best thing that ever happened to a Blackman and once you drive one you’ll never go back to 200 HP again. The 30% increase in power really makes a difference in the way the boat handles and in overall speed as you’ll never drive @ full throttle again; the boat wasn’t designed to travel @25 knots much less the 32 knots we achieved with 3 guys full fuel and bait tank when it was first installed. W.O.T. Should be 3500 RPMs and I run 18knots @2650 rpm 19.5-20.0@2750. The boat just loafs along and you never hear excessive intake noise like the motor is struggling to keep up. When I ran my AD41 I normally cruised @ 3150 going 15.2-15.5 knots fully loaded and 3200 on the way home 16.5 knots with the swell. I only ran it once @ 3400 18.5 knots when I was down below South Island and my buddy called me into a hot WSB bite in Imperial Beach kelp. I was told the new DPH our drives were an improvement but I still had to replace mine @ 1800 hours just like the older 290 drives. My trips average almost 3.0 MPG which is about .5 better than the AD41 got and @ $4/gallon that makes a big difference

I use to have some aluminum flat stock that had a rubber seal on one side i got off a job site but couldn't find it . I was thinking it might be able to be installed with the rubber side up and it would be able to be bent around the corners. Looks like you got it with the metal you have . I'm not super familiar with the d4 or what under the metal that you would want to look at for service was my only thought . On another note how many house batteries and starting are you running ?

I’m running the same batteries it came with 4-12 volt Deep Cycle Group 27
I used to run Delco but can’t find them anymore so now it’s Interstates about every 3-4 years