Replacing Raw pump and fuel cooler is off

[Mike Uliasz]

In the process of removing old raw water pump and we had to take the fuel cooler off to get to the 2nd water pump bolt due the generator being pigeon toed in between the motors.

Considering leaving the fuel cooler off for good. Reading thru the ‘Understanding Marine Fuel Coolers’ it sounds like even in a hot climate, it’s only going to effect MAX HP, correct? We’re hot for a couple months, water in the 80’s and air temp in the mid 90’s but nothing extreme long term. My buddies Cummins 300HP does not have them. Motors are 97’s, probably original fuel coolers so it’d remove a failure point too along with cleaner access to the pump/impeller. Seem like the right way to go?

Pump came out fine, did not have to mess with the motor mount, cast is slightly bigger on the seaboard pump, mechanic buddy was a little worried, sure it’s fine. And it sounds like the 27000K impeller can be used as a replacement.

Thoughts on dropping the fuel cooler would be appreciated. Boat is recreational use, 1-2 hours at a time on a plane, but most times trolling in 20 – 30 minutes. Won’t be any top end usage either.
Thanks
Mike

Topic

[Mike Uliasz]

Thanks Rob, Yes, buzzer alarm box inside the helm. Reason I ask is had a close call when relocating the boat after purchase. The turbo oil return line sprung a leak, oil pressure dropped and the engine ‘powered’ down to limp mode. Shut it down within seconds.

[Rob Schepis]

The top row across the block is all oil pressure. The center top is oil pressure sender. The top left is a normally closed oil pressure switch. That switch is likely driving a redundant low oil pressure alarm, likely not an engine shutdown, but I guess anything is possible… Do you have an added alarm panel, buzzer, or light, etc ?

https://www.sbmar.com/articles/understanding-the-6bta-5-9-combo-block-manifold/

[Mike Uliasz]

Fuel cooler removal – 2 oil sensors

pics attached

[Mike Uliasz]

Fuel cooler removal – 2 oil sensors

More a curiosity question on the configuration of the fuel manifold and removal of the fuel cooler.

Guessing the black oil sensor on top left is an engine shut down sensor due to oil/pressure loss?

Going to reinstall the block to keep the two sensors in place unless there are better recommendations?

Thanks

[Mike Uliasz]

Thanks again Rob, I’ll leave as is since the port side has the cover and all the fresh water plumbing, pump and pressure tank on the fire wall and the other side with no front cover does not have much.
Mike

[Rob Schepis]

Good on the tach – consider it a “cushion”.

Your call on the belt guards but consider a few things, pros/cons etc:

If the belt guards are removed and you need to get in and around the engine while underway will this be risky as to safety?

If the guards are removed and the engine throws a belt is there anything that could be directly impacted by the belt?

The plus is that it makes the front of the engine and all things that spin up there that much more accessible for routine checks, cleaning, servicing etc or even an unexpected repair.

[Mike Uliasz]

Think my WOT throttle issue came up responding to another thread to a person with the same boat as mine.

Did the photo-tach on one engine right B4 hauling, front belt cover was off. She’s running a bit quicker than the boat tach is reading. Thoughts on leaving front covers on or off?

[Rob Schepis]

Sounds good Mike. Not sure if we already had a thread about yout WOT RPM but be sure to photo-tach the engines for real rpm readings.

[Mike Uliasz]

Steve,
Good info, thanks. Boat is in a covered slip too, so she’s not getting cooked in the sun prior to going out. 2200 rpm seems to be the sweet spot with a nice cruise speed and noise level😎 for me.

Rob,
Will update as things progress. Next is to get the bottom blasted, barrier coated and painted. Throttle cables replaced/adjusted to hit WOT. Test run and determine how over prop she could be. Guessing I’ll need the props tuned to pickup an extra 200 RPMs to hit Tony’s recommended magic number of 3150 RPMs at WOT Under a load.
Mike

[Stephen Oliver]

I took mine (330hp) off here in Aus.. ambient temps can get to 45degC (113f) + and frequently stay above 40 (104F) for a few days at a time mind you the ocean is cold – normally about 23degC (74F). Our usage is similar and I have not noticed anything detrimental by removing them.. only easier impeller access (all relative after the port impeller experience ive just had) Mind you I only cruise at 2200 – 2400rpm so i’m not asking everything out of the engines!

Steve

1 user thanked author for this post.

Rob Schepis

[Rob Schepis]

You are quite welcome. Try to keep this threaded updated with progress, photos and any questions along the way.

[Mike Uliasz]

Rob,
Thanks for confirming👍
Mike

[Rob Schepis]

Drop that fuel cooler, no doubt – yes one less thing to fail but cleaning up that area and getting better pump access is huge. You’ll never notice a difference as to performance.

[Author]

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