getrdunn

Anyone notice loss of water pressure or water temps rising. I installed them on my 12 m with NA 565’s. I like the way they plumbed in and easy access but noticed rising temps when I was on the pins. First time out last fall and only couple runs to do a shake down.

The impeller size is much smaller than traditional also.

TomZ

Mine dropped temperature when getting on them though I wasn't on the pins. Water pressure was 25+ psi at anything above 40 MPH. I'm closed cooled with idle temps right around 170, 150 running hard.

getrdunn

Merc impeller vs crank mount

TomZ

The Merc impeller is larger yes but not as many fins. Not sure how that equates to total volume but I know it works for mine.

speicher lane

What rpm are you turning? Most crank mounts max spec is 5k....

getrdunn

6k.

What I noticed on water temp gauge last fall was much above 4k temps jumped up quickly. I’ll find out soon. Although I love the concept just not certain they’re for my builds etc. possibly something else but I’ll find out. 330/365 under 5k likely perfect.

Dry to the tip should be pretty apparent water dumping but not. I believe the dumps at end of tips are 1/2”-5/8”

TomZ

Hey John,

Just checking in... Did you do get to the bottom of your rising temps? Curious to see how you made out.

I know it's already midsummer here, but I have not been out yet this season to test it out more. Weather, schedules, and a new driveway (with weather delays) have kept the boat on the hard. Next weekend hoping to be out and about.

getrdunn

Just getting back on the water myself likely this weekend. I had called cp tech and questioned him about the crank mount pumps and he said perfect for their application but went in to say with my current builds, hp, rpm and dry exhaust/headers they wouldn’t be adequate. I just got the bravo style pumps on and re-routed plumbing etc (pita).

I did increase exhaust hose size to 1” so it’s not going to be a true comp. I almost left one side the way I had it.

weather here all messed up and lake mi just getting comfortable to run any kind of speeds without needing winter gear on. Lol

I do have two used only an hour of run time at best crank mount pumps for sale. I really like the concept and simplicity of install and impeller replacement of these. That’s for certain.

getrdunn

To be perfectly honest though the one thing I never did was verify my water pick up hoses from boat bottom to sea strainers were 100% clear. Going to disconnect both on each side and stick a garden hose in them to be certain. Boat sat for a few years before last fall.

Abones gave me a heads up on that one! Mud bees etc?? You’d think would’ve cleared out after 10-15 min of running but rather be sure. I have two 2 1/4 inlets per side.

TomZ

Cool beans.

I was surprised to hear that you were having issues really. I could be wrong but my understanding is that once you’re really moving, water pressure is being provided by the movement of the pickups through the water with the pump helping things along. I know mine was maintaining good water pressure at 68 mph and 4700 but I wasn’t pushing her that hard either. If I started trimming and getting some more rpm, then maybe it would have shown something different. Time will tell. Max rpm for me will be 55-5600.

Hope you get out get to enjoy her!