Peninsular, Reworked Prop.

[Denis]

I put my boat in last friday and took her for a short ride. The weather was raining pretty good so we didn't stay out very long. This may be of interest to the Peninsular guys. I had my prop. checked and adjusted during the winter. I started out with an 18" x 18" three bladed propeller. I had it scanned and found it to be pretty much right on the money. I was only able to get 3,300 RPM and about 20 knots with the propeller in this configuration. The prop. shop took one inch of pitch out of it and adjusted it to get a 2 degree misalignment out of it. The boat feels very different now, much more responsive. I took it up to WOT after warm up and it wound up to 3,650 RPM and it read 23.3 knots on the GPS, this done in 1-2' seas a full fuel tank, a full water tank and two people on board. My 300 HP Peninsular had about 650 hours on it. I thought it might be of some interest for those with a similar engine. Denis

[DougSea]

Hey Denis,

My apologies for not getting back to you on your PM. That's great news on the prop! Since I think our props are now close to identical I'm very optimistic that my missing speed and RPMs will return.

Now I just need to get her into the water!

Did you happen to notice any difference in noise or vibration? That's another selling point the prop scan guys use, and given how out of true my prop was I'm expecting a slightly quieter ride as well.

[tomcat rio]

denis, do you have a fuel flow gage?
if so, maybe you could post that data.
also, what is your transmission ratio. most likely, its about
1.57:1.00
i decided to go with a 2.00:1 hurth and an 18x26 nibral prop with my new peninsular 310 hp.
as previously posted,my best cruise is about 15-16 kts at 2900 rpm and 9-10 gph (gps and flowscan).
thx.
ed

[jcollins]

I've forgotten and I'm too lazy to search the board today.
What is the rated WOT for our setup? (same as Denis)
Last year I said I will write down the information and post. This year I will do it!

[DougSea]

I've forgotten and I'm too lazy to search the board today.
What is the rated WOT for our setup? (same as Denis)
Last year I said I will write down the information and post. This year I will do it!

Should be 3600 rpm. So his ability to turn 3650 means that when he's fully loaded and has some nice summer growth on his bottom he should still be right in that range.

(I cannot wait to try out my "perfect pitch" prop!!)

[Denis]

Tomcat, I do not have a fuel flow meter, I can't help you there. But my transmission has a tag on it that says 1.56 - 1.57. I assume that one of those is forward and one is reverse, not sure which is which.
I am going to do an engine alignment this weekend just to make sure all is ok there. I never really had much vibration before the prop scan and I don't have any now. My problem before was not being able to turn up to the rated rpm, 3,600 as listed in the manual.
I am very happy so far.