Prop pitch of your 5288/5788

[Omega]

Hi all,

The subject of prop size/pitch has been an interesting point of discussion among a few of my friends and I who own 5788s. It seems that when the 5788 was built and powered by MAN 610 diesels, there soon became a disagreement between Bayliner and Man concerning several things, one being how the engines didn't perform as Bayliner intended with the prop sizing etc. In a nut shell, the props were pitched too high and bogged down the engines to the point Bayliner released a memo to the owners to not run thier boats over 2000 rpms except under emergency circumstances. I found one such letter in my paperwork. It was interesting.

As i hauled Omega out of the water for servicing yesterday to do th zincs, upgrade the tabs and a few other things, I pulled the props to have them repitched, as well.

I've been having issues with sooting and have spent the past couple months rebuilding this and that trying to get better performance. I replaced the injectors and think I have most things as good as they can get, but still have hindered wot rpm. After hauling out, I finally got a chance to look at props. They are four blade 32 diameter with 35 pitch. From everything I've heard, 35 pitch is way too high. It kind of explains why I run about 6.5 knots at idle... lol...

As I'm getting the props done, I was wondering if any other owners with 5288 or 5788s have redone thier props and/or knew what thier props were pitched at and how they performed. I've calculated the proper sized props should be 32 with about a 33 pitch, but as I'm not super sure what the proper hull factor is, i think it's about 6.8. As I'm unsure though, I thought I'd see what everyone was running.

I look forward to hearing about your props and your boats performance....

BJ

OMEGA

5788

[ELNIDO 3]

BJ

This is George with the Elnido. I am hauling the boat to repair my props this week. What did you end up doing to your props. I too go 6 knots at idle and have sooting issues.

Best Regards

George
ELNIDO
2000 5788

[Omega]

Hi George...

I’ll have to check my records for my pitch, etc. The thing to realize is my props are Michigan and NOT the Nakashima (sp.) props that the 5788’s where delivered with. Do you know what type of props you have? Do you know how hot are your engines running under load? That can help know if your over propped. I ran about 196-200 and when I reproved, I instantly ran under 180...

Also, something to look at that can cause sooting are the injectors. I had mine rebuilt and it helped. But I still saw a bit. So I redid my prop pitches and that helped even more.

~BJ

[MerlinV]

The prop sizing on Merlin V is 32”x33” and was this way at the time of purchase.
At WOT the engines quickly achieve maximum RPM and we get no signs of sooting at all and temperatures remain at around 180 degrees.
As it happens, we never run at maximum RPM, other than the odd occasions when we let the engine breathe to clear out the cobwebs.

[ELNIDO 3]

Rob

Thank you for your information. I will know where we are at once the props are off and they are measured. It sounds like we are close to your prop pitch. I tend to baby my engines also. These boats get up and go when you throttle them up . I hope all is well and look forward to getting back up north. The San Juans were way to crowded. I was trying to get out of Westcott Bay, dodging boats and crab pots, when we hit a shoal and did some minor damage to the props.

Thank You

George
ELNIDO

[ELNIDO 3]

BJ

I have to assume they are the originals. The props were repitched about a two years ago, on the advise of a past Byliner guy familiar with the 5788. . When RDI did the full service with injectors last year we sea trialed and determined that 2100 to 2200 was the max RPM. Even though we had more throttle, the exhaust temp was rising past were they liked. We don't, have a lot of smoke when start up, except in the winter. May look into block heaters. When I replaced the water jacketed exhaust elbow there was some evidence of wet stacking. Unfortunately we don't run our engines that hard. I have the flow scans and see what we GPH at the higher RPMs. I do run them up from time to time though.

Thanks Again

George

[Omega]

Hi George,


It sounds like you are propped pretty well. If your props are stock, I’d agree with Rob and pitch them at 32 x 33”... I pitched my Michigan props at 32 x 31”. They were originally pitched as the originals were (32 x33), but it loaded the engines way too much, causing horrible sooting. It turned my stern pretty black after a 120 miles or so... Ugh!

I have block heaters and use them during the winter, and have little to no smoke at start up when I use them, if you don’t have them, they are nice. The engines light up instantly...It’s nice.

~BJ