prop size for 28TE-370 Cummins

[Robb]

I'm working with Acme Marine on getting a new prop spec'ed and there is a big difference between what his program is specifying (18x17- 4 blade) and what I am currently running (18x23- 3 blade). Bill from Acme recommend I contact others with the same hull/power to see what they are running. Acme came highly recommended by Tony Athens over at Boatdiesel.com.

I need to know the current prop and WOT speed/RPM from some other 28's running the 370 Cummins.

Here is what I believe is my current set-up:

Hurth 800 V1-1.4 transmission (1:1.4?)
Prop: Federal Nibral 3 bladed 18x23 cupped LH
26.8 knots @ 3048 WOT (RPM on phototach with clean bottom)
I'm estimating my displacement loaded with fuel, water, 4 guys and fishing gear at about 11k lbs. I hold 192 gal. fuel all full w/ 60 gal second tank full.

Questions:

1. How are other 370 owners proped and what is WOT speed/RPM?

2. Boat is in the water and I have not weighed. What are other 28TE owners estimating for a loaded displacement?

I really appreciate any feed back for other 370 owners.

Thanks,

[RobS]

Kevin on Pitou is going to be one of your few comparisons, lucky for you he know his s***. Here's 2 prior posts where he notes his specs.

viewtopic.php?f=5&t=2227&p=13592&hilit=prop#p13592

viewtopic.php?f=5&t=2165&hilit=prop

[Robb]

Rob,

Thanks for the links. I read them and they are not specific enough. What props are you 370 owners running? Please

[RobS]

Searching Pitou's posts with the word prop I found this thread:
viewtopic.php?f=7&t=5123&p=30286&hilit=prop#p30286
He's running a 19x21

[Robb]

This confused the prop shop even more. What gear are the other 370's running? I have a Hurth 1.4.

[Pitou]

Hey Robb - CORRECTED INFO .............
Pitou came through with the 370 6BTA and the same Hurth gear / 800 / 1.4 ratio running a Teignbridge 19 x 17 / 4 blade prop. It couldn't have been a better fit. With your extra 60 gals. of diesel you have 420 lbs under the center hatch in the pilot house where I have 170 lbs. in generator. You've got the equivalant of one more big guy aboard with that load. Otherwise were pretty similar, Alaskan Bulkhead and all. Max speed / mill pond 1/2 a tank of fuel ... 27.5 - 28 knots at 3000 RPM / 25.5 full tank. CORRECTED INFO .......

H&H Prop in Salem, MA spec'd these boats out & provided running gear for Albin. If you end up buying a new wheel, remember, it must be tuned using MRI or other similar equipment. The owner Bob Pelletier used to cruise the AOG site now and again searching prop threads and chime in, but unfortunately he got bumped for inactivity a while back. Give them a call their techs have an Albin fit manual at the ready.

http://www.hhprop.com/

[Robb]

Kevin- THANK YOU for the detailed reply. Just out of curiosity, what do you estimate your displacement at? I was using 11k loaded to go fishing with the boys, but I'm wondering if I'm a little too conservative on this estimate.

[Pitou]

Robb -

In my haste I had previously provided you with some pretty inaccurate information above, but it has now been corrected.

I'm ready to take my licks. I've had 2 gears and 2 prop adjustments in my head and previously spewed garbage to your issue. I should have checked paperwork sooner. My apologies. Again, I've corrected the post above to reflect accurate information for your set-up.

Last summer I had transmission issues and needed to rebuild the 1.4 gear .... guess what ... ZF no longer supports the hard parts for this tranny and has only made the soft parts since '07. The closest I could get to fit the Cummins, and they called it plug and play, was a ZF 85 IV which is a 1.6 gear. I've been screwing with the prop tuning ever since and should now finally have it dialed in for this springs splash at 19 x21 with 3 degrees of cup leading all the way to the trailing edge. I wish I could have rebuilt my 1.4. It is now crated in the barn. At layup I was at the 19 X 21 with 3 degrees at 3000 with a slow creep to 3175. H&H has deepened the cup all the way to the trailing edge to hopefully stop the creep. We'll see.

Your issue ... With the 1.4 gear I was dead on at 3000 rpm, which is its load speed at 370 hp WOT running. The 4 blade teignbridge at 19 x 17 and 3 degrees of cup not running fully to the trailing edge.

I'm sorry for the previous misinformation as when I first looked at this post I had just clicked through from Rob's link above and I knew something didn't seem right so I had to dig through my stuff. That info is from my reworked wheel and the new gear.

This info and the corrected post you can take to the bank.

I owe you major cocktails and if and when we meet you hopefully won't keel haul me or tie a cinder block around my neck and throw me overboard!!!

[Robb]

Great info and I think I'm the one who owes you a drink!

This would explain why the prop guy thought it did not make sense.

Thanks,

[Robb]

Kevin,

Just out of curiosity, how many hours on your engine and gear? What failed with the gear? I've got 2600 hours on my gear, just serviced and am hoping it will last a while more...

I talked to ZF at the boatshow about the 85 and they also told me it was a direct replacement. It wasn't too painful a switch out I hope.