53MY Original Props Cup?

[cww]

My boat has the original 28x31x4 dyna quad props. I can’t seem to find anything on whether the OEM props have any cup and if so what number? I need to order a spare set, and I also need to reduce pitch on the originals to achieve 2300 rated, and am in need of this information. Because I only have the one set that’s on the boat, the answer to this question means the difference between a short haul to swap props and blocking the boat on the hard for a week and a half while they’re sent off to find out.

 

[Captain Ralph]

Probably no cup.
Sams or Hatteras may be able to answer your question with high detail.

 

[SeaEric]

Isn't the original prop spec listed in the owner's manual book?

 

[cww]

Isn't the original prop spec listed in the owner's manual book?

Yes it does, that’s how I knew they’re 28x31. Just doesn’t say anything about what number cup. I’m guessing that means there likely isn’t any but just wanted to confirm. Having no cup on large inboard props isn’t that unusual unless the boat has tunnels or clearance issues so it wouldn’t be that surprising. Just wanted to verify if somebody knew for sure.

 

[OVERBOARD]

I have the original props for my 53 MY 1979 and they are 28x31 federal EQUP Quad Dated 2/79 they were not cupped (old version of the modern dyna-quad Michigan wheel)
Originals are bronze. I just received a set of NIBRAL 28x30 dqx props that I have not installed. Prop shop said they have a larger surface area so they recommended less pitch to maintain the same RPM's. I did not have a spare set and as you know they are a uncommon size. It took 120 days to get them. Hope this helps, I have dd8v71ti.

 

[cww]

I have the original props for my 53 MY 1979 and they are 28x31 federal EQUP Quad Dated 2/79 they were not cupped (old version of the modern dyna-quad Michigan wheel)
Originals are bronze. I just received a set of NIBRAL 28x30 dqx props that I have not installed. Prop shop said they have a larger surface area so they recommended less pitch to maintain the same RPM's. I did not have a spare set and as you know they are a uncommon size. It took 120 days to get them. Hope this helps, I have dd8v71ti.

I am VERY interested in what performance differences you get with the DQX’s. They’re a much newer design and supposed to be more efficient. I would love to know the results.

 

[OVERBOARD]

I got them on board tonight, I will let you know next year, May some time. Too late in the season for haul out. I need to make some a stand of some sort in my starboard engine room for storage of them. I need more weight on that side of the boat.