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Viewing 6 topics - 1 through 6 (of 6 total)
    • Cummins Marine Forum Topics
    • Prop set back from face or transom

      This topic has 6 replies, has 4 voices, and was last updated byTony Athens 1 year ago

      May 17, 2022 at 2:15 pm Ā Ā  Is there some sort of formula for the distance from transom face to closest prop. blade?Ā Ā  How do I know how far under the hull the prop should be? Ā  The picture shows the prop blade being 2 1/2 inches from the face of transom. In this position I can take the prop off without removing the rudder. The rudder is a transom mount rudder.Ā Ā  I am more concerned with being too close to the transom face.Ā  How do I know where the prop should be positi…

      Started by: Darren Kinvig in: Boats & Repowers


      6 Replies
      May 30, 2022 at 4:25 pm Darren, Ā  I really do not think there is a cut & dry answer to your question.. All has to fit, allow clearance for the prop to R&R it ( hopefully without pulling the rudder), all tip clearance, allow a minimum space between the prop hub and a cutless bearings, etc. Every boat is different.. Ā  I grabbed of few pics –As you can see, the mountings/setupsĀ  are all over the place.Ā 

      Last Post by: Tony Athens posted: 1 year ago

    • Prop clearances/distance. Two questions.

      This topic has 4 replies, has 3 voices, and was last updated byDarren Kinvig 2 years ago

      January 9, 2022 at 10:21 pm Ā Ā  Can someone clear up these clearances/distances for me. Ā  What is the recommended clearance from the prop to the underside of the hull.Ā  Also. I have a transom mounted rudder. I understand the idea of having enough clearance from prop to rudder to change the prop without removing the rudder. What is the distance from the prop to the face of transom. Is there a Min. that should be observed?Ā  Will there be cavitation issues if the prop is too c…

      Started by: Darren Kinvig in: Boats & Repowers


      4 Replies
      January 11, 2022 at 10:00 pm Ā Ā Ā Ā  Ventilation?Ā  is this a condition where air can enter the prop wash/ prop from the end of transom into the prop? Looking at some drive examples where props on some boats appear to be close to the face of the transom, I have seen that the transom has been extended in the area above the prop. Is this a solution to prevent Ventilation? Ā Ā  Thanks for your advice and knowledge.

      Last Post by: Darren Kinvig posted: 2 years ago

    • Gear and engine bed/supports

      This topic has 5 replies, has 4 voices, and was last updated byTony Athens 3 years ago

      February 15, 2021 at 7:24 am Working through a re-power. Two part question.. Using a ZF68IV gear and a 6bta 315 H.P. engine. The mounts for both the gear and the engine line up almost dead center of boat Stringers. I need to drop my gear down into the stringer. This means that I need to cut into the top of the stringer about 2″ deep. The total depth of the stringer is 7″ and 4″ wide. My first instinct is to box the stringer with aluminum, bolting a weld…

      Started by: Darren Kinvig in: Boats & Repowers


      5 Replies
      February 20, 2021 at 8:42 am Darren, I see two very viable solutions here………………Send me those pics and more, direct——————-.jpg attachments–Not embedded in the emails or they go into the round file ……………… Add a few more too.. Lay you camera in the bilge, both ends, and shoot a pic so I can see under the engine and gear. But before anything can really be done, the…

      Last Post by: Tony Athens posted: 3 years ago

    • prop shaft coupler

      This topic has 2 replies, has 2 voices, and was last updated byDarren Kinvig 3 years ago

      November 9, 2020 at 9:25 pm Question about couplers…..I am presently looking for a coupler for my prop shaft to ZF V drive transmission. It isn’t difficult to find companies willing to sell couplers, however it can be difficult to get the needed information about the differences between couplers and how it may apply to my particular re-power. With that being said, re-power is a 6 bta cummins. 315 H.P. a ZF68IV trans. What kind of coupler is more appropriat…

      Started by: Darren Kinvig in: Marine Transmissions


      2 Replies
      November 11, 2020 at 11:14 pm 1. Prop shaft will be new. has not been ordered/made yet. Starting from Scratch. 2. Prop shaft is aprox. 5’5″ long Need to fit Transmission and get proper length of Prop shaft. 3. Prop shaft diameter is 1.5 inches 4. Prop Diameter is 20″. I would like to do the final fitting to the shaft.

      Last Post by: Darren Kinvig posted: 3 years ago

    • shaft log and shaft diameter

      This topic has 2 replies, has 2 voices, and was last updated byDarren Kinvig 3 years ago

      November 1, 2020 at 10:04 pm I have a question about shaft diameter VS shaft log diameter. I am doing a re-power. I need to increase the shaft diameter from 1 3/8 to 1 1/2 diameter. I would like to keep the same shaft log. The inside diameter of the shaft log is 1 15/16 That leaves a bit more than 3/16 clearance around the 1 1/2 diameter prop shaft. How crucial is the clearance between prop shaft and shaft log. Is this enough clearance?

      Started by: Darren Kinvig in: Boats & Repowers


      2 Replies
      November 5, 2020 at 11:49 pm Thanks for the reply. I am starting with nothing but the shaft tube/log in the boat. The strut will need to be replaced. The prop shaft that came with the boat was an 1 3/8 . I will go to an 1 1/2 shaft diameter. I was hoping not to replace the shaft log. My first time doing an inboard/v drive set up. So the extra clearance sounds like a good idea. Your shaft was so miss aligned that it was wearing at the shaft log/tube itself. Allot to le…

      Last Post by: Darren Kinvig posted: 3 years ago

    • Repowering Cummins engine with V-Drive

      This topic has 9 replies, has 3 voices, and was last updated byDarren Kinvig 3 years ago

      September 13, 2020 at 9:32 pm I have a question about Re-powering my vessel with a V-drive using a Cummins engine. I am hoping someone can help with this. The manual for the cummins engine states the engine needs to be mounted in a nose up application. Between 3 and 12 degrees nose up. The shaft that is in the boat now sits at 12 degrees. That leaves enough room for a 20 inch wheel on the shaft. The ZF V drive transmission I am planning to buy is a 12 degree transmission.…

      Started by: Darren Kinvig in: Boats & Repowers


      9 Replies
      October 29, 2020 at 9:00 pm Thanks Tony Is it possible for you to modify or supply an X tank that will work in my application? If I could get some of those fittings and water line I could do it myself. Your explanations to these questions sure helps to clarify allot of questions that come up in the planning stages. It can be difficult to understand where to start and what parameters to plan within. there is no written installation manual pertaining to each particular…

      Last Post by: Darren Kinvig posted: 3 years ago

Viewing 6 topics - 1 through 6 (of 6 total)