Pod depth

[Dignity]

I have an Allison 195 which comes standard with a pod with a 150 4 stroke yammy hanging off the end, but the pods bottom is about 9 inches higher than the hull bottom. The problem I have is the motor sits too low in the water, the cav plate sits about 2 inches below the waterline when on the plane. The motor is at its highest position and I feel that with the pod sitting so high it is causing a suction effect when underway as I do get a wet motor in fairly sloppy conditions, I do have trim tabs which helps somewhat but not enough.

The height from the top of the bracket to the cav plate is 25 inches, from the bracket to the bottom of the pod 19 inches, my idea is to build up the pod to give me increased lift.

Has anyone done this and what are the benefits or side effects. I was thinking it would give me additional lift of around 80 to 90 lbs but will it affect anything else eg steering esp in following seas, effect the transducer etc. It is not a difficult proposition to do but I want to make sure I don't make it into a pig of boat.

[BM]

Go to a metal supplier and get a plate made up from 25mm thick ally. Bottom engine bolts go through the plate and the pod. 2 bolts external to the motor mount and as high as possible go through the plate and the pod and top engine bolts through the plate only. Plate sits about 2 inches above pod.

Usually with stepped pods such as yours every foot away from the transom you lift the engine 1 inch to maintain the correct setup.

[Noelm]

Bit hard to guess without seeing it, or a picture, but, it does kind ofsound like your motor is way too low, probably find the hull was made for a standard long shaft (20") but a 25 has been fitted?

[Dignity]

Go to a metal supplier and get a plate made up from 25mm thick ally. Bottom engine bolts go through the plate and the pod. 2 bolts external to the motor mount and as high as possible go through the plate and the pod and top engine bolts through the plate only. Plate sits about 2 inches above pod.

Usually with stepped pods such as yours every foot away from the transom you lift the engine 1 inch to maintain the correct setup.

BM, I suspect that short of redrilling the holes in the transom I still need to lift the motor another 2 inches and there isn't physically the ability to do so. To do it in fiberglass is easy enough as I can make a mould out of melamine easy enough and have access to gear to make the job easy.

[Noelm]

The alloy plate will work, it's been done many times, have a look online and see of you can find a cheap(ish) jack plate.

[Dignity]

Bit hard to guess without seeing it, or a picture, but, it does kind ofsound like your motor is way too low, probably find the hull was made for a standard long shaft (20") but a 25 has been fitted?

Noelm, the boat needed to have an extra long shaft so the cav plate sat around the level of the bottom of the hull, probable a 20 inch would have sufficed however the motor would then still be too low. My concern is the effect the adding depth to the pod will have on maneuverability, depth sounder etc, one advantage I can think of would be driving on the trailer I would have more lift in the rear.

[Dignity]

Thanks Noelem, I think I misread BM's post, I now see what he means. I am still sure that the way the pod is setup contributes to a suction effect pulling the aft end of the boat down, adding a 25 mm alloy plate would also add more weight than the fibreglass, also bloody expensive, the last time I bought a sheet 10 mm thick 400 mm square I nearly fell over with the price.

[Noelm]

The pod does not cause "suction" building the pod to match the hull bottom will be a lot of work, what happens (in very simple terms) when the boat is on the plane the boat is not exactly skimming the surface, it is more or less digging a V, water runs along the bottom of the hull, and as soon as it clears the rear, it starts to rise up, the further back you go, the higher the rise, back to the surface level, so... Seeing as your pod has a "step" you can have the motor (cav plate) well above the bottom of the actual hull, get the idea? So, you can have your 25" leg, and lift it much higher than if the pod was flat like the hill bottom, but in your case, you have to find a way to lift the motor beyond the transom mounting holes, that is done with thick plate, or a jack plate. Just blindly guessing, I would say you could raise the cav plate to about 75-100mm above the hull bottom, but, that said, it will be very much trial and error

[BM]

Dignity, the last time I priced a piece of ally to do such job it was about $130 (in Vic). The weight is about 10kg. Looking at your pod pic you would want to be at least 2 inches higher than level with hull bottom and you can go higher again than that. The 1inch up per foot out is a guide and from there it's up to experimentation.

[Dignity]

Thanks guys, I will consider jacking it up.

[Dignity]

BM, I think I paid a lot more for my 10 mm a couple of years ago, will check around again.

[BM]

I think prices in Qld are dearer than Vic.

[Noelm]

Seeing as you are in Golden Beach, I have a good mate at Caloundra that just might be able to get a piece of Aluminium for you, I will call him tomorrow, get me the dimensions of the bit you need, allow for all four existing bolt holes, and long enough to lift the motor the amount you think you will need.

[Smithy]

See the boys at Solas and see how much a proper jacking plate is.

[Marchy001]

Vance manufacturing in the states sent me my jackplate. 3" setback so didn't change balance of boat much but ability to change engine height to fine tune is great.
Was under $300 delivered from memory and I won't own a boat without one again.