C&C style engine mounts

[phorvati]

Hi I have the C&C style engine mounts on C&C38, and I am unhapy because there just too much vibration. I would like to add rubber somwhere along the way between oil pan and engine beds. Vibration is not due to alignment because its there while in neutral. I also have ericson 27 with regular mounts and a4 with nowhere near the vibration. I had both of the engines in and out of the boats on few ocasions and I can say that I am pretty good at aligning the propeller shaft coupling. Thats definately not the cause of vibration. On ericson, the vibrations are much much lower, at idle and while in gear. I have the boats side by side in a marina and I've tested this thoroughly.
I belive there should be a way to add rubber between the negine bed and the mount. I just don't know exactly what to add, and how to add it.
Petar

[Don Moyer]

Petar,

You are apparently not the only one who has noticed vibration associated with the C&C mounts. We have seen several engines come to our shop over the years which have had C&C type mounts still attached to the engine with small pieces of rubber still sticking to the bottom of the mounts. If memory serves, the rubber was quite thick, sort of what I would imagine being cut out of the side wall of an automobile tire.

Hopefully some other C&C owner will come to your aid, but my recollection is that the rubber was thick enough to have required that the top of the mounting rails would have had to have been lowered a bit to accommodate the thickness of the rubber pad.

Don

[phorvati]

Thank you very much. Spring is slowly comming around here in the north east. good time to take the engine off the mounting stringers, and saw off portion of the stringers to accomodate the rubber. Then reallign the packless shaft seal. Is it just me or the packless one is much harder to reallign? It just moves too much.

Thanks, again
Petar

[castinemarine]

Aligning an A$ w/ C+C style engine mounts?

Hello,

I too have C+C style engine mounts on my 1972 C+C 35' Mk I. I am l;ooking for a procedure to align my new Moyer Marine rebuilt engine.
The old mount didn't have any rubber material between the mounting rail and the engine feet. Can anyone describe in detail the best process to follow to align the engine and propellor shaft? What sort of tools are needed etc.? Thank you in advance for any input or ideas!

[Don Moyer]

The attached guide may help,

Don

[keithems]

Petar,

You are apparently not the only one who has noticed vibration associated with the C&C mounts. We have seen several engines come to our shop over the years which have had C&C type mounts still attached to the engine with small pieces of rubber still sticking to the bottom of the mounts. If memory serves, the rubber was quite thick, sort of what I would imagine being cut out of the side wall of an automobile tire.

Hopefully some other C&C owner will come to your aid, but my recollection is that the rubber was thick enough to have required that the top of the mounting rails would have had to have been lowered a bit to accommodate the thickness of the rubber pad.

Don

my a4 is now out of the boat, and i too would like to do something bout the engine mount vibration.

can i just buy and install the "standard" engine mounts mmi sells? looks like they have some rubber in them to reduce vibration. or do i have to stick with the all steel c&c mounts currently in place?

kk

[Dave Neptune]

Suggestion

kk, I suggest that possibly you start a new thread and post a pic or two. There were many ways of mounting and the rubber filled base type are nice and quiet and vibration absorbing. Most mounts are somewhat universal but a shot of your particular instalion may yield a bounty of posibilities. Have you checked the mounts available to see if they will fit?

Dave Neptune

[Mo]

I would think that careful measurement of the space between the mount and the engine is imperative.

ie) If the rubber mount takes up 2 1/2 inches of space before it bolts to the wooden rail bed in the boat, the rail would need that 2 1/2 inches trimmed off to maintain your current alignment. If you have that kind of room to work it shouldn't be too bad. The thing you want to try and avoid is to having to change out the cutless bearing support strut, near the prop, because the angle is changed. This, in my opinion, is not the way to go. If the angle leaving the boat changes you are better off to stay with your current system. I have a C&C 30 and my engine is sitting on rails with angle iron bolted through the wood....it works Ok, no serious vibration or anything like that.

[keithems]

that's what i have also now

however, just took the engine out to replace broken cam, redo valves, etc., etc. -- remember me from last summer? i'm the guy you advised not to get an outboard as a temp a-4 replacement...

[Mo]

I remember. I told a few guys that were selling A4's to contact you via private message. One just last month or so. It will all get done and good luck with it

[joe_db]

I have a C&C 35 with these mounts. There is not enough wood to trim on my boat to use rubber mounts. The engine sits too close to the hull. These mounts were made to fit an optional diesel on 14-15" centers and then adapted to the A4 11" centers. One thing you could do is sister new timbers inside the existing mounts until you get the engine sitting ON wood instead of suspended BETWEEN the mounts. This would be fairly easy to do since the original mounts give you a perfect surface to align to. For the 38, you need to take some measurements using the available rubber mounts and see if any combination of brackets and/or trimming will work.
Note that a worn cutless bearing, bent shaft, bent/dinged prop, or bad alignment all contribute to vibration. I had the yard look at my boat last summer and every item on that list needed fixing except the last one. Seems hitting a log under power did some damage

[keithems]

I have a C&C 35 with these mounts. There is not enough wood to trim on my boat to use rubber mounts. The engine sits too close to the hull. These mounts were made to fit an optional diesel on 14-15" centers and then adapted to the A4 11" centers. One thing you could do is sister new timbers inside the existing mounts until you get the engine sitting ON wood instead of suspended BETWEEN the mounts. This would be fairly easy to do since the original mounts give you a perfect surface to align to. For the 38, you need to take some measurements using the available rubber mounts and see if any combination of brackets and/or trimming will work.
Note that a worn cutless bearing, bent shaft, bent/dinged prop, or bad alignment all contribute to vibration. I had the yard look at my boat last summer and every item on that list needed fixing except the last one. Seems hitting a log under power did some damage

partially cuz of your suggestions and partially cuz the engine is out now, so removing the prop and shaft was surprisingly easy ......

i decided to redo the stuffing box [again, looks really easy with the shaft removed....] and the shaft log rubber tubing [which i'd recommend to anyone any time they remove their engine...]

my question: there is some scoring on the shaft at both the cutlass and the stuffing box ends...how do i know if and what i should do about it?

there has never been any play in the cutlass and the stuffing box always worked properly...so maybe i want to leave it alone? i'm thinking if i polish out the scoring....then there will be play at the cutlass, meaning i'll have to replace that as well

or should i just bite the bullet and replace the shaft?

k

[sastanley]

Keith, it might be worth it to take your shaft to a prop/shaft shop. Of course they want to sell you a new shaft, but they'll likely also gladly service your existing one for less than a new one.

I do agree with doing all this while the engine is out. Much, much easier work.

My $0.02

[msmith10]

I just completed this process. The rubber portion of the shaft log was so old it kept me awake at night, and I had considerable wobble in the shaft despite alignment within 3/1000.
I agree with Shawn. Take the shaft to a shop and let them check it. A little scoring at the stuffing box and cutless bearing is OK but if there's too much the stuffing box will never seal. In addition they can check the shaft for straightness and check to be sure the face of the shaft coupler is square to the shaft- if it's not, you'll never be able to align the shaft or get vibration out.

[joe_db]

I would replace the cutless too while it is all apart.