deep low vibration from stern/ marine to car engine conversion

[Jhilton0816]

Basically when I'm pulling a tube with my Larson 234 escape deck boat, or when I have a lot of people on board, there is noticeable deep vibration coming from my stern drive when I'm taking sharp turns.... My buddy told me it's probably just the gimbal bearing needing to be replaced. Now when it's just me and two others on the boat just cruising, I don't notice it. Not even in the turns. Is that all it is? And should I replace it adapt before tubing weather is here?

I also had an old 5.7l Volvo pefs bored .40 over... Which I had replaced with a new engine due to the Pistons being completely jacked... I believe who had it before me did a fresh rebuild and didnt use marine pistons.... I was wondering if I could rebuild it and use it in a car.... Is there much to a conversion? I was thinking maybe making it a 383. I don't know anyone who's used an inboard marine 350 in a car.

 

[thumpar]

My GF's dad had a previously marine 350 in his race car. If it is for a car you would want a different cam. Cars run steel core plugs but I don't know if that is required to be switched from brass. That carb and distributor would be different from a car setup also. Marine pistons are the same at car pistons.

 

[alldodge]

Don't see it being the motor, could be the gimbal bearing. There is a lot of load on it with that amount of weight.

 

[Tail_Gunner]

Pull your drive and do a alignment check also check the ujoint assy very closely, there greaseless heavy joints make sure there also original equipment. When volvo had that drive built the cv joint was assy and then balanced very fickle stuff there if one was to disassemble the joints and reassemble them in the wrong order they would be unbalanced, If the joints are bad its better to get a whole new joint assy for the simple reason of balance. A very low rumble while turning at low rpm is very common on sx drive's....with that said they are a very capable drive that can handle up to 400 hp plus.

 

[Jhilton0816]

Here is the sound at idle
https://youtu.be/J2GQ0MNpapo
Here is the sound while driving
https://youtu.be/sG2WWBnXrkQ
Now I noticed this because it never happened before so I know it's not normal.

The new crate engine only has about 100 hours on it, so it is possible the guy that put it in before me might of not aligned something properly. I don't know.
Any ideas before I go and take this to the local marine dealership to get fixed. The guy said it sounds like a go ball bearing and said it would probably cost about 550 dollars all said and done with to get fixed
That involves removing the lower unit so I figured it's a good deal

 

[Jhilton0816]

Any ideas??

 

[alldodge]

Was hoping to here from the VP guys, my thought is it sounds like your low on drive lube.

As TG said, have you pulled the drive and checked the alignment, gimbal bearing and U joints?

 

[Bondo]

my thought is it sounds like your low on drive lube.

Ayuh,.... I donno's I'd use it again, without findin' out what's goin' on,....

Drain the drive oil, 'n look for metal bits,....

Gimbel bearin', or u-joints usually make noise in tight turns, or at extreme trim,....

Those vids sound bad goin' straight ahead,...

 

[Jhilton0816]

WELP bad news.... this boat has really been a pain. I took my boat to a mechanic to look at it to see if my engine hydrolocked, ended up finding out the engine is fine, but the upper of my outdrive is cracked/ bad. He wont break into it to look how bad because he cant warranty it if he messes something up. However he said the gears are probbaly shredded in there...... Now there is no way i can sell this boat in this conidition. So my only option is to fix it.... and the mechanic told me those volvos are expensive as hell for outdrives.... soo i need some help here guys. he gave me the info on what to look up.

sx-m
ratio: 1.43
sn: 4202024737

now he said the lower part of the unit with the prop looks fine, but the upper is not.... so if i can save money and just buy the upper then thats cool.