I just purchased Vetus k-75 motor mounts and need to raise my engine height by 10mm for a new transmission.
How does one raise their engine?
Are there metal shims you can purchase or do you have to just make them?
Does anyone know the metal type in the Vetus motor mounts? I couldn't find a good web site or phone number to inquire directly.
Found Vetus's phone number: 410-712-0740
yellow passivated steel
Kable : Look in the Mainsheet tech note articles and WiKi . I first lifted my old engine with a 4:1 boom vang attached to the boom. You can lift the entire engine with a chain hoist attached to a 4X4 across the open companion way. You can also have the travel lift come over the boat and their Crain can lift the engine (expensive). There are all kind of ways to lift the engine!!
I also replaced my rear mounts by taking them apart the reassembling them in the engine mount bracket - while the engine just sat there!!
A few thoughts
Thanks Ron.
I had read your posts and I am planning on using the 4x4 w/ a come along / harness. After I am done, the final engine needs to be raised 10mm higher. Was wondering how people do this. Someone said wood shims and that doesn't seem right. I don't see metal shims to purchase so I guess you have these 'made' by someone? I then assumed they would want to know what type of metal the mounts would be that they are touching.
Oak would fine, I'd give em a coat of 'poxy.
Or G-10.
My personal for boat projects is a cheap hdpe cutting board from wally world.
It might be 1cm or you could belt sand it thinner. No great need to overthink this.
Good to know.
As you can tell, I tend to overthink things (computer engineer not mechanical/handy) ;>)
Kable : You might also consider using 5/4 pressure treated which is 1 inch thick. It's yellow pine (Hard wood)
A thought
Quote from: KWKloeber on July 23, 2022, 01:43:12 AM
Oak would fine, I'd give em a coat of 'poxy.
Or G-10.
My personal for boat projects is a cheap hdpe cutting board from wally world.
It might be 1cm or you could belt sand it thinner. No great need to overthink this.
@Kable
I measured the HDPE that I got from W-Mart (a cutting board) and it is 9.8mm -- pretty darn close.
Kable -
I installed the K-75's when I replaced my transmission with a PRM90 and I think I had to raise the engine the same 10mm. I didn't add any blocks or anything. There was plenty of adjustability with the studs on top of the mounts. Maybe I should have added something but my engine just sits a little higher on the mounts now and I've never had any issues. 10 mm isn't that much.
Jim
Mates
Just to clarify maybe a misconception - the engine doesn't get "raised" - it wants to sit in exactly the same position (it must, to stay in alignment w/ the prop shaft!) no matter what engine isolator is underneath, holding it and the bell housing UP. i.e., the isolator gets shimmed, not the engine raised!
The conventional wisdom is that the engine/bell housing mounts (brackets) should sit in the lower half of the isolator stud. As long as its in that range it's ok.
There's the rare possibility of snapping the stud if the torque is applied too high on it.
KWKloeber,
In my case, changing out the transmission to a ZF12M which has a 10mm output shaft drop from crank, I need to raise my engine 10mm, correct?
But that was already stated, so I am not understanding you post.
If the engine stays in the exact same position, won't it be out of alignment because to get the shaft to attach, it will have to angle down a bit?
Kable
Mea culpa. I misunderstood your application. DUH.
I was referring to just changing isolators that might have a different height, not if a different tranny output shaft is in a higher/lower plane than the original. You're absolutely correct the OUTPUT shaft must stay in alignment.
The comment about where the engine/bell housing brackets should sit on the isolator stud remains valid, no matter.
Apologies for the confusion!
Phew.... I thought I was really off.
(as you can tell, I am in way over my head on this stuff)
kable : It was WAY back (20+ years ago) when I changed my Hurth50 to a Hurth100 transmission. I remember having to shorten the shaft, but I do NOT recall having to shim up the engine. The engine essentially stayed in the same place. The new (longer) transmission just moved closer to the packing gland!!
A thought
Ron
To redeem myself for the prior faux pas about what Kable is doing - the 50 and 100 have the output shafts in the same location, vertically.
(Apparently) the new tranny he's installing has the output shaft 1cm lower than the Hurth. Hence the tranny/engine is raised so that the output remains at the same elevation as before.
1cm isn't a lot so it depends where the new K75s studs sit in relation to the engine/bell housing brackets whether it's advisable to shim the K75s. I don't know offhand the bottom of stud height (above the stringer) on the DF vs. K isolators but that info could be gotten. Also don't know where his brackets sat on the DF's studs.
To have the engine/tranny brackets hit the lower half of the studs, maybe the K75s should be shimmed 1cm, or maybe more, or maybe less - can't determine that given the info so far.
So this brings up a question. A few years ago I swapped our gearbox for the ZF12 and raised the engine accordingly. The engine is now higher on the mount studs with more threads below than above. I had wondered about the leverage on the mounts but opted to ignore that thought. I suppose using the top end of the stud would and does allow excessive movement. Maybe I should raise the mounts by shimming underneath. So, should I?
Ken & Kable : This is a real test of my memory about the old (replaced) M25XP engine. I double nutted all of the top nuts on my K75. As I recall (I have no pictures) there was still about a 1/2"' of threads above that top nut!?!
I'll guess that there is going to be plenty of threads. If not I'd take 1/4" thick aluminum and make a shim the same footprint of Vetus mounts.
A few thoughts
Dietrich : I'd leave the engine where it is as long as there isn't excessive vibration of the engine when running.
A thought
Quote from: dfloeter on July 27, 2022, 01:11:24 PM
So this brings up a question. A few years ago I swapped our gearbox for the ZF12 and raised the engine accordingly. The engine is now higher on the mount studs with more threads below than above. I had wondered about the leverage on the mounts but opted to ignore that thought. I suppose using the top end of the stud would and does allow excessive movement. Maybe I should raise the mounts by shimming underneath. So, should I?
Dietrich
It depends where the engine/bell housing brackets land on the K75 stud. See my previous post/warning. Pics of yours??
**its best that the brackets sit in the lower half of the studs.**
I saw a pic of a snapped off stud (apparently) where the engine torque was applied too high. I cant recall if it was an M25 or XP and whether it was on a 30 or 34.
@Kable
Here's some specs below that might help you.
If you measure where your engine brackets currently sit (or sat?) on the DF studs, w/ the new tranny they'll sit 8 mm above that spot on the K75 stud.
So depending where your brackets currently fall (fell?) on the stud (mid? above? below?) you can decide whether to shim and how much.
Thanks for the info. It'll be a few months before I get back on the boat but this looks like a great winter project. Maybe even swap out the mounts while in there. Happy cruising.