Perkins 4.236 engine mounts

[BrickSailor]

So, for the second time in 5 years the engine mounting bolts on our perkins have sheared and the engine has shifted; probably new gearbox and shaft required!
The first time this happened we put it down to the mounts being old as we assumed they were the original 20 year old ones, and replaced them with new ones of the same size which have 10mm bolts. This time I have done some research while waiting for engineers to arrive with suitable lifting tackle - in a SW gale in a port that is "exposed to strong SW winds"!! My research shows that engine mount manufacturers recommend 16mm bolts for this weight of engine - yet the lugs on the engine will only accept 10mm.
Has anyone else had similar problems? And how did you sort them?

Thanks in advance from windswept Sweden.

 

[Sandy Bottom]

So, for the second time in 5 years the engine mounting bolts on our perkins have sheared and the engine has shifted; probably new gearbox and shaft required!
The first time this happened we put it down to the mounts being old as we assumed they were the original 20 year old ones, and replaced them with new ones of the same size which have 10mm bolts. This time I have done some research while waiting for engineers to arrive with suitable lifting tackle - in a SW gale in a port that is "exposed to strong SW winds"!! My research shows that engine mount manufacturers recommend 16mm bolts for this weight of engine - yet the lugs on the engine will only accept 10mm.
Has anyone else had similar problems? And how did you sort them?

Thanks in advance from windswept Sweden.

I have just been down to measure ours and each engine lug (as standard) will take 14mm - though each has been enlarged to take 16mm (no problem, there's plenty of metal there). As an aside, you are using the mounts correctly I presume (i.e. with the engine lugs sitting right down on the mount not part way up the thread?). Sorry if that's grannie's egg sucking!

I have two separate (genuine Perkins marine) 4236's on two separate boats and they are both as above so that is almost certainly the standard set-up.

 

[BrickSailor]

Thanks for the quick reply, it has confirmed that my plan is probably the best course of action. The current plan is to put in 10mm ones just to get us back to a yard where the boat can be lifted then drill the lugs out and go for the 16mm ones!

All the best,

BrickSailor

 

[Deleted member 36384]

There are two types of mounts: slim line and standard. The slim line is easily identifiable as most of the rubber was buried inside the engine bearing beds, instead of above the bearers. On my own yacht the bolt OD is about 16 mm, I would need to check to be sure, however, the engine lug is attached with what looks like a pair of larger bolts. Perhaps yours are the same and as such you have a different lug from original. Mine are L shaped, as expected of course, but have integral webs across the right angle i.e. cast webs, not welded, very easily removed to modify or change.

I have part numbers for slim mounts and contacts. I am sure the same people will have access to the correct parts if yours are not the slim type. You are aware that there is a difference between the front and rear mount rubber hardness? Also check the propellor shaft as mine bent when the shaft coupling failed due to a failed mount. I took the opportunity to fit a Halyard Aquadrive CV type coupling when I had all the gubbins refitted with new parts, something to consider if you have to pull the shaft and lift the engine.

Change all 4 at the same time, not just the front two, for example.