Ruston 4VSH and 2VSH

[IanR]

We have a 4VSH in our boat. It's been very reliable, ie always started well enough, and run for hours and hours without issue. But, it's always had a lumpy bit on the throttle and I've always thought that a 4cyl lump could run slower than it does on tickover. Saying that, I don't know what revs it actually does on tickover it's just a feeling it leaves me with! I always planned to take the heads off for a clean up but never have as I haven't any new head gaskets, nor a template apart from the two that are on it. So we are reluctant to split the heads to find it needs gaskets etc whilst it still is running well. The 4VSH comprises of 2 x 2VSH heads on a 4 cyl block.

 

Now to the point!, I'm on the verge of acquiring a fairly complete 2VSH, of very similar vintage. This motor needs some valve work but has already been disassembled to check its condition, the gasket is in good order so would be good for a template or annealing for use. Would it seem a good idea to refurb the 2VSH head and then swap it for one on the 4, refurb that and swap it for the other 4 head, finally refurbing that to again swap it so the 4 has its original heads as before? 

 

Also, while I'm at it, because I suspect the 4VSH is down on power (not that you'd suspect, it has tremendous pulling and stopping power) and it is on tickover most of it's life, if the mounting bearer dimensions and output heights are the same, (which I suspect they are since they apparently have the same size flywheel) would it be a half decent idea to pull out the 4 and fit the 2 and be able to use the same shafts, gearbox and prop? I think I'd at least have to fit a less pitchy prop perhaps.

 

Any thoughts folks?

 

Many thanks, Ian.

[BEngo]

Your rolling head refurb sounds like a good plan to me. If you cannot find NOS head gaskets or other specials like sandwich exhausts, Gaskets to Go (Google)  are very good and well priced IMO.  Usual disclaimer.

You will certainly need to change the blade if you fit a 2 cyl instead of a 4.  I would guess it will involve more than reducing the pitch and holding the diameter, unless you are happy to be rather inefficient.  Shafting, box etc should be OK provided the box mounting to the engine is the same.  You may need to adjust the control runs to new locations.

N

[billh]

These old Rustons are great engines, very reliable, plenty of power. They just lack the bling of a Kelvin or Gardner. The 2VSH will be fine in a narrowboat. The four is ,in my opinion,over the top . I bet it smokes a bit as it won't get up to proper operating temperature? I have used (and abused in the past), 2VTH and 3VRH , both now over 70years  old and they run fine. Re-used head gaskets a few times, just be careful not to damage when removing.

[IanR]

Many thanks for the input gents, much appreciated. Good to know about the possibility of head gasket reusability, though the 'new' engine would yield a template to send off before splitting the two I have on ours. I know the 4 is a bit big, but we've got to know it quite well and more importantly it's already in there and won't come out without a fight. 

 

Ian.

[sansouci]

I have a 3vsh and have reused the head gaskets after annealing and then using soft soap to squeeze it down. It worked well for me. The tick over on mine is about 200 rpm and it maxes out at about 800 normal canal speed, it will go up to 1500 it says in the manual but that's scary.....I am just to start restoring a  2vsh with electric start as a spare for mine. My prop is a 22x22 it's a hefty lump

[MtB]

22 minutes ago, sansouci said:

My prop is a 22x22 it's a hefty lump

 

Presumably you have a direct drive then, rather than a reduction box?

 

 

 

[sansouci]

No its via a prm 260 box, never had any problems with power although we do collect rubbish in shallow areas. Initially we had a 22 inch with a smaller pitch but it didn't have much of a grip and didn't load the engine, this prop suits us well