Kelvin J2 Governor Leak

[gbclive]

I’m on a mission to reduce my J2’s various diesel drips.

There are several culprits, but the governor is the main one.
I initially assumed that the governor case was leaking, as there is usually a pool of diesel where the governor flange mates with the engine, which then drains down onto the adjacent engine bearer.

However, at some time past, my J2 has had a small open topped fuel reservoir added to the top of the front plate of the governor - presumably connecting to the small vent hole.
This is to enable the governor to be topped up without removing the filler plug. This is in addition to the injector drain manifold feeding into the governor.
The cranked rack enters the reservoir above an overflow drain, which is above the top of the governor.
The only visible attachment points of the reservoir to the governor are 2 studs through the lower part of the reservoir.
Using fluorescent dye and a UV torch, it appears that diesel is weeping from the interface between the reservoir and the front plate of the governor and perhaps also from its two attachment studs.

I’d like to cure the reservoir leak to see if that is the root cause, rather than the governor case itself.
I’ve included some photos - I’m a bit concerned by the involvement of the injector slide as I’ve not found much info on the normal arrangement or how it connects to the governor in my case.

Before I attempt to separate the reservoir, I’d be very grateful for any thoughts and advice on how best to proceed. My engineering “prowess” is solely down to what I have gleaned from the kind folks of this hallowed place, so please keep it simple

Thanks guys!
Clive.

Edited January 17, 2018 by gbclive

[BEngo]

Wow. What a contraption.  It seems to be designed to overfill the governor, but I have no idea why.

The normal arrangement is for the governor piston rod to be connected to the fuel pump rack by a piece of chain.  The spring link from this arrangement is visible at the pump end in one of your pics. 

With the standard set up the piston rod can (does) wear the hole in the front face of the case and fuel pisses out when the throttle is shut quickly. The best solution is to find a local (model) engineer and bush the hole with some leaded bronze so it doesn't leak. 

In your case I would dismantle the add on bits to the governor and ensure that the seal to the governor is well made, sealing the join with hylomar or Heldite. Longer term I would aim to revert to standard.

The governor case joints themselves have no gaskets and I seal mine with Hylomar.  The securing bolts are sealed by lead washers.

Hth.

N

[gbclive]

Thanks BEngo - that’s very helpful.

I’m girding my loins before I get stuck in - I appreciate this would be entirely routine for the engineers amongst us, but this will be the first time since 1972 that I’ve done proper mechinical stuff (when I re-built an old MG Midget and it’s engine under supervision).

If anyone has a photo or tech drawing of the normal connection between the governor and the injection pump, it would be useful to see what I would need in the future in order to return things to standard.

in the short term I’ll try Heldite as I have some already.

Thanks again,

Clive.

 

 

[BEngo]

I will try to get a piccy of mine next time I am there. Probly not till next month tho. Essentially it is only about 4inches of 1/2 in  pitch chain and two spring links. Goes straight between the governor piston rod and the pump rack.

A gasket between the add-on bits  and the governor may  be helpful.  Brown paper works if you coat it in heldite or wheaty packets similarly. The model engineering suppliers also do small sheets of gasket paper.  Draw round the  add on bit onto the paper then cut it out carefully with sharp scissors.  Holes can be cut with a knife if youdon't have a wad punch.

N

[gbclive]

16 minutes ago, BEngo said:

I will try to get a piccy of mine next time I am there. Probly not till next month tho. Essentially it is only about 4inches of 1/2 in  pitch chain and two spring links. Goes straight between the governor piston rod and the pump rack.

Thanks - that would be great - no rush at all.

18 minutes ago, BEngo said:

A gasket between the add-on bits  and the governor may  be helpful.  Brown paper works if you coat it in heldite or wheaty packets similarly. The model engineering suppliers also do small sheets of gasket paper.  Draw round the  add on bit onto the paper then cut it out carefully with sharp scissors.  Holes can be cut with a knife if youdon't have a wad punch.

I have various grades of card like gasket material from a previous engine cooling circuit flang leak and also a set of wad punches, so will crack on with this next week. Cheers.

[Guest]

Pic of mine if it helps

[gbclive]

5 hours ago, Badminton355 said:

Pic of mine if it helps

Thanks very much - I can just make out the simple chain BEngo referred to.

Seems a previous owner must have realy had a problem with checking / topping up the governor?

[BEngo]

2 hours ago, gbclive said:

Thanks very much - I can just make out the simple chain BEngo referred to.

Seems a previous owner must have realy had a problem with checking / topping up the governor?

  No idea why that might be so.   Topping up the governor is semi automatic in the normal set-up.  The injector drains fill it up quite quickly whilst running on petrol.  If more is needed during the day then open 1 injector drain whilst running and tick over on 1 cylinder for a few minutes, in or out of gear until the level  tap starts to drip.   Dead easy, no mess.  I find this can happen if the governor gets hot during a long high-power run- Gloucester to Tewkesbury say.  The cause is the diesel evaporating or getting hot and  thin and leaking out of the stuffing boxes and the piston rod entry.  The answer is to keep the engine cool so the governor doesn't get overheated.

If it was not an over-engineered answer to a leak, I guess it may be to do with the chain wheel on the speed control being in the way of the normal overflow connection.  Whatever, the add-on seems to have its own overflow at a very much higher level than either the original overflow or the level testing tap.  That means the governor has a lot more diesel in it than it should, but I can't see any benefit (though nor any risk either) from this, except that it will encourage the stuffing boxes  and the casing joints to leak.

 

N

[billh]

We have a J2, petrol start here. The governor set up is pretty similar to Clive's so it isn't a one off work around, maybe a Kelvin modification for an unknown reason? I do recall we had another J2 years ago that had the short chain link , described here  as "normal",setup.

Bill

[BEngo]

Thanks Bill.  I had a nagging suspicion I had seen this set up before. I wonder if it is a half-way house between the (bronze) vertical piston governor and the cast iron horizontal piston ones?

Still can only think it is there to deal with leakage around the piston rod though.

N

[gbclive]

Thanks guys - that’s very interesting.

I assumed that mine was a one off modification as I had not seen anything similar before.

It does seem to have been carefully made.