[VicYouel]

Good point Paul; I continue to be surprised at the tiny diameters of the three holes but I suppose the suction from the pump improves the flow over that achieved by gravity.

Leads me to wonder about the efficacy of the oil pump in this case.


Vic

[phutton]

Does your machine have a three-position oil supply tap? Check that all the holes a free (some owners solder up the smallest to act as a stop-tap). I usually run mine on posn 2, but it might be worth starting off on posn 3 and see how big the smoke-screen is!

P.

[VicYouel]

I have always found it best when having a rebore to specify an extra 2 thou to be removed. Also I tend to ring gap at 5 though per inch bore diameter. I have had too many seizures using the standard piston recommendations. Somehow we ask much more of these elder machines to run faster in modern traffic and I suspect they run hotter with modern fuels.

I am suspicious of the oiling system though..... are the pipes all clear of sludge?

Vic

[shorrog]

I am no expert so treat my thoughts with a pinch of salt.
I would have thought that there must be something significantly wrong with either the lubrication or the temperature the engine is running at to seize in such a short time. Did the engine appear to be running very hot?
My guess is that it must be something to do with the lubrication system but I don't know what.

[Lagonda man]

It is a pre-alloy (1934) Lion 600 outfit.  My fault initially - left the oil off (yes, I know there is a valve and tell-tale but a previous owner put a tap in).  After the seizure the compression was poor and it smoked a bit but otherwise ran OK.  I thought I should take a look and found considerable piston damage but all else seemed OK.  I could not find a replacement +060 piston anywhere (they changed the next year).  My local man said he could salvage the piston but on the first run after putting it all together again it seized within 2 miles.  There was oil pressure and the telltale was out and I have checked the ignition timing.  So I am considering using the piston (and maybe barrel) out of the spare engine which happens to be +060 too.

Is there anything else I should check please?  I am not familiar with the bottom end but I guess there must be some sort of splash reservoir to feed the holes in the piston with it being a dry sump.  Might there be a lubrication problem despite oil pressure and tell tale?  I am hoping that it is just that re-using the seized piston was optimistic and all will be well with the spare. . .