Lagondaforum

Subject: Severe Oil leak

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We have started to strip my De Ville for renovation and last weekend we had the engine running (Sweetly)for a while as we worked on removing the chrome bits to be sent to the platers.
The car was on a slope and when we stopped the engine oil literally poured out from what looked to be the rear oil seal, I suppose the first laymans question is "does it have one " and the second is to ask you all if this is common ? The oil level was OK but when we transported the car on a low bed trailer , when I bought it, it the same thing happened when it was being winched onto the back of the truck.(engine stopped). Does anybody have a sketch of the rear oil seal arrangement ?

Subject: Re: Severe Oil leak

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Hi,
I believe the original "seal" was simply a return scroll..I know my engine has been rebuilt with a conversion to a normal oil seal...unfortunately I don't have details, but I recall the rebuilder saying the scroll return wasn't satisfactory. Scroll return threads were a common alternative to crankshaft seals.
You possibly have two separate issues here. One is that it is likely your engine has been overfilled with oil. Check the level gauge...but it might be that the float has sunk or is sticking. Easy enough to drain the oil & check the quantity. Hopefully that is all that is wrong. Other problems could be a blockage to the drain from the return scroll, perhaps also worn bores/broken rings pressurising the crankcase...but not in isolation...mine used to burn & blow out oil in prodigios quantities, but not from the rear of the crankshaft.

Subject: Re: Severe Oil leak

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Thank you , I,m familier with scroll seals and that could be the problem, associated with a high oil level. The oil literally poured out.
We will remove the engine next week as part of the renovation and I will remove the sump to check. The engine sounds sweet enough but is very tatty in appearance so all that needs to be attended too.
Can I buy a book that shows all the engine parts or an exploded view ?

Subject: Re: Severe Oil leak

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Realised I have the original cranshaft here in a box...just checked, & there is a return scroll. Removing the sump...have fun! You will undo a squillion nuts & bolts, heave away a large aluminium casting, peer up in wonder, to see...nothing. Well nothing apart from more aluminium & the gauze suction filter for the oil pick up. The actual sump is the next level up...I think I figured the engine needed to be out to remove that. Bentley/Tresilian's little joke, perhaps.
A book with exploded diagrams/pictures even, of the entire engine, would be great, but there isn't one. The original handbook is fairly detailed, the club sell a V12 manual that is pretty helpful, but short on pictures. Apart from that, there is the "Motor Trader" service sheets, which are pretty detailed & shows some fresh pictures not in the handbook.
Incidentally, if you're rebuilding the engine & sleeving back to standard, I have a new set of pistons spare. They are to 8.25:1 compression ratio, but of course could be machined to a lower figure if preferred. They are exactly as the original Lagonda pistons, other than the higher compression land. My rebuilder said every V12 block he'd worked on had proved to be porous, hence the original plan was to sleeve, and I had these made in advance...but testing showed mine was the exception which proved the rule, so it ended up being bored to + 60 thou, with another set of pistons being used.
PM me if they're of interest.

Subject: Re: Severe Oil leak

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I will keep that in mind thanks, it is a long term project and I was hoping not to have to dismantle the engine ,just cosmetic stuff but you know how it evolves

Subject: Re: Severe Oil leak

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I am pretty sure we have an exploded diagram of the V12 engine that my dad got from Maurice Leo about half a century ago. He is away from his home at the moment (not holidaying but a chemotherapy course) and we shall look for it amongst his extensive archives when he returns. Hopefully I can photograph it then post it on the forum.
I thought the shaft had a conventional oil seal.
Mark

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Subject: Re: Severe Oil leak

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We have finally remooved the engine and there is no way we will go through that again !. The rear oil seal we will rework with a stainless steel sleeve pressed over the scroll and a proprietory seal , I,ll advise the size, looks fairly easy.
We have all the expected problems ,corroded ally parts , block full of debris etc ,and that was all in the first day, not a good start.
I,ll post some pictures later in the week

Subject: Re: Severe Oil leak

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These pictures show the sediment in the water jacket and a general view of the flywheel end seal assembly.

Thumbnails of attached images:

Subject: Re: Severe Oil leak

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Hi,
Very common sediment for a V12, mostly due to very poor water circulation around the block from side to side and front to back!
Several mods to do to help with that while you are doing your rebuild! Hope this answer is not too late. Drop me a line if I can help.

Regards,
Julian

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Subject: Re: Severe Oil leak

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Thanks Julian, I am still waiting for the radiator and new side plates to be made so any advice would be welcome