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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 ?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.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 ?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.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
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.
MarkWe 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 weekThese pictures show the sediment in the water jacket and a general view of the flywheel end seal assembly.
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,
JulianThanks Julian, I am still waiting for the radiator and new side plates to be made so any advice would be welcome
Hi,
We have side plates in stock if you are in need!However, water mods,
Depending on how far you are going with compression ratios and other mods etc do the following work and modifications.1. Cylinder head and cylinder block, right front 3 cylinders, looking down from above you will see very small water transfer ports taking water from the block to the head, these are usually 1/4″ in dia. Increase all of these “on this area only” to the largest size you feel comfortable to do, keeping them matched to each other. We usually do these to about 7/16″ or so.
2. modify the gasket to match.
3. clean and check the water transfer tubes between right and left sides, inside the block.
4. Top pipes from rear of inlet manifold to front water outlet.
These pipes should CROSS OVER right front to left rear and vice versa! they only need to be about 1/2″ dia though as too big and you get no cooling on the front right 3 again!!
5. If going performance route you can also make external piping to both sides and front and rear equally, this will give you a much better and much less heat temperamental V12 if you intend to drive large hills and mountains etc.Radiator and general cooling wise.
1. Make sure you have a NEW core! old ones will never clean well enough and an engine rebuild is far more costly than a new core!!
2. Remove the heat shrouds from around your exhaust manifolds and cover the exhaust with Thermotec exhaust bandage, do this well and put it on “Very Wet” This will keep hot exhaust out of your engine bay but also allow the hot air that has gone through the radiator to escape to the outside via those lovely big louvres. If you imagine the air trying to get past the engine under the car you will see why V12s regularly over heat! Especially if you remember that ALL old cars and most moderns have a positive pressure under the car when at cruising speeds! Thus hindering the cooling further!
3. Then the final cooling “Coup de gras” is to replace your fan blades for those of a Jaguar Mk11, these are of much better design, flow more air, sap less power and look good also! Easy to fit with only some hand tools and a bit of thought!
A non overheating V12 will emerge, even with a short rad DHC up the mountains!! But keep the cooling system clean!!Good luck.
JulianJulian,
on other discussion boards there is criticism that using Thermotec can retain too much heat in the manifolds and cause them to overheat/crack. Have you ever had this experience?Like most V12 owners I am looking for any way of keeping the driver and passengers cooler (ie not just the car’s engine!) especially in warmer weather when the passenger compartment heats up even with the roof down
rgds
Hi Alistair,
No, never had any problems due to the wrapping,
I have seen many cast manifolds crack due to old age and lean mixtures and or retarded ignition though! It is easy to blame something like thermotec etc or antifreeze for causing manifold cracks or water leaks but we are talking about 70 year old parts now! that were not particularly well designed or developed when new! so it’s about time that some of them show their age ;o)
But no, if the manifold is absolutely flat, fitted well and not over tightened or forced on to tight studs (the manifolds need to slide on loosely before tightening nuts) then you will not have any problems that can not be attributed to old age! If the mixture is correct then the manifolds should be very cool compared to any normal more modern type engine. We regularly check manifold temps while running on our rolling road and never see over 400 deg C even at full throttle with powerful engines on the rolling road!
Though you certainly will if the engine is not setup correctly. You can easily see the manifolds glow red hot if the timing is retarded or mixture to weak!!One of the bigger difficulties is to seal the manifold to the head “without” over tightening! We use black silicone sealer which is absolutely the best exhaust sealer you will ever find!!
And on engines where we are expecting high outputs compared to std, we use no gaskets and use Only Silicone sealer! But again the importance of flat manifold flange faces can not be over stressed!!!Best regards,
Julian
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