Should I drop the bottom end of a 144,000 kilometers, 1992 Daimler Double Six, SAJDDALW4CM486688, that I bought unseen from Denmark, with blown head gaskets, leaking PAS, etc etc.?
My mechanic works only on classics and is very reasonable with labour rates. He suggested that, since we are doing so many other jobs (*), we should also drop the bottom end, and replace main and conrod bearings. I am already spending north of €6,000 for mechanical repairs only (plus a respray), and I would prefer not to spend unnecessary money. But he offered me to drop the bottom end for an additional €600 only (plus parts). The front gasket is already going to be replaced as we are replacing distribution chain.
The engine did not make any weird noises from the bottom, there are no irregular vibrations, and the pressure instrument is unreliable (after so many years).
Some experts (Tom Lenthall, Chris Knowles) suggested that it is completely unnecessary to drop the bottom end, as it is far sturdier than the top end and, usually, it does not give up that easily.
Any thoughts on how to go about this decision? Is the bottom end really stronger than the top end? With no sign of damage, should I spend 20% more ?
One of mine just ticked over 800K kms, and the basic engine, top and bottom, are as made in Coventry. Albeit it a 1976 PreHE, same, same. OK, it leaks a tad amount of oil, so what, there is 10+ ltrs in the sump, and its only gravity oil at the tappet blocks, mainly.
The 2 HE are all at or over 300K kms, and untouched.
The weak things in there are the oil pump suction and supply o/rings, and YES, that sandwich plate needs to come of to do them. I have done many, too many, and never been tempted to touch the crankshaft. NO REASON, it aint broken, dont mess with it.
Tommaso
Do not touch the bottom end, other than as Grant advises. These engines were built to a standard, not to a price and they are bulletproof mechanically.
Replacing the oil pickup O rings is easy, assuming the engine is out of the car. Pics attached. Basically there are two pipes with O rings to seal them, one a pickup from the sump and another going from the pump to the oil filter and main oil gallery. You just unbolt the sump and the sandwich plate and there they are. You can see the O ring on the end of this pipe In this shot the O ring is in the casting Sump pickup filter on end of pickup pipe Another pic of oil pickup
principles shown above.
If your car has full flow oil cooling, it may be slightly different from the above, as the return line from the cooler to the engine is different. but nothing that will change the principles explained. Try to get O rings made of Viton if you can as they are more resistant to heat. https://www.barnwell.co.uk/products/viton-o-rings/
Thank you Grant and Doug, for your advice, it will save me somewhere in the region of €1,000 that I had budgeted, which I can spend on something else.
The engine will not come out of the car, if I will not replace bottom end bearings. I presume that my mechanic should be able to replace the timing chain and service belts, by removing the front radiator (which is being replaced anyway). He is also replacing the head gaskets, without taking the engine out.
Thank you for the links. I will buy those O-Rings. Any advice for the oil pump?
The sandwich plate might be tricky to remove with the engine in the car, as the subframe runs under it; at the very least I think the engien will have to be lifted a touch to give room to remove the sandwich plate.
If he cannot lift the engine to remove the sandwich plate, then that might be more difficult, as he will charge me to drop the engine.
I would drop the engine to change the oil pump, if it were an advisable precaution, in pursuit of reliability, for a car that was in very poor conditions, very much neglected, as oil pressure is key. The oil pump seemed to be working. Are the oil pumps reliable? Since I had budgeted about €1,000 to drop the engine, to replace the bearings (which I am no longer doing), I could drop it, if advisable. But if unnecessary, I would rather not. In which case, I ask: when should these O-rings be changed?
That oil pump is bigger and stronger than the crankshaft. No need to even touch it.
A simple cross bar, chains or threaded rod and raise that engine about 6", which is EASY with the radiator etc out. The fiddly part is replacing that plate without damaging the gasket, BUT, slow and steady, will always win.
Thank you. What would I do without this forum? The amount of money and errors that I saved ... if anyone who has helped me, here on in other threads, ever visits Naples (Italy), you have a place to stay in a villa, and a Daimler to driver around in!
The oil sump cannot cost that much, I will buy a new one, just in case.
Good decision Tommaso. This is the ype of bar you need to support the engine, and the chains go onto the lifting eyes near the front water manifold/thermostat housings:
Best to use shackles to attach the chains. The only other thing is that you need to undo the engine from the engine support mountings. You need a 9/16s ratchet spanner to do it, and to remove the air cleaner boxes to get to them, one each side.
I'll have to check if he has that pontoon to bridge the engine.
My mechanic is a a wonderful and very reasonable chap, but dislikes being told how to do stuff and can't speak a word if English.
I'll have to remember this thread, as I'm in England, while the Daimler and mechanic are in Italy. I'm afraid that he might squash that heater tap at the rear, that you mention.
Looking at my list of repairs and upgrades, do you have any other recommendations?
I saved about €1,000 that I can invest in other overhauls or improvements. If possible, I'd rather not spend any of it, but ...
