Smoking Duesenbergs

Usually,ANY engine that smokes at idle has a valve guide problem. I once had a 1969 Lincoln with the 460CID engine that developed this problem and I replaced all 16 valve stem seals. This was a rocker arm design and not an overhead cam system like a "J". I'd say on the "J" that valve guides would be the problem and possibly a wear out of the bored recesses the valve tappets work in or maybe a worn tappet alone. These things look like and are steel cups that house a shim adjusted valve clearance hollow nut that once set up right seldom need any attention. It would not take all 32 of them to be worn out to create smoking due to oil leaking into the cylinders,one could do it. Also,this condition would be unusual but repairable. I saw a Murphy Clear Vision sedan smoke heavily on starting at Auburn in 1986 but I think the whole engine was worn out in that one.
Quality control on the iron/steel mixes these engines were made from at the Lycoming foundry apparently varied a lot from block to block. I told Jim Schneck who owns SJ525 that when the block from J467 was bored out to 3.875 that the man who did the boring said he never wanted to see another one of those engine blocks again due to the hardness of it. Jim told me the block in SJ525 wasn't really hard at all. J467was the block we used to replace the damaged block #J528 which was later sleeved and restored as a complete engine.
If I were going to rebuild one of these engines for my own use,ALL eight cyinders would be sleeved with something of uniform quality and then modern pistons with narrow rings installed.That along with steel rods and insert bearings would make a useable engine out of a questionable relic.

Bob Roller

Looking at videos, I noticed several Model Js emitting smoke at idle. Is this characteristic of all Model Js, or just a sign that engine work is needed?