ring seating

[Guest]

Thank you for your reply to my post. The cylinders were rebored .040 oversize and I installed .040 pistons and rings.I have good compression.Some of the cylinders read around 115 to 120 pounds.I have a lot of power and all the parts were balanced so it runs quiet and smooth.At first it smoked badly but it is much better now but it still using oil. A few days ago I drove 50 miles and used a quart of oil. I use 30 wt oil because I was told there is no such thing anymore as breakin oil.There is about 300 miles on the engine since overhaul.Does this help? What about the breakin oil.Any recommendations on that?

I hope this helps .Thanks for your help

Jim Lawrence

[Guest]

Hi Jim, H-V-12's have been plagued by this condition a lot, some have said it is the 75 degree angle of the cylinders in the block, others say that because of the relatively small bore and number of cylinders, you have to run less tolerance on the piston to cylinder than is normal rebuild practice, still others say, that in an effort to thwart the problem, people use chrome or other supposedly "good" quality rings, that are too "hard" and do not seat well in the small bore. I have recently been made aware of a problem in a Flathead Ford V-8, where the owner started right in with synthetic oil, and the rings will not seat, the claim is it is too "slippery". One "cure" that has been effective in a number of cases in the V-12's, is to run the oil level one quart low, many engines seem to burn off that top quart of oil, and use very little after that. One other question is, are your compression readings all in that range you said, over 100 lbs, with not too much variation? If so, there is a good chance your rings have seated properly, and running a quart low will be the answer. There is much to be learned about these engines, it seems each is unique, keep us informed of your progress, please, incidentally, the cylinder angle theory has been largely discounted, because some engines have little or no problems, so the debate rages on, OC

[Guest]

I am curious about your statement about the block/cylinder angle being 75 degrees. I have never heard this before at least on a Lincoln. Some Ferraris did this I believe to achieve more room for the intake manifolds but I’m not completely sure of this.

The standard angle in this respect is 60 degrees. This from the general rule of 720 degrees that it takes to complete the four-stroke cycle (720 degrees) time divided by the number of cylinders is 60 degrees. This would be a discrepancy of some 15 degrees. I am wondering if this something you have personally checked or how have you come about this figure? My old L/Z was very smooth running and no one has mentioned this problem.

This would result in some degree of Secondary Shake as the piston end of the conrod and wrist pin are out of phase with one another. Yours , M.L. Anderson

[Guest]

Hi ML, I candidly admit I have never personally got out my protractor, and measured the cylinder angle on a V-12, but instead have blindly accepted this published information, let us know if this, like so much LZ information is in error, OC

"Repair Manual Lincoln V12 Engines H-Series 1936-1947.

1. DESCRIPTION.

The Lincoln 12 cylinder engine is a V-type, 75 degree, L-head engine. The

cylinder block and crankcase are cast enbloc, with full length water

jackets. The engine is liquid cooled with thermostatic control.

2. DATA.

Type...............V-12, 75 deg., L-head

Horsepower:

1936 through 1939..............110 at 3600 RPM

1940 through 1941..............120 at 3600 RPM

1942 to engine No. 138051......130 at 3600 RPM

1946 starting with engine No. 138052...120 at 3600 RPM

[Guest]

One thing Jim, did you ever install the proper oil seals on the '49-'53 Ford intake valve guides you used in your engine?? If not, that could well be the problem, should have them on the exhausts too, but the intakes are critical, if the work and expense of the repair are not worth the effort, you may just have to buy bulk oil, and live with it, it shouldn't hurt anything, as long as you keep adding oil, OC

[Guest]

Well I can't argue with,"THE BOOK", however my statement about block angle still stands. Whether it is valid or not I don't know! I can't see any reason for a passenger car needing a wider block angle like a racecar. But there it is! You sound very erudite about these cars and I know nothing about the K model. At Atlas Formula 1 there is a continuing discussion about block angle on V-10 Formula 1 racecars. Since I know nothing about V-12 Lincolns as the one that I owned was back in 1949 I don't believe I am very knowledgeable about them but I am still very interested in them. I just could not afford them. I'm sure you have heard this before. Getting information on even the K model is even more difficult, almost impossible,I can easily see that almost everyone makes statement as;maybe& or.almost.

One of the things that has escaped me is just how many main bearings and crankshaft counterweighs are on the Zephyr crankshaft. According to theory the V-12 crankshaft should not need any counterweights at the speed that the Zephyr crank turned. But I believe that they did. In view of the 75-degree block angle this may be the reason that the crank needed the counterweights. Altho this again goes against theory as counterweights only influence the primary Shake and not the Secondary Shake.

The formula for firing angle is 720 degrees divided by the number of cylinders or in the case of the V-12 60 degrees. This formula is a rule and not a LAW! But when it is applied in a logical manner it becomes very useful in designing engines. For example a 12 cyl. can be at 0 degrees, 60 degrees, 120 degrees or 180 degrees. But 30 degrees, 90 degrees, 150 degrees are verboten. This is the angle that Secondary Shake comes into full force! There has been considerable discussion at Atlas F1 on this vibration problem.

I hope this may be of some service to you as it is to me. Yours, M.L. Anderson marion5drsn@earthlink.net

[Guest]

Rolf; your picture of the engine is similar to mine but for some reason is much clearer than mine! The engine appears to have four main bearing and 8 counterweights. This would imply to me that it has insufficient mains and an overabundance of counterweights. The counterweights needed to keep the crank whip in check.

I just can’t see any reason for the cracking in that area. A real mystery.

I would have an idea that it is due to a casting defect and not much worry. This would be confirmed by the finding of a lot of sand and casting debris in the crack itself.

A 12-cylinder engine needs seven mains just due to the fact that the crank is very “Whippy”

I have another idea that a lot of trouble in this engine and likely many others is the distance from the two-barrel carburetor to the end cylinders, but there is little to be done about this except to keep the right foot under control. A twelve cylinder needs four three barrel carburetors to do the engine justice. But this is no Ferrari. Yours M.L. Anderson

[Guest]

Hi ML, I agree that the H-V-12's are not designed as well as they might have been, I had one excellent running one back in the '50's, and when I added a pair of Stromberg 1 barrel carbs fore and aft, that kicked in at 3/4 throttle, the 3700 pound Lincoln would really scoot, Main and Rod bearing failure was seldom a problem, leaking out the rear main was, the split shown is actually quite common, as that is where the "freeze plugs" are located, and in freezing conditions often do not pop out as they are supposed too, so the block cracks instead, that is the same as the flathead Ford V-8. Even when tired and smoky, V-12's are noted for being exceptionally smooth, but problem free, they are not--

[Guest]

Rolf, “freeze” plugs are not actually for the purpose of saving the blocks when water coolant freezes. They are there for the purpose of holding sand cores in place when the cast iron is being poured. This myth was started to cover up the manufacturers techniques in the pouring of cast iron. Their real name is Welch core plugs and is for that purpose. The crack you speak of is, I believe, the result of gasses collecting in that area when the block is being poured. If you have any friends in the casting business you might ask one of them to look at this area and see what he says. That is the reason I made the statement that I made.

Another thing about the oil being run low in the pan is the failure of the people who have worked on Lincolns is the fact that the oil dip stick is, as you know is a float, and the float gets a tiny tiny hole in it and no one sees it and the result is the oil level looks low. This is what happened to my old LZ. The mechanic who told me this worked in the Lincoln-Mercury dealership in Quincy Ill. in 1949. It has been a pleasure conversing with you. Yours , M.L. Anderson