MTFCA Forum

Did Ford ever cut X oil groves in T rods? My thinking is the X gives the oil a path in —-but it also gives the oil a path out under pressure. And I’m thinking the surface area of the bearings is greatly diminished leading to a shortened rod life.

Bob ;
I have seen rods who had big groves, and so deep nearly to the metal of the rod .
And two holes drilld from the top .
I think about one third of the surface area was gone . Toon

Xing would probably help hold some oil in the bearing during shut down, and it would help oil get in during cold starts and while running cold, especially with holes drilled in from the top. It might help cool the rod bearings on a car built to run fast by enhancing oil flow through the bearing, but it would certainly reduce the bearing area. That could probably be offset to a degree by using "hard" babbit. It might also lead to an increased chance for dirt or metal flakes to get into the bearing and get trapped there and cut the crank pin. As far as oil distribution within the bearing, the way the load forces move around the rod bearing as the engine revolves and the direction and the intensity of rod loading changes would probably do a great job of spreading the oil, so long as plenty of oil and oil clearance was available. The cap side of the mains might be a better place to do any grooving, with the same caveats as grooving rod bearings. An engine with aluminum pistons and a modern oil ring might get better cylinder lubrication with grooved rods with scoops. I'd think they'd tend to sling more oil than a plain bearing with no scoops.

Most cars with splash lubrication, have holes at the top of the rod so oil can flow down and X grooving along with hole at bottom and dipper, including the Model A, Dodge and Chevrolet. You have to make sure the wells are not cut to the end of the joint. The bearing ride on a cushion of oil and should not be in contact with the journal when the motor is running.

Did Ford ever cut X grooves in rods was your question.

Yes he did, the first of Ts had x'd rods and a built in dipper in the rod cap, part No's 487 and 488.
Finding a high failure changed to non X'd and no dipper rod No 3024 in 1909'

The why is Hydrodynamic oil pressure that works correctly on a bearing surface area the size of the T crank, X'ing works fine on bigger bearing surface areas.

It has been proven by high mileage T'ers that the X' rods do not last as long as non X'ed rods.

I believe the width and diameter of rod bearings is limited somewhat by weight considerations as well as the need to keep the crankshaft reasonabley short. In 1909, the Model T engine was a high speed engine, and inertia forces had to be allowed for, so far as was practical.

Late ‘27 Ford added dipper rods, the X type.
The dipper is angled to catch oil rotating , and the rod cap has angled hole with an oval hole in the babbitt, seems a good way to supply extra oil.

The Model A's 1927-1931 had dippers on the caps and X in the bearings. They also used splash for the rods and pistons, but had an oil pump to deliver the oil through the valve cover into the pan. They worked very well. I also have the dippers and X in my Model T's. I have no way to compare the life of the rods without the X and those with them, but mine work very well when the bearings are properly adjusted.
Norm

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Dan, that rod doesn't seem to be a popular idea at that time, no mention of it in service Bulletins for 1926/7 or available as a spare part even into the 1930's parts books. Maybe a bit like the tin piston