FoMoCo claimed that they had a new alloy for the Y-block crankshafts in 1954. Which was the alloy? Except for the forged crankshaft have all y-blocks the same alloy? How about the South-American cranks?

Which was the material for the C1TE crank?

Have anyone increased the strength of the Y-block crank by rolled fillet?
I believe it will increase the fatigue strength a lot, may be as much as four times.

How about nitride and induction hardening on the Y-block cranks?

Are cracked y-block cranks a result of harmonics, i.e. lack of good vibration damper or balancer?

What about a 312 crank turned down to 292 journals, rolled fillets, and hardened?
Strong as a C1TE crank?

1955 Mercury

For the mainstream Y crankshaft material, Ford used nodular iron which had the same strength throughout. GM on the other hand used material which required surface hardening to get the right wear characteristics at the journals. It’s the GM crankshaft material that started that ‘blanket’ statement “Don’t use a crankshaft turned more that 0.010” but that simply didn’t apply to the Ford crankshafts. The Ford cast cranks turned 0.125” wear the same as the standard sized journals.

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The C1TE cranks are forged steel. Where crankshaft snout strength is necessary such as in a supercharger application, then steel cranks have the edge over the cast cranks. Steel is also desired in the trucks where heavy accessory loading may be imposed on the damper end of the crankshaft. In the dirt racing applications, the cast cranks tend to last longer than the steel in part due to the cast cranks being more flexible and forgiving than the steel cranks. I've seen a multitude of broken steel cranks where they broke through the first journal and significantly less breakage after the same racers switched to cast iron.

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Oil retention is superior in the cast cranks versus the steel units so bearing life ends up being better on the cast cranks. As long as an oil film is maintained between the bearings and the journals, additional hardening is not required. Quality oil tends to help here also. That also means not using oil rated for diesel engines if going for mileage records on the bearings.

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I’ve seen Y cast cranks cracked at the journals and those were the result of a rod bearing that either hammered itself or allowed the insert to spin within the connecting rod. In general they are very robust units as cast and if they do break, it seems to be the front crankshaft snout being the part that gives up more often than any other part. The cast cranks for the Y have the advantage of being fully counterweighted (eight counterweights) versus only six counterweights on the steel cranks.

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Not sure what you mean by rolled or hardened fillets but insuring that adequate fillets or radii are maintained at the journal edges is a prerequisite for keeping crankshaft breakage to a minimum. When turning the 312 cranks to the 292 main sizes, just insure that the grinding rock is dressed appropriately to maintain an adequate fillet or radii at the journal edges. An undressed rock is an invitation for a crack to develop in the radii.

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Here are some past threads discussing fillets or crankshaft radii in general.

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http://forums.y-blocksforever.com/FindPost17427.aspx

http://forums.y-blocksforever.com/FindPost53891.aspx

http://forums.y-blocksforever.com/FindPost19159.aspx

Lorena, Texas (South of Waco)

Seems like the cast crank is not bad . Rolled fillet means that a hard wheel is rolling around the radius of the fillet pressing the surface down like shot peening, increasing the strength of the crank 2 to 4 times . It is used on Turbo Regal crankshafts. Would be very interesting to do that on a Y-Block crank.http://www.teamicms.com/Products/Deep_Fillet_Roller/Fillet_Roller.htm http://www.sciencedirect.com/science/article/pii/S1350630712001586

1955 Mercury