Hey folks, let me get some opinions here. 76 440 block. All machined and balanced with 440 source rods and Pistons, but thinking about a crank. Have a virgin standard size journal cast crank, or could buy a standard size stock forged crank for $250.00 without machining. Should have about 600 horse and will use a main girldle and ARP studs on everything.

I think that a forged crank is in order at that hp level. Why didn't you just buy a full rotating kit from 440 source to start with? A stroker kit wouldn't have cost you any more than a standard 440 kit.

I've never had a problem with a cast crank.

It was the stock, cast pistons that were my undoing!

Yes we all would prefer the steel crank over the cast but how many have you seen let go ?

My first race engine was, still is, a cast crank stock LY rod engine. It's been to hell running 11.00's for years and then high 9's on the bottle over a 150 times. it has a sleeve, 7 TRW pistons and 1 Manley that was shaped with a grinder to match the others, ran a best of 9.69 @ 135. The engine is still going hard in my sons Aussie A body N/A running 11.2.

I would say that a cast crank will be fine up to 600hp.

Well it's all going in a 4,000 pound shortbed dodge truck. Don't plan on anymore than 6,500 rpm. I haven't bought a rotating assembly just yet, but that's what I plan on running in it. Block is getting machined as we speak.

Cast crank and ly rods at work https://www.youtube.com/watch?v=nt4DpdAI7Fk

This made me laugh............a lot..........

The people that were following me when it went "boom" on US 54 and had to drive through the cloud of antifreeze probably weren't laughing...

You know if you could get that thing to hook up, it would accelerate a lot faster... Crazy Aussies!

(I wanna be a tire salesman in Austrailia!)

I think some of that dirt from the return road next to the strip got on it somehow...

$250 for a stock forged crank that still needs machining??? Holy crap that's high! You ought to be able to find one cheaper than that!

Realistically, I think a cast may be fine for what you want to do, but I'd rather see a forged crank in a motor making that much power. You've already spent good money on a girdle, studs, etc. Get a forged crank and don't worry about it.

Bottom line is this, can you afford the steel crank, if so, put it in there. Me personally, I won't use cast crank in anything other than a stock build..........don't care how many, have done this, or been this fast. Not worth the risk

Should be a million of the steel 440 cranks laying around with everyone using strokers now, and cheap too. Like the guy above said, maybe $250 for a done crank.

Jason Pettis found my 413 forged crank 13 years ago ready to drop in my 400 block for about $250 iirc w/chevy rod sizing.........

As said in the next post, RB steel cranks hold a premium to go into a B-motor budget stroker. At least $100 for a core that needs turned. $200 at a swapmeet.

Not splitting hairs, but they are both steel....its not cast iron v/s forged steel. One starts out as a forged billet the other is a poured casting.

Consider this, if you are a budget build (say <500hp) or a just for fun test and tuner, it probably doesn't matter much. If you are hitting it fairly hard, or drive the stripe with the throttle pedal, you should probably stay away from cast.

No they are not both steel
one is iron and the other is steel
its sort of like saying brass and bronze are the same

cast crank is ok for stock. if you're after performance, you've got that big, ugly,heavy balancer.little stall converter availability /special offset flexplate to buy. balance job will cost more and you've got a externally balanced engine vs internally [the right way] btw,the only cast crank iv'e seen broke was a dodge camper special 400 when I wrenched in the airforce. it broke right in the middle of #3 main but was still running with a knock.it drove in the shop! i'm sure it took a lot of abuse.

I dont remember the ASTM number right off , but here is a link you can refer to until I find or remember it....they ARE cast steel. Not totally relevant, but as in your comment - its like calling brass and bronze as the same.
Bottom line, go forged.

http://www.hotrod.com/how-to/engine/1405-how-to-tell-forged-crank-from-cast-spotters-guide/

Im not sure why hotrod is calling it steel?
Its a ductile cast iron afik but hey I could be wrong
I agree keep away for performance.

I know of a low 9-second n/a smallblock mopar w/a cast crank..........

Can a cast crank be used in a 600 hp combo? Sure. Build anything you want. Would "I" take a chance on it living, for that small of an investment? No way!
I can't afford a billet crank, or an aftermarket block, but I would find a way to come up with $200.00 for a forged crank over cast. Machine work and balancing would be the same for either crank.

They all start out as steel... forged are pounded
to get a tighter density and to align the molecules..
the cast is just that.. cast and thats the end of it
(other than the machining)

So they are not the same


Cast Iron vs Cast Steel

Firstly, let us know what is the cast iron and cast steel.

Cast iron usually refers to gray iron, ductile iron and malleable iron, which is iron casting with carbon content upper than 2%.

Cast steel usually refers to normal carbon steel and alloy steel, or called steel casting with carbon content lower than 2%.

Therefore, no big difference considering from the chemical content and raw materials for cast iron vs cast steel. However, their physical properties have many differences.

The advantage and disadvantage of cast iron.

The grey cast iron has good casting properties, good vibration damping, good wear resistance, good machinability and low notch sensitivity. However, its tensile strength and elongation are very low, so only can produce some metal parts with low physical requirements, such as protective cover, cover, oil pan, hand wheels, frame, floor, hammer, small handle, base, frame, box, knife, bed, bearing seat, table, wheels, cover, pump, valve, pipe, flywheel, motor blocks etc. As for the higher grades, grey cast iron can withstand greater load and a certain degree of tightness or corrosion resistance of the more important castings such as cylinder, gear, base, flywheels, bed, cylinder block, cylinder liner, piston, gear box, brake wheel, coupling Plate, medium pressure valve, etc. refer to iron-foundry.com.

The ductile iron and malleable iron have high strength, ductility, heat-resistance and toughness, so a wider application, in some cases can replace the carbon steel. However, its production technology is high, production process is more complex, and production cost is higher than normal grey cast iron and cast steel, therefore, there are more casting defects for ductile iron. There are many fields that ductile iron are using for, such as Pressure pipes and fittings, Automotive applications, Agriculture, road and construction applications, General engineering applications.

The advantage and disadvantage of cast steel.

One of the advantages of cast steel is the design flexibility, the designer of the casting have the greatest freedom of design choices, especially the complex shape and hollow cross-section parts.

Cast steel has the metallurgy manufacturing flexibility and strongest variability, you can choose a different chemical composition and control, adapted to the various requirements of different projects. By different heat treatment choice in the larger context of the mechanical properties and performance, and good weldability and workability.

Cast steel is a kind of isotropic material and can be made into the overall structural strength steel castings, thereby improving the reliability of the project. Coupled with the design and weight the advantages of short delivery time, price and economy has a competitive advantage.

The weight range of steel castings is larger. Little weight can be only a few dozen grams of molten mold precision castings, and the weight of large steel castings up to several tons, dozens of tons or hundreds of tons.

Steel castings can be used for a variety of working conditions, and its mechanical properties superior to any other casting alloys, and a variety of high-alloy steel for special purposes. To withstand high tensile stress or dynamic load of components, it is important pressure vessel castings in low or high temperature by the large and important part load key parts, in principle, should give priority to steel castings.

However, the cast steel has comparatively bad shake-suction, wear resistance, mobility and the casting performance are compared bad with cast iron, moreover, the costs are higher than normal cast iron.

Crankshaft Materials

…

Crankshafts materials should be readily shaped, machined and heat-treated, and have adequate strength, toughness, hardness, and high fatigue strength. The crankshaft are manufactured from steel either by forging or casting. The main bearing and connecting rod bearing liners are made of babbitt, a tin and lead alloy. Forged crankshafts are stronger than the cast crankshafts, but are more expensive. Forged crankshafts are made from SAE 1045 or similar type steel. Forging makes a very dense, tough shaft with a grain running parallel to the principal stress direction. Crankshafts are cast in steel, modular iron or malleable iron. The major advantage of the casting process is that crankshaft material and machining costs are reduced because the crankshaft may be made close to the required shape and size including counterweights. Cast crankshafts can handle loads from all directions as the metal grain structure is uniform and random throughout. Counterweights on cast crankshafts are slightly larger than counterweights on a forged crankshafts because the cast metal is less dense and therefore somewhat lighter.

Generally automobile crankshafts were forged in past to have all the desirable properties. However, with the evolution of the nodular cast irons and improvements in foundry techniques, cast crankshafts are now preferred for moderate loads. Only for heavy duty applications forged shafts are favoured. The selection of crankshaft materials and heat treatments for various applications are as follows.

Spend the small amount of extra money and get a forged crank.

A buddy of mine used to race FE Fords in the 70's. He started using cast cranks because they were lighter and figured that was an advantage. He used to break forged FE cranks. According to him he never broke a cast one.

I saw a quote from Joe Sherman in Hotrod many years ago. At the time he was building some pretty stout SB 400's. He said that forged cranks were for people that couldn't sleep at night.

Kevin

My buddy races his 52 ford PU with w 460 BBF..
he sprays it also... the journals on that crank
are huge.... its a cast one... and HEAVY

And when they come apart they Come apart! The 460 blew and the crank "parts" where in the pan, snout and flex plate flange where the biggest pieces with the rods hanging onto there parts, never saw anything like that before. But it was making about 700 hp and had 400 or more passes.