I have a 78 440 in the shop I've been debating building.

I'm debating rather to buy a 493 stoker kit with everything or just throw some pistons and rods at it and go.

The pistons and rods were wasted from the oem build. Looked like someone ran the old school Pennzoil which sludged all the way up until it blocked the pickup, killed a lifter, and smoked the bearings.

Several of the rods and rod bearings were purple/blue with hot spots but the crank itself looks like new.

This would probably be an old school .550-.590 cam, 11.5:1 , Edelbrock or 440 source head type build. Something to maybe run 10.90's in a bracket car.

I've always heard that cast cranks are junk. but who has really broken one and how.

I'm pretty sure it wasn't the Pennzoil. That myth is as old as the hills, but still not true.

You aren't going to break a cast crank with 440 Source heads.

I don't know what oil they used but it was cooked. We scraped inches of paraffin like crud out of that oil pan. It was knarley. I hoped to build a roadkill motor for a shop truck but it was too wasted. The rods and pistons went with the garbage yesterday.

Andy - I think I bought a 3.89 stroke 413 crank from you years ago. That engine is still ripping 10's in my old dart 20 years later.

Hmm... I might throw some lighter rods and pistons at it and make a nice street strip engine.

Nobody has ever broken one. Nobody would dare to race a cast crank to find out.

The crude with the best lubricating properties comes from Pennsylvania. But whatever.

I used to take my cast crank to 6K every run, but then also found it it performed the same at 5,500 so we started doing that. It was a low 13 second car and we had a lot of fun with it. My cousin is still driving the car now.

Never ran a cast 440 crank in a mild race engine, as there were always a lot of stock forgings around. I have built several big block Chevy's with cast cranks at around 500HP level and no problems. I would think a cast crank Mopar at the same level of power would work just fine especially if you use lighter rods and pistons.

Police engines in late 70s had special cast cranks, got one, but my 74 cast crank engine was running 7.70s in my 64 Plym for a year or more before I changed to the steel crank engine. The 74 engine is now going in my Lil Red, maybe 15,000 miles on it. 5500 and both are done up top so that helps a lot, anything will break but I doubt you’ll have a problem
btw mopar stocker racers search out for the cast cranks to run in their engines, lighter. 340s (use 318), 383s, 400s and 440s

If you do a search of the archives, I believe most people are on board that a cast mopar BB crank is good for about 600 HP. I had a high twelve second car (street tires) with a 4 speed and ran it for years without a problem.

I checked here, moparchat and big block a bodies but have not seen anybody say they had actually broken one.

Seems like they may have been highly underated.

I know my buddy cracked an eagle crank after about 2,000 runs...lol. It really didnt tear anything up as he caught it during a refresh and just noticed some bearing worse than normal.

Thank for the replies.

It gives me some food for thought during this long winter.

I agree it is alway a forged crank for a build

In a basic 440 that I am planning to have fully machined, start from scratch and "build" (not just re-ring a stock cast crank engine),
I'd rather go with a reworked stock forged crank if I can find a good one at reasonable cost.

Not because the cast crank will break (it won't) but because "built/fully machined" means it will be balanced too.

Personally I feel like I am cheating myself if we get all the components
weight matched including the rods end for end, and then kind of wimp out at the end of the process by hanging
a bunch of weight off the ends of the crankshaft because it's too light.

It's more "ease of internal balance + easy parts interchangeability that follows" rather than any concerns the cast crank is going to break.

However even if we're not machining much of anything, and we're not balancing anything either, we can still have some fun with a good old 440
regardless of what crankshaft is in it. https://board.moparts.org/ubbthreads/ubbthreads.php/topics/1235800/1.html

Not a Mopar but, I have a friend that ran Eagle cast cranks in a stroked Big Block Ford. It made around 850HP on an engine dyno. He would freshen the engine every 3-4 years and find cracks in the crank via magnafluxing. He'd rinse and repeat every 3-4 years. The cranks were like $500 at the time and he just didn't want to spend the money on a forged unit any time he freshened the motor.

So; completely broken, no but, not perfect either.

Some NHRA stock guys use the cast cranks since they are lighter. Those engines are usually in the 500 to 600 range since they are limited to OEM castings and very limited porting.

i had a steel 440 crank and '73 cast 440 crank.. put them both on the bathroom scales and they weighed the same. i know it's not precise weighing but it was what it was .i wouldn't be afraid of a cast crank at a reasonable power level. reasonable is maybe 500hp to me.

I've weighed both as well. 73 lbs. as I recall regardless of whether they are cast or forged.

that sounds about right to me. i didn't think they were that heavy but seen no difference in weight.

I weighed a 383 steel, 400 cast, 440 steel and 440 cast, all 4 were 76 lbs.

If this is true then it begs a couple questions...

1. Why do the SS racers run them?

2. Why did they require weight added on both ends of the crank to get them to balance with the same rods and pistons as a forged crank?

Maybe it's only 1/2 pound and the less weight is worth it like a thousand other tiny seemingly insignificant things the SS racers do.

seems odd but maybe it's the 1/2lb thing or counterweight location. i should've looked closer. i've got a 440 that i took about 3/4lb per cylinder of weight off vs stock by using light parts and it didn't seem that much weight was removed from the crank.