Aftermarket Cranks

[jmantle]

Larry, I thought your post was right on before it disappeared.

I just read the whole stock section in the new 2013 rulebook about a dozen times, didn't want to miss anything. Found the following,

"Any special equipment export kit
(superchargers, dealer-installed options, etc.) automatically
disqualifies car."

That should take care of the group 19 AMC stuff.

"Lightening of crankshaft other than normal balance job prohibited."

How can turning a 2.437 journal down to 2.200 not be considered lightening the crank?
That's almost 2 lbs.

Jim Mantle U/V/SA 6632

[SSDiv6]

Originally Posted by jmantle

Larry, I thought your post was right on before it disappeared.

I just read the whole stock section in the new 2013 rulebook about a dozen times, didn't want to miss anything. Found the following,

"Any special equipment export kit
(superchargers, dealer-installed options, etc.) automatically
disqualifies car."

That should take care of the group 19 AMC stuff.[/QUOTE]

Before the parts were approved for the AMC, similar parts have been approved for Chevy, Ford and Mopar. Such as a Chevy 327 intake on 283 engines; Boss 351 using a Holley in lieu of the Motorcraft carburetor, 4BBL Hemi Nascar engine and more...

Originally Posted by jmantle

"Lightening of crankshaft other than normal balance job prohibited."

It has been going on for years; you can even buy an OEM light crankshaft from Crower for Chevy engines.

Originally Posted by jmantle

How can turning a 2.437 journal down to 2.200 not be considered lightening the crank?
That's almost 2 lbs.
Jim Mantle U/V/SA 6632

How did you calculate the weight loss when you do not have an idea of the material density removed? The crankshaft journal size change was dictated by the NHRA approved rod, the same as other engine makes such as the Oldsmobile small block and Chevy.

[SSDiv6]

Originally Posted by Paul Precht

Yes but the Maxi mani doesn't fit a low block (400) without obvious mods but the Edelbrock 383 6 Pak mani fits a 400 block just fine and it's been done. The 400 block is stronger and 25 lbs or so lighter plus the advantage of the lighter piston and rod.

X2
I still remember of at least 2 Stockers and 1 Super Stock running the 383/400 block with custom pistons and the Edelbrock low block manifold. In addition to the strength and lighter weight, it positions the intake runner at a better entry angle in relation to the intake ports. Also allows the use of shorter push rods...less flex.

[Dinsdale]

So, let me get this clear in my head. "Stock Eliminator" allows aftermarket blocks, heads, rods, pistons, transmissions, clutches, rear ends, wheels, tires, suspension, shifters, unheard of cam durations. Lately added are valve job modifications roller rockers, now replacement seats and cranks. I find it hard to believe anyone would bitch about rod journal diameter while endorsing all the other "Safety" enhancements they now enjoy in "Stock"

Nothing even close to Stock with this class for a long time so might as well count the days until it's dead and you're a SS car like it or not.

[Jeff Lee]

Originally Posted by Paul Precht

Yes but the Maxi mani doesn't fit a low block (400) without obvious mods but the Edelbrock 383 6 Pak mani fits a 400 block just fine and it's been done. The 400 block is stronger and 25 lbs or so lighter plus the advantage of the lighter piston and rod.

All I said was the 413 & 426W share the same structure as a 440 (except bore). You can legally use a 413/426W block for a 440 if you choose.
The 361/383/400 B block is different. It is a low deck and uses a smaller main bearing.

[Paul Precht]

Originally Posted by Jeff Lee

All I said was the 413 & 426W share the same structure as a 440 (except bore). You can legally use a 413/426W block for a 440 if you choose.
The 361/383/400 B block is different. It is a low deck and uses a smaller main bearing.

Yes I know Jeff, I quoted you to keep the focus on the BB Chrysler for a moment, it had nothing to do with you or what you said, Paul.

[RJ Sledge]

JimR

Wake up Buddy, the 400 block 440 Combo has been around for quite awhile, can't believe you haven't known about it. The Wizard might not be the smartest guy around, but I don't believe that "ignorant" is the correct definition for him. I would have to put him on a short list of most knowledge engine people, but what the hell do I know its just my opinion.

Larry.......Hello?....where'd you go....Larry? did we lose you?? LOL

2.437?

RJ

Happy Thanksgiving everyone.

[jmantle]

Originally Posted by SSDiv6

That should take care of the group 19 AMC stuff.

Before the parts were approved for the AMC, similar parts have been approved for Chevy, Ford and Mopar. Such as a Chevy 327 intake on 283 engines; Boss 351 using a Holley in lieu of the Motorcraft carburetor, 4BBL Hemi Nascar engine and more...

It has been going on for years; you can even buy an OEM light crankshaft from Crower for Chevy engines.



How did you calculate the weight loss when you do not have an idea of the material density removed? The crankshaft journal size change was dictated by the NHRA approved rod, the same as other engine makes such as the Oldsmobile small block and Chevy.[/QUOTE]

I fully acknowledge this stuff has been going on for years, just pointing out that some of us don't agree with it, especially in stock.
NHRA could have published separate approved rod lists for stock and SS and kept stock journal sizes in stock, never understood why they didn't.
As far as the weight of the cranks goes, steel weighs .283 lbs per cubic inch, ductile iron a little less depending on the grade.

Jim Mantle U/V/SA 6632

[Larry Hill]

When you grind a 3.980 FE crank to 2.200 the crank is lighten about 1.625 pounds. I said pounds not ounces. The big gain is the change in polar moment of inertia. The weight reduction and where it occured is a big reason why the engine will accelerate faster. Multiply that times three if an automatic and four if its a stick and Ta-dah the car is faster.

And why does the 390/ 427get to use these rods?

[SSDiv6]

Originally Posted by Larry Hill

When you grind a 3.980 FE crank to 2.200 the crank is lighten about 1.625 pounds. I said pounds not ounces. The big gain is the change in polar moment of inertia. The weight reduction and where it occured is a big reason why the engine will accelerate faster. Multiply that times three if an automatic and four if its a stick and Ta-dah the car is faster.

And why does the 390/ 427get to use these rods?

Just 1.625 pounds?
I know of many that have removed a lot more by just using a different year crankshaft; there are OEM crankshafts for alter model car that have the crankpins and main journals drilled from the factory...and yes, the rules say no parts crossbreeding, however, how they can know?

As an example, you can get the "Stock Plus" GM forging crank fro Crower that is around 4 ~ 5 pounds lighter than OEM.

The rods were approved because at the time, it was the only rod that was close to the actual FE rod length. The same with the Oldsmobile small block rod; the first approved rods were 6" Chevy rods. It was the time of the advent of many new rod brands and makes, using forgings made in China.