440/451 crank specs for best bang

[enemy]

Hey guys names Josh this is my first post , looking forward to doing my first build(1970 coronet 440). first with some needed advice on the engine combo i want to do...the famous 451. Haven't picked up the 400 yet, but i did get a 440 forged crank of a guy yesterday for $80.I'm interested as everyone probably is ,in the strongest most cost effective way to do this right(right as is shake the ground).

-Ive heard of guys cutting it down to fit gm rods and a piston combo thats stronger and cheaper all around, if so what are the dimensions? and what would be the best combo to look at that would fit.
-Going to the machinist by my work and want to confidently tell him what i need done.
ps.... if anyone wanted to link me to some of the things(seals/rods/pistons) with the right dimensions so i can see what im looking for in the near future id appreciate it.

 

[Donny]

I was going to do this years ago myself, but, my 400 block that was in my GTX was just too shot; already was bored .60 over, not much room for more of a bore, so, I scrapped that idea -- mainly b/c I was heading over to Korea, then, came back and went to Iraq; fun fun! So, since then, I have said Eff that with my plans, but, the torque of the 451 was killer! Good luck!

 

[Cranky]

Generally what people are doing when taking the crank down to Chevy size rod bearings are offset grinding it for even more stroke. IIRC, you end up with 472 in a 400 block.

 

[73rr]

Your browser is your friend...
http://www.440source.com/strokerkits.htm

 

[enemy]

k so have him grind the mains down to 2.2 for the chevy rods. Any other details i need to tell him about the offset grinding ? is there a specific dimension on the counter weights ?

 

[Al K]

Welcome;you need to get over to the "Welcome Wagon" for a proper introduction. We like pics,as well!

Good luck with the build;you'll get good advice here.

 

[Evil Mopars]

Generally what people are doing when taking the crank down to Chevy size rod bearings are offset grinding it for even more stroke. IIRC, you end up with 472 in a 400 block.

Yea, if your going to grind the crank so you can use Chevy rods, you might as well grab some extra cubes for free! :headbang:

 

[cj's mopar]

Hey guys names Josh this is my first post , looking forward to doing my first build(1970 coronet 440). first with some needed advice on the engine combo i want to do...the famous 451. Haven't picked up the 400 yet, but i did get a 440 forged crank of a guy yesterday for $80.I'm interested as everyone probably is ,in the strongest most cost effective way to do this right(right as is shake the ground).

-Ive heard of guys cutting it down to fit gm rods and a piston combo thats stronger and cheaper all around, if so what are the dimensions? and what would be the best combo to look at that would fit.
-Going to the machinist by my work and want to confidently tell him what i need done.
ps.... if anyone wanted to link me to some of the things(seals/rods/pistons) with the right dimensions so i can see what im looking for in the near future id appreciate it.

Read THIS about the 451
http://www.arengineering.com/articles/articleframe.html
Good luck finding a machineist to turn your crank many of them complain that cutting down the crank counter weights is to Hard on their equipment .

 

[Cranky]

Read THIS about the 451
http://www.arengineering.com/articles/articleframe.html
Good luck finding a machineist to turn your crank many of them complain that cutting down the crank counter weights is to Hard on their equipment .

A good machinist won't complain about doing machine work. Hard on their equipment? Find a machine shop that has the equipment that will handle it. They either don't have the right equipment or the machinist is lazy or doesn't know what he's talking about.

 

[73rr]

A good machinist won't complain about doing machine work. Hard on their equipment? Find a machine shop that has the equipment that will handle it. They either don't have the right equipment or the machinist is lazy or doesn't know what he's talking about.

The complaint is usually from the crank grinders not an industrial machinist. Cutting the counterweights is best done on a lathe so quiz 'your' guy. Whether or not to change to gm rods is a personal choice as H beam rods are available just as easily for a 400-440, and they will be the correct length if you want to go with off the shelf pistons. GM rods and offset grinds will require custom forged pistons.
Your profile only says Portland...Oregon or Maine? If you are in Oregon then I can recommend a top-notch machine shop down in Albany, let me know.
[email protected]

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[Supershafts]

what you do is turn the journals down for the H beam gm style 6.3" rod.
That lightens the rotating up to lighter than a sb and brings the rod ratio to the heavier breathing side, which increases low and mids, and allows the use of more cam, more intake and heads and you get a much all around stronger long curve...

I have done this numerous times in the past.

Yes machining hardened surfaces is hard on the tooling.. some shops would rather buy whats available then make it, as back 25 and later years ago, we didn't have these cranks avail so this is how we made them doing just like this...