gtxtra361
Well-Known Member
What does it take to put a 440 crank into a 400. And any down sides to doing so.
Thanks cliff
Thanks cliff
400 with 440 crank
- Thread starter gtxtra361
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I did this to a 74 charger back in 07/08. It's pretty straight forward, a good shop can do it and balance everything for you. They essentially just grind the main journals to the smaller B series sizes. Now a days though, the prices on 440sources stroker kits make it more economical to just get one of their kits.
As for clearances, it depends on the block, the later years(76-78) have thinner walls than other years but not by much. Mine didn't require any clearancing to be done but consult with your engine builder.
As for downsides, not many at all. A 451 (400 with a 440 crank) is gonna make good reliable and useable power especially torque.
gtxtra361
Well-Known Member
Thanks for the response
What rods do I need to use
The counter weights also have to be ground to an overall smaller diameter......something on the order of .250" or so.
540slant6
Mopar SB Ripper
You essentially end up 426 C.I. but you have weak cast internals.
aaronk785
Well-Known Member
Turn down the mains to b engine size. Lots of pistons available for that build. Use a 440 length rod and piston weight goes way done. Of course a balance job. Which might include cutting the counter weights to loss weight. End up with a 451 or close.
No not even close. A 400 has a larger bore than a 440 @ 4.342 vs the 440's 4.32 bore. Putting the larger 3.75 inch crank in a 400 nets a minimum of a 445 if no over bore, an overbore of .030 Nets roughly 451 cubic inches.
Plus, you don't do this with a cast crank. 440s pre 73 had forged cranks, easily found these days
I called up a place called RPM international for mine. Told them what I was doing and they sent me a set out, it was roughly 350 buck for the set including ARP bolts. But that was ten years ago, I don't know what they charge now a days
No. The combo results in "around" 451 cubes, depending on finished bore size.
Also, what cast internals are you speaking of? Even if he used a cast 440 crank, they can withstand 600 plus HP with a good quality balance job, just like the stock rods reworked and with good rod bolts installed. Chrysler bottom ends are very strong even stone stock. You got your information from a bad source.
You certainly can use a cast crank.......it's just that most people "do not".
pishta
I know I'm right....
old way was grind the journals down and then grind the throws down to fit. Alot of material off those throws.....You can use either long or short rod depending on what piston you want to use, they make both combos. Nowadays, you can get a cast 400 stroker crank for less than the machining of a 440 crank to fit, and they are plenty strong. 451 is a great combo, They could have made it a production motor easily but it would have stepped on the 440, probably on the 426 too with some good heads.
whitepunkonnitro
Well-Known Member
Building a low deck stroker with a 440 crank, and using 440 length rods completely defeats the purpose of building such a beast...just keep it simple and use the 440 block.
That combination using a B length rod is a whole different story.
By shortening up the ratio and increasing angularity, you're talking about a combination that literally pukes instant torque.
That combination using a B length rod is a whole different story.
By shortening up the ratio and increasing angularity, you're talking about a combination that literally pukes instant torque.
Yeah but it fits better than a 440.
Unconventional
Well-Known Member
You can keep your power brake booster with a low deck.
I built them with the long rod and short piston and the short rod with the taller piston. Really not much difference in overall performance. Kim
The 383 block has the same bore as a 426 at 4.25 by putting a 440 crank into the 383 block you would have 426 cubic inches
440outlawdart
Well-Known Member
i built one back in the early 90s,turned the mains down to 400 size on a steel 440 crank,used 440 yl rods and ross pistons,car ran 10.30s on alky
Contact member fast01, (Fast01)
He has one sitting around since he went to 500+ cubes.
Tell him I made a mention of it.
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famous bob
mopar misfit
long rod is supposed to have better "wear" caracteristics.
famous bob
mopar misfit
whitepunkonnitro
Well-Known Member
Peak numbers are going to be about the same. The real difference is how the short rod engine will hit the converter.
Back to back, the difference is pretty profound
famous bob
mopar misfit
splain that to me. I`ve never had a problem hitting the convertor> LOL
whitepunkonnitro
Well-Known Member
A shorter rod sees greater angularity earlier, as measured in crankshaft degrees than a long rod, so it is pushing into the cranks rotation rather than down on it.
At lower RPM this gives peak pressure more leverage to spin things
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