Has anyone 'destroked' a 440? Outcome?
You know, kinda like a 377 Chevy. BIG bore, smaller stroke.
NOT lookin for 8000rpms, just trying to gain more knowledge..
Can stock Chrysler crank shafts be utilized?
And yes, I know that this might call for custom rods and/or pistons.
Errol
NOT lookin for 8000rpms, just trying to gain more knowledge..
Can stock Chrysler crank shafts be utilized?
And yes, I know that this might call for custom rods and/or pistons.
Errol
1 - 8 of 8 Posts
I'm sure that various racing applications have probably called for reducing the volume of an engine, there were small blocks reduced to less than 355ci if I remember my racing history correctly.
On the other hand, I don't think that a "B" crank" will fit into an "RB" block, doesn't the "RB" have a bigger main bearing? I think that if one wants to use an RB crank in a B engine one has to have the crank main journal turned down to fit...
I expect that one can do all kinds of things so long as the spacing dimensions are right, but unless there's a reason for it I don't see a lot of people doing what you bring up. Most seem to want bigger, not smaller.
On the other hand, I don't think that a "B" crank" will fit into an "RB" block, doesn't the "RB" have a bigger main bearing? I think that if one wants to use an RB crank in a B engine one has to have the crank main journal turned down to fit...
I expect that one can do all kinds of things so long as the spacing dimensions are right, but unless there's a reason for it I don't see a lot of people doing what you bring up. Most seem to want bigger, not smaller.
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87 Posts
My buddy, (the one selling all his stuff) said that the 'trick' thing was to grind down a 440 mains and use the 400 block for a 472??
I was JUST THERE and forgot what he said if its' the 400 rods or 440's..
I'm Just getting idears guys. NOT jumping into an engine build just yet.
I mean if it's gonna only be around 10-12mpg anyway, I might as well have fun..
Thanks E
I was JUST THERE and forgot what he said if its' the 400 rods or 440's..
I'm Just getting idears guys. NOT jumping into an engine build just yet.
I mean if it's gonna only be around 10-12mpg anyway, I might as well have fun..
Thanks E
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6,103 Posts
The mains are a different size, so, the way to destroke a big block is with a custom crank, starting with a forged steel crank, not the nodular crank. Essentiailly the crank shop can then reweld the rod journals (you want to keep the RB main journals), and the stroke on the rod journals is then shortened. From there it is a matter of determining how short a stroke you want, use the stock 440 length rods and custom pistons with the piston pin located lower on the piston.
Now, the thing is, shortening the stroke on a 440 isn't that great an idea, the piston diameter is pretty large, so the B block 361 will give you a 4.125 inch bore, which is a great winding engine and except for the pistons themselves, is a 383 (4.250 bore) or a 400 (4.340 inch bore, which is larger than the 440 bore at 4.320), which is way large in the filling and burning in the shorter stroke engine, so take that into consideration if building this engine.
As a side note, the 361 is a truly awesome capable engine, and the older closed chamber heads keep the compression up in the 9:1 very easily, and the aftermarket Edelbrock aluminum heads can fit the 2.18 intakes within the bore easily for even more fun.
Now, the thing is, shortening the stroke on a 440 isn't that great an idea, the piston diameter is pretty large, so the B block 361 will give you a 4.125 inch bore, which is a great winding engine and except for the pistons themselves, is a 383 (4.250 bore) or a 400 (4.340 inch bore, which is larger than the 440 bore at 4.320), which is way large in the filling and burning in the shorter stroke engine, so take that into consideration if building this engine.
As a side note, the 361 is a truly awesome capable engine, and the older closed chamber heads keep the compression up in the 9:1 very easily, and the aftermarket Edelbrock aluminum heads can fit the 2.18 intakes within the bore easily for even more fun.
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87 Posts
PM me info on this '361' with casting numbers if you can. I'm still learning.
He had stated to use the ground down 440 crank in addition to the 440 rods in the 400 block..
Also stated of the better rod angle of the 440's versus the 400's Used in that application.
I just don't want too high of piston speeds either.
What heads to look for too!? (like said before, I'll probably do a quick port job to what ever ones that I end up with)
Errol
He had stated to use the ground down 440 crank in addition to the 440 rods in the 400 block..
Also stated of the better rod angle of the 440's versus the 400's Used in that application.
I just don't want too high of piston speeds either.
What heads to look for too!? (like said before, I'll probably do a quick port job to what ever ones that I end up with)
Errol
1 - 8 of 8 Posts
