skep419
No show, all go!
Which build would be better and why? Street strip dart. Just picked up a 4 speed. Looking to build a high winding monster. Top end will be same as listed below. Cam is still up in the air.
Going to pick up a 340 block tomorrow
- Thread starter skep419
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dodge freak
Well-Known Member
There is one more option, a Scat forged 360 stroke crankshaft with 340 size mains for about $700 . The same price as the 4 inch stroke true but the block can handle the 3.58 stroke easier and the pistons have a longer skirt than the 4 inch stroke pistons.
That be the best, IMO. You got a bit more stroke but not too much. This way it last a nice long time with no excuses, beat on it as you please. Built right it still should have a safe 7,000 rpm red line, maybe 6,500 to be extra safe but heck the 3.38 stroke 340 built right was good till 7,500, even higher with more mods
RPM and CI are king, I rather have a 7,000 rpm 378 engine than a 6,000 rpm 416 but in terms of raw power it be really close, at some rpm's the 416 would make more power, true.
That be the best, IMO. You got a bit more stroke but not too much. This way it last a nice long time with no excuses, beat on it as you please. Built right it still should have a safe 7,000 rpm red line, maybe 6,500 to be extra safe but heck the 3.38 stroke 340 built right was good till 7,500, even higher with more mods
RPM and CI are king, I rather have a 7,000 rpm 378 engine than a 6,000 rpm 416 but in terms of raw power it be really close, at some rpm's the 416 would make more power, true.
Guitar Jones
aka Angry Johnny
If you really want to twist it stick with a shorter stroke, good rods and lightweight pistons. I was twisting my 340 to 8000, 8500 in the water and running 10.50's with it. But you are going to need at least a big mechanical flat tappet, single plane intake and a big carb.
LH23H2R
Well-Known Member
I didn't know that forged cranks were made for the 360 !
skep419
No show, all go!
Also wondering on the heads. I have the 63cc edelbrock's. They list a 65cc head for the 340's. But the 63cc heads are suppose to work with 318,340, and 360.
LH23H2R
Well-Known Member
Guess I've just always viewed the cast crank as a cheap move ; however , they've been proven to be durable enough.
Then there's the idea that the 360 -- originally a 2 Bbl station wagon / 'C' body grunt motor -- replaced the vastly superior 340 .
LEVOHS
Well-Known Member
I've got my short block together now.KB 243 + .040 took .027 off top to zero deck heigth. Scat H-beam rods,forged 340 crank 10/10.Mopar aluminum 340 replacement heads minor port and polish 61cc.Still up in the air on my cam choice,leaning toward lunati voodoo 60405.I'll be running 4.10 gears and 4-speed.Mostly street and a little strip.Not trying to still your thread,but seems a lot of engine building happening.
In a lighter car like an A Body you'll probably never get beyond the need for a cast crank. Especially in a Street/Strip situation. Really! How often do we see or hear about someone breaking a crank at this level? Then taking into account the lower weight of a cast crank and I'll lean towards this direction.
1970Duster
Well-Known Member
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When I build any of my motors I over build them for their intend level of power (here is a link to my entire 340 internal specs and parts)
http://www.forabodiesonly.com/mopar/showthread.php?t=153956
My whole theory on this is "When you need it and don't have it, you'll sing a different tune"
http://www.forabodiesonly.com/mopar/showthread.php?t=153956
My whole theory on this is "When you need it and don't have it, you'll sing a different tune"
Guitar Jones
aka Angry Johnny
I have a stock cast crank in my 363 cube short block and it's been good but I treat it nice too. I always warm the motor to 180, let it soak for a bit then cool it to 130 before I hammer it. I've heard of quite a few lower horsepower Eagle 4" stroke cast cranks that have broke, the reasons for it though are unclear.
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