67gtx
Well-Known Member
Has anyone taken a crank from a 318 ploy and put it in a 360?
318 ploy crank swap
- Thread starter 67gtx
- Start date
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grumpuscreature
Resident Curmudgeon
I guess you could try it but there are a couple things to watch out for. The Poly had 318/340 mains and a 3.31" stroke.
daredevil
Well-Known Member
why? you can turn down a 360 crank to go in a poly but how would you (shim)a poly to go in a 360
3404spdvaliant
Banned
What year poly crank? you know about 8 bolt & no pilot right?
dusterdon
Well-Known Member
A 318 poly crank is the same as a 318-340 crank. Won't fit in a 360 block. The strongest LA motor cranks came out of 318 industrial motors (trucks). those are the 318-3 cranks mentioned in the mopar books.
daredevil
Well-Known Member
thats what i was getting at when i said how would you shim it.
3404spdvaliant
Banned
Easy guy's, here's your main spacer kit MRE36040
I believe all that 318-3 crank is =left over 273 steel.
And I don't believe they were any stronger than 340 cranks were.
The 67' truck motors also came with closed chamber 324 heads which I have On a low comp piston 340 cam'd rebuilt 318.
Hope that helped. good luck
I believe all that 318-3 crank is =left over 273 steel.
And I don't believe they were any stronger than 340 cranks were.
The 67' truck motors also came with closed chamber 324 heads which I have On a low comp piston 340 cam'd rebuilt 318.
Hope that helped. good luck
mikedevore
Well-Known Member
I THINK WHERE THE STRENTGH COMES FROM IS THERE ARE NO MATERIAL DRILLED OUT OF THE #1 & #2 OR #7 & #8 CONNECTING ROD PINS. IF YOU LOOK AT THE 340 CRANK, IT WILL HAVE A 5/8 HOLE DRILLED THRU THESE PINS. THIS IS A GOOD WAY TO TELL A 340 FROM THE 273 & 318 CRANKS. THIS WAS DONE, DUE TO THE 340 ROD IS HEAVIER.
3404spdvaliant
Banned
I've never broke a 340 crank even at 8500-9000rpm at cajon spd way, so to be concerned about the the way they lightened it is for me ridiculous.
And to just go by what you said means that 318-3 story is well...........
Good luck.
And to just go by what you said means that 318-3 story is well...........
Good luck.
mikedevore
Well-Known Member
I Have Never Broke One In The Rod Pin Areas. I Have Broke One In Half, Just Behind The Thrust Bearing. This Was In A Street & Strip Engine, That I Shifted @ 6800 Rpms. It Ripped The Back Two Mains Out Of The Block, What A Mess! However, The Front Four Cylinders Were Still Running Until I Shut It Off. They Did See 8500 Rpm, Per My Tattle Tale Tach.
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