Oh dear God! 318 stroker

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My original plan was a 4.025 bore and an offset 318 steel crank with 3.334 throw.
This gives exactly 340 cubes.

But why all the drama when you can just use a 360 to start with???
Bore it plus 60 thou and you have a 6 litre small-block...:BangHead:

371 cubes, or a 'stroker' crank to get 408...(+30)
 
Then there is the 360 100 thou overbore at 4.100.
Offset grind the 4.000 to 4.030 and 'hey presto' its 426!!!

Just got to find some 4.100 pistons lol:thumbsup:
 
polyjohn said:
If you read the famous 'Hinkles 426ci Poly build' they have sonic tested several 318LA blocks and...

They have the same liner wall thickness as a 340 block...:lol::thumbsup::drama:
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So,,,,,,,,,,, are you saying that,,,,,,,,,, If I wanted to bore a 318 from a 3.910" bore to a 4.000" should be a cake walk and the " lil " teen can handle it????
 
Cylinder wall thickness may be very similar. All LA engines are thin wall castings keeping weight down, but limits the amount the blocks can be overbored. 0.040" to 0.060" is considered maximum on most modern engine blocks of any manufacture. For a performance build with higher cylinder pressures, some are recommended 0.030" maximum.
The A block 315 and 318 CID Polyspherical engines were not thin wall and can be bored out more. By how much I do not know. The Poly engines were heavy thus the lack of the L that LA engines have. So it may be possible to bore an A engine out 0.125" oversize. Chev 283 early blocks could be safely bored that much to fit 327 pistons. They called this a 301 but bore and stroke are identical to the Z28 302 dimensions. Later blocks were thin wall and can not be bored over 0.060".
 
polyjohn said:
Then there is the 360 100 thou overbore at 4.100.
Offset grind the 4.000 to 4.030 and 'hey presto' its 426!!!

Just got to find some 4.100 pistons lol:thumbsup:
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Better be sonic checking the cylinder walls first. Could end up with a tin foil thickness in one spot that breaks at first start. Years ago my dad related he and his buddies bored a block to fit I think it was Cadillac pistons. That is what happened to them, got through cam breakin but blew first time the driver lailed the throttle in gear.
 
A safer plan is an overbore of 0.030" to 3.94" and an aftermarket 3.75" stroker crank, which gives 365.76 CID or 6l. The only way you punch holes in that is missing a shift and a rod airs out the block.
 
Shorty Thompson said:
So,,,,,,,,,,, are you saying that,,,,,,,,,, If I wanted to bore a 318 from a 3.910" bore to a 4.000" should be a cake walk and the " lil " teen can handle it????
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A lot of people say that they can, don't know if true but 60 thou is only 30 short of 4" and there's off the shelf pistons.
 
273 said:
A lot of people say that they can, don't know if true but 60 thou is only 30 short of 4" and there's off the shelf pistons.
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Poking a 'teen 0.090" over is pushing things in my mind. Piston availability is not the issue, metal in the cylinder walls is. These are not thinwall castings for no reason.
I would not do it!
 
Not a LA block for any reason. An A block with sonic test. These are not the same blocks. A blocks still used the thick wall casting.
 
Now that everyone's sounded off about that. Why not with Gleaner combine engines? Industrial use engines. Has anyone thought about these?
 
Shorty Thompson said:
Now that everyone's sounded off about that. Why not with Gleaner combine engines? Industrial use engines. Has anyone thought about these?
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The Yellow Fellows? Forgot about those having industrial 'teens in them. I do not know if they have thicker cylinder walls. Someone would have to get an industrial 'teen and sonic test the thickness.
What did ma Mopar do with the industrial slants, thicker cylinder walls for stability under prolonged high loads?
 
Dale Davies said:
The Yellow Fellows? Forgot about those having industrial 'teens in them. I do not know if they have thicker cylinder walls. Someone would have to get an industrial 'teen and sonic test the thickness.
What did ma Mopar do with the industrial slants, thicker cylinder walls for stability under prolonged high loads?
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Something to think about!
 
Dale Davies said:
Probably pretty worn by now. Might use the block with the rest from a car. Good chance the cranks could be forged steel. Ford 391 truck and industrial cranks are forged steel but the front is larger diameter for strength driving an air compressor.
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Couldn't imagine blocks being worn-out, considering they never seen anything over 2,100 rpms.
 
Shorty Thompson said:
Couldn't imagine blocks being worn-out, considering they never seen anything over 2,100 rpms.
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Built for low RPM torque for sure. What RPM they ran at I do not know. I would figure more like 2,500 RPM to 3,000 RPM. Then they ran at or close to wide open throttle and high load. Not many days of running in a year but long days when they did. By the time the combine was retired it was usually the threshing components that were really worn. But the engine rings and bearings would take a beating.
 
Dale Davies said:
Built for low RPM torque for sure. What RPM they ran at I do not know. I would figure more like 2,500 RPM to 3,000 RPM. Then they ran at or close to wide open throttle and high load. Not many days of running in a year but long days when they did. By the time the combine was retired it was usually the threshing components that were really worn. But the engine rings and bearings would take a beating.
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Could very well be, but I'd still like to know what it sonic tested at.
 
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