to stroke or not to stroke...that is the question
05-27-2008, 09:11 PM
#11
4th Gear Member
Join Date: Sep 2006
Location: 1984
Posts: 1,188
RE: to stroke or not to stroke...that is the question
You guys are way too sensitve. It's all good.
A shorter stroke means the piston travel per revolution is less. Therefore, all things being equal quality (crank, rods, pistons, etc.) the shorter stroke engine will produce more rpms for any achievable piston speed. And do it faster. But don't confuse that with power. It's a balancing act, and many engines are more powerful, but nothing revs like a Ford 289.
My ears told me this 40 years ago when I first heard one really wind out.
A shorter stroke means the piston travel per revolution is less. Therefore, all things being equal quality (crank, rods, pistons, etc.) the shorter stroke engine will produce more rpms for any achievable piston speed. And do it faster. But don't confuse that with power. It's a balancing act, and many engines are more powerful, but nothing revs like a Ford 289.
My ears told me this 40 years ago when I first heard one really wind out.
05-27-2008, 10:48 PM
#16
2nd Gear Member
Join Date: Dec 2006
Location:
Posts: 298
RE: to stroke or not to stroke...that is the question
331's have less trouble. The 347 has oil control ring issues.
IMO I would not want the 347 but would not hesitate to go with the 331. It is true the shorter the stroke the faster the motor will rev but it will not have as much torque. Longer stroke = More torque and slower rev. The torque is what slams your a$$ in the seat and does not let you lean forward until you hit 100 or so. Add a turbocharger to a 331 and you get the best of both worlds. Torque and Horsepower. A 331 will take a little longer to hit top RPM but you will get a lot more off of the line than a 302. A 331 will launch harder plus you can advance the timing further due to the decreased dwell time. The piston spend less time at the top of the cylinder which is ideal for turbo chargers and superchargers.
IMO I would not want the 347 but would not hesitate to go with the 331. It is true the shorter the stroke the faster the motor will rev but it will not have as much torque. Longer stroke = More torque and slower rev. The torque is what slams your a$$ in the seat and does not let you lean forward until you hit 100 or so. Add a turbocharger to a 331 and you get the best of both worlds. Torque and Horsepower. A 331 will take a little longer to hit top RPM but you will get a lot more off of the line than a 302. A 331 will launch harder plus you can advance the timing further due to the decreased dwell time. The piston spend less time at the top of the cylinder which is ideal for turbo chargers and superchargers.
05-27-2008, 11:08 PM
#17
3rd Gear Member
Join Date: Mar 2008
Posts: 755
RE: to stroke or not to stroke...that is the question
ORIGINAL: kilgorq
331's have less trouble. The 347 has oil control ring issues.
IMO I would not want the 347 but would not hesitate to go with the 331. It is true the shorter the stroke the faster the motor will rev but it will not have as much torque. Longer stroke = More torque and slower rev. The torque is what slams your a$$ in the seat and does not let you lean forward until you hit 100 or so. Add a turbocharger to a 331 and you get the best of both worlds. Torque and Horsepower. A 331 will take a little longer to hit top RPM but you will get a lot more off of the line than a 302. A 331 will launch harder plus you can advance the timing further due to the decreased dwell time. The piston spend less time at the top of the cylinder which is ideal for turbo chargers and superchargers.
331's have less trouble. The 347 has oil control ring issues.
IMO I would not want the 347 but would not hesitate to go with the 331. It is true the shorter the stroke the faster the motor will rev but it will not have as much torque. Longer stroke = More torque and slower rev. The torque is what slams your a$$ in the seat and does not let you lean forward until you hit 100 or so. Add a turbocharger to a 331 and you get the best of both worlds. Torque and Horsepower. A 331 will take a little longer to hit top RPM but you will get a lot more off of the line than a 302. A 331 will launch harder plus you can advance the timing further due to the decreased dwell time. The piston spend less time at the top of the cylinder which is ideal for turbo chargers and superchargers.
05-27-2008, 11:26 PM
#19
6th Gear Member
Join Date: Apr 2007
Location: California
Posts: 10,468
RE: to stroke or not to stroke...that is the question
Oil control issues.
My Mahle's have the pin intersecting the ring land and I have 0 oil control issues. And you're better off on a blown app with lower piston speed at TDC(more piston dwell, the piston spending MORE time at TDC) since it promotes more effective combustion and reduces timing requirements, thereby reducing detonation, so you can run less total timing with something like a turbo and still have an ideal tune without having to retard timing to avoid detonation issues.
My Mahle's have the pin intersecting the ring land and I have 0 oil control issues. And you're better off on a blown app with lower piston speed at TDC(more piston dwell, the piston spending MORE time at TDC) since it promotes more effective combustion and reduces timing requirements, thereby reducing detonation, so you can run less total timing with something like a turbo and still have an ideal tune without having to retard timing to avoid detonation issues.