Stroker Motor Silly Question
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Pro
Joined: Oct 2004
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Stroker Motor Silly Question
For the life of me I cant work out how a motor can be signifantly stroked without the pistons contacting the valves. Probably a really silly question, but what bits get changed when a motor is stroked?
Thanks!
Thanks!
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Crank is also different.
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From: The Top of Utah
Originally Posted by 89 Paul in Cal
...and the rods can be longer.
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Safety Car
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From: Salem NH
If you plan to use the stock pistons, the rods had better be shorter. How many people know that you can build a 383 with stock 350 pistons if you use the 400 rods? Conversely, you can build a 377 (4.155 bore X 3.48" stroke) using stock 400 pistons on the 350 rods.
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Safety Car
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From: Salem NH
That combination won't rev any higher than with a 5.7" rod. Granted, the rod angle is better.
The point was about what HAD to be changed. You could use 6.00" rods, 6.125" rods, or...??? If you are willing to change everything, the combinations are almost infinite.
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The point was about what HAD to be changed. You could use 6.00" rods, 6.125" rods, or...??? If you are willing to change everything, the combinations are almost infinite.
RACE ON!!!
When you think about it, a 383 is horrible for loading the cyl walls. Which is why most 383 cyls end up egged shape after time.
A 6" rod will do the same thing as a 5.850" rod on a 3.48 stroke, but the more you move the wrist pin up on the piston the less crown you have to take the heat.
But yes, this is off topic.
-- Joe
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From: The Top of Utah
Originally Posted by anesthes
You can also use 5.850" rods, stroker pistons, and a 3.48 stroke crank which improves rod angle, and revs high.
-- Joe
-- Joe
The point was about what HAD to be changed. I merely gave two examples of the reutilization of more parts than most. You could use 6.00" rods, 6.125" rods, or...??? If you are willing to change everything, the combinations are almost infinite.
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Race Director
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From: The Top of Utah
Originally Posted by anesthes
A 3.48 stroke with a 5.850" rod will rev "better" than a 5.7 rod 350,
Originally Posted by anesthes
When you think about it, a 383 is horrible for loading the cyl walls. Which is why most 383 cyls end up egged shape after time.
Originally Posted by anesthes
A 6" rod will do the same thing as a 5.850" rod on a 3.48 stroke,
Originally Posted by anesthes
But yes, this is off topic.
-- Joe
-- Joe
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From: Slidell Louisiana
I used 6" rods and 1.25" compression height pistons. The chosen pieces were stronger and lighter than the stock rods/pistons. To balance the assembly the machinist had to remove weight from the crank.
The lighter assembly should rev quicker and hold together at higher revs than a heavier assembly. So another benefit of longer rods is shorter/lighter pistons, however, a shorter piston has its drawbacks too. So choose wisely, and match all of your components to the desired usage. IE don't install a 3.875 stroke cast crank if you want a 10,000 rpm screamer and the inverse is just as bad don't build a 3" bore 1.5" stroke engine with a 245* cam and expect stump pulling torque at 800 rpm.
MIke
The lighter assembly should rev quicker and hold together at higher revs than a heavier assembly. So another benefit of longer rods is shorter/lighter pistons, however, a shorter piston has its drawbacks too. So choose wisely, and match all of your components to the desired usage. IE don't install a 3.875 stroke cast crank if you want a 10,000 rpm screamer and the inverse is just as bad don't build a 3" bore 1.5" stroke engine with a 245* cam and expect stump pulling torque at 800 rpm.
MIke
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From: Salem NH
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