Stroking vs De-stroking
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Big Pat
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Smaller stroke engine, as a general rule, will be able to rev higher than those with longer strokes.
Longer stroke engines, as a general rule, will not rev as fast, but will tend to generate more torque vs a short stroke engine of the same design.
And any change of the stroke will require either a new crankshaft, or extensive machining of your current one. Neither option is particularly cheap, and both will probably require you to change your rods, which also means more $$$.
Longer stroke engines, as a general rule, will not rev as fast, but will tend to generate more torque vs a short stroke engine of the same design.
And any change of the stroke will require either a new crankshaft, or extensive machining of your current one. Neither option is particularly cheap, and both will probably require you to change your rods, which also means more $$$.
BlueDSM
Legacy Member
Longer stroke = more torque/less rpm potential.
Short stroke = more hp/more rpm potential.
Another problem with stroking is that if you use stock length rods, this will usually produce a bad rod/stroke ratio - which will affect the rate of acceleration in the rotating assembly and may also stress the rods more due to more severe angles. So an increase in rod length is better - and IMO is absolutely neccesary.
Theres also clearance problems with strokers, which requires griding and should not be done by someone inexperienced or untrained.
As said, neither is cheap unless you're running a small block Chevy V8.....
For street applications, torque is usually something that you will find more useful, and have more fun with
Short stroke = more hp/more rpm potential.
Another problem with stroking is that if you use stock length rods, this will usually produce a bad rod/stroke ratio - which will affect the rate of acceleration in the rotating assembly and may also stress the rods more due to more severe angles. So an increase in rod length is better - and IMO is absolutely neccesary.
Theres also clearance problems with strokers, which requires griding and should not be done by someone inexperienced or untrained.
As said, neither is cheap unless you're running a small block Chevy V8.....
For street applications, torque is usually something that you will find more useful, and have more fun with
Big Pat
New member
I don't think the Cobalt engine was "de-stroked" to two liter, because originaly, it's a european engine. 2.4 liter 4 cylinders, is not something you see very often in Europe, so I do not think the Ecotec was designed with this displacement in mind.
I think it's the case of the engine being "stroked" to 2.4 rather than "de-stroked" to 2.0l to give the american version more low down torque, and I suspect to give it more punch in the marketing department (a 2.0l ecotec would have done the same job, but perception would have been "it went from 2.2 to 2.0, so it's cheaper/slower"). Marketing is one weird way of designing, but a very essential one.
As was said elsewhere on MR, the 2.0l in the SS is also very significantly different from the 2.4 in various areas (all internals a beefier, cylinder head is different etc. etc.). It was not just a matter of it being "de-stroked".
As for the H engine being destroked to race, I do not know the definite answer, but maybe it was deemed that it would be more reliable or have more potential than a stroked B-series for example (the K-series was not available at the time). Also, having a large bore on a race engine is critical, because it allows you to fit much larger valves.
Or perhaps the design of the combustion chamber on the H-series was more efficient? I'm no expert on Honda engines... Does the H-engine use rockers like the B-series? If not, than that is another advantage - less valve train mass.
I think it's the case of the engine being "stroked" to 2.4 rather than "de-stroked" to 2.0l to give the american version more low down torque, and I suspect to give it more punch in the marketing department (a 2.0l ecotec would have done the same job, but perception would have been "it went from 2.2 to 2.0, so it's cheaper/slower"). Marketing is one weird way of designing, but a very essential one.
As was said elsewhere on MR, the 2.0l in the SS is also very significantly different from the 2.4 in various areas (all internals a beefier, cylinder head is different etc. etc.). It was not just a matter of it being "de-stroked".
As for the H engine being destroked to race, I do not know the definite answer, but maybe it was deemed that it would be more reliable or have more potential than a stroked B-series for example (the K-series was not available at the time). Also, having a large bore on a race engine is critical, because it allows you to fit much larger valves.
Or perhaps the design of the combustion chamber on the H-series was more efficient? I'm no expert on Honda engines... Does the H-engine use rockers like the B-series? If not, than that is another advantage - less valve train mass.
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