While not pertaining to performance I would argue a con for a stroker set-up is cost! you could use the $2-3k that you would use to buy the kit and have the block machined and invest in a turbo set-up and megasquirt EMS and have more horsepower/tq for your money. sorry that might be off subject but cost should be factured in.

BigNugg99 said:

While not pertaining to performance I would argue a con for a stroker set-up is cost! you could use the $2-3k that you would use to buy the kit and have the block machined and invest in a turbo set-up and megasquirt EMS and have more horsepower/tq for your money. sorry that might be off subject but cost should be factured in.

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That's only if you compare not rebuilding the stock engine to going stroker. If you compare going stroker to a built 2.0, then it's not nearly as big of difference on how much it costs.

Going stroker all depends on what you want to do with the car. I plan on stroking mine, and the reason being is that I want a bit more oohmph in my DD, better spool, and something thats going to be down right evil at autocross events. Seeing as how stroking it allows me to spool a bigger turbo in the same or less time that it would take me to spool a smaller turbo on a 2.0 block, this fits my desires.

Noted the point and i agree. with cost aside i would then argue that nearly every aspect of the disadvantages of a stroker motor build over non stroker motor can be overcome by quality parts and a great quality tune but you cannot gain the advantages of a stroker motor from a non stroker motor thus going back to the saying "No replacement for dsplacement"

Seeing as how stroking it allows me to spool a bigger turbo in the same or less time that it would take me to spool a smaller turbo on a 2.0 block, this fits my desires.

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Yea but so would going to a higher compression 2.0 build and with the extra rpm available to the 2.0 you can take advantage of the power band also.

Short but sweet. Strokers gain 3-500 rpm's of spool, to lose 1000 rpms of powerband up top. I'll take the wider powerband. Who cares if it's higher up in the rev range? That's what the little shifter thingy is for.

With a properly build stroker motor tuned right it can reach the same rpm than a 2.0 non stroker motor and can have a very wide power band thats nearly flat. given that money isnt a factor and you have resources to a top notch machine shop its in MHO that a stroker motor with more displacement will outperforme a non stroker motor in all aspects because of the displacement aspect. a perfectly tuned 2.3l vs equallually efficient p 2.0 motor ... the more displacement lends its self to more to make power with.

Personally I will never build a stroker. Keep it simple forged 2.0 and be done with it.

dsm_ftw said:

So I have read several articles and debates on whether or not to stroke an engine. Most of the arguements seem to be based on the breathability of the stroker engines. I want to create a list of pros and cons between the 2.0 and the stroked 2.3.

2.3L Stroker Pros
1. More Displacement. Almost 18% more displacement.
2. More low/mid range torque.
3. More tolerant of aggressive cams.
4. Faster spool up.
5. Higher effective compression ratio.
6. More tolerant of timing advance and lower octane fuel.

2.3L Stroker Cons
1. Higher native harmonic imbalance.
2. More sensitive to engine balance.
3. Lower RPM potential from higher piston friction from side loading and velocity.
4. Higher tension loads on rods, both in tension and bending.
5. Volumetric Efficiency drops off at lower RPM’s than 2.0L

If there is anything else you can think of please list them.

Sources:

http://www.kidzuku.com/StrokeOrNot.pdf
and TunaTalon for giving me the link.
The PDF has a whole list of sources to back this information and instead of listing those I decided to link the PDF.

Click to expand...

The argument is actually regarding strength... strokers like to break cranks, which was solved with the intro of stroker cranks, but they still seem to break, and even if they don't the cost of building a stroker can be better spent elsewhere... it all depends on what you want to do.... if you have a limitless budget then go for it!

3kgt2nv said:

Yea but so would going to a higher compression 2.0 build and with the extra rpm available to the 2.0 you can take advantage of the power band also.

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Not really true. Higher compression will give better throttle response, but negligible spool gains.

BigNugg99 said:

With a properly build stroker motor tuned right it can reach the same rpm than a 2.0 non stroker motor and can have a very wide power band thats nearly flat. given that money isnt a factor and you have resources to a top notch machine shop its in MHO that a stroker motor with more displacement will outperforme a non stroker motor in all aspects because of the displacement aspect. a perfectly tuned 2.3l vs equallually efficient p 2.0 motor ... the more displacement lends its self to more to make power with.

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Please explain how a 1.5/1 rod ratio can rev as high as a 1.7/1. Also, if you care, explain how the higher displacement cylinder can fill at high rpms and not lose ve, through the same head as the 2.0, with the higher piston speeds a stroker has.

Finally, the fastest 4g63, and fastest awd dsm both use a 2.0. Why aren't the stroker cars putting up more big numbers than the 2.0's?

donniekak said:

Please explain how a 1.5/1 rod ratio can rev as high as a 1.7/1. Also, if you care, explain how the higher displacement cylinder can fill at high rpms and not lose ve, through the same head as the 2.0, with the higher piston speeds a stroker has.

Finally, the fastest 4g63, and fastest awd dsm both use a 2.0. Why aren't the stroker cars putting up more big numbers than the 2.0's?

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Im not arguing for one side or the other as I have a built 2.0 in my 1g and a long rod 2.4 for my 2g. But maybe the reason for the last part of your statement has to do with how long people have been building the 2.0 motors. Sure stroker kits have been around for a long time, but not many have taken that route... and with costs what they, are I can't say I blame them. My magnus 2.4 kit cost over 3k for pistons, rods and crank! But then again I am talking about a 2.4 4g64 not a 2.3 4g63. If my memory serves me correctly, the fastest time at shootout last year was maperformance's FDSM (8.1x)and I belive it has a 2.4l according to their website. So what I am trying to say is maybe we will see faster times out of the higher displacement options over the next few years as more people try to push them. Just trying to add some things to think about, but I would love to hear more from people who actually have 2.3l setups.

You pay your money and pick your poison.

I stroked my Talon because it's a DD and I spend way more seat time in traffic than at WOT.

Not only stroked, the Talon had all decisions made in favor of low/mid range torque. Telling me that I could have made more power at high RPM is not new information.

If your desire is more top end power then build up the 2.0. If you want to drive in traffic like a V8 and still have the DSM kick while on full boil then stroke it.

The last bit of StrokeOrNot.pdf give the reason for my decision.
1. Hmmm torque good.
2. Me stroke Talon.
3. Make tires happy.

Your mileage may vary.

donniekak said:

Please explain how a 1.5/1 rod ratio can rev as high as a 1.7/1. Also, if you care, explain how the higher displacement cylinder can fill at high rpms and not lose ve, through the same head as the 2.0, with the higher piston speeds a stroker has.

Finally, the fastest 4g63, and fastest awd dsm both use a 2.0. Why aren't the stroker cars putting up more big numbers than the 2.0's?

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correct. It is this same principle that makes F1 engines do what they do. a stroker engine is not going to be able to rev as high.

Secondly, since you can rev much higher, hp can be higher as hp is just an equation based on work done over time. Higher rpm range with a flat tq curve that, a proper turbo can provide will yield more hp because, the rpms are higher as in f1 engines.

a stroker is no match for a screamer in the FI world. Only a change in fuel will help the stroker as they do in topfuel racing. (Keep in mind that Nitro destroys the engine after every run)

I would like to make it clear that i am still on the path of abundant knowledge and havent personally built a stroker motor but its my thinking that if you set a car up for a stroker and take advantage of the low/mid hp and tq you would be able to obtain more perforfance from more displacement. you would also build the he to suit the bottom end. with theadvances in mettals and hardening processes along with thrigt tunig and setup i would believe that more displacement would allow for more perfomance given the right set up. i could very well be wrong though!

you can rev the hell out of a stroker with good parts, but it just isn't going to rev as high as a 2.0. I really don't like 2.0s and Ill never build one on any of my street cars ever again, but their awsome race motors and very good motors for the street. I'd rather have the faster spool and extra torque on the street since I have a street car. Id take mine up to 8500 or so all day long.

I really didnt expect this kind of turn out when I started this thread. So to sum up what I have read so far, strokers are less reliable long run, but makes more power with less money up front. Where as the 2.0 takes more money to make the power it is capable of? Or it could be the other way around depending on what your basis of money is in the argument. Im so lost.

I will make it simple. It is all about area under the curve. There is no way you can remotely rev a stroker engine as high as you can an non-stroked engine.

Area under the curve is like calculus.

When you have more rpms to use, you can get more power with less torqe as long as the torque is constant.

Example. It only takes 233 lbs of torque to achieve 798 hp at 18000 rpms. As torque stays linear, hp goes up. This is the reason you get 800 hp from an f1 engine. Those are 3L v10s with very little stroke. The reason they can achieve this is due to very light parts and strict tolerances. Their efficiency range is broad as power builds fairly quickly due to gearing. The reason you dont see stroked engines in that kind of racing is the very reason why short stroked engine works well. It can breath well at high rpms as a stroked engine cannot do this.

In the case of the 2.0L vs the 2.3L there are very many variables that have not been addressed. The bottom line is, if you rev both to the same rpm, the stroker is going to be less efficient and have less hp up top due to this and other factors that I am not going to list right now. That being said, the stroker will get off the line faster (again assuming everything equal like turbo and other factors) but will fall off on top end cause it cannot efficiently breathe. The 2L will get off the line a little slower but, will maintain power up top do to being more efficient at higher rpms and can maintain torque and wont be starving for air.

Keep in mind this is assuming many constants. Piston speed affects top end power. Example, shake your fist up and down about 1 inch. Now try 2 inches and maintain it.

Just physics alone tells you that the engine is working harder to overcome inertia of the piston's weight and requires more work to change direction of the piston itself.

Yes there is more but, dont want to type a book here.

It really comes down to what you want. Feel the tq, stroke it, feel the hp, dont stroke it. It is not going to be all that different unless you have lots of time and money to play with, then you can nit pick.

cliffkemp said:

Keep in mind this is assuming many constants. Piston speed affects top end power. Example, shake your fist up and down about 1 inch. Now try 2 inches and maintain it.


It really comes down to what you want. Feel the tq, stroke it, feel the hp, dont stroke it. It is not going to be all that different unless you have lots of time and money to play with, then you can nit pick.

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LOVE IT! Thanks for the help.

The discussion of advantages of 2.0L and 2.3L is relevant only while on the ranch of normal driving. How do want your own car to feel on the street.

Get off of the ranch and throw big bucks into the engine to get maximum power and the length of the stroke is pretty much irrelevant. Both versions of the 4G63 have the same 4G63 heads capable of the same air flow through the same valves.

When air flow through the valves approachs mach 1 no more air can get through. No more air for long strokes, no more air for short strokes. There will be some difference because high rod ratios are more efficient at converting cylinder pressure to torque at the bottom of the stroke and low rod ratios are more efficient at the top of the stroke.

The 2.3L will reach sonic flow at lower RPM and the 2.0 can rev freely to reach the same sonic flow wall at a higher RPM.

Of course there are many more technical details to throw cash at to get the last bit of HP our of an engine but the sonic flow through the valves is common to all engines and is not subject to nuance or being stretched by hundred dollar bills rolled up tightly and stuffed into the weak places.

TunaTalon said:

The discussion of advantages of 2.0L and 2.3L is relevant only while on the ranch of normal driving. How do want your own car to feel on the street.

Get off of the ranch and throw big bucks into the engine to get maximum power and the length of the stroke is pretty much irrelevant. Both versions of the 4G63 have the same 4G63 heads capable of the same air flow through the same valves.

When air flow through the valves approachs mach 1 no more air can get through. No more air for long strokes, no more air for short strokes. There will be some difference because high rod ratios are more efficient at converting cylinder pressure to torque at the bottom of the stroke and low rod ratios are more efficient at the top of the stroke.

The 2.3L will reach sonic flow at lower RPM and the 2.0 can rev freely to reach the same sonic flow wall at a higher RPM.

Of course there are many more technical details to throw cash at to get the last bit of HP our of an engine but the sonic flow through the valves is common to all engines and is not subject to nuance or being stretched by hundred dollar bills rolled up tightly and stuffed into the weak places.

Click to expand...

my point is, no matter flow, a stroked engine is going to lose power up top due to rotational forces being greater. It will be more efficient at lower rpms and have more tq but less hp up top due to rotational forces at higher rpms.

Example is a diesel vs gas. The diesel can only rev to about 5500 due to stress at higher rpms. (poor example due to different fuel but concept on stress and inertia to overcome as piston tops and bottoms out is the same)

A better example would be older cars vs newer cars. In the early 80s, most engines were 'stroked' compared to what they are today (changing rapidly, I know with better metal and tuning) To get better mpg, they simpley lowered the operating range of the engine by having a longer stroke. This gave good low power and less hp as torque decreased rapidly as rpms went up.

It still comes down to what you want. There is always a give and take.

dsm_ftw said:

So I have read several articles and debates on whether or not to stroke an engine. Most of the arguements seem to be based on the breathability of the stroker engines. I want to create a list of pros and cons between the 2.0 and the stroked 2.3.

2.3L Stroker Pros
1. More Displacement. Almost 18% more displacement.
2. More low/mid range torque.
3. More tolerant of aggressive cams.
4. Faster spool up.
5. Higher effective compression ratio.
6. More tolerant of timing advance and lower octane fuel.

2.3L Stroker Cons
1. Higher native harmonic imbalance.
2. More sensitive to engine balance.
3. Lower RPM potential from higher piston friction from side loading and velocity.
4. Higher tension loads on rods, both in tension and bending.
5. Volumetric Efficiency drops off at lower RPM's than 2.0L

If there is anything else you can think of please list them.

Sources:

http://www.kidzuku.com/StrokeOrNot.pdf
and TunaTalon for giving me the link.
The PDF has a whole list of sources to back this information and instead of listing those I decided to link the PDF.

Click to expand...

#6 on the pros:

Being tolerant of lower octane fuels has to do with compression ratio and not stroke itself. You can have a stroked engine and low compression to help with tuning issues associated with effective compression. This pro is a tuning issue and not relavent to what the stroke is unless the stroke change will change compression. Compression can be changed by simply changing the pistons and not necessarily the crank. It depends on the set up really.

There are a lot of things that are assumed and this topic could be nit picked all day long.

i am buying a 2.3 from a friend and i love it. yes i need to buy a balance plate to see if it changes anything

cliffkemp said:

my point is, no matter flow, a stroked engine is going to lose power up top due to rotational forces being greater. It will be more efficient at lower rpms and have more tq but less hp up top due to rotational forces at higher rpms. .

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It's really the reciprocating forces that are greater on a stroker, not the rotational forces. In any event the greater stress on components don't cause a loss of power. Until they break, then there's a lot less power.

It still comes down to what you want. There is always a give and take.

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Yep, yep, right you are.

#6 on the pros:

Being tolerant of lower octane fuels has to do with compression ratio and not stroke itself. You can have a stroked engine and low compression to help with tuning issues associated with effective compression. This pro is a tuning issue and not relavent to what the stroke is unless the stroke change will change compression. Compression can be changed by simply changing the pistons and not necessarily the crank. It depends on the set up really.

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The stroker's tolerance of lower octane fuel is due to the different velocity profile of a lower rod ratio engine. With the lower rod ratio of the 2.3L the piston is farther down from TDC and already moving faster than for a stock 2.0L at the same crank angle. With the piston farther down and moving faster, detonation is less likely.

There are a lot of things that are assumed and this topic could be nit picked all day long.

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Yep, yep, right you are.

Another thing to think about, is a stroker is harder on a tranny to take due to the higher torque if im not correct???

TunaTalon said:

When air flow through the valves approachs mach 1 no more air can get through. No more air for long strokes, no more air for short strokes. There will be some difference because high rod ratios are more efficient at converting cylinder pressure to torque at the bottom of the stroke and low rod ratios are more efficient at the top of the stroke.

Click to expand...

This is one of the main reasons to choose a 2.0. The piston speeds around tdc, and bdc, are much higher in a longer stroke engine. The gives less actual time for the air to flow in to the cylinder through the ports. This requires a higher air speed to flow the same amount of air. The amount of air you can get through the same head is higher in a 2.0. The 2.0 piston speed is lower at tdc than the stroker. This longer dwell time gives the port more time to flow the same amount of air.

What this all boils down to, is the mach limit is reached at less flow on a stroker than a 2.0.