Has anyone taken apart the Mazda 3 engine and noticed if it was at all possible to increase the bore on the engine. If so how much do you think we could bore the cylinders?
*Angel-Of-Darknes*
well i bought the 2.0 for a reason. and the reason is as follows. they 2.3 has a long stroke and 2.0 has a short one. so in theory i was going to increase the bore on my car and increase the 10:1 compression up to 11. or increase the bore ;pwer the compression ratio then throw on a turbo and have a sickening fast 3. short stroke big bore and turbo = fastness. And yes i plan on doing it but not for another year untill the warrenty is up.
As long as you get a reputable engine builder with experience overboring blocks then it's definitely do able. It will probably run you about 2-3k for the machining and parts to assemble the bottom end the way you want it. Remember with any piston changes you will need a new ECU. The stock ecu will not be able to adjust for higher compression pistons or overbored parts either.
Total cost if you can't do any of the work is probably prohibitively expensive... Probably cheaper to hiboost it.
-fish
Total cost if you can't do any of the work is probably prohibitively expensive... Probably cheaper to hiboost it.
-fish
In my opnion i wouldnt buy hi boost. IF anything i would have my own custom built turbo kit. would cost me the same anyways. and yes i know we would need a new ecu i see progress in that market finally so that makes what im talking about possible. and yeah boring out your cylinder is expensive. but after wards you would have an engine that could withstand some serious punishment. You would need new valve springs, pistons and all the rings for them you would need new rods, and valves, new ecu, you would prolly want new cams and a new crankshaft also. but yeah after all that good stuff your allready in about the 4k range.
Never looked in an MZR engine, but most cylinder liners can manage a 1.5mm over bore with seriously compromising the integraty of the liners. With a turbo I would want to step the over bore down by at least .5mm.
In the end a tenth or two of a liter is not going to matter much when it comes to your power output if you are going turbo. If you are going turbo then it wouldn't hurt to say get lower compression +.5mm pistons and a slight overbore...but I don't see much value in doing more then that unless you have serious money to burn.
By the way, your logic on short stroke being benificial for a turbo motor is not correct. A short stroke is good for producing high RPM power...so raising the RPM limits of the motor is a good reason to want a short stroke (and actually it is the rod ratio, not the stroke that matters...though the 2.0 does have a much better rod ratio then the 2.3).
Look at one thing though, the 2.3 still produces more power then the 2.0 and a lot more torque. The 2.3 at similar boost levels is GOING to produce more HP and more torque with somewhat less boost lag then the 2.0 can manage unless you are thinking of raising the operating engine speed of the motor by another 500+ rpms.
There would probably be a bit of a longevity bonus to the better rod ratios and shorter stroke of the 2.0 motor as it would produce much lower cylinder sidewall pressures and rod pressures with cramming in a lot of fuel and air into the cylinders.
-Matt
*EDIT* all that extra cylinder pressure is part of the reason why you don't want to go to thin on the cylinder bores, you are more likely to bust into a coolant path if you detonate with all that extra pressure and fuel and air. The gains in power from a much larger bore just aren't worth it on a turbo motor without money to burn. turning up the boost another 1-2 psi is probably going to gain you as much as boring the cylinders out 1-1.5mm and would be safer then boring out the cylinder liners that far.
In the end a tenth or two of a liter is not going to matter much when it comes to your power output if you are going turbo. If you are going turbo then it wouldn't hurt to say get lower compression +.5mm pistons and a slight overbore...but I don't see much value in doing more then that unless you have serious money to burn.
By the way, your logic on short stroke being benificial for a turbo motor is not correct. A short stroke is good for producing high RPM power...so raising the RPM limits of the motor is a good reason to want a short stroke (and actually it is the rod ratio, not the stroke that matters...though the 2.0 does have a much better rod ratio then the 2.3).
Look at one thing though, the 2.3 still produces more power then the 2.0 and a lot more torque. The 2.3 at similar boost levels is GOING to produce more HP and more torque with somewhat less boost lag then the 2.0 can manage unless you are thinking of raising the operating engine speed of the motor by another 500+ rpms.
There would probably be a bit of a longevity bonus to the better rod ratios and shorter stroke of the 2.0 motor as it would produce much lower cylinder sidewall pressures and rod pressures with cramming in a lot of fuel and air into the cylinders.
-Matt
*EDIT* all that extra cylinder pressure is part of the reason why you don't want to go to thin on the cylinder bores, you are more likely to bust into a coolant path if you detonate with all that extra pressure and fuel and air. The gains in power from a much larger bore just aren't worth it on a turbo motor without money to burn. turning up the boost another 1-2 psi is probably going to gain you as much as boring the cylinders out 1-1.5mm and would be safer then boring out the cylinder liners that far.
[quote author=azazel1024 link=topic=54714.msg901589#msg901589 date=1156171304]
By the way, your logic on short stroke being benificial for a turbo motor is not correct. A short stroke is good for producing high RPM power...so raising the RPM limits of the motor is a good reason to want a short stroke (and actually it is the rod ratio, not the stroke that matters...though the 2.0 does have a much better rod ratio then the 2.3).[/quote]
That sounds absolutley true, doesnt the Audi/VW 1.8T have a huge stroke? People have gotten that up to 360-380 hp with larger turbo/intercooler etc...
By the way, your logic on short stroke being benificial for a turbo motor is not correct. A short stroke is good for producing high RPM power...so raising the RPM limits of the motor is a good reason to want a short stroke (and actually it is the rod ratio, not the stroke that matters...though the 2.0 does have a much better rod ratio then the 2.3).[/quote]
That sounds absolutley true, doesnt the Audi/VW 1.8T have a huge stroke? People have gotten that up to 360-380 hp with larger turbo/intercooler etc...
what im after is a high compression 3 with more rpms 7000 or 7500. i know everything u said is true, thats why i wanted to get cams that would allow me to run at higher rpms. a short rod has a long stroke and a long rod has a very short stroke 
the only reason the 2.3 produces more power is becuase of the short rod which allows more air and fuel to be mixed in the cylinder chamber. I dont really care to turbo the 3 honestly just do like i said previously and get some extra power out of the car thats all.
the only reason the 2.3 produces more power is becuase of the short rod which allows more air and fuel to be mixed in the cylinder chamber. I dont really care to turbo the 3 honestly just do like i said previously and get some extra power out of the car thats all.correct me if I'm wrong, but aren't the 2.0 and 2.3 the same bore (and same cylinder castings) anyways, just the 2.3 has the longer stroke?
http://en.wikipedia.org/wiki/Mazda_MZR_engine
http://en.wikipedia.org/wiki/Mazda_MZR_engine
[quote author=rubyred3 link=topic=54714.msg901884#msg901884 date=1156178681]
correct me if I'm wrong, but aren't the 2.0 and 2.3 the same bore (and same cylinder castings) anyways, just the 2.3 has the longer stroke?
http://en.wikipedia.org/wiki/Mazda_MZR_engine
[/quote]
+1. You are correct.
correct me if I'm wrong, but aren't the 2.0 and 2.3 the same bore (and same cylinder castings) anyways, just the 2.3 has the longer stroke?
http://en.wikipedia.org/wiki/Mazda_MZR_engine
[/quote]
+1. You are correct.
hey hey hey, and 05's. Don't be shorting us 05's with the S-VT (it is actually Sequential-Valve Timing, not VV-T on the Mazdas).
Generally you are right that short stroke engines have long rods and long stroke engines have short rods, but that is not always the case. Some engine from the factory have short blocks as opposed to tall blocks (in regards to the height, not the length is is normally the case when you are refering to short or long blocks). Some engines are designed so that even with a very short stroke (generally having a shorter stroke then bore is considered a short stroke motor) they also have very short rods. Others have very long rods with long strokes as well...of course these blocks also tend to be very tall.
A long stroke and short rod is going to be very benificial to producing torque low down, but it is going to suck for high engine speeds. The MZR motor seems to be built such that it produces very good high rpm power. The lengthening of the stroke (and shortening of the rods) in the 2.3 adds the benifit of a fair bit more torque low down...but it does not pan out in the upper rpms that way. It produces some extra power, but only a little bit.
The 2.3 produces 156hp in the revised SAE system, the 2.0 motor produces 148hp in the revised SAE system. That means that by lengthening the stroke they gained 5.4% more power. The motors produce the same torque as before, or 150lb-ft and 135lb-ft so the gain in torque was 11.1% more torque. You can see just how benificial to torque it is by adding a longer stroke and the fact that it is not that benificial to upper RPM engine breathing and production of power. Something else to keep in mind going from 2.0 to 2.3L (actually it is about 2.25L, they round up) is an increase of 12.5-13%...you can find the difference in torque by taking into account that they added balance shafts that eat up 2-3lb-ft of torque...which is enough to about bump the increase in torque up to 13% if the balance shafts were not there.
Anyway, back to boring. I think you could get the motor to 2.1L by boring the stock liners, but I doubt you could get it higher then that...at least not much. If you are going NA then I highly suggest you do this. If you are getting custom forged pistons anyway it is no cost increase there and you are going to need to get the cylinders honed anyway for the new pistons and rings, it is a small cost increament to get the cylinders bored out at the same time as being honed. Maybe an extra 100-200 all around to increase the bore if you are adding new higher compression pistons.
-Matt
Generally you are right that short stroke engines have long rods and long stroke engines have short rods, but that is not always the case. Some engine from the factory have short blocks as opposed to tall blocks (in regards to the height, not the length is is normally the case when you are refering to short or long blocks). Some engines are designed so that even with a very short stroke (generally having a shorter stroke then bore is considered a short stroke motor) they also have very short rods. Others have very long rods with long strokes as well...of course these blocks also tend to be very tall.
A long stroke and short rod is going to be very benificial to producing torque low down, but it is going to suck for high engine speeds. The MZR motor seems to be built such that it produces very good high rpm power. The lengthening of the stroke (and shortening of the rods) in the 2.3 adds the benifit of a fair bit more torque low down...but it does not pan out in the upper rpms that way. It produces some extra power, but only a little bit.
The 2.3 produces 156hp in the revised SAE system, the 2.0 motor produces 148hp in the revised SAE system. That means that by lengthening the stroke they gained 5.4% more power. The motors produce the same torque as before, or 150lb-ft and 135lb-ft so the gain in torque was 11.1% more torque. You can see just how benificial to torque it is by adding a longer stroke and the fact that it is not that benificial to upper RPM engine breathing and production of power. Something else to keep in mind going from 2.0 to 2.3L (actually it is about 2.25L, they round up) is an increase of 12.5-13%...you can find the difference in torque by taking into account that they added balance shafts that eat up 2-3lb-ft of torque...which is enough to about bump the increase in torque up to 13% if the balance shafts were not there.
Anyway, back to boring. I think you could get the motor to 2.1L by boring the stock liners, but I doubt you could get it higher then that...at least not much. If you are going NA then I highly suggest you do this. If you are getting custom forged pistons anyway it is no cost increase there and you are going to need to get the cylinders honed anyway for the new pistons and rings, it is a small cost increament to get the cylinders bored out at the same time as being honed. Maybe an extra 100-200 all around to increase the bore if you are adding new higher compression pistons.
-Matt
worth noting though, any increase in bore that the 2.0 could achieve could be physically achieved in the 2.3 as well, whether or not its a good idea is another question though, b/c as another member pointed out, the side loads on the cylinder walls in the 2.3 are greater than those in the 2.0. Either way its a bad idea in a turbo app due to higher cylinder pressures. For NA, its probably a good idea for the 2.0, probably not in the 2.3 (its got a pretty long stroke). How long are the rods on the MZR, anyone know?
I doubt you will get that much out of it without custom liners and possibly custom block. Most engines can tolerate around 1.5-2mm of over bore before the cylinder wall thickness is getting dangerously low. a 2mm over bore equates to 89.5mm and gets about a 2.1L (2091cc) displacement on the 2.0l engines. Doing the same on the 2.3l motors will net about a 2.4l motor (2365cc, up from around 2261cc for stock displacement for the 2.3L motor).
You really can't increase displacement all that much with boring unless you are getting a custom block, custom liners, or both. My suggestion is getting either a 1 or a 1.5mm over bore when getting high compression pistons. I don't know that anyone has attempt to push the limits of what the cylinder liners can handle, and I doubt you want to be the first one to find out the hard way that they can't tolerate a 3mm over bore or even a 2mm over bore. I suggest 1.5mm over bore on the 2.0l motor and 1mm over bore on the 2.3l motor. It won't do a hell of a lot, but on both motors it should be enough to tack on about 2-3% more power and torque. Not a lot, but just a bit extra and always good when you are all motor.
-Matt
PS by the way as I mentioned custom block and new liners or sleeving the motor can accomplish the same thing, fairly large over bore, however both are VERY expensive. Custom block and liners gives you effectively an unlimited displacement on the over bore...because well it is custom. Sleeving a motor can net you more then you can get on stock liners (also known as sleeves), but not that much more, maybe double the over bore. Which going by that means you MIGHT be able to get a 2.2L displacement out of the 2.0L engine, 2.3L if you are lucky and the block design allows for it. You are also probably talking 2-3 grand for custom sleeves plus re-sleeving the motor (or more).
You really can't increase displacement all that much with boring unless you are getting a custom block, custom liners, or both. My suggestion is getting either a 1 or a 1.5mm over bore when getting high compression pistons. I don't know that anyone has attempt to push the limits of what the cylinder liners can handle, and I doubt you want to be the first one to find out the hard way that they can't tolerate a 3mm over bore or even a 2mm over bore. I suggest 1.5mm over bore on the 2.0l motor and 1mm over bore on the 2.3l motor. It won't do a hell of a lot, but on both motors it should be enough to tack on about 2-3% more power and torque. Not a lot, but just a bit extra and always good when you are all motor.
-Matt
PS by the way as I mentioned custom block and new liners or sleeving the motor can accomplish the same thing, fairly large over bore, however both are VERY expensive. Custom block and liners gives you effectively an unlimited displacement on the over bore...because well it is custom. Sleeving a motor can net you more then you can get on stock liners (also known as sleeves), but not that much more, maybe double the over bore. Which going by that means you MIGHT be able to get a 2.2L displacement out of the 2.0L engine, 2.3L if you are lucky and the block design allows for it. You are also probably talking 2-3 grand for custom sleeves plus re-sleeving the motor (or more).
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