4G63 2.3 versus 4G64 Long-Rod 2.4
Evolving Member
Joined: Sep 2005
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From: Afghanistan
2.4L 4G64 can rev little higher, and has .1 liters more displacement but probably cannot take the amount of power a built 4G63 can handle (900 HP +)
2.3L 4G63 cannot rev as high, has less displacement, and is subject to increased piston side loading because of the crappy rod length/stroke ratio, however it can hold theoretically more power because of the thicker cylinder walls.
2.3L 4G63 cannot rev as high, has less displacement, and is subject to increased piston side loading because of the crappy rod length/stroke ratio, however it can hold theoretically more power because of the thicker cylinder walls.
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Joined: Oct 2005
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From: Scotland
I live down the street from JAM, and have spoken to them on many occasions. They are, without a doubt, one of the best (if not the best) 4G63/4G64 machine shop on the planet. They seem to recommend keeping the balance shafts with the 2.3L, they claim that if you remove them, you will make LESS power than if you kept them in. I think this might depend on how well the stroker assembly is balanced. Maybe there is some inherent balancing problem with the 4G64 stroker cranks from the factory, I am not sure. There really ISN'T any problem with keeping the balance shafts, if you install them right, they will not break. If you DO remove them, you WILL have oil pressure problems, which has been known to cause many failures.
As far as the 4G64 2.4L setup vs 2.3L 4G63 argument goes, I think the 2.4L 4G64 is a superior platform. Not only does it have more displacement (slightly better spoolup, better midrange power) but it has the ability to rev higher than the 2.3L. Although it does run the risk of cracking the thinner cylinder walls under high boost, this is rarely a problem for those who have chosen this type of engine. I think the trick is to be very careful when over boring at the machine shop. When you retrieve these blocks out of the junkyard, .020 is the maximum you will be able to go, and after that, the block is done. Most people who are interested in the 4G64 2.4L setup are not after stratospheric (900hp+), drivetrain shattering, dyno queen horsepower numbers anyways. They want a nice torquey, usable, fat midrange, 500-600hp road racing monstrousity that will spool up those laggy GT-series turbo's on a road course, and have plenty of rev's to do it with.
It should be noted that there also exists the fabled 2.1L 4G64 (destroker setup) that should not be dismissed as an option. With this type of setup, a 4G64 block (taller deck height) is used with a 4G63 crankshaft, to achieve an even better stroke/rod length ratio which allows a 10,000 rpm+ redline for drag racing or high rev'ing road course applications.
As far as the 4G64 2.4L setup vs 2.3L 4G63 argument goes, I think the 2.4L 4G64 is a superior platform. Not only does it have more displacement (slightly better spoolup, better midrange power) but it has the ability to rev higher than the 2.3L. Although it does run the risk of cracking the thinner cylinder walls under high boost, this is rarely a problem for those who have chosen this type of engine. I think the trick is to be very careful when over boring at the machine shop. When you retrieve these blocks out of the junkyard, .020 is the maximum you will be able to go, and after that, the block is done. Most people who are interested in the 4G64 2.4L setup are not after stratospheric (900hp+), drivetrain shattering, dyno queen horsepower numbers anyways. They want a nice torquey, usable, fat midrange, 500-600hp road racing monstrousity that will spool up those laggy GT-series turbo's on a road course, and have plenty of rev's to do it with.
It should be noted that there also exists the fabled 2.1L 4G64 (destroker setup) that should not be dismissed as an option. With this type of setup, a 4G64 block (taller deck height) is used with a 4G63 crankshaft, to achieve an even better stroke/rod length ratio which allows a 10,000 rpm+ redline for drag racing or high rev'ing road course applications.
Last edited by sonicnofadz; Jul 10, 2007 at 11:24 AM.
I live down the street from JAM, and have spoken to them on many occasions. They are, without a doubt, one of the best (if not the best) 4G63/4G64 machine shop on the planet. They seem to recommend keeping the balance shafts with the 2.3L, they claim that if you remove them, you will make LESS power than if you kept them in. I think this might depend on how well the stroker assembly is balanced. Maybe there is some inherent balancing problem with the 4G64 stroker cranks from the factory, I am not sure. There really ISN'T any problem with keeping the balance shafts, if you install them right, they will not break. If you DO remove them, you WILL have oil pressure problems, which has been known to cause many failures.
As far as the 4G64 2.4L setup vs 2.3L 4G63 argument goes, I think the 2.4L 4G64 is a superior platform. Not only does it have more displacement (slightly better spoolup, better midrange power) but it has the ability to rev higher than the 2.3L. Although it does run the risk of cracking the thinner cylinder walls under high boost, this is rarely a problem for those who have chosen this type of engine. I think the trick is to be very careful when over boring at the machine shop. When you retrieve these blocks out of the junkyard, .020 is the maximum you will be able to go, and after that, the block is done. Most people who are interested in the 4G64 2.4L setup are not after stratospheric (900hp+), drivetrain shattering, dyno queen horsepower numbers anyways. They want a nice torquey, usable, fat midrange, 500-600hp road racing monstrousity that will spool up those laggy GT-series turbo's on a road course, and have plenty of rev's to do it with.
It should be noted that there also exists the fabled 2.1L 4G64 (destroker setup) that should not be dismissed as an option. With this type of setup, a 4G64 block (taller deck height) is used with a 4G63 crankshaft, to achieve an even better stroke/rod length ratio which allows a 10,000 rpm+ redline for drag racing or high rev'ing road course applications.
As far as the 4G64 2.4L setup vs 2.3L 4G63 argument goes, I think the 2.4L 4G64 is a superior platform. Not only does it have more displacement (slightly better spoolup, better midrange power) but it has the ability to rev higher than the 2.3L. Although it does run the risk of cracking the thinner cylinder walls under high boost, this is rarely a problem for those who have chosen this type of engine. I think the trick is to be very careful when over boring at the machine shop. When you retrieve these blocks out of the junkyard, .020 is the maximum you will be able to go, and after that, the block is done. Most people who are interested in the 4G64 2.4L setup are not after stratospheric (900hp+), drivetrain shattering, dyno queen horsepower numbers anyways. They want a nice torquey, usable, fat midrange, 500-600hp road racing monstrousity that will spool up those laggy GT-series turbo's on a road course, and have plenty of rev's to do it with.
It should be noted that there also exists the fabled 2.1L 4G64 (destroker setup) that should not be dismissed as an option. With this type of setup, a 4G64 block (taller deck height) is used with a 4G63 crankshaft, to achieve an even better stroke/rod length ratio which allows a 10,000 rpm+ redline for drag racing or high rev'ing road course applications.
Evolving Member
Joined: Sep 2005
Posts: 261
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From: Afghanistan
i actually have only given serious thought to the BC 2.4 or a 2.1 oiling became an issue when considering revvs over 10k however. so for the few guys helping me with this and my extremely limited knowledge we decided a dry sump was too expensive and balancing a motor for the occasional road course or autocross coupled with some street fun, the screamer was put off to the side.
Always run squirters if the car is street driven. At lower rpms the oil pressure isn't that high so the pistons are not getting sprayed with oil. I would use the squirters in every engine I have. It provided extra cooling, lubricant and insurance, so you see you can't really go wrong by keeping them. I think Mitsubishi put squirters in turbo engines for a good reason. Notice the 2.4 block comes from an n/a car. Also did you notice that an n/a cars engine after an hr of driving is and will never be as hot as a turbo cars engine after 20min. of driving?
There in there for a reason guys! They can also be drilled and fitted into any 2.4 block. My 2.4 runs squirters and balance shafts!
There in there for a reason guys! They can also be drilled and fitted into any 2.4 block. My 2.4 runs squirters and balance shafts!
Evolving Member
Joined: Sep 2005
Posts: 261
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From: Afghanistan
Always run squirters if the car is street driven. At lower rpms the oil pressure isn't that high so the pistons are not getting sprayed with oil. I would use the squirters in every engine I have. It provided extra cooling, lubricant and insurance, so you see you can't really go wrong by keeping them. I think Mitsubishi put squirters in turbo engines for a good reason. Notice the 2.4 block comes from an n/a car. Also did you notice that an n/a cars engine after an hr of driving is and will never be as hot as a turbo cars engine after 20min. of driving?
There in there for a reason guys! They can also be drilled and fitted into any 2.4 block. My 2.4 runs squirters and balance shafts!
There in there for a reason guys! They can also be drilled and fitted into any 2.4 block. My 2.4 runs squirters and balance shafts!
The 2.4 and 2.3 should have the same RPM potential since they share the the same crank and rods. 
The only way to get more RPM out of them is to increase the rod length, like Magnus offers (2.4 block with 2.3 pistons and 6mm longer rods).
The balance shafts don't have anything to do with the actual balance of the assembly, they are only there so you feel less of the motor's natural vibrations. I have heard them refered to as "silent shafts" which is a much more appropriate name IMO!
The main reason the shafts should be removed is the liability that comes from a shaft spinning at about twice the motor's RPM. The bearings can lock up and spin and cause all kinds of trouble. The belt can break, the shrapnel of which then takes out your main tbelt. Etc. Not worth the risk IMO, I remove them any time the motor is out of the car.
The only way to get more RPM out of them is to increase the rod length, like Magnus offers (2.4 block with 2.3 pistons and 6mm longer rods).The balance shafts don't have anything to do with the actual balance of the assembly, they are only there so you feel less of the motor's natural vibrations. I have heard them refered to as "silent shafts" which is a much more appropriate name IMO!
The main reason the shafts should be removed is the liability that comes from a shaft spinning at about twice the motor's RPM.
The bearings can lock up and spin and cause all kinds of trouble. The belt can break, the shrapnel of which then takes out your main tbelt. Etc. Not worth the risk IMO, I remove them any time the motor is out of the car.
Last edited by kjewer1; Jul 11, 2007 at 02:55 AM.
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Joined: Aug 2005
Posts: 282
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From: Mooresville, NC
ok, first of all, there are two 2.4's being mentioned in the thread..secondly none of the 2.3, 2.4 (BC) or 4g64 will have the same revability...
all have different rotating masses and rod ratios...
the 4g64 can have a longer rod/lower acceleration at the piston for the same rpm than the 2.3 ro BC 2.4 and a bigger bore than both...
the 2.3 has less reciprocating but has a shorter rod ratio than what can be had in the 4g64...
the 2.4 BC just has the shortest rod ratio and is most likely the least revable...but also will be the fastest to spool any turbo do to the short rod ratio...
so...
4g64 seems the best all around mid and top end power based on rod ratio and displacement size
the 2.3 seems to be good all around as it falls between both 2.4's
the BC 2.4 would seem to be the best for a big turbo on the street, auto-x or tight road courses...or those with a non-driver
all comment above are just opinion based on studies from a bore sizing and rod ratio...its just an air pump
all have different rotating masses and rod ratios...
the 4g64 can have a longer rod/lower acceleration at the piston for the same rpm than the 2.3 ro BC 2.4 and a bigger bore than both...
the 2.3 has less reciprocating but has a shorter rod ratio than what can be had in the 4g64...
the 2.4 BC just has the shortest rod ratio and is most likely the least revable...but also will be the fastest to spool any turbo do to the short rod ratio...
so...
4g64 seems the best all around mid and top end power based on rod ratio and displacement size
the 2.3 seems to be good all around as it falls between both 2.4's
the BC 2.4 would seem to be the best for a big turbo on the street, auto-x or tight road courses...or those with a non-driver
all comment above are just opinion based on studies from a bore sizing and rod ratio...its just an air pump
Last edited by homemade wrx; Jul 11, 2007 at 07:59 PM.
Evolving Member
Joined: Aug 2005
Posts: 282
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From: Mooresville, NC