Know Your K-series

[MyNameIsThien]

I just copied and paste this from clubrsx.com.

all of them share:
* Displacement: 1998 cc
* Bore and Stroke: 86 mm x 86 mm

K20A - info to be added soon.. or someday


K20A2
Found on: 2002-2004 Acura RSX type-S
* Compression: 11.0:1
* Power: 200 hp @ 7400 rpm
* Torque: 142 lbs-ft @ 6000 rpm
* Redline: 7900 rpm


K20A3 - Torque output differences attributed to intake manifolds
Found on: 2002-2005 Civic Si
* Compression: 9.8:1
* Power: 160 hp @ 6500 rpm
* Torque: 132 lbs-ft @ 5000 rpm
* Redline: 6800 rpm
Note: shares the same intake manifold found on RSX type-S


Found on: 2002-2006 Acura RSX base
Note: shares the same intake manifold found on 2003-2006 CR-V

2002-2004
* Compression: 9.8:1
* Power: 160 hp @ 6500 rpm
* Torque: 141 lbs-ft @ 4000 rpm
* Redline: 6800 rpm

2005-2006 {revised SAE hp rating, same engine as 2002-2004}
* Compression: 9.8:1
* Power: 155 hp @ 6500 rpm
* Torque: 139 lbs-ft @ 4000 rpm
* Redline: 6800 rpm


K20Z1
Found on: 2005-2006 Acura RSX type-S
Note: shares PRC series camshafts with K20A

2005
* Compression: 11.0:1
* Power: 210 hp @ 7800 rpm
* Torque: 140 lbs-ft @ 7000 rpm
* Redline:8100 rpm

2006 - {new SAE hp rating, same engine}
* Compression: 11.0:1
* Power: 201 hp @ 7800 rpm
* Torque: 140 lbs-ft @ 7000 rpm
* Redline:8100 rpm


K20Z2 - Drive-by-Wire™ Throttle System
Found on: 2006+ Acura CSX base, 2006+ Honda Civic (JDM), 2006+ Honda Accord (Europe)
* Compression: 9.6:1
* Power: 155 hp @ 6000 rpm
* Torque: 139 lbs-ft @ 4500 rpm
* Redline: 6800 rpm


K20Z3 - Drive-by-Wire™ Throttle System
Found on: 2006+ Honda Civic Si, 2007+ Acura CSX type-S
* Compression: 11.0:1
* Power: 197 hp @ 7800 rpm
* Torque: 139 lbs-ft @ 6100 rpm
* Redline: 8000 rpm
Note: RBC intake manifold listed as 17100-RRB-A00


K20Z4 - Drive-by-Wire™ Throttle System
Found on: 2007 Honda Civic type-R (FN2)
* Compression: 11.0:1
* Power: 198 hp @ 7800 rpm
* Torque: 142 lbs-ft @ 5600 rpm
* Redline: 8000 rpm


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all of them share:
* Displacement: 2354 cc
* Bore and Stroke: 87 mm x 99 mm

K24A1
Found on: 2003-2006 Honda CR-V
Note: shares the same intake manifold found on base RSX

2003-2005
* Compression: 9.6:1
* Power: 160 hp @ 6000 rpm
* Torque: 162 lbs-ft @ 3600 rpm
* Redline: 6500 rpm

2006 – {revised SAE hp rating, same engine as 2003-2005}
* Compression: 9.6:1
* Power: 156 hp @ 5900 rpm
* Torque: 160 lbs-ft @ 3600 rpm
* Redline: 6500 rpm


K24A2 - please check below for specs.


K24A3 - info to be added soon.. or someday


K24A4
Found on: 2003-2005 Honda Accord, 2003-2006 Honda Element*
* Compression: 9.7:1
* Power: 160 hp @ 5500 rpm
* Torque: 161 lbs-ft @ 4500 rpm
* Redline: 6500 rpm

2006 Element – {revised SAE rating, same engine}
* Compression: 9.7:1
* Power: 156 hp @ 5500 rpm
* Torque: 160 lbs-ft @ 4500 rpm
* Redline: 6500 rpm


K24A8 - there are some discrepancies for this motor (ie: torque output). It might have to do with the new SAE rating.
Found on: 2006-2007 Honda Accord
* Compression: 9.7:1
* Power: 166 hp @ 5800 rpm
* Torque: 160 lbs-ft @ 4000 rpm
* Redline: 6500 rpm


Found on: 2007-2008 Honda Element***
* Compression: 9.7:1
* Power: 166 hp @ 5800 rpm
* Torque: 161 lbs-ft @ 4000 rpm
* Redline: 6500 rpm

***(i confirmed this visiting at my local dealership. the MSRP paper read K24A8. the previous years were said to have had the K24A4 engines instead, the same engine the 2003-2005 Honda Accords were using. i know honda was using drive-by-wire in their K-series in their updated 2006-2007 Honda Accord. I don't know if the Honda Element received the same update at the same time.)



K24Z1 - Drive-by-Wire™ Throttle System
Found on: 2007+ Honda CR-V
* Compression: 9.7:1
* Power: 166 hp @ 5800 rpm
* Torque: 161 lbs-ft @ 4200 rpm
* Redline: 6500 rpm


K24Z2 - Drive-by-Wire™ Throttle System
Found on: 2008+ Honda Accord LX/LX-P sedan
* Compression: 10.5:1
* Power: 177 hp @ 6500 rpm
* Torque: 161 lbs-ft @ 4300 rpm
* Redline: 6800 rpm
Note: radical exhaust port design. no exhaust manifold. will not mate up with other K series manifolds.

-----------------------------------------
the K24Z2 & K24Z3 share the same camshafts [intake: 14110-R40-A00, exhaust: 14120-R40-A00], pistons [set A - 13010-R40-A00, set B - 13020-R40-A00 (both sets listed for each specific engine)], and connecting rods [13210-R40-A00].

however, parts listing differ for general cylinder block assemblies [K24Z2: 10002-R40-A00 - $3005.40] [K24Z3: 10002-R46-A00 - $1407.21].

speculation of the power difference is mostly attributed to the difference in the redline. more or less from these facts, the two engines are one and the same if not for a few minor differences in parts.

The K24Z2 and K24Z3 also have a radical, new design for the head on the exhaust side. instead of having an exhaust manifold with four individual exhaust ports for each combustion chamber, a sort of pyramid shaped collector diverts all the exhaust into a single square exit. this was done for various reasons such as bolting the catalytic converter close to the engine for faster heating in cold starts and doing away the header for cost reduction.



neither has the aggressive form of I-VTEC as clearly exhibited in the camshaft designs compared to the 2006+ Civic Si K20Z3 camshafts.

K24A2 Diagram
K24Z3 Diagram
K20Z3 Diagram

however, it should be taken note of how much power and specs wise the K24Z3 closely compares to the Acura TSX. comparisons between the two engines can be seen below.


**(substantial differences between the TSX model years exist for the engines. however, Acura refers either as K24A2).
for more in depth details between the 2004-2005 and the 2006-2008 models, please refer to Hondata.com: 04 TSX and 06 TSX Comparison

Wiki quote:

The 2006 Acura TSX features a new 2.4-litre in-line 4 cylinder engine making 205 hp (153 kW) SAE J1349 net. The advertised increased power figures on previous models were over-estimated by +10 hp (7 kW), the actual power rating is 205 hp (153 kW). SAE J1349 is a third party program designed to eliminate ambiguities that allowed engine makers to cite power and torque ratings higher than the engine's actual capabilities.[6] The most significant changes to the motor are described as follows:

On the intake side of the TSX engine, the diameter of both the throttle body and the intake duct were enlarged to increase induction flow rate from 95 liters per second to 110 liters per second. In addition the diameter and shape of the intake valve were enhanced to help increase intake flow by 16 percent and the high RPM cam profile for the intake cam was modified to provide increased intake valve lift and duration. In addition, a ventilation passage was machined into the engine block to reduce pumping friction by increasing air flow between cylinders.

Also significant of the i-VTEC system on the TSX and RSX-s is that unlike other Honda K-series motors vtec is used on both the intake and exhaust ports in its three rocker design.

K24A2 - ** Drive-by-Wire™ Throttle System
Found on: 2004-2008 Acura TSX

2004-2005
* Compression: 10.5:1
* Power: 200 hp @ 7000 rpm
* Torque: 166 lbs-ft @ 4500 rpm
* Redline: 7100 rpm

2006-2008 {new SAE hp rating since 2006 & engine revisions}
* Compression: 10.5:1
* Power: 205 hp @ 7000 rpm
* Torque: 164 lbs-ft @ 4500 rpm
* Redline: 7100 rpm

-----------------------------------------

K24Z3 - Drive-by-Wire™ Throttle System, check compression ratio and possibly intake manifold.
Found on: 2008+ Honda Accord EX/EX-L sedan & coupe, LX-S coupe
* Compression: 10.5:1
* Power: 190 hp @ 7000 rpm
* Torque: 162 lbs-ft @ 4400 rpm
* Redline: 7100 rpm
Note: radical exhaust port design. no exhaust manifold. will not mate up with other K series manifolds.

Found on: 2009 Acura TSX
* Compression: 11.0:1
* Power: 201 hp @ 7000 rpm
* Torque: Manual - 172 lbs-ft @ 4300 rpm
Automatic - 170 lbs-ft @ 4300 rpm
* Redline: 7100 rpm
Note: radical exhaust port design. no exhaust manifold. will not mate up with other K series manifolds.

[exelr8]

Are all of the K24A8's Drive by wire as well?

[NVA-AV6]

Great info, two things of note...

Look at the way compression effects these engines, there were several that went from 9.X:1 to 11:1 and jumper from 155HP to 20X HP, anyone planning a NA k-build 11:1 should be your target for street use maybe push to 11.5:1 if you have 93 octane gas avalible.

The intergrated exhaust mani is also in the J sereis V6s and was introduced in the 03 AV6 and 03 MDX and in now standard for all J engines, I personaly have not seen any draw backs to it as the port are quite large and flow well.

[CrackerTeg]

Are all of the K24A8's Drive by wire as well?

Yes sir. I could be wrong though.

[exelr8]

That is what i thought but was not sure... I have to admit DBW BLOWS!! throttle response is shit

[stirfriedferret]

Solution? Buddy Club e-Throttle Booster

[timot_one]

All the newer K24s also have the integrated exhaust manifold also.  The TSX changed the exhaust cam from a 3 lobe design on the 1st Gen to a 1 lobe design on the 2nd Gen.  Kinda weird.

[exelr8]

Thanks Brian now i must search for one... i absolutely hate the DBW system

[K24power07]

sweet i was looking for a list like this...

[rjp6262]

raising the compression ratio has to due with pistons correct?

[Rustywaffle]

raising the compression ratio has to due with pistons correct?

correct

[wai_pang2]

That is what i thought but was not sure... I have to admit DBW BLOWS!! throttle response is shit

Don't mean to bring up the dead but in any case. I don't believe the DBW affects the throttle response. Reason being is that I have a 05 Legacy Gt which is also DBW. When I drove on the highway in 5th gear, it would just lag and I would have to downshift to 4th gear to pick up the pace a little. When I upgraded to stage 1, throttle response improved significantly in 5th gear as if I downshifted to 4th. You guys maybe thinking that "well that's because you raised the boost and such." stage 1 consisted of raising the boost from stock 14.7 psi to 16 psi and on top of that, the car was running pig rich at 10:1 afr. my tuner tuned it to 11:1. It really has to do with your afr maps instead of because its DBW. but you guys are still going to think what you guys want.
My suggestion is to read up on the Subaru legacy gt SI drive system. That will explain how they improve throttle response without raising the boost. read this: http://www.theautochannel.com/news/2006/04/13/003926.html

Sometimes I wish this would work for the 03 + Accords. Maybe we can get together and have somebody contact them to make it work for our cars instead of getting Kpro'd.

[thisaznboi88]

just buy my TSX TB. Someone installed and it told me it does not lagg as much anymore

[NVA-AV6]

That is what i thought but was not sure... I have to admit DBW BLOWS!! throttle response is shit

Don't mean to bring up the dead but in any case. I don't believe the DBW affects the throttle response. Reason being is that I have a 05 Legacy Gt which is also DBW. When I drove on the highway in 5th gear, it would just lag and I would have to downshift to 4th gear to pick up the pace a little. When I upgraded to stage 1, throttle response improved significantly in 5th gear as if I downshifted to 4th. You guys maybe thinking that "well that's because you raised the boost and such." stage 1 consisted of raising the boost from stock 14.7 psi to 16 psi and on top of that, the car was running pig rich at 10:1 afr. my tuner tuned it to 11:1. It really has to do with your afr maps instead of because its DBW. but you guys are still going to think what you guys want.
My suggestion is to read up on the Subaru legacy gt SI drive system. That will explain how they improve throttle response without raising the boost. read this: http://www.theautochannel.com/news/2006/04/13/003926.html

Sometimes I wish this would work for the 03 + Accords. Maybe we can get together and have somebody contact them to make it work for our cars instead of getting Kpro'd.

11:1 is still pig rich and will destroy your bearings and pistons, I know the EJs like to run a bit fat, but damn, you are pushing raw gas past the rings into your oil at that AFR, check your oil for gas smell, even at WOT and stage 1 cobb tune you still want about 12.5:1 afr........

[wai_pang2]

12.5 AFR sounds like what a B16 turbo would be running safe at but on a subaru motor, anything above 11.5 is deemed not safe.

I'm sure I'll see knock if I do that and I'm not going to risk that.