Alright, here it is, I have owned my 240sx se since 11\05, and don't have many resources in my local area to turn to. (Missoula, Montana) I have heard people suggest many swaps (sr20det most common) and i have found resources for almost any swap i want to do, but I have been unable to get a direct answer on a few questions.

First, I know an RB swap will require everything swapped (engine, mounts, tranny, ecu, wire harness, etc.) however, what all is needed to do sr20 or ca18 swap, ecu for sure, and wire harness, but do the ca or sr blocks mount to the ka24 tranny? or can the ca or sr engines use the stock ka24 motor mounts? what about the drive line for ca or sr swap?

Second, those were for future reference, I currently am keeping the KA24E, (since I have 2 good engine right now, for 1 car) does the dohc head utilize the same bolt pattern as the sohc, i.e. could I swap a dohc head onto a former sohc block so long as I had the correct wire harness in place, or would I encounter any problems in such a swip swap. I don't see where a problem would be, but don't have a dohc in my possesion to cross examine, and as I started this forum with, I have few resources to discuss these matters with. the best I can get out of anyone here is "don't turbo a ka, go sr20", or "any swap but a sr20 is pointless, it's a powerhouse". Then as i do my research online, I keep finding people that are running the hell out of their ka's to 170,000+ miles, and sr20's that are blown with hardly 5,000 miles on them (in addition to the 30-60k miles it started with). And I am aware of the power differance the engines have, but I am not satisfied with the weakness present in the aluminum block engines.


Thank you for reading, any help or correspondence is appreciated

 

A SR20DE-T swap is pretty much straight forward you need motor mounts, motor, tranny, wiring harness.

you might able to swap the heads to DOHC i've personally never seen anyone do this, so i dont know alot about it.

My SR motor has 97,XXX miles on it and still runs as strong as can be, KA is one of the weakest motors out there to build, you cant boost is with out a serious re-build. SR's can hold 400hp with a stock bottom end. People are probably running the hell of them and over revving them all to hell, redlining every gear, spinning the tires at every light thats why they havent lasted.

 

SR20DET would be the engine to go with. You are gonna have to get motor mounts, harness, and im not sure if youll have to change the Tranny although you should consider upgrading it to a 6 spd. KA24 are good but you cant really push them to the potential that a SR20 has. I think you can put a DOHC on a SOHC engine but am not too sure whether you'll get the right fit on the block. I got a Magazine that has an article about a guy that put a SR20DET head on a SR20DE Bottom. Or it might be the other way around, but he did do custom work to it.

 

All SR20's are the the same DE-T or not, both twin cam fwd SR's and rwd are both set up a little different.

 

Investigate more owners of the SR20DET swap you will find that for those who arent hopelessly obsessed with sliding thier cars around corners can swap, modify and still be left unsatisfied. Most people turn around increasing bore and or stroking the motor, the SR20's only setback is the lack of displacement. I am not an SR20 hater, i love the motor. I think the S14's SR20DET is perfect from the factory, and can be made exceptional with limited modification.

But consider the advantages that the KA24 offers... Iron block (which for those of you that dont know, do not use piston sleeves), extra displacement, similar injectors, and the simple convienience of not tearing the harness apart to run a little bit of boost. Not to mention, the fact that the SR20DET has such a great demand that you are paying double what the motor is likely worth, and the KA that comes in your car obiviously costs you nothing. Im not sure on the specifics of changing the single cam head out for a dual cam head, i think it is unlikely. But with everyone swapping out thier motors there are plenty of KA24DE's to be found.

And in the end, on 7psi of boost on with an aftermarket fuel pump, fuel rail and injectors KA24DET's are known to see gains that will slightly out-perform the SR20DET.

The only worries for KA-T builders are rods and pistons...

As for SR20's being the same, as ghetto as it sounds i know a guy that put together a S13 with a SR20DE from a sentra in it... Even managed to run it on the KA24's transmission and ECU... if you arent talking about a JDM swap.. forget about it.

And i have to dispell this rumor of the KA24DE being weak... Listen to what you are saying, people are abusing thier motors and therefore causing them to explode.... Well duhhh! Any production car with stock components cannot be expected to be reliable under the stresses of hard driving/racing. And anyways, how many SR20DET's with stock bottom end components do you hear of producing upwards of 320whp? Not many, because people dont brag about motors that they destroy. Nothing lasts forever, which is why if you want to be the boss, you have to pay the cost. Modify correctly, and completely where it is needed.

 

people are always saying a KA24DE-T will out perform a SR20DE-T, but no one ever says what it is going up against with what the KA has.. what the SR has... stock internals, what turbo are they running, how many lbs of boost they are running, slicks, the list goes on... of course a aftermarket setup is going to out perform a stock one. A KA24 with aftermarket turbo, exhaust, etc.. against a stock SR20DE-T, yeah it probably will.

Mod for Mod SR will out perform hands down.

 

Thank you for your help thus far, anyone else who may have some input, please post it. I have found a number of sr20 engines i can source from my local wrecking yard, (all from fwd N/A sentras, and compression tested) so I may just have to attempt a swap into one of my projects. I now have my 240, and the one parts car, and 2 more "junkers" lined up for when I have the funds. I think my goal will now be to build the swaps in the differant options available, so I can determine the "best" setup available. As stated earlier, many crave the swap, leaving many good ka24s on the market, thus cheap core parts for my daily driver. The swaps will be extras, and most likely sold off after construction and due time testing and tuning. (Although if I get the oppurtunity to do an RB25/26 conversion, I may have to keep it for 'extended' testing )

 

ok guys im a converted chevy guy with a 91stanza xe, whats the difference between a ka24e and a ka24de motor?

 

SR20DET has such a great demand that you are paying double what the motor is likely worth, and the KA that comes in your car obiviously costs you nothing.

 

why pay for something that could cost you nothing?