I want to buy a 1997-1998 240 SX and probably install a SR20DET engine in it. I have a few quesions though.

-Will the RWD transmission from the KA24 bolt up to an SR20, or will I need a tranny from a Silvia?
-What cars sold in america carry the SR20 engine?
-What cars sold in america have RWD drivetrains that will fit into a 240 SX chassis?
-If I get an SR20DE engine, will it be able to handle the same amount of boost as an SR20DET?
-What are the compression ratios on the different SR20 engines?
-What is the weakest point in the engine as far as boosting? ie what parts will break first? sleeves, pistons, rods, head gasket... etc
-What are the advantages of the SR20 over the KA24?

I am going to rebuild an SR20 to handle huge amounts of boost, would it be a bad idea to just rebuild the KA24? I am very curious to find out why everyone is junking their 2.4 liter engines to install 2.0 liter engines. If I installed forged pistons and rods, resleeved, blueprinted, and balanced a KA24 and an SR20, would the SR20 still be better to run high boost (~2 bar)?

The search function helped answer most of my questions, these are the ones that I could not find answers to. I had already posted this in the newbie section, but I don't think anyone is there.

I have been modifying cars for a while but I am not very familiar with Nissan / Infinity. So any help or advice on this new venture would be most helpful.

Originally posted by Dokta

-Will the RWD transmission from the KA24 bolt up to an SR20, or will I need a tranny from a Silvia?
I *believe* so. I have seen where one swap used the front section (bellhousing) from the KA tranny and the rear section from the SR20 tranny. I'm a FWD guy, so if I am wrong someone will surely correct me.

-What cars sold in america carry the SR20 engine?
In no particular order: SE-R, 200SX SE-R, NX2000, G20, Sentra SE and SE-L

-What cars sold in america have RWD drivetrains that will fit into a 240 SX chassis?
I've heard of VG30 (Nissan V6) swaps. I'd also like to see a small block Chevy fit in one, but that's just me. :)

-If I get an SR20DE engine, will it be able to handle the same amount of boost as an SR20DET?
Pretty much. 400hp is not uncommon at all on US DE engines. The DET engines have lower compression (about one point) and oil squirters over the DE engines.

-What are the compression ratios on the different SR20 engines?
Again, all FWD knowledge here: Pulsar GTi-R turbo engine is 8.3:1, Bluebird/Avenir turbo engines are 8.5:1, US models of the NA SR20DE are 9.5:1, and there were some JDM NA motors that were 10:1

-What is the weakest point in the engine as far as boosting? ie what parts will break first? sleeves, pistons, rods, head gasket... etc
Ring lands have been known to break. You can hole a piston, but you really have to try. Head gasket needs upped for double-digit boost duty on a daily basis.
-What are the advantages of the SR20 over the KA24?
Aluminum block and aluminum head, for one thing. KA has an iron block. Not a handicap by any means. SR20 was designed for turbocharging from the outset, so in the NA form we were stuck with here in the USofA, it is really understressed. Thick, solid deck. There is a fair amount of webbing surrounding the crankshaft, too, on the SR20.

I am very curious to find out why everyone is junking their 2.4 liter engines to install 2.0 liter engines. If I installed forged pistons and rods, resleeved, blueprinted, and balanced a KA24 and an SR20, would the SR20 still be better to run high boost (~2 bar)?
See above. 2 bar (28-29psi) of boost is rare air, my friend. It can and has been done, but you're really way out there. You will need more than a stock DET to do that with any kind of reliability, IMHO.

If I missed anything or made a mistake, feel free to correct me, guys. :)

Thanks for the help. I know that 2bar is alot of pressure, but this is going to be a project that may need it. It will be sponsored by a local speed shop. They have definately hinted that they are willing to spend some money on this (30K+). But in return they want a car that is driveable on the weekends, street legal, and able to run 9.99 or better with the boost turned up at the track. I know this is not going to be easy. I have been contemplating using the 300ZX TT engine, if it will fit into an S14 body. I think that may be easier than using an SR20DET. Please keep the information coming

Great write up Greg. That covers things great. I have heard of some KA24 motors with big boost, but they usually blow up after short time. The SR20 is just much stronger.

BRent

As far as I know, the KA series of motors do NOT bolt to any SR tranny or vice versa. The KA motor weighs as much as the entire SR20det and tranny. You want to shed 200 lbs. off your 240sx, junk that KA24 truck motor and tranny. The KA is an iron block, rev less heap. It produces good numbers when well built, but that time and money would be better spent on the SR motor. If drag racing is your thing, buy the "sylvia" swap, a toda stroker kit, bore it, huge turbo, water injection, stand alone, etc. Look up the HKS 180SX for inspiration.

Or use the Q45 V8, build it up, twin turbo it, squeeze it in the chassis. Something different.

If you want to see a fast sylvia, just check out the JUN one. It's already run 8's on the SR20. Well, stroked out to 2.2 using their stroker kit. I'm sure the specs are on their website. www.google.com is great for finding things :) And again, TONS of 240sx info in the forums at freshalloy.com

Khiem

Aluminum block and aluminum head, for one thing. KA has an iron block. Not a handicap by any means. SR20 was designed for turbocharging from the outset, so in the NA form we were stuck with here in the USofA, it is really understressed. Thick, solid deck. There is a fair amount of webbing surrounding the crankshaft, too, on the SR20.


You mean my SR20 is understressed?? Well ain't that a kick in the pants??!! So whay did Nissan never bring over the DET?? See now i'm getting pissed at Nissan for jipping us outta a sweet ass engine!! Makes me wanna get a WRX!!