Datsun Roadster Forum-311s.org

Hey guys new to the community and trying to clarify a few things about engine swaps,

I will be buying a roadster next spring for sure and still trying to figure out where i want to go with it mechanically , This will be mostly a fair weather and weekend getaway car with maybe a few auto-x here and there , I have a fairly good idea on suspension and brakes but still undecided on drivetrain. I know I want to stay NA and power goal is ~145-150hp at the wheels but not sure how to get there

On the one end I really like the idea of having someone build me a 150 whp U20 and spoke with a few builders but that's $10K USD ($13.5K CND) before I do any of the other drivetrain upgrades necessary (transmission, intake etc) so I can see myself easily spending $20K CDN on this , I know the car could be worth more especially if its a 2000 to start with but damm that's a lot of money .

So an engine swap is looking real good cost wise , Locally a good S14 SR20DE from a reputable shop complete with transmission, Harness and ECU is ~$1200 CDN and a a little cheaper for a KA24DE , I really like the torque on the KA engines but they are harder to find these days

So here are some questions in no particular order :

• --Everyone say a KA swap is much easier than an SR , can someone elaborate on why that is?
  --I've read a couple of places that you can drop in an SR in the engine bay of a 240Sx and it bolts right in, would that mean that they use same mounting points and if that's the case wouldn't Michael's Jig and engine mounts also work for it?
  --Other than , bushing , Brakes ,Cooling/radiator , fuel pump, intake, exhaust what else do I need to think about ?
  --Any modification required to run 205 tires all around?

I've already spoken to a few folks already including Kevin and Michael and will continue to do so and looking forward to join as a fellow Fairlady owner
Thanks for all your help

This is just my understanding, I have redone swaps of FJ20s into my 311s, but have not done either a KA or SR into a roadster.

KA swap, usually the location is determined by the shift lever. Its necessary to modify the frame for an SR swap to clear the oil pan and lower the transmission, while the KA, they usually just remove the budge on the side of the oil pan for clearance.

I would suggest an LSD, its easier and might be cheaper to swap a shorten RX7 axle than build a roadster axle.

205 fit the front of 67.5 on with the correct offset wheels....usually 7" rims between +12 and +18 offset.
205 on the rear will require some rolling of the fenders along with the correct offset.....the offset is usually rear axle dependent. Many people like to shorten the RX7 an additional 1" or more so they can run "0" offset rims.

A couple things to note about putting a SR20DE into a roadster chassis:

1. We move the driver's side motor mount forward to allow for an exhaust manifold which will clear the steering.
2. While yes, a SR will fit where a KA fit on a S13/S14 chassis, the roadster frame is considerably narrower and has a crossmember that needs to be modified to clear the front sump oil pan of the SR20DE engine-- there are lots of threads here in the engine swap section which discuss this.

If you have any further questions, please don't hesitate to ask!

Michael

I did a CA18det swap and the engine fits directly, even the shaft has not to be modified.
you have to make new mounts for the engine and the tranny, and you have to cut a small piece out of the tunnel for the shifter.
The only cutting at the chassis I did was for the exhaust pipe 2" in the cross member, but you can do that without lifting the body.
The engine runs great and makes 220 hp with 300nm but can make easily 260 hp with 350 nm with a larger turbo.(T28)
http://www.311s.org/phpBB3/viewtopic.php?f=15&t=25068
if you have more questions let me know.