Motor swap

[JadeDatsun620]

Hey Guys,

 

New to the Datsun world. I just picked up an 1973 620 automatic in good condition. I'm looking to completely modify the truck and was wondering if anyone had any recommendations on what sort of engine swap I could do that would fit and that is still in the Nissan family of motors. 

[Ben_upde]

A swap is always a lot of work so why limit yourself to just Nissan? If that’s what you want, that’s all good, but there are many many other options out there that may be better for the truck depending on what you intend to use it for. 

[]2eDeYe]

Welcome, what kind power are you looking for? 

Lot's of options out there. 

[420n620]

8 hours ago, JadeDatsun620 said:

Hey Guys,

 

I just picked up an 1973 620 automatic in good condition. 

 

I'd / we / Ratsun members would like to see the 73 Datsun 620 in good condition before you start the project. 

Welcome, as Redeye says, lots of info - on this site. 

[datzenmike]

The 620 used 3 engines during it's run. Your L16 for '73, a slightly larger L18 for '74 and even larger L20B for '75-'79. They are practically identical to look at with the L20B being 3/4" taller. The L20B has 25% more displacement, about 20 more horse power and more torque. Because these engines are all from the same family they will swap, practically 'drop in' easy.

 

L18........ easiest of all because it will bolt up to your automatic. If from a car the L16 oil pan and engine mounts can be swapped on to fit the 620 frame.

 

L20B.... engine will swap right in using L16 exhaust manifold and if from a car the L16 oil pan and engine mounts. You can't use the L16 automatic on an L20B so you will need a car or truck automatic from another L20B. In theory an L20B with attached flex plate should bolt to your L16 torque converter though I have never checked the bolt patterns.

 

From here on the engine choices are more rewarding but much more complicated. I would just drive it as is and enjoy it while figuring out which way to go and collecting the parts for a swap.

[yenpit]

Outside of the L series family, the most common swaps today, are likely the 1991-1998 USA-spec Nissan 240SX KA24DE twin cam naturally aspirated & the 1992-up (??) JDM-spec SR20DET twin cam turbo.  You CAN turbo a KA24DE, allowing I think up to 6-8psi on a stock engine, but adding a turbo is not necessarily cheap & requires fab work.  There is somebody here on Ratsun that makes engine mount bracket kits, I think for either option.  Beyond those two, there are LOTS of other option, mostly governed by your budget & your fabrication skills.  Pretty much ANY swap (other than the L series family) will require some fabrication.  If you don't have fab skills, stick to an L series...........like datzenmike points out, the 75-80 L20B is likely your best option!

 

I am moving slowly at installing a 1980 L20B & 5speed manual in my 1972 521.  Was a 77k mile wrecked rusty 1980 720 donor, so clean up, reseal & stuff it in...........fingers crossed it runs out well!

 

Being an automatic, if you are considering swapping to a manual trans, most of the parts to swap to manual are bolt in, so relatively straight forward!

[JadeDatsun620]

Thank you all for the help and information. My intended use for the truck is to be used as a daily car. I want to have a smooth ride but with power. I want my daily drives to be enjoyable but at the same time reliable. I want an engine that wont give me problems and easy to modify and tune. 

[demo243]

6 hours ago, JadeDatsun620 said:

Thank you all for the help and information. My intended use for the truck is to be used as a daily car. I want to have a smooth ride but with power. I want my daily drives to be enjoyable but at the same time reliable. I want an engine that wont give me problems and easy to modify and tune. 

Based on that KA is probably your best bet- it’s about as bolt in as you can get if you use Redeyes mounts and the CanAm board for wiring it up.  The KA has lots of low end torque that match the truck great and make for good street manners. There is still a lot to figure out though- radiator, speedo, fans, driveshaft, brakes (Drums up front won’t cut it)... lots of info on here.

You’ll want to find a the engine, trans, harness and ecu. Try and get them all from one source for the best deal and the best chance of the the harness not being cut.
 

 

Edited February 12, 2021 by demo243

[yenpit]

3 hours ago, demo243 said:

Based on that KA is probably your best bet- it’s about as bolt in as you can get if you use Redeyes mounts and the CanAm board for wiring it up.  The KA has lots of low end torque that match the truck great and make for good street manners. There is still a lot to figure out though- radiator, speedo, fans, driveshaft, brakes (Drums up front won’t cut it)... lots of info on here.

You’ll want to find a the engine, trans, harness and ecu. Try and get them all from one source for the best deal and the best chance of the the harness not being cut.
 

 

 

Agree.........KA24DE twin cam out of a USA-spec 1991-1998 240SX.  Lots of people use the Can Am box, but we have used the Wiring Specialties KA engine harnesses in a couple 510 swaps.................NOT cheap, but plug & play simple!  I think I saw the guy that makes the engine mounting bracket kits "like" this post...........maybe ]2eDeYe??

[]2eDeYe]

Yep, that's me. I have mounts for KA and SR swaps. 🙂

Icehouse offers the can-am box for wiring simplification.