advice on upgrading to L20 from L16

[nickeldime69]

i'm hoping that i'm not going to sound too green here but i need a new engine for my 510. the engine failed and i've decided to swap it out instead of doing a rebuild. (i don't have the mechanical abilities or access to the proper tools/space for such work. i've decided to do an engine swap in order to keep the cost with the mechanic to a minimum. the easier the job is the better). that being said, replacing my current engine with an L16 seems like the best bet, however an L20 would provide more power.

 

from what i understand, the L20's are larger and won't fit under the hood without some work. is this the only hurdle i would potentially face with upgrading from an L16 to an L20 (or even an L18)?

 

engines aren't cheap (especially the remanufactured ones) and i don't want to dive into this and drop a bunch of money if i'm not properly informed.

 

thanks in advance for any helpful feedback.

[datzenmike]

The L20B is only 3/4" taller if on the old L16 engine brackets and should fit ok.

 

The L20B could have come with a 200mm (car) or 225mm (truck) flywheel and clutch. The flywheel isn't larger, it just has a different bolt pattern for the two different size pressure plates and clutch discs.

 

If you have the '200mm' flywheel your current PP and clutch disc from the L16 will bolt right on and everything goes in and together.

 

If you should have the 225mm flywheel, you will need a new 225mm PP and clutch disc. Your L16 clutch release bearing collar won't work, as it is sized for the 200mm clutch.

 

The L20B can probably use your exhaust manifold but if the L20B has a U67 head you will need to also use your L16 intake under the L20B carb. The head ID is cast into the bottom of the aluminum head just behind the fuel pump.

[Draker]

If hood clearance is an issue.. (It was for me) you just need to slot the engine brackets to lower the engine a bit. It fit under the hood, but I could hear it hit if I slammed the hood too hard.

 

It's a pretty straight forward swap though. Mike covered the hard stuff. 

 

Also the crank vent is slightly different.. minor issue.. can be addressed after the swap is complete.

[flatcat19]

Don't pay the mechanic. Use that money to buy tools an do it yourself.

 

 

And those words are coming from a mechanic.

 

Very rewarding doing it yourself.

[DatMo]

Agreed with what everyone said as well. Also, i had my block entirely out and fit the tranny to the long block to make it easier since I didn't want to deal with working under the car since it was all already out. You could try this as well as it was still very easy to get the engine in.

 

Best of luck! The actual block removal and swap in only took around an hour and a half but I also had a friend with me.

[Doctor510]

L16 and L18 flywheel WILL NOT fit the L20b crank flange, 5 bolts vs 6 bolts.

[datzenmike]

Yes, and why you may have 200 or 225mm flywheels. With luck this is a car L20B and already has the 200mm one.

 

Because the L20B uses a different exhaust manifold with a single large down pipe it would be easier to use your L16 exhaust manifold so it connects to your exhaust system. You may have to use your intake also if the L20B is a '75-'77

 

Put your L16 oil pan and lick up tube on the L20B so it will fit the 510.

[flatcat19]

Lick up tube. Ha.

[Noflers]

Don't pay the mechanic. Use that money to buy tools an do it yourself.

 

 

And those words are coming from a mechanic.

 

Very rewarding doing it yourself.

This! Most things are only intimidating because you haven't done them before. Once you have the right tools and a little know-how, everything is a matter of nuts, bolts, grease, and proper torque #'s...

[datzenmike]

Lick up tube. Ha.

 

Ha ha ha... the shit I right.... well the P is near the L

[russaroll]

Do it yourself. You will gain more knowledge of your car and once you are done you will be glad you did it. Before my Datsun I barely wrenched on my cars, I only knew the basics. L20b swap was the first swap I ever did and I never looked back.

You will get frustrated but YouTube and forums are just a click away. Everything you need to do can be done in your driveway in the course of a weekend.

[racerx]

if you are running a weber 32/36 w L20, you may have to get a thinner carb filter.  May hit the hood.

[shacks510]

The exhaust will probably hit the floor, so be prepared for that.

[Dolomite]

Put the 510 oil pan on the l20b, even if the exhaust doesn't touch the body it's close enough to heat the floor so use some insulation, be patient and calm wrenching on a datsun is simple and enjoyable, try to get it to sit low as possible so there's no binding in the throttle linkage.