L20B block differences? If any

[juanjr84]

Hi everyone,
I know this engine was used in a few different platforms. Have the opportunity to get a decent 2 liter off a 80 720 for my 77 620. Block is stock.

Feedback and comments welcomed.

[racerx]

What do you mean decent L20? Is is rebuilt? Did you do a compression check? What's the history?

[juanjr84]

A bit of history 20 thousand miles since it was rebuild compression checks out on all cylinders.

 

Can the block be used on a 620 even if is a later 2 liter?

[Draker]

All L20B's are the same the only difference you will find between vehicles is the oil pan and pickup tube. In this case they are probably the same. If not just swap with your current pan if you have one. 

[datzenmike]

There were some minor casting changes around '79/'80. The newer ones had 4 bolt holes around the oil filter boss I think. This same block casting was also the block for the Z20 engines. No matter, it is completely interchangeable with earlier L20B applications.

 

A compression of over 160/170 would be nice.

[juanjr84]

Appreciate the prompt response guys I will use my existing or new auxiliary items n oil pan.

 

Gracias

[datzenmike]

You could use the W58 head that is on it as it has the better water cooled/warmed intake.  Your U67 head has the co-joined intake and exhaust manifold using hot exhaust to warm the under side of the intake. These rust and jam either on or off and over heat the intake in hot weather. They're only ok when working properly. The water cooled/warmed intake keeps the intake air at a more uniform temperature over a wider range.

[juanjr84]

Will do just that and keep the w58 head/ intake suggestions keep getting better and better.

[racerx]

So what was the compression?

[juanjr84]

Pretty steady at 155-160 across all 4 clyinders.

[racerx]

That's good reading.

[distributorguy]

The '80 has the same motor mount locations, but one less hole on the oil filter side and more holes on the driver's side.  Use your old motor mounts, not the ones that may be on the '80.  

[datzenmike]

Look along the top edge of the block just below where the two exhaust ports would be. The older casting is bare...

 

 

This is a later casting. Has the 4 bolt holes around the oil filter. Has a casting boss above the starter for L20B, but if you look on the other side between cylinders 2 and 3 you can just see the boss used for stamping Z20 on.

 

 

Here's a better view...