L16 and L18 heads

[Recon716]

Hey guys, in need of an answer here. Are the heads interchangeable between the L16 and the L18? Or the L20 even?

[datzenmike]

There are two different combustion chamber sizes 41cc and 45.2cc for all or most other L 4 cylinder heads. All North American L18 and L20B engines came with open chamber 45.2cc heads in a variety of valve and port sizes. There are also several styles of closed chamber heads that arrived on import motors.

 

Any head other than the stock 210 L16 head will lower the compression on an L16. The 210 head on the L 16 is the smallest combustion chamber, (38.5cc) valve and port head so using a larger combustion chamber will lower the compression. Yes all L18 or L20B heads will fit the L16 and have larger valves and ports.

 

 

L16 engine

L16 stock open chamber head................. 8.58

L16 L18/L20B open chamber head........... 6.72 This is a huge drop and hard to overcome.

L16 L18/L20B closed chamber heads....... 8.21  This isn't so bad and a small shave would fix it.

 

L18 engine

L18 open chamber heads........................ 8.43 .... usually an A87 casting

L18 closed chamber heads...................... 9.0

 

L20B engine

L20B open chamber heads...................... 8.4..... usually a U67 through '77 and W58 after.

L20B closed chamber heads.................... 8.9

 

 

List of L series heads... http://www.olddatsuns.com/html/tech/head_ID_2.htm

[Recon716]

Hey thanks man

[Recon716]

Or woman. Either way, thanks kitten.

[datzenmike]

I'm ambidextrous so it's ok..

[Recon716]

You can use both hands? Allllllllright.

[Jetboater Pop]

sorry to drag up this old thread but I have anL16 engine and an A87 L18 head. Can I fit it without fear of the exhaust valve hitting the edge of the cylinder as the bore size on the L 16 is slightly smaller.??? Or is my thinking totally wrong.

[datzenmike]

There is no worry about valves hitting the edge of the cylinder walls.  The wall on an L16 is only 1mm (0.040") closer that an L18 that also used the A87 head. That's about the thickness of your thumb nail.

[Adam Jopek]

Hi

I also have one question. I need to build L18S engine but I have only L18 engine in need of rebuild. I also have some parts from L16S with 2xSU carbs. Can you let me know if I'm able to build L18S from this set? I've found that:

 

-L18 has other pistons shape than L18S because of compression;

-L18S head has other intake and exhaust valves

-not sure the sam is the same in L16, L18 and L18S (but pistons shape)

-not sure of L18S manifold and carbs if they are the same as L16S of not

-not sure of camshaft if it's the same in all these engines

 

 

Thank you for help!

Adam

Edited April 17, 2022 by Adam Jopek
small changes

[datzenmike]

L16 piston dish is 7.01cc

L18 piston dish is 4.36cc

L16SSS and L18SSS pistons are flattop, no dish or dome.

 

Both L16SSS and L18SSS use the 219 head which is a closed chamber, smaller than the open chamber heads but still larger than the L16's 210 head. The combustion chamber size and the flattop pistons do raise the compression on the SSS engines to 9.48 in the L16 and 9.69 on the L18. The advantage of the 219 head are the much larger ports and valves.  

 

Both L16SSS and L18SSS us dual SU carburetors. I think they both use a 38mm throat size and intake. Basically 1.5"

 

Both SSS engines use a slightly 'warmer' cam with higher lift and duration almost identical to the stock cam used on the L20B engines.

 

Dual carburetors, special cam, flattop pistons and the 219 heads are what makes L16/18 engines into SSS engines.

[Stoffregen Motorsports]

I don't have much experience with European spec Nissan/Datsun stuff. Is it possible that the cams over there were "hotter" to begin with? Here in North America, the engines were choked down to meet emissions requirements.

[datzenmike]

To be clear the L16SSS and L18SSS (in the 510 Coupe anyway) was strictly JDM. Europe did get a 910 that optionally has twin SU carburetors on the 4 cylinder engines and long doglegs. I don't know if these also had the 219 heads, flattops etc. The 610 in Australia also got a similar engine and dogleg.

 

As to regular L16s and L18s in Europe, I don't know.

 

I have a '73 620 FSM and the cam specs for lift and duration are the same as the L20B. There are differences for cam timing events.