L16 head on L20B

[sdsurf]

What are the pros and cons to putting a L16 head onto a L20B block?

[datzenmike]

If a true L16 head with about 38cc chambers, the compression would be way up there. (9.32} Depending on the head number, the valves and ports would likely be smaller and have a 'lighter' cam although an L20B one could be installed in it. Also the port shape might not match the L20B exhaust manifold. Square vs. round?

 

I have put an L16 from a '71 521 onto an L20B motor. I checked with the Datsun dealer and they said it would not fit, so I did it anyway and went back and showed them. Ran fine without pinging.

[DanielC]

I am no engine expert, but off the top of my head, you get smaller valves, but a higher compression ratio. Try to use the L-20 camshaft and rockers.

The ports on the manifold side of the head probably are smaller, and may not match the exhaust manifold. L-16 has a semi square port, L-20 has a round port.

[banzai510(hainz)]

if you have a 521 with the stock squareport exhaust manifold.

it will be OK for a daily driver.

As the others said it will have smaller intake ports and valves.

I woundnt ever worry about swapping the cam. Esp if you dont know what your doing. the rockers belong to the cam lobe they cam from and shoulf not mix them.

 

L20 heads

U67 square port

 

W58 round exhaust port

N60 (i think is another)

[sdsurf]

The head is a 210 that was on a early 510. I also have 210 head on a 72 521. I was thinking just a straight swap for know as I have the complete manifold and carb setup from the 521.

[Pacific coast Datsun]

Hainz, how much a a gain would it be to swap in a stock L 20 cam & the correct rockers onto the L 16 head? That whole assembly basically can be removed intact if done carefully. Mike, that may be an option if youd gain a few HP out of it.

[datsunaholic]

The main difference will be in the HP/torque curves. Due to the tiny valves all the power will be low, with OK torque, but it will strangle the engine over 3-4K RPMs. But it will run great down low because the velocity will be quite high.

[banzai510(hainz)]

Pac coast.

I would NOT waist your time with a 210 head in the first place unless its just to drive around. Daily driver ect. Thats it.

just use the 210 to get the car/truck going.

 

wait long enough a A87/w53 head can be had for cheap.

 

I have a stock L16 210 head I keep, I used to trouble shoot when my motor had oil going in the pan. thinking it was the head/or head gasket but finding out later it was a hole in the front cover.

 

If anything I have learned is Bolting a 38DGES Weber down draft carb on a L motor gave the most performance gain and didnt have to break open a motor.

[sdsurf]

Yeah, I just want to get the thing going for now... The reason I say the 210 head is I have the complete manifold (intake and exhaust assembly. I also have the U67 head off the L20B but no intake or exhaust manifold. I have an intake but it is taken apart. I would use it if I knew what vacuum holes to plug and what to use as a block out plate for PCV.

 

[datsunaholic]

You can put the L16 intake and exhaust on the U67, just plug the water oulet on the manifold. Or drill the requisite holes in the U67 head (seen it done either way). The U67 has the larger valves that are correct for an L20B.

 

The L16 intake has smaller ports, but it's not that big of a difference (the other way around would be a problem). 210 and U67 are both squareport heads, and you really don't want to run the crappy stovepipe U67 intake/exhaust anyway.

[datsunfish]

Why would you need to plug or drill the water ports out?I have been told it would be bad not to but,I have a w53 without water ports on my l16 in my dime with the stock intake with the water line connected.No changes and it works fine.Has for a while.

[sdsurf]

ok... so if i use the L16 intake do I plug or not.... concensus people :):D:blink:

[Pacific coast Datsun]

Mike, on my L 16 intake the water outlet is plugged.......i circled it,[follow fuel line]

[datsunaholic]

Do you need to put water ports in the head or block the intake? No, but here's the thing...

 

If you keep the head with no ports, but leave the intake inlet connected it's a dead end for the water. With no circulation the water stagnates and can cause corrosion.

 

The reason for drilling out the head, and leaving the intake inlet hooked up of course is to get circulation. The purpose of coolant in the intake is to HEAT the intake to prevent carb icing. If you don't drive in cold (subzero), or just freezing high altitude locations like Denver, it's not a big deal.

[sdsurf]

Thanks!!

[banzai510(hainz)]

i like the L16 intake and exhaust. if you have bigger intake ports in a different head you could always hogged it out

[DanielC]

Years ago, I biought a JDM L-18 engine, (Fuel injected) to put in my 521. Like am idiot, I got rid of the fuel injection stuff years ago. I hate myself for doing that.

I just put the L-16 manifolds, and carb on the L-18, and ran that. I did drill the two holes in the head for the intake manifold water passages. It helps the engine warm up faster. It vaporizes gas going into the engine. Liquid gasoline in the combustion chamber washed oil off the cylinder walls, and contaminates the crankcase oil. Vaporizing the gasoline also helps cool the engine.

[datsunfish]

Gotcha.It makes sense to avoid corrosion for obvious reasons.I change out parts so often I loose sight of the longevity factor.