L16 intake manifold on ported head

[datzenmike]

Hey there datzenmike, I didn't really notice that your photo was of a modified intake till hainz mentioned it was being hogged out, so will it make a differance with a L16 intake manifold?

It's hard to tell if the L20b manifold and the L16 manifold have the same runner size back closer to the carb, or if the L16 is smaller, as the L16 manifold has a water jacket for warming the manifold, when the L20b manifold does not, as it is warmed using the exhaust manifold.

Another reason is I don't want to remove the L16 manifold now, as I just mounted it with a new gasket.

Are the intake runners the same size inside?

 

The left side had been gasket matched by the look of it. The scribe lines on the right side show the relative differences. L16 runners are smaller all the way back, L20B would be larger. No harm in a smaller port runner as mentioned here. I would port match so there is a smooth transition into the head. An L20B intake would have the most mid-top and top end power.

 

Only L20B intakes that are bolted to the exhaust do not have the water heated runners. Usually with the U-67 head. All '78 and up W-58 heads do.

[Z-train]

9 MM difference.Or 4.5 MM smaller I.D. centered.I'm going to say it'll at least work decent under 5000 rpm.Higher?-nope.

[banzai510(hainz)]

Wayno

your head intake ports is 1.5 inch.We know this.The SSS manifold is MATCHED. so its a a mated pair.

 

Now try to get the L16 intake close to it buy hogging it out so the air has a smoother transistion in to the head.Another matching pair.

 

It helps I guess ,Its Free besides rotoring that bitch out. Persoanlly I hated doing it.

Later L20(non stove pipe) intake were bigger like 1.375 ,just had to make a block off plate fit the PVC set and all that.

the L16 at 1.125 I think is just so small.

 

as for power lose at Low end Its going to a single carb I think the air vol would be higher than say dual SUs at idle, so Im thinking fine. But Im not a real expert on this.

I match ported close to 1.375 in a U67 head and smooth out the down draft ports and enlarged them also to fit a 38/38Weber I had on there. It goes pretty good in a 521 but 38/38 went bad and now a 32/36 on there and seems like ai lost 15% /torq HP off the bat

 

As for the single side draft comment I just dont like them and always jeting proplem with a single carb as most people split a dual set that is set up for a dual set up jetting.

[Sealik]

No clearance for SUs...?

 

Hmmmm...wonder if this Lynz (on right) intake would work...

 

[wayno]

No clearance for SUs...?

 

Hmmmm...wonder if this Lynz (on right) intake would work...

 

 

 

Hey Sealik, the SUs from the head face to the face that the filter mounts to is aproximately 9", from the face of the head to the master brake cylinder is about 8", I have the engine tilted properly, as I had the tranny connected to its mount, and to the engine, and I determined the tilt by the transmission shifter stick.

The 1966 datsun 520 brake master cylinder is located a couple inches towards the pass. side compared to the 521 M/C, so the SU package just isn't going to fit.

I'll look around for a L20b downdraft intake that isn't connected to the exhaust manifold, if there is such a thing.

[Sealik]

Hey Sealik, the SUs from the head face to the face that the filter mounts to is aproximately 9", from the face of the head to the master brake cylinder is about 8", I have the engine tilted properly, as I had the tranny connected to its mount, and to the engine, and I determined the tilt by the transmission shifter stick.

The 1966 datsun 520 brake master cylinder is located a couple inches towards the pass. side compared to the 521 M/C, so the SU package just isn't going to fit.

I'll look around for a L20b downdraft intake that isn't connected to the exhaust manifold, if there is such a thing.

 

 

Yeah...not much room

I figured the Lynx might raise the SUs enough to somewhat 'clear' the MC..?..then just tilt the float bowls to level.

[wayno]

Yeah...not much room

I figured the Lynx might raise the SUs enough to somewhat 'clear' the MC..?..then just tilt the float bowls to level.

 

 

I am just going to live with the weber for now.

BTW, I started it today, warmed it up, the auto choke worked and everything, the only issue was the temp gauge goes to full hot when I turn the key on, didn't even matter if it was connected to the senser or not.

[Tucson620]

I've been pondering the same things for an L20 I'm building for my 521. I have two A87 candidate heads, one ported to 1.5" for SUs with bigger intake valves (44mm), the other stock (1.375"). L16 intake is tidy packaging-wise. The non-stovepipe L20 intake (from W58) is gonna flow better, but bulky with all the EGR and whatnot. Z-Train's been convincing when he says not to worry about the little intake and port step for a truck where low end torque and driveability is the goal. The 1.5" ported head is maybe not a good candidate for that.

 

The L16 (A46) casting is much less beefy than the W58. If you did want to match to 1.5" it would be a steep expansion in the runner, could be tricky not to hit a water passage.

 

The two intakes - L16 ports are nominally 1.25". Note the downdraft carb ports are a little smaller too. Forgot to measure my Weber and adapter.

[wayno]

I like the L16 intake manifold, small/compact/clean looking, but if it is going to have issues on the hiway, then I am going to have to do something about it.

If there are going to be no issues below 5000rpms, then I will port the intake manifold to match the head, how about it guys, will the ported L16 intake work below 5000rpms without issues, or do I need to find an L20b intake manifold for better flow and clean it up?

[bonvo]

No clearance for SUs...?

 

Hmmmm...wonder if this Lynz (on right) intake would work...

 

for when you want to run z carbs wow i like that manifold