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Twin cam head for the L6 from Derek at Datsunworks


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This is all Tony D’s fault:)   Hi everyone. Some of you know me from my  DIY EFI manifold project http://forums.hybridz.org/topic/63445-making-my-own-efi-intake-the-first-casting/ &#

Machine work finished!   I can relax a little:) Just got done with their first bath. Still need de-buring and edge finishing but the majority of the work is done.    

Yes, the exhaust port 'could' use some work, the as-cast cleaned intake is flowing within 10cfm of a 4 hour port job on an OS Giken head.   Those numbers outflow most max ported SOHC heads

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Thanks

And yes it is February. But I didn't say what year:)

Got me on that one! That'll learn me to sass a man who grapples with problems I cannot comprehend.

 

The fit looks amazing in a Z. Hopefully I'll have a little more room in my C110. And as its a RHD setup those headers may work as they have to clear the idler arm, not the steering.

 

I'm thinking high rpm NA howler application.

 

Btw reported for porn for those last pics.

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IMG_0947_zpscvzbm6jq.jpg

 

Hood clears no problem. The gyrations I have to go through to get the valve cover on qualify as performance art. It just clears the hood latch bracket. I think most of the problem is with the oil supply plate that I added. It won't be on the production heads so I hope it won't be an issue going forward.   Yes I know the wiring is a mess. It's on the list:)

 

 

 

 

 

It clears the hood, but will the ITB's sneak in there? looks like it'll go close. I'm sure you already know the answer to this ;) 

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Derek will this head support a L20 6cyl bottom end, or is it way to much head for that capacity.

 

Just curious as only L28 and greater is mentioned. I realise high rpm will be required to make it work, just spit balling some ideas about sneaking into U2L class racing hehe

I'm not familiar with that block. If it's the same as a L series except for bore then yes it will fit. I don't think you could move enough air though.  

 

 

 

Hood clears no problem. The gyrations I have to go through to get the valve cover on qualify as performance art. It just clears the hood latch bracket. I think most of the problem is with the oil supply plate that I added. It won't be on the production heads so I hope it won't be an issue going forward.   Yes I know the wiring is a mess. It's on the list:)

 

 

 

 

 

It clears the hood, but will the ITB's sneak in there? looks like it'll go close. I'm sure you already know the answer to this ;)

 

ITB's fit with about 1.5" between the shock tower and the velocity stack.

 

Looking at the pic, the ITB's will be fine once that black box is moved.  I'd throw it where the battery tray is, and move the battery behind the passenger seat :D

 

The black box is moving forward and the battery is staying put. Got enough on my plate already:)  

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Derek will this head support a L20 6cyl bottom end, or is it way to much head for that capacity.

 

Just curious as only L28 and greater is mentioned. I realise high rpm will be required to make it work, just spit balling some ideas about sneaking into U2L class racing hehe

Can't move enough air. I can tell you with the noncrossflow head we had, the L20A was still good at 12,000+ rpms doing Valvetrain stability testing... This head exceeds that head's flow numbers by close to 40% (and not the 300% as claimed on some websites already touting this head with BS and insane salesmen's gibberish!)

 

That being said, there's nothing that says a run with smaller ports couldn't be done given the core technology used. Maybe use a set of B16 valves which would roughly accommodate similar swept volume per cylinder.

 

Short stroke on that L20A is a real natural buzzer when it comes to RPM's.

 

You would never punch it out to 2300 like in Japan with that head on it...thinking everybody would attribute the added performance to the fancy head and not an illegal over-capacity displacement.

 

That would be against the rules, and deceptive....

Edited by Tony D
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Biggest issue I see is my header work. That #6 runner needs a big radius mandrel bend that I just couldn't get without ordering 10 of them, so it has the "patch" on it.

 

Derek, that header will fit the L28, KA24, and Z24 bellhousings, so if you find that you need to rotate the engine to a more upright position it'll still clear. It will push the exhaust down under the car with the KA24 bellhousing though.

 

Can't wait to hear it run!

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It's got a 2.5" stub on it at Derek's request, but ideally a 2.5 to 3" cone about 4" long would be welded directly onto the end of the collector. It's all there for when it's needed.

 

This header is just a prototype, I gave up on the jigging when I learned that there was  a major revision to the Gen2 head.

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This is a 3"+ exhaust....right?

 

2.5"

 

 

Dry fitted the induction system yesterday. No surprises. And at this point in the project that's a good thing:)

 

20170707041114-eb5421e3-me.jpg

 

Since I have a large audience on this I thought I would pass along a tip I did. I normally glass bead aluminum parts to clean them up.

 

These were really ratty so I knew they would only come out marginally well.

 

20170707041056-f21a38ac-me.jpg

 

But then I tried something extra. I threw them in my vibratory finisher with ceramic media.

 

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Almost brought them back to original die cast look.

 

So there is derek's tech tip for the day:)

Edited by Derek
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Derek, I definetly see a Bill Coffey garage party award in your future. :-)

 

Actually Bill and rich came down to the shop on Friday to check it out. I'm hoping to get Bill to start up the garage parties again.

It's got a 2.5" stub on it at Derek's request, but ideally a 2.5 to 3" cone about 4" long would be welded directly onto the end of the collector. It's all there for when it's needed.

 

This header is just a prototype, I gave up on the jigging when I learned that there was  a major revision to the Gen2 head.

 

I knew money would be tight at this point so I wanted to stick with the exhaust I had. And that was 2.5".  

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