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Twin cam head for the L6 from Derek at Datsunworks


Derek

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Yea hopefully it will open up some options for people. SN005 took a bullet for the team and payed for the fixtures and the programing. The tentative pricing I saw seemed pretty reasonable depending of course on the flow gains. I hand cleaned up the ports on my new head only removing the casting finish and then smoothing. I'm going to get if flowed so there will be some sort of base line.

 

 

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  • 2 weeks later...

I am EXTREMELY happy that someone has availed of the CNC porting experience that is out there on the K20 Head, this is EXACTLY as intentioned!

The only thing remaining is for Derek to ship him a kit of Red and Blue colored expanding silicone foam to do the intake and exhaust ports once ported so he can scan them and incorporate them as a "Race Ported' option with accompanying flow expectations...

You can do this with the sand print technology.

This pleases me greatly.

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On 5/30/2018 at 6:05 PM, Pharaohabq said:

Question though,  How did you figure the cam profile for 6 cylinders vs the Honda 4cy? Is it based on any existing L6 cam, or fully custom, derived from L28 cams?   I will keep watching this thread and lurk your Datsunworks site.  Amazing work! 

 

Phar

 
You index the cam lobes for a six cylinder firing sequence, and use the Honda Profile. The CC of the cylinder is similar and it will work reasonably well out of the gate. The Rod-Stroke and piston position should come into a proper lobe design, but I forecast that the Hondas will be close enough on an 89mm bore due to strokes being almost identical that they will work without any major modification (like I've mentioned before, there was 500 hours a year on transpacific flights in Coach that I had considering a LOT of variables before deciding on the K20 as the example to emulate!)

These are symetric profiles in many cases. If you get radical with some of the assymetric cam profiles available for Hondas out there, all you need to do is specify the cam be ground for 'reverse rotation' as these cams actually spin opposite of the way they spin in the Honda application. Not an issue on symetric bumplobes, but it does matter on the  assymetric stuff.

Once on the cam grinding machine, they index for a six cylinder with the cam profile blanks  indexed...and now I'm talking out my arse due to age because I'm almost betting the old tracer profile grinders used back in the 70's and 80's are not used in the USA at these new high production shops anymore, and they have CNC lobe profiles they simply specify and then grind on a six cylinder firing order cam blank... no more metal profiles clamped in a tracer profile slot on the grinder... 

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5 hours ago, Tony D said:

The only thing remaining is for Derek to ship him a kit of Red and Blue colored expanding silicone foam to do the intake and exhaust ports once ported so he can scan them and incorporate them as a "Race Ported' option with accompanying flow expectations...

 

Nope nope nope.   Derek won't be lifting anyones port work nor will he be offering a "race version" so lets nip that right in the bud. I'm done with versions and design changes. This is the final version.

 

It's amazing how even minor changes in a design can lead to a ton of extra work in downstream operations.

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This is so amazing...   I can't wait to hear the next version run.  Which will make it first?  The #0005 or the VCT head.  #0005 sounds like they're going to do an amazing job. Have they contacted you for consultation?   I wonder what their CR will end up with after all that work.  What will your CR be with the VCT head? Will you require higher octane?  Lastly what engine control are you going to use? Does Megasquirt handle VCT, or is this an oil pressure thing? 

 

So... stupid numbers, but a turnkey bolt on head complete might run how much $$$$???  Are you relying only on Rebello or another distributor or could we buy one straight from Datsunworks Complete?  Sorry I haven't checked your site yet.

 

Phar

 

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Hi Phar

On 6/28/2018 at 1:04 AM, Pharaohabq said:

This is so amazing... 

 

Thanks

 

On 6/28/2018 at 1:04 AM, Pharaohabq said:

I can't wait to hear the next version run.  Which will make it first?  The #0005 or the VCT head.  #0005 sounds like they're going to do an amazing job. Have they contacted you for consultation?

Probably the VCT version will be running first since I have a running motor in a car to put the head on.

 

On 6/28/2018 at 1:04 AM, Pharaohabq said:

I wonder what their CR will end up with after all that work.  What will your CR be with the VCT head? Will you require higher octane? 

 

Not sure what they will end up with. I'm planning on 11.5:1 on mine which will easily run pump gas. But that won't happen until I build my stroker.  I'm helping SN005 with things directly related to the head but as far as engine building they know more than I do for sure. Xtreme is only doing the head machine work the owner is doing the rest of the build himself.

 

On 6/28/2018 at 1:04 AM, Pharaohabq said:

Does Megasquirt handle VCT, or is this an oil pressure thing

I'm going to be running MS3 as it's required for the VCT. It uses pulse width modulation to vary an oil valve to the phaser and a sensor on the crank and intake cam to determine position. Jeff at Linfert Performance is handling all things ECU and VCT for me. He is doing SN005 as well. It is non VCT and running a MS3 and using Jenevy Heritage ITBs.

 

On 6/28/2018 at 1:04 AM, Pharaohabq said:

So... stupid numbers, but a turnkey bolt on head complete might run how much $$$$???  Are you relying only on Rebello or another distributor or could we buy one straight from Datsunworks Complete?  Sorry I haven't checked your site yet.

 

No numbers on a turnkey head because (by design) currently no two head builds are the same. Of the three that have been sold they are very different levels. I upped the basic estimate on my  FAQ for DOHC to $14-16 K at this point. Keep in mind this is without induction or exhaust. 

On 6/28/2018 at 1:04 AM, Pharaohabq said:

Are you relying only on Rebello or another distributor or could we buy one straight from Datsunworks Complete?

 

I'm not relying on Rebello as the sole source. Xtreme Has a lot of experience with K20 heads and that directly applies to the KN20. Right now I'm being very picky about who I sell to because it is really easy to get sideways on certain aspects of this. I only sold the head to SN005 because he had lined up Xtreme already and I made him qualify with me over the phone that he had the skills to do the rest of the build.

 

I have no plans at all to offer a ready to bolt on head. 

 

 

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On 7/3/2018 at 11:27 AM, turbogrill said:

Curious, who are the customers? A public build?

 

He has gone public so I'm assuming it's ok for me to post this link.

 

72 GTX Skyline build page

It looks like it is going to be an epic build. 

On 7/3/2018 at 11:36 AM, SleeperZ said:

OMG Derek, I know I'm not alone in vicariously living my car fantasies through you.  That is amazing.

 

I'm living vicariously through V3 and SN005 since I can't seem to find time to get my car back on the road:)

Edited by Derek
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I didn't realize Garage_junkie had a build thread here on Hybridz so I updated the the link in my earlier post to direct you there.  I'm seeing most of these pics the first time and I'm just blown away how cool this build is going to be.  

 

Derek

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  • 1 month later...

And yet another timing chain mockup series.

 

I'm convinced when they design a motor the first thing they do is the timing chain. Talk about restrictive.

 

SN005 is building a tall deck motor so I needed to work out what we were doing on the timing chain. I was hoping that my normal KA setup would work with a redesigned pivot for the tensioner arm.

 

20180818135754-63f7e427-me.jpg

 

Actually worked out better than the normal setup. It looks like the extra height on the head will allow the arm to clear the timing cover without modifying the cover.

 

It uses all the stuff from a KA24 timing chain kit except the bottom chain needs to be a 94 link instead of the 92.

 

 

I was trying to get the arm closer to the tensioner but this is the best I'm going to get. Each full link you add or subtract shortens or lengthens the chain by 5/8” so the adjustment is pretty coarse.  The guides are stock out of the box Nissan KA24. The jumper brackets on the tension side are temporary. I’ll design something a little better.

20180818135819-e0da84f7-me.jpg

 

I'm happy with the angle on the top tensioner. The upper brackets should start to become a standard item at this point. I changed the way the cam cores are being produced. I'm bringing the cams to length after heat treating and then shipping them to Schnieder for OD turning. This is giving me a lot more control. 

 

 

20180818135844-a13f3995-me.jpg

 

 

 

I know it probably seems like this project has stalled but far from it. I just decided to concentrate on getting my build, V2 and SN005 finished off. I realized after selling 005 that there are still a lot of little details to work out and I don't have enough free time to do my regular work and support any more builds. The next three heads will go a lot smoother now that I have all of this worked out.

 

Derek

 

 

 

 

Edited by Derek
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Hi Derek, 

 

as I said before,  Great work..

Can you do a picture or two from the top,   side showing how far the sprockets sit way from the head, and the alignment,

also, can you show some picture how the mid 2 sprockets attach to each other ( to lock them together ), and how the sprockets connect to the head

thanks you in advance

 

Nigel

 

 

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4 hours ago, Noddle said:

Hi Derek, 

 

as I said before,  Great work..

Can you do a picture or two from the top,   side showing how far the sprockets sit way from the head, and the alignment,

also, can you show some picture how the mid 2 sprockets attach to each other ( to lock them together ), and how the sprockets connect to the head

thanks you in advance

 

Nigel

 

 

 

Hi Nigel

Unfortunately I took everything apart already so I can't get any pictures. The entire chain setup is stock Nissan KA24 stuff and for the most part the spacing on my head is designed to match that.   The middle idler gear is all one piece.  

 

I know that's not much info but it' the best I have at this point:)

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I was happy with the layout so I went ahead and made the parts.

 

This is what I settled on. A sub plate for the idler and a sub plate for the pivot guide and tensioner.

 

IMG_2201.jpg

 

Then a spacer plate to bring the tensioner into the correct position.

 

IMG_2202.jpg

 

I drilled the top gears so that they have 2.5 degrees adjustment and the cams are doweled to break that into 1.25 degree increments.

 

IMG_2204.jpg

 

Bottom gear is new. It is a triplex 06P sprocket from Martin Sprocket with the teeth case hardened. I then bored, reamed and honed it out to 35mm.

Before and after.

 

IMG_2209.jpg

 

The idea is that the inner and outer sprockets will provide strength to the middle driving set. This is way better than what I was running on the prototype. There is 3.5mm of adjustment front to rear via shim packs. This will make setting up the chains a lot easier.

 

IMG_2210.jpg

 

Came together just fine.

 

IMG_2214.jpg

 

IMG_2211-1.jpg

 

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