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Twin cam head for the L6 from Derek at Datsunworks

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Derek    46

Putting the finishing touches on V3. 


I decided to put the head back in the mill to do more work to the face. This is no easy task because I have to hang the head off of the table and rack the mill over.  Originally I was going to put the sealing o-rings in the sub plates. I realized that this would make it really difficult for someone with a manual mill to make new plates. I also determined that the idler sub plate was going to be around 6mm thick. This wasn't going to be enough meat for the bolt so I made a pocket in the head so that the plate could be thicker in that spot.  The oval holes are oil scuppers. 






Oh look a pile of speaker panels on the floor:)




I had to offset the bolt holes on the idler to miss an oil passage. 





I'm so happy with the sub plates that V2 will be going back in the mill for a modification.






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Derek    46

Would be cool if you could fit VVT sprockets to the cams.


Mr Monkey you really need to pay better attention. Post #1116 clearly shows VCT being implemented.  You are receiving 1 demerit :)



Here is one of the pics to make it easier





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Derek    46

Family Portrait. 

V1 V2 V3

I snapped this before I shipped V3 to Rebello and V2 went for a visit to it's owner. Probably (hopefully) the last time they will be all together.


My feeble attempt at an art shot :)



Run off to the jungle to get chimps throwing crap at me through the fence, work 176 hours, and come back to find all this..


Things move pretty quick around these parts:)

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Derek    46

Since I'm planning on trying out VCT on my build I figured I'd better finalize the valving. For me it's alway a balance of (not necessarily in this order)  function, manufacturing and style. On the VCT it's always function first since what's the point if it looks better than it works.  I knew what valve I wanted to use ( manufacturing) and where it needed to go (function) but not how to make it work ( manufacturing ) and not have it be butt ugly (style).


I picked the valve I did because of the fact it came with it's own manifold. This makes manufacturing a lot easier since I don't have to do any precision boring. Since it's an open pressure (bleed) circuit believe I need to locate the valve as close to the cam phaser as possible to try and minimize the response lag. I also have to deliver a pretty good volume of oil at times where a fast response is necessary. 


I mapped out the valve with the 4 circuits. Oil in, 2 drains, advanced and retard. 




The valve is a spring return and defaults to retarded cam position. Retarded seems to be the default for the phaser as well. Which makes sense.


Lets start with the fact that I'm not crazy style wise about hanging this valve off of the front of the timing cover. But it's the closest I can get it to the phaser and still be able to plumb it. Here is a shot of the final plumbing. Red is oil in. Light blue are the drains. brown is retard and purple is advance.




Since I didn't want the valve there to begin with you can imagine how I felt when I finally gave in to the fact that I needed a .625" thick manifold block to handle all the cross drilling. I tried a bunch of scenarios but it would have added a ton of time to the machining because of doing that kind of work on a short production run casting is tough. 




I also had to flip the valve 180 from my original position to get the advance and retard ports to match the head.


It's all about compromises in life:)







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