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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.    

Ready for battle!       Getting geared up to start machining the heads. Officially the first production run.    

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I’m sure OSHA would have no complaints with anything in this picture:)IMG_3537.jpeg.de062c1cd9b7dfdaeb376721f3638f98.jpeg


Now that I have a surfacer I’ve decided to play around with CC’ing chambers after I make my final pass.   When I originally modeled the chamber in 3D I left a 1mm straight wall plus machine allowance for the builder. The reason for that was to create a known steady surface area if you wanted to really dial in the chamber volume. A .010” surface cut will remove approximately 1.3 CC’s.  The problem is Even though there are seats in the head you can’t put valves in since the guides are not sized and even if you could  they would sit proud of the seat since they are not angle cut. So I machined out some plastic plugs to sit as close as I could to flush with the seat face.




Not perfect but it's as close as I'm going to get. 




I almost look like I know what I'm doing :)  Actually this isn't part of my normal operations so I'm still in the "get fluid everywhere but where you want it" mode.





Right now the math is following pretty closely to the actual measured chamber size.  Not sure what my ultimate goal is since I have no plans on hitting a target CC when it leaves the shop.  Ideally in my thinking you would do the valves and make your final surface cut and CC the chambers. Then you would order pistons designed to meet your CR goals. The problem is that can add months to a build.  I’m basically grabbing data to see how much variance there is from head to head.  I think that ordering pistons based on a certain CC chamber and then have the builder surface and CC to dial it in will be the safest approach.

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