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Everything posted by Derek

  1. Yea I hate guesswork too. It's as simple as "that's how Honda does it". I never considered it because I don't like to change Honda's design much. Looking at it again I don't know if you could make the journals big enough to clear the lobes and not hit the tower bolts. Also it would make plumbing the VCT a little more difficult. Interesting thought though.
  2. 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/ Well now I’m tackling a DOHC head. Some history: I get a PM from Tony D in September of 2012 about the Goerz-Paeco DOHC L6 Head coming up for air.http://forums.hybridz.org/index.php/topic/109116-dohc-l6-was-somebody-looking-for-the-goerz-paeco-dohc-l6-head/?&gopid=1020596 Which led to a brief discussion about what would be involved in producing a head. And that was the end of it... Or so you thought. Tony and I started trading emails about the feasibility of producing it and what kind of heads we could use as a donor for the valve train. Tony suggested bringing Jeff P on board because of his work with cooling the L6 head. Tony and I kicked around RB and KA motors for a while and then Tony suggested checking out the Honda K20. Bingo. Removable cam towers, factory roller rockers and a plethora of aftermarket parts. I called one oh my clients that is big in the import drag market and procured an old K20 head. I did some quick measurements and decided that it was probably workable. And so the journey began. The idea is to use the cam towers and valve train from a K20. I grabbed a quick scan with my white light scanner of the exterior. It’s dirty because I’m only using it as a reference scan to design against. I imported the scan into my solids program and then proceed to replace the mesh with solids. Jeff provided me with a great CAD drawing of his head gasket to work from. I decided to take a module approach to model the head. I made a single cylinder complete and the copied and offset it for the other cylinders. I then pulled the solids together to create a single model. At this point I was at a standstill until I could figure out what to do about the timing chain. Jeff and I had a long conversation about pros an cons of various designs. The preference would be a single chain so I ordered up a K20 set to see if it was workable. NOPE. Lower timing gear is too small to bore out to fit the L6 crank. Back to the drawing board. I decided to give the KA set a try. I decided the Altima set would be a good choice as it’s only a single row chain up top. With the roller rockers I don’t think you need a double row. I did a rough mockup on a piece of wood mounting all the pieces. Then I machined a chunk of plastic so I could actually mount it to the block. You can see I’m trying to incorporate the KA guides and lower tensioner but that won’t happen without a new lower timing cover. Here is the lower section with stock modified L6 components. The only tricky bit is I need to remove one link from the chain. I think this is a workable solution. Now I could finish modeling the front and back of the head. Next the front timing cover. The water outlet exits the head in the front and makes a 90 degree turn through the timing cover where the thermostat housing will mount. Now the valve cover. The K20 cam towers kind of dictated the overall size but I was still able to get the styling I was looking for. I was trying to have the flavor of the S20. I’m still tweaking the design but so far I’m pretty happy. The “NISSAN” and “3000” will be machined in so they are kind of placeholders for now. After talking with Jeff about his testing on coolant flow I decided to get the most out of the 3D sand printing process as I could. I designed a water jacket that would be pretty hard to duplicate traditionally. There is a lot of surface area so hopefully there will be large improvements in cooling. Here is a nice shot of the intake and exhaust cores, water core, and upper tensioner. You can see where the cross drilling will go to supply oil to the head, tensioner and idler gear lube. There will have to be additional oil supplied to the last three cam towers as the single feed in the front won’t cut it. Here is a cross section of the head. The cut plane is through the center of one of the intake valves so the ports look a bit off. There is machine allowance on the bottom so the combustion chamber is a little larger than it will be after surfacing. Well like I said in the original Goerz-Paeco post I think this is a very viable approach to producing DOHC head. Should make for an interesting conversation. Derek Oh and one more thing. What good would a thread about casting a head be without....... / / / / / / / / / / / / / / / / / / / An actual casting. We poured this Monday and I just got these pics from the foundry today. I haven't seen the head personally but we're pretty sure it is good enough to move forward with. Still lots to do but you can't imagine how happy I am to get the first one right. As long as things proceed as planned I will be selling these. There is still a lot to figure out. I have the foundry working up some pricing for me and I'll post that as soon as I can. Thanks for looking Derek EDIT: I now have a blog about this head on my site. I'm going to continue to post here but the blog is a condensed version of what you see here. There is a FAQ on the left side bar that has a lot of data. If you are new to this build you may want to come up to speed there and then start following it here as there is a lot of great back and forth that isn't on the blog. http://www.datsunworks.com/Blog/
  3. Finished machining the cam towers. I already posted some of these on my blog and facebook page but figured I'd go ahed and dump them here as well. First up is really the last but since is the most interesting part I figured I'd lead off with it. So from V3 forward I have been working on making sure that people who wanted to upgrade to VCT down the road wouldn't be stuck buying a whole new head. This has turned out to be pretty difficult but not impossible. Complete redesign of the valve cover and modifying the pattern, new timing cover design and pattern, modification to the front of the head and redesign of the cam towers. Finding room to fit two oil delivery systems was the trickiest part. Here is a shot of two number one towers with the caps off. VCT on top and regular on the bottom. The only modification to the head and cam towers to switch to VCT is to mill two channels from the 6mm holes out to the oil grooves. To be clear you will need VCT cams and all the timing and valving bits. My opinion on VCT is still that it's probably an expensive gadget but I needed a new challenge and figured I'd see if I can make it happen. So if you are planning on a budget build I wouldn't be holding out for VCT:) Here are some in progress pics. Regulars to this thread have seen this stuff before but people seem to like shots of me making chips. Thanks Derek
  4. L28 head 3D scan, flow, CNC

    I would use the faro for sure. Develop guide curves and cross sections from the points. Use those to develop poly surfaces then convert to mesh. If you are trying to improve the flow with CNC machining then the wall thickness data is as important as the actual port shape.
  5. L28 head 3D scan, flow, CNC

    Having done a fair amount of this work in the long run you may be better off getting your data from a touch probe in a mill or a digitizing arm. Getting a proper scan can be really challenging. When I did the Honda head I split the port along the casting part line then created a two piece mold with spacers to make up for the band saw blade kerf. I then made a resin plug and scanned it. Since I wanted something I could develop I ended up pulling curves from the mesh and used them to create my ports. Derek
  6. Just new here

    Welcome fellow Floridian:) Do you have a Z car?
  7. New Moderators

    Yea but you know when a thread is going off the rails
  8. New Moderators

    I'm flattered but I can see a conflict since I'm a vendor as well as a user. I nominate JSM. He always seems to have a level headed approach.
  9. I've been running a Spartan for a while and have had zero issues. I had nothing but headaches with my Inovate LC-1. Probably killed 3 or 4 O2 sensors. Derek
  10. Project Binkey

    So I posted this in another thread but figured I should put it here. They are doing a AWD conversion on a Mini Cooper. The fab work is really amazing. The video series is entertaining and really filled with a ton of great ideas. Derek
  11. Cam core lathe work finished. Gun drilled S7 tool steel. Eight standard and two VCT. My poor little lathe got quite the workout:) These are the fronts of the VCT cams. I'm copying the K20 dimensions as closely as possible. For some reason they use a very shallow feed groove on the cam bearing and a much deeper groove on the phaser end. Number one cam tower with the VCT grooves machined in. The drilled holes lead down to the head and the grooves will line up with the cam when I bore the towers. The letter C is where the intake cam will be. Although that is a coincidence as this is tower 1 set C. The next step is numbering the towers and after that they are machined as sets. I'm doing five sets this run. Making progress! Derek
  12. Thanks for the info. Yes I meant either would do a good job of consistency. Seems like ethanol and dry ice would be easier to manage. I'm going to talk to my local guy. He has the skills for sure it's just that I know the value of technology and precision and his gear is on the older side. My valve seat didn't fail due to lack of technology. It failed because of poor installation and a Serdi won't help that. Derek
  13. Project Binkey

    I like how they finally timed how long it took to make one of the parts. They really should buy a cheap CNC plasma table though. The guy has mad skills for sure but this is 2017 after all
  14. I believe I called him and he doesn't have a Serdi. He also seemed to take offense that I asked. Maybe I caught him at a bad time. I have a local guy here that can do it with the older style equipment. I'm really thinking about cutting the seat pockets on mine myself. I mean it's in the 4th axis and it should be more accurate than lining up via the guide. A tech at Ferrea told me about mixing dry ice and acetone to shrink the seats. Or I may look at nitrogen. It seems that shrinking the seats in a controlled bath would give predictable results. My guides and seats were installed by someone who was very capable. They were just having a bad day. I'm hoping to minimize that by going with the Serdi. I may be fooling myself though. Thanks Derek
  15. RIP Joel Soileau

    Man that really sucks. I was just exchanging PMs a month or so ago. So sad. My condolences.
  16. Replacing dash with dash cover

    Those are all the pics I have. I will say that it is still in perfect shape with no de-lamination and up until I blew the motor it was parked out in the Florida heat every day. Realistically I'm thinking it's better than stock as far as longevity goes. I did the SEM fill the crack method and it just cracked in another place. Anything you paint on is a temporary fix. My experience thermoforming speaker panels made me realize the problem isn't the quality of the cover but the stresses put against it when you install it.
  17. Question for you Florida peeps. I'm looking for a machine shop in central florida with a Serdi valve machine. After my problem with V1 dropping a seat I'm inclined to steer away from any shop that doesn't do seats on a regular basis or with a modern machine. Rebello is hooked up with someone but I really don't want to ship my head across the country and back if I don't have to. Thanks Derek
  18. Replacing dash with dash cover

    Caps get a bad rep because they don't fit perfectly and then they are installed poorly. If you look at what I had to do in my thread in order to get it to fit you'll see that there is a ton of material that needs to be removed.
  19. Replacing dash with dash cover

    Here is how I did mine.
  20. Does auto body paint go bad?

    Silly me:)
  21. Does auto body paint go bad?

    Single stage or base/clear. What brand. Absolutely need new hardener. If you are paying to get it done you may have trouble getting the paint shop to get onboard using paint of unknown origins. Derek
  22. Does auto body paint go bad?

    Instead of spamming this forum maybe you should go away.
  23. That looks normal to me for glass beading. Raw castings are usually shot blasted then machined. I found that putting parts in a vibratory finisher after blasting restores some of the luster. I can fit my DOHC valve cover in my finisher. If you look closely you can see the difference. V3 is in the foreground and it has been shot blasted and then run in my vibratory finisher with burnishing media and liquid. V2 in the middle has only beed shot blasted. You can see a slight luster on V3. Here are two parts I glass beaded. And here they are after vibratory finishing. There are many types of finishing media. Burnishing media is what gives the parts the luster. Derek
  24. Well that looks like fun. I was messing with Rfactor for a while and even started modeling a 240Z for it. I decided to make a twin cam head instead:) The thing I noticed was it's more about the physics settings on the car more than the look of the car. Garbage in garbage out. I may have to pull my driving seat out of storage!
  25. 2009 WRX drivetrain to 280z

    I think what project binky showed me the most was that you can fit stuff in the space pretty easily. Getting it all to work properly without killing you is the tough part. What good is all that effort if it handles like a mini van.