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Derek

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Everything posted by Derek

  1. 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/
  2. VCT Progress! So slowly but surely I have been chipping away at making the VCT fit in the available space. What a freaking PIA. The problem with timing chains is you are constrained distance wise by the pitch of the chain and the adjustment can be a bit coarse. Multiply that by two and you can see how it can get tricky. I model things the best I can in 3D but when it comes to something like this I find a hands on approach leads to a more satisfactory result. Machined of the small gear from the KA24 idler. I'm using a 5C expanding mandrel that I machined to fit. Test fitting the Honda exhaust cam gear that I machined previously. Happy with the fit for sure. Quick test fit with the first idler sub plate. Looks good but I know from experience that there is a really long road from this point to the final fitting. Here are the finalish mockup sub plates for the idler gear and the tensioner arm pivot. I may move the idler up another .010" but I haven't decided. I do the majority of my prototyping in plastic. Easier to work with than aluminum and a lot cheaper. The idler plate will be steel and the pivot plate will be aluminum. Upper tensioner mount. The semi finished layout. Upper tensioner is from a Mazda 626. Hybridz member Tioga turned me on to this one . I reshaped the contact shoe a bit and slapped it on there. It is a ratcheting style. They can be problematic if the lobe design on the cams are crappy. The constant pumping on the chain can break the pawls. I'm making the assumption at this point the Schneiders lobe design is a lot better than Cranes and won't be a problem. I had to reshape the contact shoe and will probably work it some more if I stick with it. Tight fit but the bottom line is....It fits. Which is a good thing since I committed to the cams before I knew for sure. Unfortunately I can't access the VCT oil ports on the head because the idler gear is covering them but I already designed a manifold as a work around. So if the pictures make it look like this was a walk in the park here is a shot of the different versions of the sub plates I made to get the relationship between all those moving components the way I wanted them as well as fitting in the space I had to work with. I picked the wrong time to quit sniffing glue:)
  3. Derek

    Project Binkey

    Episode 17 dropped.
  4. Derek

    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
  5. I already have all the stress I can take right now. Thanks anyway:)
  6. Hi blog link http://www.datsunworks.com/Blog/ FAQ http://www.datsunworks.com/Blog/faq-for-twin-cam-cylinder-head/
  7. Got the VTC cams back from Schneider so I was able to mess around a bit wit the upper chain. Machining the center out of a stock Honda exhaust gear. Holy bajezas was that thing hard. I had to anneal the center to make any headway through it. Came out great though. Action shot. Looks promising but there is a lot left to do. Best part is my stuff is always S/N001
  8. Derek

    How to mount an EDIS wheel for $0.75

    That damper is different than the ones I have. Also the rubber on yours is looking pretty tired. I'd keep a close eye on it. The good news is with the trigger wheel bolted on at least it won't fly through the radiator when it lets go:) Glad to hear you got it sorted out.
  9. Derek

    How to mount an EDIS wheel for $0.75

    For whatever reason, the dampers I've worked with are 1/4-20 imperial. The only thing I can think of since the pulleys were US dealer add on they specked out imperial.
  10. Derek

    Does anyone have experience with these filters?

    Those are designed to keep rocks out of race motors that will be rebuilt every couple a seasons:) I use oiled foam in mine. I figure the HP loss is probably equal to the permanent HP loss from scored cylinders.
  11. Owner of V3 sent me an update picture. Pretty freaking cool if you ask me. I checked the 3D model and tilted the amount they did the intake side of the water jacket is just below the outlet so hopefully there won't be any steam pocket issues. Snifff....I'm so proud:)
  12. Hi Nigel. Good catch. Yes for sure. As soon as I saw what was going on I plotted out the valve cover o-ring tool path and the .125" o-ring runs right across it. The valve cover fits on the mount bolts really well so there won't be any shift. I really really really hate welding on the castings after they have been impregnated so I opted to go another way. If it doesn't seal an epoxy repair up in that corner will work fine. This is always the toughest part. Making the compromises.
  13. Valve cover powder coated. I had powder-coated.com do the powder coating on my new valve cover. Same color as V1. Excellent quality as usual. I’m a bit away from needing a finished valve cover but never underestimate the value in having it for motivation:) So this is the big change I made to mine. This is to hold a mounting plate for the VCT sensor. Since it requires a special setup on the millI I only plan on making this mod on VCT specific builds or on special requests.
  14. I'm not sure there will ever be a turn key solution. In some ways this is a real plus because you end up with a head and valve train that is tailored to your goals. Hopefully a few other builders other than Rebello will jump in and then there will be more choices. I think it's appealing to Rebello because getting an L6 head to flow enough volume to support a 3.5L can be challenging. The owner of V2 has a 3.0L and his requirements are a lot different. From a production standpoint I've made all the changes to the head that I plan to make so the next batch should go a lot smoother. Hopefully these four will move quickly so I can get busy on the next batch. Rebellos firm on two heads and possibly a third. All five casting passed the final pressure test at 75PSI and that is the point at which I can start relaxing a bit. I still have to sweat out the finishing of the cams and hopefully at that point I'll sleep a little better:) VCT cams should be in my hands next week so I'll be able to start mocking up the gears and chains. Fun fun fun! Derek
  15. V3 manifolds finished Finished up the manifolds for V3. These were tricky because the owner of V3 decided to make my life miserable tilt the motor the opposite direction. He did this for looks plus he wanted to gain some distance for his induction system. I did a quick check on the 3D model and it looked doable. Trunnion plate on the 4th axis comes in handy for this kind of stuff. DCOE pattern matched to 48mm. Made a quick fixture/index plate to locate off of the DCOE flange. I find most people prefer that their carbs/ITBs line up when they are bolted to the manifold:) Port matched to the head and o-ringed. Rebello will blend the port match into the manifold. Since every build is different I figured the best way to handle it is to cast it a little smaller and then blend as necessary. The ripple pattern you see is from the 3D printed sand. There are certain angles where the layers on 3D printed items are fairly pronounced. I was surprised how well everything worked considering the manifold casting is 180 degrees out from it’s intended angle. I kind of cheated this shot. The manifold has already been through the vibratory finisher so this is the final finish. I threw it back in the fixture to get the picture. All done and looking pretty! Added a rib in the center so that if people have drop link type linkage they can mount the risers to it. Manifold looks a little fugly in this shot but it really isn’t:) This is the last of the V3 stuff so Rebello should be good to go at this point.
  16. I'm thinking electric at this point:)
  17. 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. The VCT holes are drilled and tapped but they haven’t been drilled all the way through. Easily opened up with a drill if needed. The head has provisions for three sub plates. Timing chain idler, upper tensioner and a slack side guide pivot. The idler and tensioner are connected to the oil system and o-ringed. It is getting really crowded in there with all the oil passages, head bolts and cam tower bolts. Next stop vacuum resin impregnation.
  18. Derek

    Back in the Datsun business!

    Let me be the first Derek to welcome you back Derek. Derek
  19. So here is what I ended up with the o-ring so far. I made the groove tighter than I normally would for a pressure seal. This way the o-ring stays in the groove well enough to handle without it falling out. For those of you that don't know o-ring grooves are wider than the o-ring to give the seal a place to go as it crushes. The valve cover isn't exactly a high pressure seal and the method of attachment doesn't have enough oomph to pull the seal down evenly. I started out with round but it seemed like it wasn’t providing enough contact area based on the mount of torque I could apply to the valve cover. I ran a square for a bit before the head shit the bed but I’m not sure if it was better or worse. My gut feeling is better because I really increased the contact area with the square profile. Makes sense in theoryville, the land of my people.
  20. Ready for battle! Getting geared up to start machining the heads. Officially the first production run.
  21. Got the valve covers done. They are machined and somewhat finished. I've decided that since I don't know what people plan to do for finishing that I would leave the final cleanup to them or their powder coater. I sanded down all of the sand tears, Rand a DA over most of it and then ran them in the vibratory finisher. The flange is grooved for a .125" o-ring. I also machine in clearance for the cam towers and bolts. There are 2 bosses on either side of the plug hole. This is for a KN20 COP. The bosses are positioned so that you can have the plug facing forward or backwards. It's up to the end user to drill and tap accordingly. Semi action shot.
  22. After this batch things should start picking up supply wise. All of the things I control move along quite quickly. Every thing else just takes forever.
  23. I did what I did because it looked nice:) Seriously.
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