Derek

More V3 porn. Just stunning IMHO

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

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.

At least I thought it was:)

I can't tell you exactly where they go but I can tell you basically what they do. The metal capillary tube goes in the evaporator. One wire is 12V from ignition and the other wire goes to the A/C compressor clutch.

Hi I just finished up the cam tower shims and they are back in stock. Shoot me a PM if you want a set. Thanks Derek

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.

Hi Yes I still produce them but at the moment I'm out. I have the material and hey are scheduled for production next week. Thanks Derek

This is a production head or V4. I now refer to the production heads by their serial number. S/N005 is being assembled buy the person who bought it. He chose Xtreme to do the head work and so far I think he chose wisely. They take raw Porsche head castings and bring them all the way to a finished product so I felt comfortable with them doing the work. They also have experience with the K20. I'm hoping they become an option for people who can't wait on Rebello or like S/N005 want's to do their own build. I'm assuming they will flow the head so they will have good data for people that want to go that route.

The owner of S/N005 sent me this video. Xtreme Cylinder Heads CNC porting. I have no idea why the video is giant. I uploaded it directly to the post Video.MOV

Hi Phar Took you long enough:) It truly is an amazing process. It opens up so many things to be produced that would not have been practical before. The profile that I machine into the cams are oversized based on a Schneider profile. At that point any cam grinder with a Honda profile can finish them off. The lobe is large enough for most builds. It's S7 which means it's through hardened so you are not restricted by case thickness. Yea the VCT should be pretty interesting. I'm starting a pool for how many valves I bend before I get it all sorted:)

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:)

Episode 17 dropped.

I already have all the stress I can take right now. Thanks anyway:)

Hi blog link http://www.datsunworks.com/Blog/ FAQ http://www.datsunworks.com/Blog/faq-for-twin-cam-cylinder-head/

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

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.

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.

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.

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:)

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.

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.

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

Where is the fun in that:)

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.