Derek

And this guy gets it. It's a 6 cylinder K20 head. Apply whats already been done and you have power. I'm not going to address every individual comment about manufacturing the cores but they all have merit. Most of this comes down to Machine capacity and talent. I can't rough out a 30" core blank between centers on a lathe. It will chatter like there is no tomorrow. That means a steady rest setup for each journal. Comp cams can't seem to do it in one shot either http://www.mmsonline.com/articles/more-effective-camshaft-machining I seriously could make twice the money doing pattern work as it would cost to buy the blanks in the time it will take me to make two cores. But this doesn't solve the problem of production anyway. So no I won't be machining cores. I suppose the way forward is to find a lower priced 8620 core. Either through group buy or cheaper source. I can make patterns and chills to do iron cores. I can get them poured and certified. But if that only satisfies he lower HP builds then it seems pointless. Resources would be better spent towards machined cores. Which would be my preference. I agree with G-E. It did seem like a "go away kid you're bothering me" kind of price

I'll just put you down for two then

Hi Dan Not sure what performance or what stock your looking at but the stock honda exhaust rockers are $25.00 each. Being a non vtech you use exhaust on both the intake and exhaust. PN 14624-RAA-A00. Ferrea roller rockers are around $80.00 each. Derek

It's most likely the machining of the 40 mm round down to the profile that is the majority of the cost. Not the hardening. If I was doing it I would do all the round work in the lathe and then switch over to the mill with a 4th axis to cut the lobes. I can do this but I can make more money doing what I do best and pay someone who does cam cores all the time. And that costs between $1300.00 and $1800.00 each. My inbox hasn't exactly been overflowing with people who want to buy a head. And the cam prices haven't made it any better. Let's face it. When we were all saying I wish there was a bolt on cross flow twin cam head for the L6 we should have added "and it needs to be under $5000.00 complete with cams valves etc". Because based on the feed back I've received off forum this is the point where the decision is easy. After that for every $1000.00 you add it becomes harder and harder. The $3000-$4000 "just for cams" pretty much killed off the two that were serious. If I pull the plug now at least I'll shut everyone up about a twin cam head for the L6 and the mods can instigate a immediate ban on anyone who mentions it again:) Because a twin cam head for the S30 can't be produced in the numbers that will be purchased by S30 owners for under $8000.00. And that's if you're creative and can scrounge. $10,000.00 or more if you don't want to scrounge and would like to make reasonable power. Even if I based it on an RB30 the additional machining costs would put it on par with the K20. There is a reason the OS Giken is $40,000. This kind of work is expensive. 4 or 5 people who are ready to commit at these price points and it can move forward if not I've accomplished what I set out to do which is to showcase 3D sand printing to my clients. And believe me at this point they're impressed. Derek

Thought I'd do a quick update. The cam situation is a lot tougher than I led myself to believe. Actually it's not tough at all it's just expensive:) Custom made steel billet cams are going to be in the neighborhood of $1300.00 - $1800.00 EACH! And this does not include the final grind. I'm working on a much saner approach using cast iron cores which is what most of the cam cores are made up of. Google "chilled iron cam cores" and you'll learn plenty. The manufacture of these cores are not at all outside the bounds of what I can do. Being a cast item it actually brings it into my sphere of influence. I have 2 foundries that can pour the cores depending on what iron needs to be poured. The general consensus of my "brain trust" is that Ron Iskenderian is the guy to talk to as he is receptive to this kind of crazy talk. He is on vacation for two weeks so unless he's following this thread it will probably be three or more weeks before I can get some answers. So we're basically on hold for a bit. I also revisited why I ultimately chose the K20 over the RB head. The RB head is a lot trickier to machine and cast. It has an internal oil passage that needs to be cored as well as 2 passages that need to be gun drilled the length of the head. They are too small to core as the sand would probably break. Plus there is the matter of machining the cam towers and precision boring the lifter bores. If we were doing a group buy of 10 or 15 heads and getting all the machining done at one time then this would be feasible. Of course if we were doing a group buy of 10 or 15 cam core sets the price would probably come down on those as well. So it goes. Derek

Happy birthday you old fart! Welcome to the club. Wait a minute isn't it tomorrow where you're at? Or is it yesterday where I'm at.

That was awfully sappy...I think I threw up in my mouth a little..

Nope:) But it is what I do for a living. So there's that. The internals are very close to the K20 with extra meat in a few areas. Honda tries to save every gram for production costs as well as vehicle weight. Me, not so much. Thicker combustion chamber, thicker bottom surface, larger radius on the fillets, every head x-rayed, every head impregnated, etc etc. But you certainly bring up a valid point so don't think I'm dismissing you. All I can do is bring everyone along every step of the way and it's a journey we'll take together. The one that goes on my car may be the last and that's ok too! Derek

Head casting pricing. Some will be happy. Some will be sad. And so it goes:) Well I was trying to get a more complete picture for you but unfortunately I don't have cam pricing yet. And I'm not a big enough fish to push. The head casting, valve cover and front cover UN-MACINED is going to be $4500.00. My ESTIMATE for machining the parts to the point that an automotive machinist can finish it is going to be in the $500.00 range. I'm counting on being able to fire and forget on the machining. This should be doable based on the fact I'm printing the cores. If I have to stand over it the whole time it will double for sure. I'll have a handle on that after I machine the first one. Every head casting will be X-rayed and impregnated. Impregnation is a processes where the casting is put under a vacuum and a sealant leaches into the pores. Not in this is the intake manifold. I'll obviously be offering one but I haven't had time to draw it up to get pricing. If you think you are going to want one of these then by all means PM me. The more people we have on board in the beginning the better. Thanks Derek

Went and picked up the casting yesterday. Looks great. No surprises. I checked the shrink rate when I got back and my edumicated guess appears to have been good. I was off by .015" or so on the total length which for this size casting is not too bad. keep in mind trying to measure a casting is like trying to measure a rock. Just to give you an idea how cool 3D sand printing is here is a shot of the part number and name. Unfortunately that's the only one you'll see like that as that area is going to be where the new water outlets will be. Not a lot of clear exterior area for branding! Met with the shop yesterday that will be doing the automotive end of the machining. He didn't see any obvious issues which was good news. I should have some rough pricing soon. I'm waiting for cam core prices. That will give you a more complete picture. So the next step is to make a plastic mockup of the head. I'll machine it as far as I need to to feel comfortable with the strategy. Which at this point will be most of the way. The worst part is I only have one 4th axis and it's making money for the next few days so I'm on severe hold I hate when work gets in the way of fun.

I believe you are correct. Tony pointed this out to me but it was too late in the process as the molds were already printed. Version 2 will have access to the water jacket above each exhaust port. If you want to get to it you mill through the head. This way if you have a high heat turbo build you can exit the water at each port tied to a single tube with thermostat. Personally I won't need it for my NA build but it will be there for those that need it. The OS Giken is this way. Yea that would suck. I thought about that a few times. I hope they are actually getting the backup service now.

Exactly. The combustion chambers, ports, water jacket and the front and back of the head are printed in one piece. If you look at the bottom picture of the casting you will see a tab on the front and a tab on ...well half a tab on the back. It short ran. Anyway on the front tab you see 2 pins. Those are hardened ground steel dowel pins that are cast in place. There should be 2 in the back, and that will be fixed on the next ones. Those pins will slide into a fixture on my rotary table. I'll then probe various points on the head to find the center of the casting. You then average out from there. I do this pin trick on all the larger castings I do. Makes life little easier for the machinest. You know how cranky they can get. When I modeled in the cam tower and rocker, the valves that I had modeled in previously didn't line up with the rocker. I tilted the valves .5 degree pivoting at the bottom of the valve guide and it lined up. So the difference between lining up and not lining up is half a degree. Now I could drill from the top like the factory and wherever the valve seat ends up well thats where it ends up. If I had a head to scrap this would be a simple fix as I will get the angle right after a couple tries. Trying to get it right on the first hole will be tricky.

Larger gear means more teeth which means new gears up top to keep the ratio correct. Also the honda chain is a smaller profile than the L6/KA chain so there might be a strength issue.

The crank gear was too small to fit over the snout. single chain was my preferred route but there was just no way to make it happen. At least not with off the shelf components.

Pretty much everything. Think of it as the ultimate Vtec killer. I still have things to work out with the cam towers and oil flow. Technically the cam gears would be in the back of the motor if all things were equal to the K20. Since I'm having custom cams made this won't be an issue. Of course since it's custom anything is possible:)

Yea if I was doing this for a customer I would tell them to budget for four heads. One for the foundry to get right. One for the machinist and one for the unknown. If your lucky you might hit on #3. There is a lot of good and bad in the 3D printing field. I just wish they hadn't settled on mesh as the modeling standard. I can be quite cavalier when I'm modeling for CAM. who cares about gaps as long as the smallest ball mill won't drop into it.

You can also just use all exhaust rockers as they aren't Vtech. As far as machining goes there is one point that may be vexing for people (me) who have never machined a raw head casting. Getting the tops of the valves to line up with the rockers. I modeled in a cam tower and two rocker arms. The models are based on high res scans so they are accurate. I based the location of the tops of the valves from one of the heads I purchased. As you can see in this screen grab there isn't a lot of room for error as far as the angle of attack of the rocker to the valve top. This has been my biggest worry. I imagine you only get one chance to get the angles right on drilling the valve guide bores. I'm not totally sure if the head casting is any good or not. Castings shrink as they cool and you factor that into the design. The problem is at the level I work at it's guesswork. The more cores a casting has the harder it is to predict the shrink rate because the hard sand reduces the shrink. So the reality is the casting may be too long or too short. It may also fail when I have it X-rayed. If the casting is junk then I have 12 tries to determine the right angle. If the casting is good then I'll probably machine a plastic test head that matches the actual casting and practice on that. If anyone has any experience on this kind of valve work I'd love to hear from you:)

Hi I wasn't. I was merely using it as an example of the high end of things. Not the market I'm going after. This project is as much about proof of concept as anything else. Patternless casting has arrived. It seems expensive, but for this type of project it's ideal. I'm not the only one doing this. Ford racing bought a few of the 3D sand printers and are using them in their head development. There is a guy reproducing Ferrari heads that are NLA, and I'm sure there are more. I do a lot of motorsports work. This head will open up some of my clients eyes even further as to the possibilities. I'm doing this head for the Z because it interests me. And I have a car to put it in! I mentioned in the post that the nissan and 3000 were going to be machined in. The actual castings will be blank.

Love it. I think I want my member name changed from "That Horny Z Guy" to "That Derek Fellow"

Cheap as compared to the OS Giken:) I think that comes in around $40,000.00.

All Honda. At least the intake inlet and the exhaust outlet. What happens in between is my design. I could but in reality it's a Vtech killer. I suppose if someone was inclined they could make it a Vtech but that is a hill I'm not climbing! No problem prodding! I'm going with custom Crower cams. This is not as big a deal as is it used to be. Thank you technology:) Here is the really neat thing about 3D sand printing. If you want intake on the left and exhaust on the right all I need to do is 3 mouse clicks and the entire mold package is mirrored. Sometimes cost goes beyond the price of the components. The RB has cam saddles that are part of the head. This requires line boring. The K20 has bolt on cam towers. This reduced the cost of machining greatly. That was the tipping point for me. I don't own a line boring machine:)

Hey I just noticed that I failed to mention that ALL of the foundry sand for the mold was 3D printed. not just the cores. There are no patterns except for some exterior gating pieces. This is pretty cutting edge stuff. I've been woking with the process for a few years now and it's really amazing. Any changes I need to make to V2 are done digitally which is nice.

Thanks. The intake will be custom and will be flanged to accommodate the DOCE pattern. I think the port spacing on the DOCE pattern will work so I can use 6 individual Jenvy ITBs. My plan for the exhaust is a little more convoluted. L6 block on engine stand, Mount P90 on block, bolt on header and fixture it to the side of the block. Remove header and p90. Saw flange off of header. Mount new head on block and return header to fixture. Manipulate tubes with heat and fabrication to match new flange and weld. This build really is about how cheap. Although the Jenvy ITBs are a luxury, I still want them! I could go with OBX stuff and may have to if I bust the budget.

Hi Ray. Since I'm using the Honda K20 valves and valve train I felt it was best to stay as close to their design as possible. We decided against the RB as a donor because the K20 just had so much stuff easily available. This build is going to be the budget build. I bought 2 K20A3 heads used. That will give me enough parts to do one head plus some spares. Since I'm not using the Vtech option I needed 4 additional exhaust rockers. Derek

Well you know..Idle hands. I'm finally going to use the .040 motor I bought from Tom. It's going to be the mule for this head.