Derek

That's one of the reasons I went with the KA setup. When I pulled the K20 chain out of the box I was like "is this a joke". It's soo small. Time will tell If the single roller will work or not. There is no way I'm going to make a set of gears until I see this one stretch

I need to mention that the Honda chain is a standard style chain and not a roller. Also it is closer to a .250 pitch not .125" Too many details rolling around in my head to keep it all straight:)

Single up top or on the bottom. Non of the KA sets that I saw have a double on the lower chain. I did see some that had a double up top and that set will work on my head as well. My theory is the roller rockers should reduce the forces enough so that a single row will work. The K20 only has a .125" pitch single row chain. It is also one single chain. The KA chain is .375" pitch. Because of these differences my gut feeling is it will be fine. When I build the head I'm going to buy a set of (probably) Brian Crower BC1040 springs. Even though my build would run on stock springs I'm hoping to replicate some of the stresses a higher HP build would have. This should give the valve train a pretty decent test. I realize there are more dynamics than just spring rate at play but it's the best I can do. Derek

Made a little progress Saturday. Machined the front of the head. I knew this was going to be a PIA from the word go. I just don't have a proper angle milling head to really go at it. I bought a used angle head on ebay a few years ago. It's designed for woodworking but it was cheap so I went for it. In the first shot I'm using the probe to indicate off of the cam bores. Here I'm surfacing the front of the head. The finish came out a lot better that I expected considering the rigging I had to do to make it work. Faced the upper timing chain tensioner and the upper chain idler mount, spot drilled the timing cover and tensioner holes. I'm going to drill and tap those manually as I didn't have anyway to hold drills in that angle head. No biggie. Got lucky on the pilot bore on the idler mount. You have to tap it on with a plastic hammer. The chain fits well. I knew I was going to make a spacer set for the bottom gear since it's a single not a double like the stock chain. The single chain tracks along the center of the guides now which is what I was looking for. Got the pattern finished for the front timing chain cover. That's heading to the foundry today. Hopefully they will cast it this week. Still have a lot to do but I feel like I have a little momentum. Derek

Got the head back from X-ray on Saturday. No big surprises. Here is a shot of the front half Here is a closeup of a known shrink porosity problem. I knew it was there because you can see it from the top. I wanted to leave it to see what it looked like in the X-ray. You can see it leads all the way over to the valve guide bore and in fact you can see it in the bore. I'll do a weld repair on the top and call it a day as it's too small a defect to affect the valve guide. Controlling solidification shrinkage is one of the tougher aspects of casting metal. We'll try something a little different on the next one. Every head will be x-rayed before they get sold. This way people can have confidence in the casting before they invest in machining.

I'll be supplying a cast steel core for an additional price. It will be up to the end user to make arrangements from there. I will also be providing the necessary data to have machined steel billet cams produced. But ultimately It's going to be up to the builder of the head to determine what they want.

Thanks Leon. I think it's important for people to realize just how much effort goes int producing things like this. In theory there is nothing going on with my head casting that would stop someone implementing iVTEC. But it would take a bit of engineering. I hope someone buys a casting and makes it happen as that would really be the best of both worlds. The way I beat...er...drive my car it would probably just be engaged all the time anyway:)

Cam scan Well everyone in the brain trust agreed that the numbers on the K20A2 cams would be a good starting point for my motor. I bought a used set of cams off of ebay. I used my structured light scanner to capture the lobe data. The scanner projects a light pattern against the object and photographs that pattern The software creates a mesh from the pictures. Here is a shot of a single pattern to give you an idea. I painted the cam white for a better scan. This is the resulting mesh. The mesh has holes as I only capture as much data as I need. I run a plane through the lobe so I can derive curves. And use those curves to develop a solid model. I can then use the deviation calculator to see where I'm at but I can usually tell if I'm off or not as I'm drawing it. On a larger project it's nice just to make sure I didn't miss a feature. Now I can start designing the cam core blanks and patterns.

Time to leave the nest! Heading to JAX for X-ray

Actually if there was a market I would make one but I think there are simpler cheaper options for 4 bangers. I could be wrong though as I've never researched it. It seems like the KA swap is pretty straight forward and affordable.

How about now So nice of you. It'll go out today Probably not

Well it's out of the mill! OOPS Not enough clearance for the tool holder. Well that's it for a week or two. Got a bunch of pattern work that backed up so I have to get a handle on that. Also realized I need the front timing cover done before I have the head surfaced. I may machine that out of billet 6061 as I'm not too sure if the production heads will have the water outlet coming out of the front. I guess I could have cleaned that block up a bit

This man has balls of steel. I machine a lot of castings and I wouldn't touch that And now that "that cat is out of the bag" will the new owner allow you to post pics of the process? I would LOVE to see that happen. I'll PM you about the cams. Derek

Please do. Preferably in the mill you're using for the work. Must be a huge!

Where were you about 160 posts ago Basically although I could do it with the equipment I have it would be a stretch. Out of all the cam companies out there very few make their own cores and those that do had an attitude like "go away kid you bother me". The pricing I got pushed the overall price of the head out past where people could justify it. I'm having them cast out of 8625 so from a chemical (or metallurgical ???) sense it's close. I know it's not as strong as cold rolled but it will probably do for the lower HP units like mine. Ron Iskenderian will be taking the cast cores all the way from the rough state to final grind including hardening and straightening. NOW if you are interested in producing cores then I'm more than happy to talk to you about it. So much so that I'm going to PM you on it. Derek

Surface the top and bottom. Install the valve guides. Cut the pockets for the valve seats and install them. multi angle valve job. Line bore the cam towers if necessary.

Here's your daily fix Got all the intake valve work done. Got a little carried away with the machine allowance on the intake side! Had to take it down almost .375". I had to leave that wall around it because the mill was hitting the side of the head. You can see where it nicked the intake bolt boss. Every port looks just like this. Man I like digital mold making. The accuracy is just amazing. I should have the rest of the machine work on the four sides done tomorrow. Then it goes to get radiology testing. I would normally do that before machining but I was going to machine it regardless of the outcome. I don't foresee any problems and it's mainly an insurance policy at this point. After that I will send it to get impregnation and then it's off to Mazworx for the headwork. Cam design, cam core pattern and cast cam cores are next on the list.

yea you won't be lacking in surface area!

Well today was a big and stressful day. I got all of the exhaust valve work done. Drilled and reamed the valve guide holes and machined the valve spring bosses. Everything seems to be working out as I planned. This is the best part. The bores came through right where I needed them to. After I had printed the sand molds I realized my valve angle was off by half a degree. That's why the bore of the valve guide is not centered on the boss. Future heads won't even have that boss on there. I'm not really sure why I put it in as there is plenty of support for the guide without it. So far so good. Tomorrow is the intake valves and Wednesday should finish off the intake side of the head.

Thanks. I feel like people need to realize just how much work it is to bring projects like this to fruition. Of course if it wasn't for the sand printing none of this would be happening. I also look at it like I have a bunch of eye's on it that may spot potential problems.

Thanks Tim Well if everyone is going to see how much ultimate power it will make then it may fail as I don't have the time and the resources available for that. But since it's based on a known design and if this head has decent longevity I think it may work out. Who knows. I'm having a blast and that's what counts. For others it may be a leap of faith. Found time to map out the exhaust ports. They were all within .005" or .006" of where they should have been. A lot of that may have been the toughness of the casting affecting my touch probe accuracy. I can tell you that is pretty accurate for a sand casting. Here is a shot of me taking a skim pass for port matching to the flange. You can see I have a little hand work to do on a couple of the combustion chambers. Exhaust side all done Tomorrow I start on the valve guide bores.

There is a rendering on page 1. As soon as the head is done I'll start on that. Actually cams first then the valve cover. I ordered a piece of 29 mm drill rod to use as a gauge rod for the cams. This way I can check the alignment of the towers and decide if I need to have them line bored.

Here is a shot of my calculated standing oil level. The cam towers dictate how the draining works. The valve guides won't be standing in oil but they will be getting splashed a bit

I saw that the engines were tilted in the pictures during the design phase and wondered why. I figured it was for oil as I was having an issue using the stock L6 drain. Tony suggested a drain in the back of the head with a hose down to the oil pan and this is the direction I'm going to go. That is probably why he was asking about it in post #230 Does the induction side need to be higher than the exhaust side? Is this for carb cars? Thanks Derek

Thanks everyone for the encouraging words. They do mean a lot. So I got the top surface done. I started out with a modified spark plug stop to use as a gauge. I used the end of the threaded rod that goes up through the head to touch off from. This let me know where I was in relation to the combustion chamber. I surfaced the top,did all the cam tower work, spot faced the head bolt bosses, bored the spark plug tube bosses to the correct depth, tapped the bosses for the tubes and drilled the oil gallery. Had to relieve one side of the cam towers for the ARP washers to clear. Set a few towers on for fun. Probably won't get much done till Monday.