Derek

Ok I want to share this link. I don't want anyone to comment here because I really want to keep this thread about my head. But this video sums up what doing research on K20's on the internet can be like. It's a honda but not a K20. But the sentiment is the same. I made a post on the general non tech board. http://forums.hybridz.org/topic/123840-video-sums-up-what-researching-a-honda-k20-head-is-like/ No replies here please:) Edit: fixed link

When I was doing research for my twin cam head I had to dig into the hell that is the Honda forum. This video really sums up what it is like:) https://www.youtube.com/watch?v=f9x74SlY1ik Derek

Well the nice thing about my conversion is it still uses the stock L6 block. So anyone making the investment in producing and adapter won't be tied to only the people that run my head. I will throw this out though. I have made bell housing patterns and I have made one for a similar application. If the lack of a strong enough transmission is holding back head sales I will look at this. I've kicked it around a few times. I'm not a big fan of spacer plates on the flywheel so a custom bell housing appeals to me. But I haven't done any research beyond the absolute basics. I do know one thing though. I'll probably blow my whole drive train on the first dyno run. It's old and tired like me. I'm happy to have this conversation but I think it's probably best to move it elsewhere and link to it from here. As it is a separate thing. Derek

On his web page he lists them but only in groups of 5. Edit: I was on the wrong page. It looks like he is working on one. Hope fully it will come to fruition.

Looks great Xnke!

Yea I wouldn't let a block hold me back on that one either. Unless it damaged everything else as well. With an over bore it's all new pistons. If only one piston is bad then that may change the dynamics as well.

It uses the stock L6 head gasket so whatever you want to source. I'm doing everything I can to make this off the shelf other than the castings, exhaust and cams.

Speak for yourself big boy. I'm 6' and a buck sixty wet:) Jeffer949 will back me up!

For me there are two ways to go. Make a fixture, weld it all together. pull it out of the fixture and watch it spring into an unusable mess. Or Use an assembly fixture, tack everything together, remove from fixture and weld. As you're welding keep checking your fit and adjusting either with force or opposing welds. On prototype pieces I've had better success with number 2.

Yes to all that....and I'll leave it at that:)

Well there was a change in plans and they are being done by Crane. Most likely Cranes custom grind numbers RHON 240/410INT and RHON 232/360EXH. Keep in mind I'm running stock springs and retainers and a low compression motor so I'm really limited on cam choices at the bottom end of the spectrum.

Stock or after you work your magic? There is still .1875" minimum wall thickness left for you to work with:) I would hope you could bump those numbers a bit. Edit: Grammer:) Yes you can dream:)

This happened last night: And then this happened:) So I took the head down to Scott's Racing engines to get it Flow tested. I'm sure TonyD will pop on here at some point and have something to say. The before column is a raw port with only the machine work for the port matching done. The after has been cleaned up really quickly with a double cut round burr and then I hit it with a cartridge roll on a mandrel. All I did was remove the sand casting texture, blend the steps between the seats and ports, and remove the additional material from the halve guide bosses. The clear acrylic manifold Had a 3.5" bore. They applied modeling clay to the intake ports to smooth the air entry and they held a tube against the exhaust port to simulate a header. Here is the before port. You can see the steps between the valve seats and the ports are still there and the valve stem bosses are too long. Here is my piss poor after port. You can see there is plenty of room for improvement with my porting abilities:) I'm presenting this data with a few caveats. Number one. This is the kind of thing that can turn ugly in a hurry as people get their panties in a wad about how accurate or inaccurate the numbers are. Try and keep it civil. They are just initial numbers but they do follow what I hoped to see based on my port volumes. When I was designing it I looked up the kind of volumes the K20 head gurus were running and I tried to hit those marks. Especially on the intake. The exhaust is fairly close to the stock K20 in shape but the intake is mine from scratch. I started with the stock entry and exits and made it look pretty in between. I don't need to be reminded how bad I am at porting. I'm happy with the flow results and that's all that matters anyway:)

Started working on cam tower mods and oil distribution. The plan is to pull oil from the oil pressure switch bung and Tee it to the front and the back. The front was pretty easy because I had incorporated material in the casting. The rear...Meh not somuch. Production heads will most likely use the #1 cam tower at the back to supply oil but that was proving to be impractical on the prototype so I opted for a different path. I took an extra #2 tower and made a manifold plate to bring the oil in. I doweled both pieces to maintain alignment. I tapped the tower and it's held together with three screws sandwich style. Oil is fed in the bottom. and it's cross drilled and plugged to supply the shafts Tight fit but it will work.

Standard dash 138 o-ring pack of 50 $6.12 Mcmaster Carr:) Edit: Make that $12.00 for 20 in Viton not Buna-N Thanks, I think putting it all out there shows people just how much work it is to pull a project like this together. The toughest part for me right now is having to work with all of the minor design flaws that you get when you do things at this low budget level. It's really hard (for me) to think of every single item all the way through during the design phase. Plus since nobody is paying me to do this the starting and stopping is a real pain. My modification list for the final casting design is pretty long at this point. A lot of it it making the machining process easier. Working with castings is always tough. Until you get a few of any particular item under your belt you're not really sure how things are going to work. 3D printed sand helps but it's a long way from being affordable by the likes of us. That's why I'm only printing the cores.

Simple....Build two:)

And then there were three..... Here are some process shots for those of you that are interested. After rough surface and fly cutting. Outlining the flange. O-ring groove. Port matched and injector clearance machined in. I'll hand finish the injector area.

Making some progress. Got the manifold to head flange done. I still need to de-burr the sharp edges but I'm happy with the results. Hard to tell in this picture but the ports match really well. 1/3 of a money shot:) Should be able to finish up the other 2 tomorrow. Now If I could just get my valve cover I'd be set for a while.

I think on any NA setup you are going to need custom pistons to make any kind of power. The K20 has a large combustion chamber and even ones that have been welded extensively are still 47 cc's. This is a head with a 47cc chamber done by theoldone.com I'm going to pattern the raw castings around this design since all of the chambers will get machined to order. I think from a off the shelf piston standpoint the turbo people will have a better chance.

It's going to be O-ring. And I'm not looking forward to it. 3/32 end mill in an old Bridgeport in cast aluminum...Ugh... 5500 RPM spindle can be a little restrictive with small bits. The stacks and hardlines are going to give it exactly the look I want. Which kind of makes sense since I'm building it for me:) I have a $20,000 white light scanner and I still use the tracing method all the time. Now though instead of a flatbed scanner I just photograph the tracing with my phone. Thanks for the compliments everyone. I'm chomping at the bit to get back at it tomorrow:)

Yes I got the from EFI hardware. They are their DC&O economy brand. The quality is quite good for what I paid.

Today....Was a good day... Got started on the first manifold. Probing the ports. This will establish my zero point. The cores were 3D printed and the ports ended up being 90.114mm apart. I can handle .114mm:) Action shot of the fly cutter doing the finish pass. on the flange. In order to make the linkage that came with my ITB kit work I needed to shift the ports .025” It is going to be a lot easier to blend the shift than rework the linkage. I didn’t have a CAD drawing of the ITB so I traced around it, scanned it and then imported it into my CAD program. I’m happy with the fit. WFO Working on the injector bungs. I drilled all the way through with a .4375” bit then opened it up to .655” part way down. I use the method described here: http://www.sdsefi.com/techinta.htm It leaves an air gap around the injector body and help guard against heat soak. It’s the same method I used on my manifold and it survives August heat in Florida. I pulled one of the injectors out of may car for a test fit. That’s going to look really good! Now that’s my kind of selfie:)

My ITBs are DCOE pattern and the cores are 3D printed so I would imagine it would be a case of printing cores with a larger bore. I think there will end up being a few choices for manifolds. That is one of the reasons I did 3 2 barrel manifolds. One pattern to carve. With the engine leaning towards the right space may get a little tight for some throttle bodies. Do you have a link to that video?

Finally got my intake castings in. They came out pretty good. I may need to tweak my pattern a bit. A good part of the flanges will be machined away. I purposely made the a lot larger than I needed. I like options. I left the intake to head port as an oval. I will machine in the injector port area after I have drilled the injector bung. While I was waiting for the castings I went ahead and made my injector caps for the hard lines. Not perfect but nothing I make is:) Here is a shot of the first two ops Next week I'll have time to get on the manifolds. I can then start to do the linkage and fuel delivery. Fun stuff!

I have the original straps and you aren't missing much:) I hope you and many others have the good fortune to have enough money to buy one of my heads. (ancient proverb)