kab-pro

Digging thrpugh the treasure box to take the head to a local workshop for guide and seat installation. And here it is as received back. The guide ends are machined manually.

Do you have any pictures from your cylinder head / intake port? I might have to order a special tool for the job. I hope you understand that it is a delicate and time-consuming process. Regards.

I didn't actually test the OEM head since my port was already modified as I got it. The 128 CFM is a figure I found on the internet after some searching and the source seems to be legit as well. Maybe your guy was reffering to a different test pressure. As I got the info, it flows as follows (all numbers @ 0.400 inches valve lift): - 116 CFM @ 10 inches of water - 128 CFM @ 12 inches of water - 195 CFM @ 28 inches of water About the valves, I only experimented with the diameter, not the shape of the valves. Maybe that is why my results for stock and oversize valves were so similar. What year is your kawasaki and is it a KX450F?

The valves do the same on every head regardless of make. All the measurements were made to simulate real life scenario as close as possible. That includes the valves, combustion chamber and even the spark plug.. I did the simulations with oversize and stock size valves, and the difference was somewhat minimal. I am looking forward to see his results with the 2016 head. And thank you for spreading a good word

I am going to use Xceldyne valves (OE size). At first the idea was to use bigger valves but as I had already decided to go with Xceldyne I had to stick with OE size since they didn't offer oversize. Nevertheless, I was able to achieve results very close to the oversize. My estimate about the time spent on the project would be very rough since it was a "free time" project. Anyhow, it took a great deal of time, several months, spread across the whole year because I had to learn every single step from scratch. But right now, since all of this is no longer new to me, the time needed for another project like this would be significantly less.

CNC headworks: Not much left to say here. Whats important has already been described earlier. [video=youtube;leQWGJwXUFw] In conclusion: Mechanical processing: - From intake side - 4 rough cuts + 1 finishing cut ~ 5 hours total. - From valveseat side - 4 rough cuts + 1 finishing cut ~ 5 hours total. Main factors influencing machining time: - thickness of soldering layer - soldering hardness - tool type

Time to test the machine code and see how it will materialize itself. The first idea was to start with a wooden block, though it was decided to begin with a piece of plastic foam since damaging the tool and machine is fairly easy to do. The amount of G-code is approx. 5 Mb which makes it physically impossible to inspect. Let's start up the CNC and munch on the foam a bit, and instantly, you can see why testing is necessary. The first try could not have been more wrong than this. But that all likes to change. Still, some G-code errors pop up and must be accounted for in the CAM system so that we can continue with the wooden block. The main reason for wood is to test how flipping the head around will work out and to see if the cutting speeds and feeds produce any smoke. And soon enough, we get something like this. Looking good so far. A few imperfections are still popping up, but those can be easily corrected.

Tool and equipment. We have finally come to the machining process. The tool type as seen below is not exactly right for such a job but it was the best option available at the moment given the resources we had. Traditionally lollipop mills are used but this cylindrical one is just enough to reach the furthest points of the port. Next up: machining a jig to fix the head with the option to flip it around without losing positioning. Flipping will be necessary due to the machine type that simply does not support full tool travel in a single setting. And of course the support spacers and bushings. Each spacer has it's own calibrated length that was calculated with FARO probe to avoid any human error. These lengths are key to preserving the positioning when the head is flipped between operations. The one mistake that was made was to machine these spacers from aluminum but I will get into detail with this as we move on.

Port welding. I would gladly hear a specialist's opinion about the technology. In the picture below you can see an intake port that has been welded. Does anyone know what tech is necessary to pull this off? Welding the intake ports on a 250cc head seems like a piece of art. I know there is a guy in the US who does this but he will only present the results and never process. Right now two options are considered: - epoxy welding (also offered by the top tuning workshops); - soldering with Techno-Weld rods. After some consulting it was decided that we will try out the soldering option. Conclusion: The actual result was not as expected but I guess we were being too optimistic since soldering material on both floor and ceiling is a tough challenge. Props to the wiz who did it. Regarding the realization process of this research - this was a long time mind boggle but the goals were of course the highest. Plan A: this has to be done by a machine Plan B: it will be done by hand using all sorts of models and comparison tools. I have to admit - Techno-Weld usage was the last impulse to carry out Plan A. The hardness of the soldering reaches ~ 93 by Brinel scale. When taking in consideration the thickness of the soldering layer, plan B is getting practically impossible. Getting ready for Plan A. CAM system is deployed to generate toolpath and couple it with cutting feeds, speeds and positioning. The G-code produced is not always perfect so this is when we alter huge amounts of it by creating a secondary program in free-pascal. After running the machine simulation we are finally looking at what could be the result of the first porting operation.

This was a major problem because the requirements for such things are very demanding on the capabilities of the software. I had tried several high end CAD systems but eventually ended up using NX.

The long road to perfection. Optimization process of the port shape involves dynamic stretch and skew + CFD simulation to evaluate the results. Truthfully, the results are like waves. Ups and downs. Main conclusion - the changes that visually seem most appealing are definitely the wrong idea. Just like an optical illusion. Try 80th.The result is as shown below. Visualisation of the CFD results. And, of course, a comparison. OEM - 128 CFM Previous owner - 143 CFM Long road to perfection - 187 CFM = + 46% vs OEM or + 31% vs previous owner. An overlap plot of the scanned facet body (red) and the freshly dveloped intake port (grey). The red spots point out to areas where welding will be necessary.

Everything is going according to plan, be patient and keep following up this thread. There is a lot more to come

Hi guys, I am finally back with some more pics to show from my CRF450R project bike. Last year we left this topic as the cylinder head and camshaft were pulled off and brought to a laser scanning office. The goal of this research was to modify every component of the gas exchange system in order to deliver more power at the top end of the rev range. Enjoy. This screenshot shows the overlap between the scanned .STL file and the CAD recreation of the ports and combustion chamber. Mean deviation ~ 0.03 mm. At this moment enough material has been accumulated to perform a flow simulation and determine the volume flow rate of the ports. The CFD simulation will be carried out using a flow bench standard of 12" H2O pressure drop. The result is 143 CFM. For comparison, a standard 2013 head flows 128 CFM @ 12" of H2O. The manually ported head trumps OEM variant by 11% To be continued...

Ouch....h

I would say so that MOM has known difficulties with meaning

I mean your writer skills Mate

Dali , you are like Jack London

Curve characteristic looks nice, quite evenly, and end of its keeps stable. According to my point of view fits well for SM. Try to dyno pants "popometer"

Mom google translator meshing me... Do you like result or not, what says your popometer:D??

What a shame ... , it would been nice to see ports from this side, never mind maybe sometime.

Dali, can you make pictures of the ports from combustion chamber side?

Do you have yoshi specification?

What was the reason you decided 13.2:1 ??

You can join to us with friends upcoming summer if want too. Everyone is welcome!! Development in process and it will be described here later as well as results. Dali, how your rebuilding is going on?

Yesss !!!