It's the old school way of doing it however it will also be the quickest unless you are striving to do it electronically. The parting line looks pretty clear cut on the original. By the way, shrinkage won't be a major issue in a part this small. You can always shim the flange faces n the pattern to give more overall length if necessary.
Probably not a good idea in this case. Figuring 1.4% shrinkage could have your finished dimensions off too far...
So I printed it out ( pretty sure the scaling is off) But yes that is one irregular parting line !! I'm going to have to put some thought into this one
Thanks and just emailed you some pictures. Yes, the scaling is off; total height of actual part is approximately 130mm.
You beat me to it. To me, with this geometry, it screams lost foam or lost wax. Masters like Olfoundryman could whip this up before morning coffee no doubt but since you have a printer you could print negative "halves" of this model in however many pieces that works for ya. Assemble and coat the negative printing so that you can pour some wax into it. This way you can melt the halves together, do your gating/spruing and make tweaks, smooth out things before starting the shell process. This would not be bad for doing ten or so castings. With the right release angles and agents, the PLA negative molds should be reusable Kelly...don't you have a CNC router?! lolol If my 5 axis upgrade for my cnc router was complete this would be an ideal job for it. (sorry team)
It would be pretty easy to print 2 of them scaled up for shrink, bed one of the prints up to the parting line on a follower board. Then ram up one side, pull the pattern and follower board and replace with the second pattern and ram the second half of the mold. Then pour the mold with plaster of Paris, and whittle the cores back out of it. You can do basically the same thing and pull a silicone mold off it to make a wax pattern. Not rocket science... I find it more fun to try and get inside the head of the patternmaker. This intake is sculpted, not just sawn out of a block of wood. Which makes it very interesting.
@Zeusguy Can you provide me a dimension drawing of the port locations/ flange faces. What I can do is model the core prints then attach them to your scanned model, shell it out, then trim the ends back. Basically this would give you a hollow pattern just like the intake. From there I can split the model and build up areas inside the runners. That would make it so you can either pull a mold from it for lost wax casting, or print it out for lost pla casting. Could also be used to make a core box for sand cores. Manipulating stl files is a pain. I've run this through 4 different programs..
Zeusguy, please correct me if I've got this wrong but, I'm pretty sure I recognize that carb flange, it fits the Weber DCOE and Dellorto DHLA carbs. There's also a 45mm version of this flange, with the exception of the ports, all of the other dimension are the same. And if you want to use studs to secure the carb, the 8.5mm holes would instead be the tap drill size for an M8 fastener.
Yes, you are correct on the DCOE flange. Sorry, I don't have any dimensions on the core yet; that's my next project
Not the core. Just the port locations on the head side. I can shell out the scanned model to a set thickness to create a hollow that can be used as the corebox.
Good idea and I tried shelling too but the end result doesn’t look anything like the core from an air flow perspective. It is almost like the designer started with a well flowing core and then put a fat body around it. I’ve also used some calipers to measure the manifold wall thickness and it is not consistent. I made a silicone core plug and plan to create a cad model from it. At that point, I plan to subtract one volume from the other to create the manifold model. It sounds simple but… The project goal or challenge is to see if I can create an exact duplicate of the original manifold. It would be too easy to waterjet a couple flanges and then tig weld a tube between them for a modern manifold. I agree with you in that it has been fun trying to figure out what the pattern maker was doing. I also think he may have created a part that cost to much in post processing which may have contributed to a short production life. However, he did boast of some interesting performance gains.
You're almost certainly correct. A number of years ago, I designed a racing intake manifold for a water-cooled 8v VW and that's pretty much what I did, first, I laid out the head and carb flanges to fit the available space and within those constrains, I modeled the ports and plenum to what I thought would be an optimal shape and fleshed out the manifold around that. It was an very interesting project, I learned a lot including that manifold design, especially for small engines, is always a balance of comprises. In the end, my design was not entirely successful, it had excellent throttle response and a very strong mid-range but dropped off a bit too much at the top end.
Since you managed to pull a silicone mold from the inside of the manifold, why not just take it and bed it into some clay up to the parting line. Then pour a plaster of Paris mold over it, flip and pour the other half and skip the cad modeling.. You would still need to add core prints to the end of the scanned model though...
