Jump to content
HybridZ

Making my own EFI intake... The casting begins!


Derek

Recommended Posts

3-6% depending on the alloy and thickness is the normal amount of shrink.

 

If it comes out a little small, an easy fix is to make a squeeze mold and glue little squares of wood that are the desired thickness on the original pattern and coat it in pattern-material (bondo) and squeeze it again. Then make another test run. If u need actual instuctons let me know.

 

If you end up having to do all that you may consider changing the set up over to an investment casting, the casting cost will go down alot not to mention a glass like finish. In DFW you can get stuff cast for $12-$15 a LB in shell.

Link to comment
Share on other sites

3-6% depending on the alloy and thickness is the normal amount of shrink.

 

If it comes out a little small, an easy fix is to make a squeeze mold and glue little squares of wood that are the desired thickness on the original pattern and coat it in pattern-material (bondo) and squeeze it again. Then make another test run. If u need actual instuctons let me know.

 

If you end up having to do all that you may consider changing the set up over to an investment casting, the casting cost will go down alot not to mention a glass like finish. In DFW you can get stuff cast for $12-$15 a LB in shell.

 

I'm not familiar with that method to enlarge the pattern. But there's a lot about pattern making I'm not familiar with!!!

All of my plates and core boxes are indexed so I can get them back in the machine quickly. I then re carve only the area's that need work. If its a large fix like when I totally screw up (yea it happens) It's usually quicker to start over with fresh material. I have 2 CNC machines and I don't mind running them 24 hours straight so I tend to let the machines do the work if I can. Plus they do a much better job than I could. I'd starve as a pattern maker If I had to do it by hand.

 

 

Derek

  • Like 1
Link to comment
Share on other sites

  • 1 month later...

Well I managed to get a little more work done on the patterns. Unfortunately work keeps getting in the way. I hate when that happens. This is the top side of the front manifold. I switched from corian as the pattern material to urethane tooling board. It carves a lot faster than the corian and it's a lot easier to work with. This is a shot of the roughing cut with a 1/2†cutter.

DSC_0006.jpg

 

 

 

Here's a shot of the finished piece after about 12 hours of machining.

DSC_0007.jpg

 

 

 

The square blocks on top of the throttle shaft bosses are so I can locate the center of the boss for machining.

DSC_0008.jpg

 

 

 

After I have the manifold casting clamped in the mill I'll map out the location of each block with an edge finder and then use that data to program in the machine ops. At this point I'm going to finish up the core box for the front manifold and go ahead and cast and machine it. This way If I have to make some changes I'll only have to modify one pattern.

 

 

Derek

Link to comment
Share on other sites

  • 3 months later...
Update?

Nothing good to update. My business picked up considerably which is a good thing for my finances but a bad thing for my extra curricular activities! I'm in the middle of a very large project that should leave me with enough time and money to finish the patterns and castings. Then comes the scary part. The EFI stuff.

 

This is definitely not a dead project but it's going to take a lot longer (they always do) than I thought. See the trick to pulling off big projects is to under estimate your time by about 90 percent, otherwise these things would seem impossible.

 

Thanks for the interest

Derek

Link to comment
Share on other sites

lol no. they are more of the prissy and likes to look good in the passenger seat type friends.... but hey they are pretty damn good at that... lol but im actually in the stages of figuring out what i want to order for megasquirting my car.. maybe we can help eachother out and learn as we go...

Link to comment
Share on other sites

Sounds great. I'm coming over on Tuesday for the car show. I need some inspiration and drooling over those cars should help. I'm bringing the patterns with me so If you want to check them out let me know. PM me and I'll give you my cell #.

 

Derek

 

 

lol no. they are more of the prissy and likes to look good in the passenger seat type friends.... but hey they are pretty damn good at that... lol but im actually in the stages of figuring out what i want to order for megasquirting my car.. maybe we can help eachother out and learn as we go...
Link to comment
Share on other sites

  • 2 months later...

I'm sure I've almost fallen into "all talk" status by now but I really am trying to make this happen!

I managed to get the core box completed for the front manifold. Now all I need to do is machine the throttle tube inserts, sand and paint the patterns and mount them to a board.

DSC_0039Large.jpg

This is both halves of the core box. Each half will be packed with a hardening sand. The two halves will then be glued together to form a completed sand core. The rectangular sections in the front and back are the prints. Prints are what locate the sand in the proper position inside the main mold.

DSC_0040Large.jpg

This is a closeup of where the stainless steel throttle tubes will go. they will be clamped in position in one half and sand will be packed inside it. on the other half of the core this section of sand will be removed. This will allow the aluminum to encapsulate the tubes. I hope!

You can also see the sand that will form the vacuum passage between the tubes.

The front tube (bottom screen) is the best compromise I could work out between having a tapered tube yet entering the port in a reasonable way.

 

Soon my precious.....

 

 

Derek

Link to comment
Share on other sites

DON'T use stainless for that. Stainless steel is notorious for galling when used in even a light-duty bearing, and a galled up throttle bearing=bad news. If anything, use a heavy wall brass tube, and ream it to size after casting.

 

I've cast quite a few things, up to and including patterning and casting an entire replica of the L24 as a fully operational scale model. Trust me, I made the SS bearing tube mistake already, and had to recast two TINY SU carb bodies...(Sadly, i couldn't get the detail required to get them to operate like real SU's, mine are just look-alikes) Total displacement in my model is a whopping 13cid. And you thought that the full size L-series could get fiddly up on top! :):)

 

When you get around to getting these cast, are you doing it yourself or jobbing it out? Doing it yourself isn't that difficult, and the learning curve is just about vertical. Once i get the rest of my car up and going, i may put the freed up space in the garage to good use and go for the DOHC setup ala 1 fast z, but as a solid casting!

 

Jake

Link to comment
Share on other sites

Errrr.... Pics? Vids? Please! That sounds so cool.

 

DON'T use stainless for that. Stainless steel is notorious for galling when used in even a light-duty bearing, and a galled up throttle bearing=bad news. If anything, use a heavy wall brass tube, and ream it to size after casting.

 

I've cast quite a few things, up to and including patterning and casting an entire replica of the L24 as a fully operational scale model. Trust me, I made the SS bearing tube mistake already, and had to recast two TINY SU carb bodies...(Sadly, i couldn't get the detail required to get them to operate like real SU's, mine are just look-alikes) Total displacement in my model is a whopping 13cid. And you thought that the full size L-series could get fiddly up on top! :):)

 

When you get around to getting these cast, are you doing it yourself or jobbing it out? Doing it yourself isn't that difficult, and the learning curve is just about vertical. Once i get the rest of my car up and going, i may put the freed up space in the garage to good use and go for the DOHC setup ala 1 fast z, but as a solid casting!

 

Jake

Link to comment
Share on other sites

DON'T use stainless for that. Stainless steel is notorious for galling when used in even a light-duty bearing, and a galled up throttle bearing=bad news. If anything, use a heavy wall brass tube, and ream it to size after casting.

 

I've cast quite a few things, up to and including patterning and casting an entire replica of the L24 as a fully operational scale model. Trust me, I made the SS bearing tube mistake already, and had to recast two TINY SU carb bodies...(Sadly, i couldn't get the detail required to get them to operate like real SU's, mine are just look-alikes) Total displacement in my model is a whopping 13cid. And you thought that the full size L-series could get fiddly up on top! :):)

 

When you get around to getting these cast, are you doing it yourself or jobbing it out? Doing it yourself isn't that difficult, and the learning curve is just about vertical. Once i get the rest of my car up and going, i may put the freed up space in the garage to good use and go for the DOHC setup ala 1 fast z, but as a solid casting!

 

Jake

 

Man that sounds way cool. I would love to get a look at that. I think you should start a thread about your motor as a lot of people here (me included) would love to see it.

 

I agree with you about the stainless galling but I'm not using it as a bearing surface. The problem with this manifold is getting a good fit between the butterfly and the tube. Since I can't machine inside the tubes very easily I'm going to cast in a machined piece of stainless tube so I have a known dimension for the butterfly. I have sealed bearings top and bottom for the throttle shafts.

I'm a patternmaker by trade and plan on getting one of my foundries to do the castings for me.

 

Again please post some shots of the motor!!!

 

Derek

Link to comment
Share on other sites

Casting a dohc head would be a minumum of 10 times the effort then bolting them together.

 

Making a series of 0.030" sections and then submitting them to a rapid prototyping company to do a lost-foam process would not be that difficult...

 

 

I second the idea of another thread to see that scale 13CID L-Motor! That sounds REALLY, REALLY COOL!

Link to comment
Share on other sites

3d printing, A is not real cheap, and B only gets you a sample, trust me, casting is NOT cheap, as far as molds go, THEN thats really the easy part, the machining afterwards on a dohc 6 head is tons of work. We suspect the next head we build is about 10 hours of labor, from when we start the edm cutting.

Link to comment
Share on other sites

Guys, I would love to post pictures and videos, but the engine is currently out of the country. I have sold it to a modeling company, along with a copy of the drawings and the casting patterns, in order to fund my college education. (helped me out quite a bit!) Now, seeing as they are going to start producing the castings as a kit and selling the plans, I can't really discuss the name of the company or it's location yet, but I am remaking my patterns and core boxes, this time a little bigger so I can make true SU carbs to go on it. When it warms up enough that I can pour the castings again, (gotta be 55-60 before my water bound sand holds up well enough to do complex castings) I'll start rebuilding it. Don't hold your breath, because it took 4 years to finish the first one. The second one shouldn't take near so long, but we'll see how it goes. I'd like to finish my first L24 before I make another L0.330!

 

 

Hopefully I can get a set of castings from the model company, seeing as they are only under license...

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...