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Making my own EFI intake... The First Casting


Derek

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Derek, do you know what type of furnace they are using? A lift out crucible furnace? Tilting furnace or cupola furnace? I'd love to see some pictures of their setup. Also what type of sand are you guys using? I've been reading a lot of Steven Chastains book's with a lot of enjoyment and had always wanted to do what you're doing. http://stephenchastain.com/store.htm

 

Thanks,

Tyson

 

Its "Green Sand" in an old school hand rammed pattern box, it mainly consist of bentonite and Oklahoma#1 sand. Pretty easy to make just don't get your moister content wrong or it goes pop! I would ask them to smut(acetylene) the mold before closing it up next time, it will give you a satin smooth surface.

 

Nice to see that the first run came out well,Good job!

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I was thinking about putting it in the Wheelabrator machine after I clean up the parting line so I'm thinking the smut treatment might be a waste. Any thoughts on this?

Derek

 

 

Its "Green Sand" in an old school hand rammed pattern box, it mainly consist of bentonite and Oklahoma#1 sand. Pretty easy to make just don't get your moister content wrong or it goes pop! I would ask them to smut(acetylene) the mold before closing it up next time, it will give you a satin smooth surface.

 

Nice to see that the first run came out well,Good job!

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I was thinking about putting it in the Wheelabrator machine after I clean up the parting line so I'm thinking the smut treatment might be a waste. Any thoughts on this?

Derek

 

Man I miss the foundry, it looks like fun.

Here are my thoughts on your project, you may already know this stuff.

 

The wheelabrator will give you a nice shiny finish, just make sure you strap the part in. If you let it tumble it can get bent and dinged pretty bad, and beware of occasional bb's from being embedded in the surface.

 

As far as the mold prep, if you use a fine screen for your first layer of sand and with a little higher moister content (the sand inside of the pile of sand your using), you can achieve a pretty good finish. I like using a air nozzle to apply the parting powder as well, just blow it across the bag and it lays down a nice even layer. Clumps of powder leave a positive bump on the surface.

 

Have fun.

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Too Cool!!

 

 

(and stephen colbert welcomed all of his writers back onto the show tonight (writer's strike is over) with a big she-bang, had them each come out one at a time, greeted them by name, had them walk to the side stage for a "Team Photo." Mr. Met was the last "writer" to come out, but the other shoe what you KNEW was gonna drop came out a face or two before Mr. Met.. and guess who??? Kevin Bacon! Ka-POW!)

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So you see it's true!

Sorry no more progress photos. I'm too close to getting the car on the read right now so the manifold is going to stall for a while.

 

Derek

 

Too Cool!!

 

 

(and stephen colbert welcomed all of his writers back onto the show tonight (writer's strike is over) with a big she-bang, had them each come out one at a time, greeted them by name, had them walk to the side stage for a "Team Photo." Mr. Met was the last "writer" to come out, but the other shoe what you KNEW was gonna drop came out a face or two before Mr. Met.. and guess who??? Kevin Bacon! Ka-POW!)

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  • 4 weeks later...
Any progress?

 

Lot's of progress on the car but nothing on the manifold. Plus I just got slammed with a bunch of pattern work. I'm so close to getting my car back on the road after a 12 year or so hiatus that I'm going to be sticking on that. As soon as I get the car drivable I'm sure I'll be itching to get rid of the SU's so things will progress rather quickly from there.

 

Thanks for the interest

Derek

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  • 2 months later...

Well now that my car is on the road I can throw a little time into the intake.

I've cut off all the gating and cleaned up the parting lines. I reamed out the embedded bushings for the throttle shafts and it worked perfectly. The shafts fit smooth as silk so I'm not planning on putting in bearings. I'll just use the bronze bushings. I sent tha manifold back to the foundry and he tumbled it in the wheelabrator machine which helped blend in the sanding marks.

DSC_0026.jpg

Here's a shot of the business end. I don't know if it's going to run or not but I love the way it looks. The step in the bell is for the inner screen. I's probably a little too big. I thing I'm going to reduce it down with a die grinder so it's not so severe, I have some alignment issues with the throttle shaft bosses but since I'm not using bearings this won't be a problem.

DSC_0029.jpg

 

This is the vacuum passage for the idle control and the brake booster. I have to open it up to the final size and tap it.

 

DSC_0030.jpg

 

Here's a shot of the bottom side. I got a little shrink at the #2 boss but it won't affect anything.

 

DSC_0031.jpg

 

I'm trying to finish up the machining on it this week. All I have to do is bore out the injector bosses and mill the flange.

 

 

YAHOOO!

 

Derek

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I don't know if it's going to run or not but I love the way it looks.

 

:iagree:

 

THIS is an ITB setup that should have some appeal to those guys who stick with webers or mikuni/solexes just for the authentic feel/sound/street cred..... (a concept I TOTALLY understand and won't ever hassle, even though EFI is in my mind a simple reality nowadays..)

 

 

I cannot WAIT to see this intake bolted to a longblock!!!!

 

MUCH admiration and envy!! :shock:

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Thanks for the feedback guys.

I had a delay of game on a pattern so I decided to knock out the machining today. It went really well. I'll make a few adjustments in the next pattern to make things better. I was trying to get some info on injector boss dimensions and settled on making a smaller hole through the runner and larger hole in the boss for the injector. I removed the cap and o-ring from the bottom of the injector and I'll use an o-ring on the shoulder of the injector for sealing.

 

DSC_0032.jpg

 

 

DSC_0033.jpg

 

I machined the flange at 14 degrees which I think is the right amount. I'm borrowing a head this weekend so I can start mocking everything up. I have enough meat left on the flange to re machine it if necessary.

I ended up with an inclusion on the flange but it's shallow and won't affect anything.

 

DSC_0036.jpg

 

The ports are under sized so I can match them to the head.

 

Next I'll be machining the throttle shafts and butterflies.

 

Derek

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You are building an extra one for me Right?? lol You know im gonna find another z and want to build a nice NA motor!!! lol

 

Yea sure thing. I'll bring yours with me on Saturday!

 

It's a good thing my customers don't read this forum. I've got about 10 other things I should be working on right now!

 

Derek

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hey, ross machine has a drill bit that they sell that will make the injector holes a one-gun ordeal.

 

costly bit at 120 bucks, but if you plan to run these... and your customers find out what you're really doing, you can make back your customers lost time!

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