Making my own EFI intake... The First Casting

[Derek]

I imaging the Balance tube would actually be a really good place to put the MAP sensor since it would then read BOTH the manifolds. A larger diameter tube would probably read best. I'm not super familar with the Mega squirt setups, but I'm pretty good at ODB1&II GM fuel injection. From What I've read it's pretty similar. I don't know if Megasquirt would also require a MAT sensor, but I'm pretty sure you'll need a TPS, (throttle position sensor) so I was thinking maybe you could extend one of your throttle shafts out the bottom and key it for a TPS. Though I'm uncertain the directonality. You might look at that before you pour your 2nd Manifold.

 

Wow, that's some pretty expensive castings. $10K each! I wouldn't be able to afford it, until you got it into production, but they do really look awesome. This Milling Machine you've been using looks really cool too. What is it that you mill? is it some type of plastic? I hope you're getting a good discount on the pours?.

 

I hope you can get back to your own project again soon. I'm still really excited to see it and hear it run. You'll truely have a 1 or a kind...

 

Phar

 

Hi Phar

 

The balance tube is 1/2" ID so I hope it's enough volume for everything. I'm hoping the first manifold works right the first time but in all reality will probably need some mods. What ever I do to my manifold will be reflected in the patterns if and when I go into production.

 

On the Hemi manifold that's $10,000 just for the patterns. That doesn't include the first actual casting or machine work! The person I'm doing the pattern for feels that there's enough of a market for him to recoup his money and then some.

Pattern making is very laborious even with the CNC machines.

I use a variety of plastics in my patterns depending on the usage. Some epoxies some PCV.

 

Derek

[Tony D]

1/2" for the balance tube / plenum log should be more than adequate.

Our Bonneville car has like 75KPA vacuum at idle, and a 1/2" pipe manifold with 1/8" taps to each runner gives more than enough vacuum for the brake function as well as a nice smooth MAP signal for the ECU.

 

TEC2 system recomended 1/2" log, and that's what we ended up with. For older manifolds without such a plenum for the MAP and Vacuum Accessory taps, a piece of Fuel Rail Stock gives a nice compliment and can be piggybacked next to your fuel rail as a visually pleasing addition when you make the conversion to EFI (or to simply get someplace to take a vacuum reading that doesn't bang your gauge to death!)

 

I previously ran my 240ZT with some 1/8" npt nipple barbs in each runner, to 1/4 tubing, which had 3/8"x1/4"x3/8" "T" fittings to manifold it all together and even that worked as a balance tube quite well with Mikuinis. The engine really smoothed out when it was put on compared to it's actions under boost before the balance tube was in place. I guess that would be equivalent to a 3/8" log, huh?

[Derek]

Well that's good to hear. Having never designed a manifold before I'm really guessing on a lot of this stuff.

 

Now you guys have me chomping at the bit again for this thing. Hopefully I'll be able to squeeze it in after the Hemi manifold. There's still so much to do after the castings are complete that at times it's a little daunting. I'm in the process of hanging a couple of servo motors on my lathe so I'll be able to automate some of the turning ops as well. It won't be a speed demon but it's better than me sitting there throwing levers!

 

Derek

 

 

 

1/2" for the balance tube / plenum log should be more than adequate.

Our Bonneville car has like 75KPA vacuum at idle, and a 1/2" pipe manifold with 1/8" taps to each runner gives more than enough vacuum for the brake function as well as a nice smooth MAP signal for the ECU.

 

TEC2 system recomended 1/2" log, and that's what we ended up with. For older manifolds without such a plenum for the MAP and Vacuum Accessory taps, a piece of Fuel Rail Stock gives a nice compliment and can be piggybacked next to your fuel rail as a visually pleasing addition when you make the conversion to EFI (or to simply get someplace to take a vacuum reading that doesn't bang your gauge to death!)

 

I previously ran my 240ZT with some 1/8" npt nipple barbs in each runner, to 1/4 tubing, which had 3/8"x1/4"x3/8" "T" fittings to manifold it all together and even that worked as a balance tube quite well with Mikuinis. The engine really smoothed out when it was put on compared to it's actions under boost before the balance tube was in place. I guess that would be equivalent to a 3/8" log, huh?

[PalmettoZ]

I would like to get a set of these if you are going to be selling some. Any info on that ? Thanks-

[Derek]

Hi

basically if the manifolds perform well and are drivable then I will offer them for sale. But there's a lot that has to happen before I get to that point!

 

Derek

 

I would like to get a set of these if you are going to be selling some. Any info on that ? Thanks-

[PalmettoZ]

Hi Tony

I'm absolutely not going to have any air gap on the butterflies. I can see the cumulative effect of a little gap on each one time six! I can also see the benefit of having the bleeder.

 

I'm in a catch 22 situation on the butterfly jig. In order to make this manifold work I have to make the jig. If I go to the trouble of making the jig I might as well make the butterflies. I called Kinsler and they want $16.00 each for the butterflies. $96.00 is close to the tipping point anyway for me to MFG them.

 

Can you go into a little more detail on this:

 

 

 

 

Thanks

Derek

 

 

Hey Derek-

Could you not make a quick fixture to hold the butterfly at the angle you need ( I assume just a couple of degrees ) and then turn this down on a lathe to the correct diameter ? This would give you the relief on the sides as required.

I can try to draw something up and show you what I am thinking about.

[Derek]

Now PalmettoZ if you had carefully read all 6 pages of this thread you would have read the post where I proposed this very thing!

 

Thanks for the suggestion and offer. That's exactly how I'm going to do it. I'm going to cut the blanks out on the mill and then true them up on the lathe.

 

Derek

 

 

 

Hey Derek-

Could you not make a quick fixture to hold the butterfly at the angle you need ( I assume just a couple of degrees ) and then turn this down on a lathe to the correct diameter ? This would give you the relief on the sides as required.

I can try to draw something up and show you what I am thinking about.

[PalmettoZ]

Now PalmettoZ if you had carefully read all 6 pages of this thread you would have read the post where I proposed this very thing!

 

Thanks for the suggestion and offer. That's exactly how I'm going to do it. I'm going to cut the blanks out on the mill and then true them up on the lathe.

 

Derek

 

Hey Derek-

Sorry I missed it, I have been bouncing back and forth reading this at work and didn't see where you had already said that. What you are doing looks awesome, I have never seen casting before and now have a clear picture of the process. You are investing a ton of time and work into this.

Great Job-

 

Scott

[Derek]

Hey Derek-

Sorry I missed it, I have been bouncing back and forth reading this at work and didn't see where you had already said that. What you are doing looks awesome, I have never seen casting before and now have a clear picture of the process. You are investing a ton of time and work into this.

Great Job-

 

Scott

 

Thanks Scott

Also I wasn't trying to shut you down. If you have Ideas throw them out there. That's what this things all about.

 

Derek

[Pharaohabq]

Hi Phar

 

The balance tube is 1/2" ID so I hope it's enough volume for everything. I'm hoping the first manifold works right the first time but in all reality will probably need some mods. What ever I do to my manifold will be reflected in the patterns if and when I go into production.

 

On the Hemi manifold that's $10,000 just for the patterns. That doesn't include the first actual casting or machine work! The person I'm doing the pattern for feels that there's enough of a market for him to recoup his money and then some.

Pattern making is very laborious even with the CNC machines.

I use a variety of plastics in my patterns depending on the usage. Some epoxies some PCV.

 

Derek

 

Okay, so vaccuum and MAP shouldn't be a problem. So back to Throttle Position Sensor (TPS) What are you thinking for that? is there a specific type/maker that you'll be looking to use? Does MegaSquirt require a TPS?

 

Phar

[Derek]

Hi Phar

I plan on using one from extrudabody

http://www.extrudabody.biz/servlet/the-126/TPS-dsh-1008/Detail

It will mount under one of the throttle shafts, Probably the rear one.

 

Thanks for the reminder I needed to order one so I can put the bosses on the pattern.

 

Derek

 

 

Okay, so vaccuum and MAP shouldn't be a problem. So back to Throttle Position Sensor (TPS) What are you thinking for that? is there a specific type/maker that you'll be looking to use? Does MegaSquirt require a TPS?

 

Phar

[Accurate Injection]

Thanks for thinking about and using Extrudabody Guys!

 

Kevin

[Guest michanic220]

what kind of filter are you going to be using? if any.

after about a hour of sitting here reading. very good read!

and great job. looks really nice.

[Derek]

Thanks!

You can see a ridge just at the inner end of the bell. A mesh screen will sit on the ledge. Then a piece of foam air cleaner will go in the end of the bell with a domed mesh screen on the outside holding it in.

 

Derek

 

 

 

what kind of filter are you going to be using? if any.

after about a hour of sitting here reading. very good read!

and great job. looks really nice.

[Derek]

Kevin from Extrudabody was kind enough to send me a 3D file of their TPS switch. I have it mounted on the bottom of #6 tube. The only thing you can see from the top is the plug so It won't be too bad.

Thanks for the reminder on this Phar. I totaly would have forgotten to put the bosses in place.

 

 

 

 

I'm pretty sure I'm going to cast a vacuum log as well. This will be machined to accept a Jeep 4.0 IAC and a bleeder arrangement for the main idle setting. It will have a small air cleaner for the intake air. This will mount on the firewall near the booster. This way I can have a single hose leading over to the manifold and it keeps the clutter kind of hidden.

Anyone see any problems with this?

 

Thanks

Derek

[Pharaohabq]

Nope, No problems here. Thanks for letting us help! I don't think the plug on the TPS will be a big deal in anycase since it'll be on the back end tward the firewall right? That TPS looks like an excellent choice, turns the correct direction, and it's small. GM IAC is a good one. When I did the EFI swap on my 87 jeep, I used a lot of 4.0 parts.

 

 

Well maybe there might be one issue I can think of that might be a problem there. Heat... The underside of the intake is just above the exhaust. I don't know how much heat the plastic of the TPS could take. You might need to include some heat shield between the exhaust and the intake. It may or may not be needed, but you might consider that...

 

It's always awesome to see the CAD files, then to see the actual pour. I'm still in awe over the work you've done so far.

 

Phar

[Derek]

Thanks Phar

I have bosses (the gray ones)on the bottom of the manifolds for mounting a heat shield. I'm thinking along the lines of a sandwich of aluminum and ceramic insulation. Maybe a ceramic coated piece of aluminum would be enough.

 

Derek

 

 

Nope, No problems here. Thanks for letting us help! I don't think the plug on the TPS will be a big deal in anycase since it'll be on the back end tward the firewall right? That TPS looks like an excellent choice, turns the correct direction, and it's small. GM IAC is a good one. When I did the EFI swap on my 87 jeep, I used a lot of 4.0 parts.

 

 

Well maybe there might be one issue I can think of that might be a problem there. Heat... The underside of the intake is just above the exhaust. I don't know how much heat the plastic of the TPS could take. You might need to include some heat shield between the exhaust and the intake. It may or may not be needed, but you might consider that...

 

It's always awesome to see the CAD files, then to see the actual pour. I'm still in awe over the work you've done so far.

 

Phar

[Tony D]

The TPS does not have to be on the throttle bodies. It can just as easily be mounted on the throttle pedal as long as you have adequate relative rotation for decent throttle resolution and a linkage without slop in it. Heim Jointing the stock ball-socket arrangement with oilite bushings works well, as does a throttle cable. Mounting it on the firewall on the back of the linkage that goes out to the carbs will work well also (get the idea someone has spent some time screwing aroudn with carb conversions?)

Makes it stealthy, as well. Nobody looks at switches on the balance tube, or firewall, or under the dashboard...

[Derek]

Hi Tony

I also heard about a Chrysler TPS with an arm on it for attaching to the throttle linkage directly. At this point Ill leave the bosses in place. This will give me plenty of options.

 

Derek

[HowlerMonkey]

This thread makes me want to go back to my high school and get all of their casting goodies out of the store room since I was probably the last person to cast anything there in 1980.

 

Just awesome the lengths people are going.