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Making my own EFI intake... The First Casting


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might try this stuff. permatex #29132

 

I've used it several times for similar issues on carburators. its awsome because its the only stuff i've found that resists gas and solvents unlike other silicone gasket makers. it might be the same as the nissan stuff. its also grey.

 

That looks like what Tony was talking about. The specs are certainly in line.

 

Thanks

Derek

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heres a site with some information on a black sealant that BMW uses on their throttle plates.

 

http://www.westcoastriots.com/htmlfiles/obd1.html

 

maybe you can contact them and ask them for a BMW part number of some kind, but I don't see why Kinsler wouldn't have something they can recommend.

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heres a site with some information on a black sealant that BMW uses on their throttle plates.

 

http://www.westcoastriots.com/htmlfiles/obd1.html

 

maybe you can contact them and ask them for a BMW part number of some kind, but I don't see why Kinsler wouldn't have something they can recommend.

 

If these products are hard then that could create problems on their own. My throttle tube is machined stainless. There really aren't any imperfections other than the ones I put in after the fact by mistake. I think my main problem is the inaccuracies in the machining of throttle plate. I talked to one of my clients who makes injection systems and carb parts for vintage hot rods. I described my angle jig for machining the throttle plates and he said that's exactly the way they did it.

 

I guess for all practical purposes if I waxed up the throttle tube and painted the adhesive on the butterfly while it was closed then the adhesive/filler would stick to the plate and not the tube. This would create a sealed edge for sure.

 

Derek

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The BMW stuff is what I am referring to, IT IS NOT RTV!

 

This is the same stuff Nissan uses on it's own throttle plates. Trust me, unless you get a throttle plate THAT STICKS SHUT you will not be able to make it seal at an angle that won't stick off-idle. The grey 'paint' lets the throttle plate seat at an angle slightly less than metal-to-metal fit---which will prevent sticking. Anybody ever get a TWM big-throat that STICKS? I did. Brushing in a sealant kept it from that annoying habit. I got mine in a small applicator-in-cap bottle from the aforementioned NISMO Employee (now former NISMO Employee...)

 

It done dried out and it was 'generic'---he had a bigger source in the shop, but he just brought me the small bottle.

 

It has to be the BMW stuff...if one person can get it, anybody can get it.

 

That is the stuff I'm talking about. The sealer makes your life WAAAAAY easier. Metal to metal will gall. Metal to metal will wear.

 

You need something to 'soft seat' onto, and make a nice seal. Paint does that. I'm thinking it's an epoxy matrix with graphite in it. Kind of like the coatings they spray on oil-free screw air compressor screw elements....hmmmm... that gives me another possible source. I gotta call Mike in Buffalo now...

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The BMW stuff is what I am referring to, IT IS NOT RTV!

 

This is the same stuff Nissan uses on it's own throttle plates. Trust me, unless you get a throttle plate THAT STICKS SHUT you will not be able to make it seal at an angle that won't stick off-idle. The grey 'paint' lets the throttle plate seat at an angle slightly less than metal-to-metal fit---which will prevent sticking. Anybody ever get a TWM big-throat that STICKS? I did. Brushing in a sealant kept it from that annoying habit. I got mine in a small applicator-in-cap bottle from the aforementioned NISMO Employee (now former NISMO Employee...)

 

It done dried out and it was 'generic'---he had a bigger source in the shop, but he just brought me the small bottle.

 

It has to be the BMW stuff...if one person can get it, anybody can get it.

 

That is the stuff I'm talking about. The sealer makes your life WAAAAAY easier. Metal to metal will gall. Metal to metal will wear.

 

You need something to 'soft seat' onto, and make a nice seal. Paint does that. I'm thinking it's an epoxy matrix with graphite in it. Kind of like the coatings they spray on oil-free screw air compressor screw elements....hmmmm... that gives me another possible source. I gotta call Mike in Buffalo now...

 

Aluminum against aluminum would be really sticky. Hot aluminum is even worse. The fact that I have aluminum against stainless will help. When I cut the plates on the angle jig the leading and trailing edges will have a chamferd edge that will aid in sealing.

My plan is to get the best fit I can without the sealer. I'm then going to put the whole rig into an oven and let it heat soak. Then I'll check the fit and stick on the plates.

At least that's the plan for now subject to change without warning!

 

My client who makes the hot rod parts also told me about offsetting the throttle plate on the shaft. This lets the engine vacuum help seal the plate in the tube when it's closed.

 

More stuff to chew on!

 

Derek

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It's amazing what you can find with a little digging!

 

http://cgi.ebay.com/ebaymotors/Tri-Power-Quadrajet-Carburetor-Throttle-Plate-Sealer_W0QQcmdZViewItemQQcategoryZ33551QQihZ014QQitemZ330250253297QQrdZ1QQsspagenameZWDVW

 

Alright now I'm sold on the sealer idea. Good enough for the "majors", good enough for me!

 

And the data sheet from the MFG (I think)

 

http://www.achesoncolloids.com/NR/rdonlyres/02BD7E6E-0BC8-41C3-93AC-EAA59144426A/0/Dag213.pdf

 

I'll do some more digging and see if I can locate it in a little larger quantity.

 

Derek

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here you go.

 

910 gram bottle enough?

 

http://www.aviatec.net/page_produit_uk.php?prod=9539

 

Wow nice find!

Unfortunately they appear to be in France. Now do that same search magic for a place in the states and I'll really be impressed!

At this point I'll probably buy a couple of kits from the guy on ebay and see if the stuff works. If it does the job then I'll try and source a larger quantity if I go into production.

 

Thanks

Derek

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  • 1 month later...

so hey any news on this, I know it's a project, but it's been a While, I hope you haven't dropped it. it's pretty awesome!

 

So how were you going to measure airflow, obviously not by AFM, really MAP is the only way, but where will you sample from? I didn't see a boss for a nipple anywhere. I imagine You'll have a balancing port between the manifolds.

 

Phar

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so hey any news on this, I know it's a project, but it's been a While, I hope you haven't dropped it. it's pretty awesome!

 

So how were you going to measure airflow, obviously not by AFM, really MAP is the only way, but where will you sample from? I didn't see a boss for a nipple anywhere. I imagine You'll have a balancing port between the manifolds.

 

Phar

 

Hi Phar

Well I've been working on a manifold just not mine!

DSC_0004.jpg

 

It's a paying job for an old hemi.

 

Hopefully as soon as I'm done carving this I'll be getting back to my manifold. The CAD and Cam work is all done I just need to get enough free time to run it.

There is a internal balance tube that runs through the manifold and has a boss on the rear manifold. I'll probably run a vacuum log for the booster and IAC. Not sure exactly where the MAP will pull from at this point. There's plenty of wall thickness to drill and tap anywhere on the manifolds.

All of the bosses are going to be on the bottom of the manifolds.

 

Derek

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So what does making a casting like that cost. (hemi manifold)

 

Your looking at $10,000 for the tooling which includes the top and bottom (cope and drag) patterns and three core boxes. The customer supplied the 3D model. Otherwise it would have been about $2500.00 more. There's a ton of work involved in making tooling. On a project like this you have to figure it's not going to work the first time and require some modifications. I'm not sure what the foundry is charging for the castings.

 

Here's a shot of the one of the core box halves with a core that has been "blown".

 

DCFN0007-1.jpg

 

This sand is what will make the casting hollow.

 

Derek

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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... :icon14:

 

Phar

 

Hi Phar

Well I've been working on a manifold just not mine!

DSC_0004.jpg

 

It's a paying job for an old hemi.

 

Hopefully as soon as I'm done carving this I'll be getting back to my manifold. The CAD and Cam work is all done I just need to get enough free time to run it.

There is a internal balance tube that runs through the manifold and has a boss on the rear manifold. I'll probably run a vacuum log for the booster and IAC. Not sure exactly where the MAP will pull from at this point. There's plenty of wall thickness to drill and tap anywhere on the manifolds.

All of the bosses are going to be on the bottom of the manifolds.

 

Derek

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