I would like to change my intake manifold out, and with there being only 1 real option. (1.6 litre Miata manifold, comes out on the left side and can interfere with cam gears/shock tower)

I have a couple of questions mainly about material.

Any problems with using mild steel/exhaust tubing?

Is there a problem with Ceramic coating the Intake manifold, what i mean is in the lower part of the runner will gas deteriorate the coating?

Though I will fab up all of the parts/tack them together myself i will pay a professional welder to do all of the final welding.

Im sure ill have more questions later on but any advice/tips are welcome .
Thanks

 

Your talking about just afew more dollars going with Alum exhaust tubing.

 

Lol. Noobs are fun. "Aluminum" exhaust tubing, by which I assume you mean aluminized, which is still mild steel.

The answer: Steel is fine. Just weighs more. Stainless steel has far superior insulative properties than aluminum, just, you know, weighs more.

A thin-walled steel IM might weigh the same as a sand cast aluminum IM, though. Never know.

But I would definately suggest stainless steel. Doesn't cost much more than mild (well, almost twice as much, but you aren't using a lot of material), is easily welded, and you won't need any coatings. You can even polish it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B6tPoweredMx3 &raquo;</TD></TR><TR><TD CLASS="quote">Is there a problem with Ceramic coating the Intake manifold, what i mean is in the lower part of the runner will gas deteriorate the coating?</TD></TR></TABLE>

Call up Swain Tech regarding coating it, they're probably half an hour from where you are (about 5 minutes from me ).

 

I thought i heard somewhere that the miata's engine has the same bore centers as a b series? meaning that you take a manifold meant for a b series honda cut the flange and mate it to the miata flange. maybe im just high, but i swear i heard that somewhere before.

 

You really dont want to use steel for the intake manifold. They retain too much heat to work optimally. If you are going to the trouble of a new intake manifold do it right and use aluminum.

Check out Ross Machining for DIY intake manfold parts

http://www.rossmachineracing.com

Justin

 

Yeah. Just not true.

Aluminum: k = 177 W/mK
Mild steel: k = 37.7 W/mK
Stainless: k = 13.4 W/mK

Compared to aluminum, both mild and stainless steels are insulative. Even if they did "retain heat", the heat transfer, either into the manifold or from the manifold to the air, is much, much less for steel than aluminum.

Since what you are worrying about is heat going from the engine into the manifold, and then from the manifold into the airstream, the steel manifolds are far superior to aluminum manifolds for keeping the airstream cool.

Even ignoring that... Aluminum has double the thermal capacitance (Cp) of steel, so the steel manifold could weigh twice as much as the aluminum one and still "store less heat" than the aluminum manifold would.

Manufacturers use aluminum for intake manifolds for 1, and only 1 reason. It is easy to cast and is therefore cheaper to manufacture.

 

Thanks guys I really appreciate the tech and ideas.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bradford &raquo;</TD></TR><TR><TD CLASS="quote">I thought i heard somewhere that the miata's engine has the same bore centers as a b series? meaning that you take a manifold meant for a b series honda cut the flange and mate it to the miata flange. maybe im just high, but i swear i heard that somewhere before.</TD></TR></TABLE>

Im going to take a look at work today, im going to compare the gaskets and see if they are similar.<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by daveG &raquo;</TD></TR><TR><TD CLASS="quote">

Call up Swain Tech regarding coating it, they're probably half an hour from where you are (about 5 minutes from me ).</TD></TR></TABLE>

Damn I didnt even know about Swain tech, thanks dave.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bradford &raquo;</TD></TR><TR><TD CLASS="quote">I thought i heard somewhere that the miata's engine has the same bore centers as a b series? meaning that you take a manifold meant for a b series honda cut the flange and mate it to the miata flange. maybe im just high, but i swear i heard that somewhere before.</TD></TR></TABLE>

That would be awesome if it were true... Because the Kia A6 engine is virtually identical to the Mazda B6 engine. Yay for me.

 

So why are almost all sheet metal manifolds out there made from aluminum?

 

Because it weighs less, and aluminum is easier to form.

 

Well the honda intake manifold idea is good in theory but has the sam problem as the miata intake, (comes out on passenger side)
Ill look into the Kia a6 but i guess if im going to be cutting and making fit with a Stock intake manifold i might as well go custom.

Keep the ideas comming, ive been reading How to tune and modify engine managment systems by jeff hartman and ive read past the intake manifold fabrication part and was wondering what other books would point me in the right direction with fabricating the I/M?

Thanks again guys.

 

Aluminum intakes are being replaced by composite manifolds...that are vibration welded. they are way cheaper to product than aluminum and their life cycle costs are much less.

I'm going to build my next manifold from the velocity stacks that RMR sells, some tapered runners from Burns stainless, a variant of the 1/2 round plenum RMR sells, the 75mm Mustang tb plate, my stock head flange and injector bosses.

All aluminum baby. I'm going to put my TB on the other side like you're speaking about to cut about 4 feet of IC piping out my system and replace it with 1 foot of 3" aluminum piping :-D

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ~RTErnie~ &raquo;</TD></TR><TR><TD CLASS="quote">Aluminum intakes are being replaced by composite manifolds...that are vibration welded. they are way cheaper to product than aluminum and their life cycle costs are much less.

I'm going to build my next manifold from the velocity stacks that RMR sells, some tapered runners from Burns stainless, a variant of the 1/2 round plenum RMR sells, the 75mm Mustang tb plate, my stock head flange and injector bosses.

All aluminum baby. I'm going to put my TB on the other side like you're speaking about to cut about 4 feet of IC piping out my system and replace it with 1 foot of 3" aluminum piping :-D</TD></TR></TABLE>

Thats actually what im trying to accomplish as well, removing 2 90* bends and the horrible design of the charge piping going over the valve cover ( anyone like heat?)

Pretty much this is going to be a DIY special, it dosent have to make me 100 more horse power, id be happy with a few and actually being able to run a normal looking hood. Thats why i mentioned exhaust tubing and ceramic coatings, something cost effective for the struggling racer .

 

Just a thought, but has anyone here considered making a manifold out of thermoset plastic using a simple foam casting process? You could just sculp the inside shape of the manifold, then carve a 2-part outside mold, fill with 2-part thermoset plastic, and then remove the foam with brushes.

 

Hell if you build it ill try it.

 

Actually, nevermind. I did a little research on google and it seems that plastics are either too brittle or melt at too low of a temperature to be really reliable in a manifold.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by beepy &raquo;</TD></TR><TR><TD CLASS="quote">Actually, nevermind. I did a little research on google and it seems that plastics are either too brittle or melt at too low of a temperature to be really reliable in a manifold.</TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">

Made from space-age composite polymer, the new FAST™ LSX™ multi-piece intake manifold shows a 20+ horsepower increase over the LS1 intake and 15+ horsepower over the LS6 intake, with no loss of drivability or low rpm torque. Best of all, the FAST™ space-age “Amodel™” polymer intake is 30 percent stronger than the stock polymer unit. Unlike aluminum intakes, the FAST™ polymer intake avoids becoming a power robbing heat sink.</TD></TR></TABLE>

 

That's a composite polymer that is vacuum molded in a permanent mold. Your average Joe Blow can't make cool stuff like that. I was actually thinking of using a product from Smooth-On, but it seems nothing they make is rated at more than about 220 degrees operating temp.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by beepy &raquo;</TD></TR><TR><TD CLASS="quote">That's a composite polymer that is vacuum molded in a permanent mold. Your average Joe Blow can't make cool stuff like that. I was actually thinking of using a product from Smooth-On, but it seems nothing they make is rated at more than about 220 degrees operating temp.</TD></TR></TABLE>

Oh, ok. I thought you were referring to polymer intake manifolds in general. Aluminum is hard to beat for one-off custom manifolds.

 

i'm not sold on the steel manifold idea... aluminum soaks heat at a much faster rate than steel, therefore it cools at a much faster rate than steel. if you had a steel im on your aluminum head, when you turn the car off all the heat from the steel im would keep the head hotter for a longer period of time. i can't see this being a positive on a race engine... if there are more benefits to a steel im, why aren't more builders and tuners using them? there is always a solution to forming steel, oem manufacturers have been forming steel for decades.

i don't know, i could be talking out my ***, but i'm just not seeing all the positives of using steel for a im.

 

See i would do aluminum but i dont have the welder to tack it together, thats why i figure use a steel Intake manifold + ceramic coating should help with the heat disapation.

Though all of this may be next years project, i just found a early b6t (with the big Rods) With a subaru Hybrid on it + the mx3 dohc head (which exits on the side i want it to ) for 500$ canadian.
Was in a guys festiva that ran a 13.2 on 9 lbs of boost.

 

By coating it you are just going to have more heat staying in it. It wont cool off or heat up as fast, but once it is heated up it will stay hot longer.

Justin

 

depends on what kind of coatings you use justin... they have coatings that do it all. So if you take it to a place that knows what the expletive they are doing...you'll be perfectly fine.

http://www.finishlinecoatings.com and http://www.nicindustries.com one is in Portland and one is in white city. NIC supplies most of your coating companies with the powders etc.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ~RTErnie~ &raquo;</TD></TR><TR><TD CLASS="quote">depends on what kind of coatings you use justin... they have coatings that do it all. So if you take it to a place that knows what the expletive they are doing...you'll be perfectly fine.

http://www.finishlinecoatings.com and http://www.nicindustries.com one is in Portland and one is in white city. NIC supplies most of your coating companies with the powders etc.</TD></TR></TABLE>

Thats why I told the original poster to call up Swain Tech. They have a shitload of coatings and have done stuff ranging from auto parts to space shuttle coatings for NASA.