Why Aluminum Intake Manifolds?

[blackstangt]

Phenolic spacers are supposed to reduce the conduction of heat trough the lower intake to the upper intake, thereby lowering the condution of heat into the air entering the combustion chamber. I've read that it makes a minimal difference, which is probably right, because the engine radiates heat and conducts to the upper intake manifold through other methods.

Isn't this the wrong way to go about reducing conduction to the induced air? Wouldn't it be better to use a material that conducts less or retains more heat? For instance, some newer cars have plastic upper intake manifolds. The plastic won't really conduct heat into the induced air, weighs less and would be much cheaper to upgrade to. Other materials, even other metals conduct less heat than aluminum, so why not use them?

What I've thought of so far is weight, which I just adressed with the plastic upper or would be possible with heavier less conductive materials if they were designed more box-like ie. GT-40.

Running boost should not be an issue if using any of these materials, because they are used in other areas of the system.

Heat could be a factor in extreme conditions with plastic, which is why I mention other materials. Less cooling of the engine, this is why there is a liquid cooling system, we're not flying Cessnas or riding motorcycles...

This could apply to the lower intake as well, as long as you're not trying to use plastic.

Anyone have any other specific materials in mind?

 

[RYC CUKR]

Ford has already gone the composite route with the mod motors and I believe that they ended up having so many problems with them leaking coolant, getting brittle and cracking that they added a lifetime warranty for the intake manifolds on the 96-98 4.6s.

I prefer aluminum just from a longevity standpoint. I have never seen an aluminum intake go bad just bolted to the car. I have seen composite ones crap out just from age, and not that much age might I add.

There used to be a few composite boxed upper intakes on the market. I believe that one was made by Cartech but I can't be 100% certain about the name.

 

[lx93notch]

yup your right about that, almost every 2v ford mod motor has a recall out for that crossover tube on the front of the intake

 

[blackstangt]

Ok, well that's one type, what about all of the others? I wonder if the GT-40 gets an unaccuonted for advantage over the thicker aluminum intakes out there because of how thin the tubes are. Thin tubes won't get as "heat soaked" as larger masses of aluminum.

I know I'm going to get a little Smokey Yunik here, but what about ceramic?

 

[86bluecobra]

just run nitrous and you will never have to worry about your intake being hot. My intake is Ice cold after a blast down the track on the giggle gas.

 

[5spd GT]

I had to swap out my 1998 plastic composite intake, but it is not because the composite, just they designed it bad and it would crack at a joint in the coolant runner. 1999 to the present day have no problems whatsoever. They are plastic composite.

LsX intakes, Hemi intakes, etc. are all the new lightweight plastic composite.

I have a handful of newer intakes at the house.

- 4.6L 3V
- 4.6L PI
- 4.6L NPI
- LS1

They are all in the 10-15 lb range. Much better than the cheap priced cast aluminum 45-50 lb intakes for the 5.0L.

 

[Sicarius428]

There are definately better materials now but a lot of engines new engines don't use the intake manifold as part of its structural integrity.The 4.6 is a pretty stout block to begin with and the fact that it doesn't have a cam also makes the valley much stronger. The Ford FE is a perfect example of the intake is designed into the integrity of the block and I would imagine that all of the engines of that era have some sort of design where the intake manifold helped the motor from splitting. It's just that we are playing with 40 year old motors is all...
Kevin

 

[monte87]

GT40 tubular weighs in at 8lbs. I'll stick with my aluminum hahaha @ least you can polish them up, cant do that with plastic!

Later Ant

 

[Sicarius428]

Ya I am not sure about 45-50 lbs... thats what both my heads weigh together. Plastic upper might not be a bad idea... might look tacky but there are a couple of box uppers that are plastic already.
Kevin.

 

[monte87]

When i did my H/C/I swap and pulled off the E7's, 50lbs and then slapped on gt40 tubular intake another 15lbs, dude seriously, the front end of the stang actually rose a bit! hahahah

 

[86bluecobra]

Personally I would want something that could displell heat rather then will just warp if things get a little 2 toasty.

 

[5spd GT]

A GT40 Tubular intake does not weigh 8 lbs.

I actually may have been a little off. I know a handful of them are in the 40 lb range (upper and lower, plus hardware).

A pair of aluminum heads weighed 60 lbs for me. The irons were just over 100 lbs for me as well.

 

[blackstangt]

I had to swap out my 1998 plastic composite intake, but it is not because the composite, just they designed it bad and it would crack at a joint in the coolant runner. 1999 to the present day have no problems whatsoever. They are plastic composite.

LsX intakes, Hemi intakes, etc. are all the new lightweight plastic composite.

I have a handful of newer intakes at the house.

- 4.6L 3V
- 4.6L PI
- 4.6L NPI
- LS1

They are all in the 10-15 lb range. Much better than the cheap priced cast aluminum 45-50 lb intakes for the 5.0L.

That's what I'm getting at, when are they going to come out with a light composite intake manifold for our good ol 5.0?

Or did they already?

 

[blackstangt]

There are definately better materials now but a lot of engines new engines don't use the intake manifold as part of its structural integrity.The 4.6 is a pretty stout block to begin with and the fact that it doesn't have a cam also makes the valley must stronger. The Ford FE is a perfect example of the intake is designed into the integrity of the block and I would imagine that all of the engines of that era have some sort of design where the intake manifold helped the motor from splitting. It's just that we are playing with 40 year old motors is all...
Kevin

The upper intake provides no strength fr the block though, and this is where much of the heat would be transferred. What about a coating for the inside of the lower intake with a nonconductive material as well?

 

[blackstangt]

Ya I am not sure about 45-50 lbs... thats what both my heads weigh together. Plastic upper might not be a bad idea... might look tacky but there are a couple of box uppers that are plastic already.
Kevin.

Who sells them?

 

[blackstangt]

Personally I would want something that could displell heat rather then will just warp if things get a little 2 toasty.

It wouldn't warp if made properly, as far as removing heat, buy a better radiator if you need to, that's what it's for. The intake manifold doesn't compare to the cooling capacity of the radiator.

 

[blackstangt]

A GT40 Tubular intake does not weigh 8 lbs.

I actually may have been a little off. I know a handful of them are in the 40 lb range (upper and lower, plus hardware).

A pair of aluminum heads weighed 60 lbs for me. The irons were just over 100 lbs for me as well.

Those Iron head are massive, they weigh almost as much as the block....

 

[Mustang5L5]

Plastic intakes are a new(er) trend. They didn't really appear until 1992 on Ford's and not until very recently on a lot of other cars.


Ford used AL on the 5.0 because it was the cheapest means to mass produce a complex intake. That's about the only reason. Sacrifice some engineering potential for the almightly buck.

If a pushrod engine were designed today by ford, it might have a composite intake. The LS6 does doesn't it?

Today's technology allows such things to be done, but 20 years ago, sand-cast aluminum intakes were the technology of the day

If an aftermarket supplier wants to put the R&D into a composite "long-runner" style intake, then they might have something. But they will also need to price it high to offset the initial capital expenditure to research and design a working composite 5.0 long-runner intake.

 

[monte87]

A GT40 tubular intake upper (plenum) weighs in 8-10lbs, I never stated the lower and all the hardware.

A GT40 Tubular intake does not weigh 8 lbs.

I actually may have been a little off. I know a handful of them are in the 40 lb range (upper and lower, plus hardware).

A pair of aluminum heads weighed 60 lbs for me. The irons were just over 100 lbs for me as well.

 

[monte87]

Not the fake one-explorer thats heavy as ****. Even my old original 93 cobra was heavy!