sheet metal intake 1

[cheapcharlie]

would appreciate any opinions on this
do most of the power gains from runnig a sheet metel intake come from better distribution or faster charge cool down

 

[patprimmer]

Compared to what.

How will the charge be cooled faster?

Why will it have better distribution?

Power increase will depend on how well it is designed and made and how this influences total airflow and airflow distribution and fuel distribution if the fuel is introduced before the runners separate into individual passage ways.

Regards

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[cheapcharlie]

lets look at this anouther way, pat. drive your car shut it off and wait an hour then open the hood and see if the exh manifold will still burn your hand. now drive your race car wait 10 mins and see if the header tubes are still hot.racing is just a hobby for me and allways appreciate input from fellow racers.

 

[patprimmer]

I do not think intake manifold construction method has anything to do with exhaust manifold cool down rate.

What technical background and engineering experience do you have.

Regards

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Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[cheapcharlie]

exhaust manifold construction has nothing to do with intake manifold cooldown rate.(as far as i know).
intake and exhaust material and construction have a lot to do with heat absorbtion and disipation rates.
question was if power gains are from charge temps or mixture distribution.maybe unrelated but i did a lot of work in the 70s and 80s on carb iceing concerns. most corps. did not want to address the problem as they were working on the fuel injection thing. GM did partially adressed the issue by going to the alloy intake. apoligize to patprimer if i offended him in some way, it was not my intent.

 

[patprimmer]

Now the question is somewhat clearer.

At WOT there will be a small, probably insignificant heat transfer from the manifold to the charge.

Any temperature increase in the air will decrease power.

Temperature transfer will be dependant on many things like material, surface area to volume ratio, sources of heat to the manifold weight of the manifold. None of these are exclusive to sheet metal fabricated manifolds.

It really does depend on the design and what you are comparing it to.

I was not offended, but from your OP and first response, I did wonder if you were wasting our time, and what level of answer you might understand, or even if you had any business participating in this forum.

Regards

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Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[izzmus]

The main reason many race cars use sheetmetal intakes is a practical one: If you want to change any critical dimensions, it's quicker to fabricate a new intake than it is to do a new casting.

 

[cheapcharlie]

Thank you izzmus, that makes sense. So basically when you see a bracket car running one the racer either has acess to a dyno and equipment for making his own or he has money to waste.Sheetmetal intakes are not cheap.

 

[IceStationZebra]

You also have to consider that every manifold is a compromise, especially one made for public consumption. A sheet metal manifold is designed for your particular engine combination, intended use and installation restrictions. It may also be your only choice for off-the-beaten-path engines.

ISZ

 

[XXXLR8R]

One-off sheetmetal intakes are much more economical to fabricate than one-off cast intakes ;~)

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