I know that aluminum radiators cool
a engine beter than stock brass radiators


so would putting aluminum heads on
a engine cool it even more ???


what do you think?????

Yes to some effect they do but moreover they cool the combustion chamber so much that you can run as much as .4-.5 more compression over cast iron heads before it pings

In conjunction with a reverse cooling system and the aluminum heads you can probably get away wtih higher than .6 more compression. What comp. ratio do the Lt1 motors have?

Plus the aluminum heads will be better machined so they will flow antifreeze better as well air and fuel.

also lighter in weight witch requires less hp to do the same work therefore the engine will produce less heat.

one hting though, since they transfer heat better than iron heads,
should you possibly have a coolant/cooling issue arise, the alum
heads will be affected worse/quicker than iron heads....

--Sherpa

Originally posted by SHERPA RIG
one hting though, since they transfer heat better than iron heads,
should you possibly have a coolant/cooling issue arise, the alum
heads will be affected worse/quicker than iron heads....

--Sherpa

You're right. I would also wonder about warping them or loosing a gasket - like on a toy since they have cast blocks and aluminum heads.

Naw, pardon a newbie speaking up here, but that's silly, all of you are wrong. Aluminum is a poor conductor of heat, that's why you can pick aluminum foil out of the oven by hand. If it ain't conducting heat away from the engine, then that heat is STAYING in the engine. The reason you have warping and gasket problems with alum heads is because they expand/contract at a different rate than iron, that's got nothing to do with heat conductivity. And how does an aluminum head cool the combustion chamber? Reverse cooling does that, but you don't need aluminum to have reverse coolant flow. And why is aluminum necessarily better machined?

Okay, fire away (flame suit ZIP ZIP BUCKLE SNAP).

Oh My GAWD.

I hope you didn't just say that aluminum is POOR conductor of heat. It is a heat super conductor, which is exactly why you can pick aluminum foil out of an oven, it sheds it's heat so quickly, that by the time you grab it, it is cooled. If it were not a good conductor of heat, why would top of the line radiators rely on it? Under your theory, radiators should be made of freakin iron!

Dude, you are fighting against science and about 100 years of internal combustion engine development technology: BACK AWAY FROM THE KEYBOARD.

Andy

Hey 92xj open the stinking box your keyboard is hooked to and take a look at the heat sink strapped to your CPU. I give you one guess what it's made out of??? What a freaking D.A.N.!:rolleyes: :rolleyes: :rolleyes:

If you were right, where does the aluminum foil in an oven conduct the heat to? To the 500° air around it? To the piece of toast? A good heat conductor does not make heat vanish, it passes it on to somewhere else.

From Mr Webster:

Main Entry: con·duc·tor
Pronunciation: k&n-'d&k-t&r
Function: noun
Date: 15th century
: one that conducts : as a : GUIDE b : a collector of fares in a public conveyance c : the leader of a musical ensemble d (1) : a material or object that permits an electric current to flow easily -- compare INSULATOR, SEMICONDUCTOR (2) : a material capable of transmitting another form of energy (as heat or sound)
- con·duc·to·ri·al /"kän-"d&k-'tOr-E-&l, k&n-, -'tor-/ adjective

OK dude, I'm gone send you a thermal dynamics textbook. Just post your address and I'll send it along free of charge, as a service to everybody on this thread.

The beauty of aluminum foil is that it is so thin and conducts heat so well tha the instant you open your oven door, part of the heat leaves the foil immediately, and when you grab the foil with your fingers, any residual thermal energy is transfered to your fingers, without you even feeling it.

Fawk man, I'm just a fisheries biologist and I know this shit!

Andy

Oh shit, just looked it up, you're right. Excellent thermal conductivity. So the foil passes it on to the air.
Ahem, please excuse me while I crawl back under my rock.

Originally posted by StoopidMonkey
In conjunction with a reverse cooling system and the aluminum heads you can probably get away wtih higher than .6 more compression. What comp. ratio do the Lt1 motors have?

If you take a carb motor with iron heads and add aluminum heads you can bump up the comp. .5 or so and if you add fuel injection you can gain about another .5 or so. These are aprox figures though.

Originally posted by 92xj
Oh shit, just looked it up, you're right. Excellent thermal conductivity. So the foil passes it on to the air.
Ahem, please excuse me while I crawl back under my rock.

look it up before u speak next time D.A.N.! the 1st step is admiting U R WRONG, U have so we will move on:D

Originally posted by 92xj
Naw, pardon a newbie speaking up here, but that's silly, all of you are wrong. Aluminum is a poor conductor of heat, that's why you can pick aluminum foil out of the oven by hand. If it ain't conducting heat away from the engine, then that heat is STAYING in the engine. The reason you have warping and gasket problems with alum heads is because they expand/contract at a different rate than iron, that's got nothing to do with heat conductivity. And how does an aluminum head cool the combustion chamber? Reverse cooling does that, but you don't need aluminum to have reverse coolant flow. And why is aluminum necessarily better machined?

Okay, fire away (flame suit ZIP ZIP BUCKLE SNAP).



http://www.3dpcgame.com/cwm/s/contrib/dvv/cwmseizure.gif


OMFG :eek:


hay man pass it over :smokin:





http://www.theunholytrinity.org/cracks_smileys/contrib/blackeye/arcadefreak.gif

Originally posted by afecko

If it were not a good conductor of heat, why would top of the line radiators rely on it? Under your theory, radiators should be made of freakin iron!


Just alittle FYI - the whole alum craze was caused because racers use it to save weight. An aftermarket alum rad will cool better than a stock brass/copper one because of the superior design of the aftermarket alum, but a well designed brass/copper radiator will out cool an alum rad because brass/copper disipates heat better. The thermal conductivity (K) of alum is 237 assuming its pure, which it usually isn't, most alloys are ~ 177. Copper and the brass used for radiators (actually it is usually a copper -brass alloy) are roughly the same at 401 - so copper/brass is about twice as conductive as Alum.
As for alum being more conductive than iron - yes, 2-3 times more conductive as most iron is around 72.

The question about machining can be true as most alum heads are CNC machined so they are going to have a better tolerance than a cast iron head that just has finishing machining done to it.

Originally posted by SeaBass44


look it up before u speak next time D.A.N.! the 1st step is admiting U R WRONG, U have so we will move on:D

I've been laboring under this particular delusion for years, because of the aluminum foil thing. It wasn't until yall mentioned the radiators that I started to doubt and looked it up. Luckily, POR was there to kindly and gently correct the error of my ways.

And oh yeah, the :smokin: is pretty good this time of year, here ya go Chief try some of mine.

Originally posted by 92xj


Luckily, POR was there to kindly and gently correct the error of my ways.

:laughing: :laughing: :laughing: :laughing: :laughing: :laughing: :laughing: :laughing: :laughing:

Acording to the Otto cycle you don't get to up the compression ratio...you have to to keep the same power/efficiency. Idealy you would want heat to only leave the chamber thru the Ex valve.

The reason you get more power out of Al heads is because of the better design and manufacturing that generally goes into them. They also weigh less so you arn't pushing around so much weight.

Right? Someone correct me if I am wrong.

triaged you are wrong.:D

according to the otto cycle efficiency depends on compression ratio. the maximum compression ratio you can run in an automobile engine is determined by preignition, when the air and fuel mixture explodes from heat and pressure before the spark ignites it. With an aluminum combustion chamber the hot spots on the combustion chamber are not as hot and so it is less prone to preignition, therefore you can bump the compression ratio. Additionally combustion chamber shape is key, and aftermarket and factory aluminum heads are generally designed well for resistance to preignition so this helps too.