Aluminum block oil temp

I remember asking Hall about aluminum radiators vs. the brass ones and he said that nope, the aluminum isn't even as good as the brass.

In his opinion the aluminum anything was just for weight savings. I supose that means engine blocks also.

Thanks Doug,
Looks like I will be using the oil cooler for the engine instead of the transaxle for now.

Blaine

quote:

I remember asking Hall about aluminum radiators vs. the brass ones and he said that nope, the aluminum isn't even as good as the brass.

In his opinion the aluminum anything was just for weight savings. I supose that means engine blocks also.

Doug, I don't understand Hall's conclusion;

FYI metals that are good thermal conductors tend to be good electrical conductors as well. Below is the thermal conuctivity of some common metals in W/m-K (Watts per meter Kelvin)

Ag (Silver) 428, Cu (Copper) 398, Au (Gold) 315, Al (Aluminum) 247, Brass (Cu 70%, Zn 30%) 115, Cast Iron (depending on quality) 44-52.

The precious metals are best, but obviously prohibitive in our aplications from a cost perspective, but they are extensively used in high end electronics. As you can see Al is considerably better than brass. Cu is the only real contender and hence its extenisve use in industry.

If we take the analysis a step further and look at denisty (g/cm3 or mass per unit volume) of the same metals vis;

Ag 10.5, Cu 8.9, Au 19.3, Al 2.7, Brass ~8, Cast Iron ~7.

One can easily work out that Al is by far the best metal on a thermal conductivity per unit weight basis.

Going back to the original question from Blaine, which compares Al to cast iron; The answer is 'Yes', one would expect much better heat transfer in a Al block vs. that of cast iron. The trick is in ensuring there is sufficient dissipation of that heat away from the Al block (i.e. cooling) or the whole system simply operates at a higher equilibrium temperature.

Julian

Julian,
I was hoping the block would act like a big oil cooler possibly transferring a fair bit of heat to the water jacket. I have an air/oil cooler but was hoping to use it for my transaxle. The radiator is a PPC unit and I never had any issue with coolant temps over the summer. I guess I will have to get that oil temp guage hooked up for this summer to see what is happening.

Blaine

Joules, I have some engineering backround to me as well and I would say according to the thermal dynamics the aluminum won't store the energy like the iron does. Yes I agree.

I personslly hsve learned by living in NY one doesn't really want to run an aluminum intake manifold in the winter. Iron is the way to go.
The carbs seem to frezze almost solid. The iron holds the heat better of course.

If all things were equal on the block, i.e., it was pure aluminum the difference would be more noticiable.

General Motors in fact tried that combination in at least one production vehicle that I am aware of, the Vega.

Functionally it proved to be a poor combination leading to premature cylinder wear.

Aluminum blocks that are used for "performance" applications in US V8's are used for weight savings. About 100 pounds.

They have nice thick cast iron cylinder sleeves pressed into them.

I don't think that I ever heard of heat conductance as the reason to use an aluminum block.

The discussion I had with Gary Hall was over which of his radiators to use. I thought the aluminum unit would be the way to go in the Pantera.

Gary said no way. The Phoenix unit was. He said only use the aluminum radiator to save weight for racing.

I stated the same story to him that you just did and he said something to the effect of "I guess that pigs can fly then".

He had both units to sell to me so it wasn't a buy my radiator, it's better. I asked him for his advice and he gave it to me.

It isn't my quote that says "you can lead a horse to water, but that doesn't make him a duck" but I guess the point is, what does logic have to do with this anyway?

Better yet, why go by what I say? Inquire with the block manufacturer and see what they say about the engine running cooler. I would be interested to hear that also.

I think that there must be more then a couple of people here running the Fontana aluminum Cleveland block? What say you guys?

Doug I think what Gary was getting at is that brass radiators actualy use copper pipes for the heat exchanger tubes and aluminum uses aluminum tubes. Aluminum is lighter but copper does do better in heat transfer. Given the same air flow through the engine compartment an aluminum engine will give off more heat. But as far as Blaines question, no one here can answer that until Blaine trys out his new engine himself. Blaine you are not running hotter because you have turbos, you are running hotter because you are running over two and a half times the horsepower that the Pantera was designed to handle. You are getting eight hundred plus horsepower because you are burning one hell of a lot of gasoline in a very short time frame in a relatively small space. No one can answer for sure what kind of overheating problems you might encounter until you just crank her up and pound on that puppy.

I can not answer for everyone else, but I switched out the Hall Phoenix radiator for a Ron Davis Racing radiator (which I believe Dennis also sells) and the aluminum ran much cooler and consistant temps. Now I want to clarify that it was an older Phoenix radiator and a brand new aluminum radiator, so that may have had an effect on the outcome. Also this was in Phoenix, Arizona so the temps are high in the summer. Also I have the aluminum Fontana block in my car and although when run hard in summer, it gets as hot as any other as far as oil temps, I do notice that it cools down faster than any engine that I have ever had before.

quote:

Originally posted by DeTom:
No one can answer for sure what kind of overheating problems you might encounter until you just crank her up and pound on that puppy.

Dont think the local law enforcement will appreciate that very much. You guys did answer my question though. I was hoping it would make more of a difference but oh well. Looks like I will need a second cooler.

Blaine

quote:

Originally posted by PanteraTurbo:

quote:

Originally posted by DeTom:
No one can answer for sure what kind of overheating problems you might encounter until you just crank her up and pound on that puppy.

Dont think the local law enforcement will appreciate that very much. You guys did answer my question though. I was hoping it would make more of a difference but oh well. Looks like I will need a second cooler.

Blaine

I am sorry, my mistake. I assumed with 830 HP this was to be a track car. If you intend to drive this car to the grocery store, I will garuntee it will overheat no matter what you do.

There is another way to find additional cooling on the Pantera that I have heard no one mention.

The cooling pipes run most of the length of the car and act as addition heat convectors.

If one was to add cooling fins to those pipes, like say residential hot water baseboards, then the heat disapation would be much greater.

It would be a function of the surface area of all those fins instead of just the surface areas of the pipes.

Now don't ask me how to do it but it would help alot.

Dont get me wrong, its built for racing and racing it will do but I would go nuts only being able to drive it just a handful of times a year. Im not worried about street driving as it is a turbo motor and drives like a mild street engine so long as I can keep my foot off the gas. Im more worried about prolonged high power use like what I would experience in a racing situation.

Blaine

quote:

Originally posted by PanteraTurbo:
Dont get me wrong, its built for racing and racing it will do but I would go nuts only being able to drive it just a handful of times a year. Im not worried about street driving as it is a turbo motor and drives like a mild street engine so long as I can keep my foot off the gas. Im more worried about prolonged high power use like what I would experience in a racing situation.

Blaine

Definetly run an oil cooler then. Absolutely.

Alum verses Brass radiators come down to the spacing of the fins. The attached document will help with the discussion as it pertains to Radiators.

Good news is that the dollar per pound for recycled Brass is way up. So one can make a few buck selling their old cores to the scrap yard recycle man. This to offset the big bucks blown on the new alum radiator.