Which is better: Aluminium or cast iron engine?

Wednesday April 18 2018
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Hello Paul, Thank you you your help and these are my questions:
1.Is it true that all engine blocks for Toyota Alphard are made of aluminium? Emmanuel Ampe
Dear Emmanuel, that is correct the engine blocks are made of aluminium. The first generation Toyota Alphard (2002-2008) comes with two engines, the 2AZFE 2.4 litre 4 cylinder straight and the 1MZFE 3.0 litre 6 cylinder V shaped engine. Both engines have aluminium intake manifolds, cylinder heads and engine blocks. However, the cylinder walls are lined with cast iron.

2.Which is better between the aluminium engine and cast iron engine?
Aluminium and cast iron are two different materials. Cast iron engine blocks and cylinder heads are cast in sand moulds, a pretty tedious and slower process. Cast iron engines are also heavier and put a bigger toll on fuel efficiency. However cast iron engines are renowned for dealing better with wear. Cast iron engines are also easier to repair or rebuild.
Aluminium engine blocks and heads are die casted and their production is faster, though more expensive. Aluminium engine cylinder walls are lined with cast iron cylinder walls for reinforcement against wear and tear.

This gives aluminium engines the benefit of light weight (economy) with the necessary resistance against cylinder wall wear. Aluminium engines are better heat conductors which gives them superior efficiency in terms of quicker cold start ignition and peak acceleration. Economy and efficiency are important considerations for post 1990 electronic fuel injection engine car manufacturers no wonder the shift to aluminium engines.

However cast iron engines have more heat retension capability. They are more tensile and can better withstand negative effects of higher engine operating temperatures such as warping. Aluminium engine cylinder heads are more likely to get damaged beyond repair during severe overheating episodes. No wonder some manufacturers of cars with big ‘muscle engines’ prefer to mix aluminium engine blocks with cast iron cylinder heads.
3. If I want to buy a car, how do I tell that this is a cast iron or aluminium engine.

A good automotive technician or professional may easily tell the difference between an aluminium and cast iron engine by looking at the colour finish and texture of the metals. However, a lay person may quickly find out by reading about the engine specifications of the car you want to buy can help determine whether its aluminium or cast iron.
4. I am planning to buy an Alphard car, is it good here in Uganda and can it last for some time.

Like all other cars on the Ugandan market the suitability depends on the purpose and functionality, how you drive it (aggressive or sensibly), where you plan to drive it (on road or off road), the technical condition you buy it (good service history, mileage) and how you decide to maintain it (quality of fuels, lubricants and parts) and where you choose to maintain it from.

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