Alloy engine parts
Discussion
Following the merlin / meteor threads (thanks Storer!) leads me to a question :
Why did the UK / US car industry take so long to adopt aluminium for heads / manifolds / blocks?
The meteor was 24 valve / all alloy in the 40's, but my 60's Triumph engine would have put a boat anchor to shame, and 70's US v8's with cast iron heads and manifolds weighed a laughable amount.
I am not talking premium / exotics here btw, a few of which had heard of this wonder material aluminium.
In comparison, the Italians and Japanese were using alloy in "mundane" cars from the 1960's or earlier.
My 1967 Toyota Corolla had an alloy head and inlet manifold (and would rev to 7500 rpm with cam / carby change, despite being a pushod engine).
1968 Datsun 1600 had SOHC alloy head, and it was a family sedan.
I navigate in a 1960's Fiat with an alloy headed twincam engine.
Was it a material shortage?
Newer factories for the Italians / Japanese from the post-WW2 reconstruction?
Short-sighted management who just did things the way they always had?
Why did the UK / US car industry take so long to adopt aluminium for heads / manifolds / blocks?
The meteor was 24 valve / all alloy in the 40's, but my 60's Triumph engine would have put a boat anchor to shame, and 70's US v8's with cast iron heads and manifolds weighed a laughable amount.
I am not talking premium / exotics here btw, a few of which had heard of this wonder material aluminium.
In comparison, the Italians and Japanese were using alloy in "mundane" cars from the 1960's or earlier.
My 1967 Toyota Corolla had an alloy head and inlet manifold (and would rev to 7500 rpm with cam / carby change, despite being a pushod engine).
1968 Datsun 1600 had SOHC alloy head, and it was a family sedan.
I navigate in a 1960's Fiat with an alloy headed twincam engine.
Was it a material shortage?
Newer factories for the Italians / Japanese from the post-WW2 reconstruction?
Short-sighted management who just did things the way they always had?
Interesting points. The Buick V8 was all alloy in the late 50's but was expensive to produce, needed different coolant from the iron block kit & was superseded by spun cast iron blocks being lighter & easier to produce.
Another point is that several very high powered engines in a few years ago where iron blocked from choice, Renault F1 Turbo & BMW Turbo being two.
Another point is that several very high powered engines in a few years ago where iron blocked from choice, Renault F1 Turbo & BMW Turbo being two.
Aluminium is a bit more sensitive the the moulds and casting methods used. It has higher thermal conductivity and less density that steel/iron (and therefore a less uniform grain structure). This means that different casting moulds and techniques are required to steel/iron casting. The way the moulten metal cools after casting has a big effect on the consistency of the grain structure, and inconsistencies in the grain structure result in undersirable inaccuracies and affects the long term durability.
On small engines, the weight saving acheived by using Aluminium instead of steel is small. On a V12 aero engine, weight is critically important- and due to the size of the castings, more complex moulds are required anyway.
Steel/Iron also benefits from aluminium in that seperate valve guides and seats aren't required, this makes steel/iron cheaper still. And due to the metallurgical properties of Aluminium compared to steel, it is more likely to warp or crack if overheated, and more vulnerable to detonation damage.
ETA: in the case of the Americans, they actively disliked the use of light alloy which is why the 'Rover' V8 came to be. In the case of the UK, I would suspect that it's due to the fact that we had a long established automotive manufacturing industry which meant that the tooling and manufacturing processes to make steel and iron parts was available, and I presume that although Aluminium could've been used, on smaller engines the benefits were negligable.
On small engines, the weight saving acheived by using Aluminium instead of steel is small. On a V12 aero engine, weight is critically important- and due to the size of the castings, more complex moulds are required anyway.
Steel/Iron also benefits from aluminium in that seperate valve guides and seats aren't required, this makes steel/iron cheaper still. And due to the metallurgical properties of Aluminium compared to steel, it is more likely to warp or crack if overheated, and more vulnerable to detonation damage.
ETA: in the case of the Americans, they actively disliked the use of light alloy which is why the 'Rover' V8 came to be. In the case of the UK, I would suspect that it's due to the fact that we had a long established automotive manufacturing industry which meant that the tooling and manufacturing processes to make steel and iron parts was available, and I presume that although Aluminium could've been used, on smaller engines the benefits were negligable.
Edited by HustleRussell on Thursday 9th January 13:09
Iron blocks I get. There was a tecnology change in casting which drastically reduced the weight of iron blocks, so that a 4 cyl iron block is not much heavier than an alloy block with iron liners.
Heads, on the other hand...
The cast iron inlet manifold on my mate's big block v8 weighs more than Jupiter!
It plus the iron heads would have to be pushing 100 kg.
Heads, on the other hand...
The cast iron inlet manifold on my mate's big block v8 weighs more than Jupiter!
It plus the iron heads would have to be pushing 100 kg.
AW111 said:
Iron blocks I get. There was a tecnology change in casting which drastically reduced the weight of iron blocks, so that a 4 cyl iron block is not much heavier than an alloy block with iron liners.
Heads, on the other hand...
The cast iron inlet manifold on my mate's big block v8 weighs more than Jupiter!
It plus the iron heads would have to be pushing 100 kg.
I am not sure about this, but in the case of a V8 I would expect that it would be desirable to keep the heads and the inlet manifold the same material to manage relative thermal expansion. This was, until profile gasket technology and injection moulding made trouble free lightweight plastic manifolds possible.Heads, on the other hand...
The cast iron inlet manifold on my mate's big block v8 weighs more than Jupiter!
It plus the iron heads would have to be pushing 100 kg.
ETA: Oh, and the base ore of Aluminium has basically always been abundant.
Edited by HustleRussell on Thursday 9th January 13:14
When did the other European manufacturers adopt alloy for heads / manifolds?
I wonder if the BMC family just didn't want to invest the money in new designs / moulds / foundries?
Or were they updating pre-war designs rather than starting from scatch?
Ford / GM also stuck with cast iron heads for quite a while - when did Ford 4 cylinders go alloy head?
(Cosworth variants excluded).
4 question marks in one post - a personal record!
I wonder if the BMC family just didn't want to invest the money in new designs / moulds / foundries?
Or were they updating pre-war designs rather than starting from scatch?
Ford / GM also stuck with cast iron heads for quite a while - when did Ford 4 cylinders go alloy head?
(Cosworth variants excluded).
4 question marks in one post - a personal record!
AW111 said:
I wonder if the BMC family just didn't want to invest the money in new designs / moulds / foundries?
Or were they updating pre-war designs rather than starting from scatch?
I'd say that your probably correct on both counts. The history stuff I'm not so good on because I only arrived in '89!Or were they updating pre-war designs rather than starting from scatch?
alftupper said:
1963 Hillman Imp
The Climax enjoyed a reputation a bit like the Rover k-series, notorious for being sensitive to overheating and prone to head gasket failure. This is why some markets, particularly the USA, quickly went cold on the idea... Ally heads weren't considered robust enough. AW111 said:
alftupper said:
1963 Hillman Imp . Austin 7 had an alloy block .
The Austin I didn't know.Good pick with the Imp - however that engine was developed from the Climax, was it not, rather than designed in-house.
Just googled the climax - early fifties design, and all-alloy!
The crankcases are alloy and after market heads were made in the 50s onwards.
Crosswise said:
The Jaguar XK engine had an alloy head and that was developed in the 40s (and subsequently used until the early 90s such was the speed of development in the British motor industry!)
I wonder whether it was to some extent down to a lack of investment. The XK engine's replacement, the AJ6, had an alloy block and an alloy head. It was the only 24v twin cam all alloy straight six engine in production back then.AW111 said:
The Austin I didn't know.
Good pick with the Imp - however that engine was developed from the Climax, was it not, rather than designed in-house.
Just googled the climax - early fifties design, and all-alloy!
But economy of mass production meant cheap head gaskets, competition versions used Wills Rings and this eliminated the head gasket failures....until you tried for 12,000 rpm Good pick with the Imp - however that engine was developed from the Climax, was it not, rather than designed in-house.
Just googled the climax - early fifties design, and all-alloy!
G
As with most things it's a mix of factors.
1. Cast iron technology was well known and understood, by both industry and the public - if it ain't broke, don't fix it.
2. Money was tight in the post-war years, followed by strikes and in-fighting (a BL brand's main competitors were other BL brands) - not a situation that encorrages investment and risk-taking.
3. We did a better job of blowing the crap out of German and Japanese industry that they did ours, which meant they were forced to start with more or a clean slate and to take risks to get recent enemies to buy their cars.
1. Cast iron technology was well known and understood, by both industry and the public - if it ain't broke, don't fix it.
2. Money was tight in the post-war years, followed by strikes and in-fighting (a BL brand's main competitors were other BL brands) - not a situation that encorrages investment and risk-taking.
3. We did a better job of blowing the crap out of German and Japanese industry that they did ours, which meant they were forced to start with more or a clean slate and to take risks to get recent enemies to buy their cars.
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