Is the Subaru 1235 F1 engine an actual boxer engine?

[mnauno]

The Subaru F1 12-cylinder engine question as to its crankshaft design configuration. As mentioned that I have read somewhere that somebody from Australia (a Subaru nut) claimed to have acquired spare engines and parts including un machined castings plus design drawings, This, his writing I managed to trace, it was something like five years back at that time, and the forum was ''Koenigsegg nearly having used the Subaru 12'' I have tried to make contact with him without success, His post on that Koenigsegg thread was as follows. ''@Anthonparle7342. lives in Australia and a Subaru nut. 5 years ago, my first purchase was the spare parts from the race team which was 3 engines in bits and a number of unmachined castings. we could build two complete engines and still have a lot of spares''.

Hi, do you have a link to that forum/post by any chance? I've tried finding it but unfortunately without success.

Try trace as follows. ''How Koenigsegg nearly used a Subaru F1 engine in its supercars'' - YouTube drivetrib 26 Jan 2019. the forum-555 comments, @anthonparle 7342 post is 4th post from top.

I actually found it! Thank you very much for your input, helps alot!

[saviour stivala]

There was no experimentation with a three main bearing crankshaft on the FERRARI 312 3-litre flat-12. The experimentations were with a build-up four main roller bearing crankshaft. A build-up crankshaft was a must because of the two center bearings. The crankshaft configuration settled upon was a six pin with four main bearing, with only the two outer main bearings being roller bearings. This crankshaft was machined from a solid billet of steel alloyed with manganese and aluminum to obtain a suitable surface for use with the outer roller main bearings. Before FERRARI introduced the 312 3-litre flat 12, they produced two other flat-12 engines, one was produced in 1965 and it was a one and a half-litre flat -12 GP racing engine, and the other was the 1969 a 2-litre falt-12 hill climb championship racing engine. It was on this 2-litre flat-12 that the 312 roller bearing crankshaft experimentations were carried out.

[saviour stivala]

Hi, do you have a link to that forum/post by any chance? I've tried finding it but unfortunately without success.

Try trace as follows. ''How Koenigsegg nearly used a Subaru F1 engine in its supercars'' - YouTube drivetrib 26 Jan 2019. the forum-555 comments, @anthonparle 7342 post is 4th post from top.

I actually found it! Thank you very much for your input, helps alot!

Good. That man Anthonparle 7342 is the man that can shed light on the actual design configuration of the Subaru F1 12-cylinder crankshaft.

[ACRO]

I know that it is a flat-12 engine, but most of the time people on the internet are saying that it is a boxer engine which would be a little different to a 180 degree V12. Thats why I was wondering if they actually tried the boxer layout, which would have more disadvantages than advantages in this case.

I think it boils down to the fact some people simply do not understand the key difference between a boxer and a flat engine ( i like to call a flat engine a "180deg vee" even when a 180deg bank obviously does not display a V ) .

The main benefit of a boxer is very good engine balance from quite a small footprint , e.g a 6cyl boxer is perfectly balanced in primary and secondary order reciprocating and rotating plane - like an inline 6 - while a v6 is not .

To build a 12cyl boxer makes no sense since a v12 is also perfectly balanced in all planes but you have the bigger bank offset so more overall lenght and more weight in a boxer compared to a 180 deg vee .

I think nobody ever designed a 12cyl boxer , in no application .

Imho the only boxer engine in f1 was the 1962 porsche 804 with a 1.5litre 8cyl .

[BassVirolla]

I know that it is a flat-12 engine, but most of the time people on the internet are saying that it is a boxer engine which would be a little different to a 180 degree V12. Thats why I was wondering if they actually tried the boxer layout, which would have more disadvantages than advantages in this case.

I think it boils down to the fact some people simply do not understand the key difference between a boxer and a flat engine ( i like to call a flat engine a "180deg vee" even when a 180deg bank obviously does not display a V ) .

The main benefit of a boxer is very good engine balance from quite a small footprint , e.g a 6cyl boxer is perfectly balanced in primary and secondary order reciprocating and rotating plane - like an inline 6 - while a v6 is not .

To build a 12cyl boxer makes no sense since a v12 is also perfectly balanced in all planes but you have the bigger bank offset so more overall lenght and more weight in a boxer compared to a 180 deg vee .

I think nobody ever designed a 12cyl boxer , in no application .

Imho the only boxer engine in f1 was the 1962 porsche 804 with a 1.5litre 8cyl .

Because the 8 cylinder boxer gets perfect primary, secondary and rocking couple balance. It would do for a very reliable high revving engine.

[Greg Locock]

Wouldn't it have a 2nd order yawing couple due to the staggered cylinders?

[BassVirolla]

Wouldn't it have a 2nd order yawing couple due to the staggered cylinders?

I think not. Each pair of pistons separating get cancelled by each pair getting nearer.

Edit: I was wrong, but if it 's made like two 4 cylinders stacked nose to nose could get 4 cylinders second order couple in one direction, and the other four in the opposite.

[ACRO]

Afaik porsche had severe problems with balance and vibration . They changed firing order twice . A 8 cyl boxer is basicly two 4cyl crankshafts bolted together with a 90 deg twisted plane between them

[BassVirolla]

... but reading ACRO post, I realize that what I say has to have the cylinders firing in pairs.

[ACRO]

... but reading ACRO post, I realize that what I say has to have the cylinders firing in pairs.

Yes .

I think the boxer has his benefits in applications with up to 6 cylinders . we see great 2 cyl boxers in BMW motorcycles , 4 cyl at subaru and many small aviation engines as well 6 cyl at porsche .

With applications above 6 cyl i think the vee concept starts to win and thats why a 8 cyl boxer was very rare and short living thing in and outside f1 .

[Tommy Cookers]

... I think the boxer has his benefits in applications with up to 6 cylinders . we see great 2 cyl boxers in BMW motorcycles , 4 cyl at subaru and many small aviation engines as well 6 cyl at porsche .
With applications above 6 cyl i think the vee concept starts to win and thats why a 8 cyl boxer was very rare and short living thing in and outside f1 .

the Porsche racing boxer 8 was hugely successful over 10 years
the 904 906 907 909 & 910 winning at 2 and 3 litres thirteen GT and Prototype world championships 1962-69

the aircraft boxer engines are an accident of history
as Continental in the 1930 economic crisis chose that because they could cast it in 1 piece (why they chose side valve)
ok in a tricycle twin

the 2 pin flat 4 engine seems in some ways better than the boxer 4 - but hasn't been used

[saviour stivala]

The 753 horizontally opposed 1.5-litre 8-cylinder Porsche engine had an individual crank-throw and journal for each of its connecting-rods, with a total of ten main bearings, nine plain bearings plus a ball bearing overhanging at the rear. The crank was an intricate steel forging, the crankshaft had balance masses integral with each of its 16 checks. Porsche tested both roller and plain bearings but settled on plain bearings. They also tested an experimental desmodromic valve gear.