[alfa] Re: alfa-subaru connection

[George Graves <gmgraves@xxxxxxxxxxx>]

I have read several magazine articles in British classic sportscar rags 
which mention that Subaru licensed the 4-cylinder Alfa-Sud boxer engine 
from Alfa Romeo in the '70's  and have been developing the motor since. 
But what I don't get is the 5-bearing crank in, what is essentially, a 
180-degree V-4. The convention is to have one more bearing than the 
number of pistons in one bank. An Alfa straight-4, for instance has 5 
bearings because it has 4-cylinders in one bank. The Alfa V-6 has 4 
bearings (three pistons/bank) and a straight-6 has 7 main bearings. Now 
a V-4, such as the Sud, the Lancia Fulvia motor, the Subaru have only 2 
pistons per bank, so the only way that Subaru 4 could have 5 main 
bearings is if they put each piston on it's own crank-throw and put a 
main bearing between each throw, in essence building the crank as if it 
were a straight four. I do NOT see the advantage to this because of the 
way V engines and boxers are timed. Also, if Subaru boxer -4's do, 
indeed, have 5 main bearings, the Subaru engine and the Alfa-Sud engine 
no longer have much in common. Am I missing something?


George Graves
'86 GTV-6 3.0 "S"



On Sep 29, 2004, at 8:10 AM, alfa-digest wrote:


> Date: Wed, 29 Sep 2004 08:37:27 +0930
> From: "Benjamin Woenig" <budweiser@domain.elided>
> Subject: RE: [alfa] alfa-subaru connection
>
> I was reading "Alfa Romeo - The Legend Revived" yesterday, and in
> the back listing of the various model specifications, there is a
> comment regarding further development of the boxer engine by AR.
> The book was printed in 1990, and the comment was that AR were
> considering a 2L variation of the 16V boxer.
>
> I assume that AR dropped the boxer engine as the 145 swapped over
> to the in-line 4 twin spark engines instead, so they had no car to put
> the boxer in any more (with the demise of the 33).
>
> Subaru engines currently have a 5 bearing crank, the AR boxer biggest
> weakness IMO is that it only has 3 bearings. I've heard of many people
> spending a fortune on turbo charging only to destroy their engine.
>
> Also, I think Subaru licensed some of the drivetrain technology for
> Alfa's 4WD sport wagon (mid 80's), as well as the 33P4 and the 4WD
> version of the 164 (also turbo charged, WRX beater?!), however Alfa
> stuck with their own transmissions, but perhaps the output drive
> box was designed by someone else?
>
> Personally I love the AR boxer, I've built 2 engines (standard), and I
> am
> putting the parts together to build my 3rd (1.5L block bored out to
> take 1.7L pistons, fully balanced and lightened everything, 16V
> heads with bigger cams and enlarged valves, breathing through 44IDF's.
> A local workshop claims they have built 8V motors for Formula 2 racing
> (in 1.6l form), and have had 10,000rpm for 10 races before a rebuild.
> Not bad for a mass volume produced engine for a city car!
>
> ~Benjamin
>
>
> "Also, he speculated that the relationship may go back further as
> Subaru's boxer engine design may have roots tracing back to the
> Alfasud."
>
> My first car was an early Subaru -- a 1975 GSR coupe 1400.
> The Subaru 1300 was made from '71-'72, the 1400 from '73-'76.  1971
> manufacture predates the Sud's '72 release; presumably the design was
> also earlier.  I strongly doubt that there was any relationship between
> the two. Boxer engines used to be quite popular, from the fifties
> through the late seventies.
>
> The Subaru engine was a pushrod OHV engine, while the Sud engine has
> single overhead cams on each bank.  Both were wet sleeved, but the
> Subaru was a completely alloy design, while the Sud engine is iron 
> block
> with alloy heads. My '75 GSR was a surprisingly good little engine.
> 60mm stroke, 10:1 compression, lumpy camshaft, twin 1.5" downdraft
> Hitachi carburettors, 6800 rpm redline, 95hp, all from the factory.
>
> The method of mounting the engine longitudinally with a front drive
> transaxle had also been undertaken earlier -- the Lancia Fulvia springs
> to mind, though Fiats and Renaults had also used this arrangement.  The
> Citroen 2CV had a 2 cylinder boxer and front drive.  Overall, there was
> no great novelty in the Sud's packaging; Alfa just made a particularly
> good job of making it fun to drive.
>
> Believe it or not, the Japanese also used to make cars with character,
> before they realised that it was not a road to financial success.  I
> loved that Subaru almost as much as I love my current Alfasud Sprint.
>
> Regards,
> Anthony White
> Wellington, NZ
> Alfasud Sprint
> 105 GTV 2000
>
>
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