Rate It: Is a Flat-Eight-Powered Porsche 914 the Best 60th Birthday Present?

The Porsche 914/6 may have offered a much-welcomed bump in power over the already stellar 914/4, but what it would have been like to pilot a 914 powered by an eight-cylinder engine?

Well, Porsche apparently wanted to know as well, so it made two prototypes in the late ‘60s.

Dubbed as 914/8s, both prototypes were powered by the flat-eight engine out of the 908. The head of Porsche’s racing department, Ferdiand Piëch, pushed the development of the first prototype, which was reported to be good for 350 horsepower.

The second prototype was registered for road use and featured a detuned 908 flat-eight engine that is said to have been rated at 300 horsepower. The car would actually go on to be a 60th birthday gift for Ferry Porsche, though now lives in the Porsche Museum.

Would a production 914/8 have dominated both the streets and the race track, or would a flat-eight have been too much engine for the car?

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David S. Wallens
David S. Wallens Editorial Director
10/1/20 8:40 a.m.

The Porsche factory shipped over one for Amelia Island not too long ago. It's subtle. 

stroker
stroker UberDork
10/1/20 8:41 a.m.

I'd think a 1hp:7lb power to weight ratio would be all the fun you could reasonably use.  Wish they'd made a limited production run, although that engine was probably pretty expensive to maintain...

 

APEowner
APEowner Dork
10/1/20 8:56 a.m.

" Would a production 914/8 have dominated both the streets and the race track, or would a flat-eight have been too much engine for the car?"

There's no such thing as too much engine.  There's just not enough tire.

Robbie (Forum Supporter)
Robbie (Forum Supporter) MegaDork
10/1/20 9:15 a.m.
APEowner said:

" Would a production 914/8 have dominated both the streets and the race track, or would a flat-eight have been too much engine for the car?"

There's no such thing as too much engine.  There's just not enough tire.

I'll take option C, all of the above. 

David S. Wallens
David S. Wallens Editorial Director
10/1/20 9:48 a.m.

Devil's advocate: If you're Porsche in 1970, though, do you want the 914 outrunning the 911? 

ProDarwin
ProDarwin MegaDork
10/1/20 9:52 a.m.
David S. Wallens said:

Devil's advocate: If you're Porsche in 1970, though, do you want the 914 outrunning the 911? 

If you slap a bigger price tag on it, sure.

Robbie (Forum Supporter)
Robbie (Forum Supporter) MegaDork
10/1/20 9:54 a.m.
ProDarwin said:
David S. Wallens said:

Devil's advocate: If you're Porsche in 1970, though, do you want the 914 outrunning the 911? 

If you slap a bigger price tag on it, sure.

I'f you've got a 914/8, why can't you have a 911/8?

nderwater
nderwater UltimaDork
10/1/20 9:56 a.m.

I wonder how much extra weight that slung over the rear axle?  I'm imagining some awesome 914 drift action here.

Snowdoggie
Snowdoggie HalfDork
10/1/20 10:06 a.m.
David S. Wallens said:

Devil's advocate: If you're Porsche in 1970, though, do you want the 914 outrunning the 911? 

What about outrunning Ferraris? 

That said, I would hate to have to replace the spark plugs on one of those. 

Robbie (Forum Supporter)
Robbie (Forum Supporter) MegaDork
10/1/20 10:13 a.m.

Also, let me be the first to make this very clear:

If you give me a 914/8 for my 60th birthday, I will be forever grateful. 

MotorsportsGordon
MotorsportsGordon HalfDork
10/1/20 11:28 a.m.
Robbie (Forum Supporter) said:
ProDarwin said:
David S. Wallens said:

Devil's advocate: If you're Porsche in 1970, though, do you want the 914 outrunning the 911? 

If you slap a bigger price tag on it, sure.

I'f you've got a 914/8, why can't you have a 911/8?

While it probably could have been built as a prototype aswell the 914/8 would certainly work out better being mid engine. The flat 8 is a pure race engine designed for mid engine use. It was originally a 1.5 formula one engine and after porsche pulled out of f1 become a 3 litre sports car racing engine.

if anything else the 914/8 would have been the successor to the Porsche 904.

plus in the early 70s Porsche was already thinking the 911 life was limited and had begun work on its planned replacement the 928.

californiamilleghia
californiamilleghia SuperDork
10/1/20 2:03 p.m.

does it have the 908 motor which I think is based on the 12 cyl 917 motor ?

or is it an extended 911 6cyl motor  ?

15f80
15f80 New Reader
10/1/20 2:47 p.m.

I will happily take on the challenge of a tail heavy 914 with 350 hp. Hopefully it will come with a 930 wheel/hub conversion. :)

Snowdoggie
Snowdoggie HalfDork
10/1/20 3:04 p.m.
MotorsportsGordon said:
Robbie (Forum Supporter) said:
ProDarwin said:
David S. Wallens said:

Devil's advocate: If you're Porsche in 1970, though, do you want the 914 outrunning the 911? 

If you slap a bigger price tag on it, sure.

I'f you've got a 914/8, why can't you have a 911/8?

While it probably could have been built as a prototype aswell the 914/8 would certainly work out better being mid engine. The flat 8 is a pure race engine designed for mid engine use. It was originally a 1.5 formula one engine and after porsche pulled out of f1 become a 3 litre sports car racing engine.

if anything else the 914/8 would have been the successor to the Porsche 904.

plus in the early 70s Porsche was already thinking the 911 life was limited and had begun work on its planned replacement the 928.

So this would be more of a fast vintage race car than a street car. I think I could live with that. laugh

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
10/1/20 3:23 p.m.
David S. Wallens said:

Devil's advocate: If you're Porsche in 1970, though, do you want the Volkswagen 914 outrunning the 911? 

Key.  Wasn't the 914 sold as a Volkswagen model in Germany?

Toebra
Toebra Dork
10/1/20 3:33 p.m.

In reply to Snowdoggie :

Just drop the motor and transmission for plugs and valve adjustments

noddaz
noddaz UltraDork
10/1/20 4:36 p.m.
Toebra said:

In reply to Snowdoggie :

Just drop the motor and transmission for plugs and valve adjustments

Every 3000 miles...   Drive like a sport, pay like a sport.

aircooled
aircooled MegaDork
10/1/20 5:21 p.m.
nderwater said:

I wonder how much extra weight that slung over the rear axle?  I'm imagining some awesome 914 drift action here.

Call me Ian

Is the 914/8 a mid-engined like the 914, or rear mounted like the 911?

I would hope they upgrade the brakes.  I am pretty sure the 914, as stock, had less then ideal braking performance.

Apis Mellifera
Apis Mellifera Dork
10/1/20 5:53 p.m.

Here's a pic of a 908 engine I snapped several years ago that belongs to an aquaintance.  Despite having both a 907 and 908, they ran Sixes in their cars because not only is the Eight less robust, it's also more costly.  If you're familiar with an AC 911 engine, you'll note the valvetrain is more bulky on this engine.  I'd be interested to see what was done to the 914 to allow it to accomodate the 908 engine.

 

MotorsportsGordon
MotorsportsGordon HalfDork
10/1/20 11:32 p.m.
californiamilleghia said:

does it have the 908 motor which I think is based on the 12 cyl 917 motor ?

or is it an extended 911 6cyl motor  ?

The flat 8 was originally an fl engine in the early 60s then modified for sports car use. The 917 engine is based on it  except that the flat 8 is a boxter while the 917 isant like Ferrari flat 12s are not a boxter.

aircooled
aircooled MegaDork
10/2/20 12:34 a.m.

Pretty sure boxster and flat are the same thing.  It's called a boxster because the rods make a motion like a boxer punching being directly opposed.

That's what I've read at least.

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
10/2/20 5:44 a.m.
aircooled said:

Pretty sure boxster and flat are the same thing.  It's called a boxster because the rods make a motion like a boxer punching being directly opposed.

That's what I've read at least.

Boxer is an engine type, boxster is a car.   All boxer engines are "flat" but not all flat engines are boxers.  There is a hugely important distinction. 

A boxer engine has opposing cylinders hitting TDC at the same time, so they have their own crank throws 180 degrees apart.  A 180 degree V8 (and V4 and V12 I guess) would have shared crank throws, so opposite cylinders would have one at TDC and one at BDC.  I don't think you can have a 180 degree V6 and retain an even firing order. 

A 180 degree V engine has better internal pumping losses and a stronger crankshaft but worse vibration characteristics.  Vibes are more important for a street car so practically all production opposed piston engines are boxer type.

(A 180 degree V4 with an even firing order would shake MASSIVELY, too, since you'd have to have both pistons on a given bank at TDC while the other bank was at BDC.  The entire reciprocating assembly would be moving in the same direction at the same time.  The engine would be an internal combustion Shake Weight laugh )

MotorsportsGordon
MotorsportsGordon HalfDork
10/2/20 9:25 a.m.
aircooled said:
nderwater said:

I wonder how much extra weight that slung over the rear axle?  I'm imagining some awesome 914 drift action here.

Call me Ian

Is the 914/8 a mid-engined like the 914, or rear mounted like the 911?

I would hope they upgrade the brakes.  I am pretty sure the 914, as stock, had less then ideal braking performance.

Mid engine well I guess listed as rear mid engine meaning the engine is a bit further back but still ahead of the rear wheels. The 904 was rear mid engine aswell.

MotorsportsGordon
MotorsportsGordon HalfDork
10/2/20 9:27 a.m.

As you can see here a non boxter flat 12 is just a wide angle v

aircooled
aircooled MegaDork
10/2/20 10:46 a.m.

Hah!  Your the one that got me saying Boxter!  cheeky

I don't see the "wide angle V" you are talking about in the image above.  Looks very flat to me (pistons appear to be 180 degrees apart), but you would need to see the crank to know if it is a boxer, right?

Wikipedia explains it as: "each pair of opposing pistons move inwards and outwards at the same time, somewhat like boxing competitors punching their gloves together before a fight" which is a more mechanical way of saying what Pete said.  They have a good illustration of it.  Not how the boxer, on the left, has opposing pistons sharing the same crank position.

Vajingo
Vajingo New Reader
10/2/20 11:16 a.m.
David S. Wallens said:

Devil's advocate: If you're Porsche in 1970, though, do you want the 914 outrunning the 911? 

Yes. Mid ship>rear ship. 

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
10/2/20 12:17 p.m.
aircooled said:

Hah!  Your the one that got me saying Boxter!  cheeky

I don't see the "wide angle V" you are talking about in the image above.  Looks very flat to me (pistons appear to be 180 degrees apart), but you would need to see the crank to know if it is a boxer, right?

Wikipedia explains it as: "each pair of opposing pistons move inwards and outwards at the same time, somewhat like boxing competitors punching their gloves together before a fight" which is a more mechanical way of saying what Pete said.  They have a good illustration of it.  Not how the boxer, on the left, has opposing pistons sharing the same crank position.

The one on the left isn't a boxer, that's why smiley

V engine can be any bank angle, 180 degrees is a perfectly cromulent angle for a V engine.  I guess you could technically go "more" but that's just less, upside-down.

californiamilleghia
californiamilleghia SuperDork
10/2/20 12:32 p.m.

I wonder if Porsche ever made a 8 cyl  motor that used normal 911 rods , cylinders and heads ?

They did draw up a 4 cyl motor that used these parts which was the basis for the Beck , Polo and Emory 4 cyl  911 based motors .

aircooled
aircooled MegaDork
10/2/20 1:55 p.m.
Pete. (l33t FS) said:
 

V engine can be any bank angle, 180 degrees is a perfectly cromulent angle for a V engine.  I guess you could technically go "more" but that's just less, upside-down.

That's like calling this a 180 degree angle (but, if that is how it's defined, that is how it's defined):

Horizontal Line - Uncyclopedia, the content-free encyclopedia

cheeky

aircooled
aircooled MegaDork
10/2/20 2:01 p.m.
californiamilleghia said:

I wonder if Porsche ever made a 8 cyl  motor that used normal 911 rods , cylinders and heads ?

They did draw up a 4 cyl motor that used these parts which was the basis for the Beck , Polo and Emory 4 cyl  911 based motors .

I know Chevy had developed a prototype "modular" engine, that could be easily built as anything from a 4 cylinder to an 8 cylinder using aircraft style "jugs" (individual cylinders and heads).  A lot easier when you don't have to worry about overhead cams:

https://www.curbsideclassic.com/automotive-histories/engine-prototype-the-stillborn-corvair-gen2-modular-engine-from-two-to-twelve-cylinders/

 

APEowner
APEowner Dork
10/2/20 2:25 p.m.

The SAE Internal Combustion Engine Handbook defines a boxer engine as "An engine with the cylinders arranged in one plane with two opposing cylinder banks."  it goes on to say "They can also be called 180 degree V engines in which the opposing pistons and conrods work on a common throw or their own throw."  When discussing V engines it says "In practice, V angles can have values anywhere from 0 degrees (inline engine) to 180 degrees (boxer motor)."

In my experience when talking with engineers at multiple OEMs as well as specialty design houses like Ricardo and Prodrive.  180 degree V engines are usually called boxers and 0 degree Vs are called inline.  If they're larger than 180 degree as used in some aircraft they're usually called inverted V.

Thus ends my geek download of the day.  Tune in at some random time in the future when I type out an unsolicited treatise on pre-ignition, detonation and pre-detonation.  Spoiler alert, There's no such thing as pre-detonation.

californiamilleghia
californiamilleghia SuperDork
10/2/20 2:39 p.m.

In reply to aircooled :

rumor had it that Porsche helped GM design the Corvair motor , 

Who knows for sure !

aircooled
aircooled MegaDork
10/2/20 3:53 p.m.

Yeah, I don't know if that is true or not, but I CAN say, I used to work for a company that was once part of Lockheed (across the street from what to used to be Lockheed's airport, now a shopping center).  There was an old school guy there (also a old flat track racer) who worked there forever and was there when it was Lockheed. 

I am not sure if this was a direct experience, or told to him, but in the late 50's, there were a number of GM engineers visiting Lockheed to find out more about casting aluminum, which Lockheed has a lot of experience with and GM had little apparently.  I suspect the primary interest was figuring out how to cast the finned cylinder heads (which stock, almost always have a good amount of flash in the fins)

spitfirebill
spitfirebill MegaDork
10/3/20 8:52 a.m.

Well I just passed my 67th birthday and nobody left one of these in my driveway.  

Toebra
Toebra Dork
10/22/20 8:30 a.m.
MotorsportsGordon said:

Mid engine well I guess listed as rear mid engine meaning the engine is a bit further back but still ahead of the rear wheels. The 904 was rear mid engine aswell.

It would stick forward more

 

914 was always neutered.  Put the same motor in that chassis and a 911 and the ass engine car gets handed its ass.

As Dana Carvey would say in his best George Bush, shaking both fingers at you, "Not gonna do it."

 

911 has been the halo car forever.  I think the Carrera GTS/904 in the 60's and that insane GT more recently were the only times they sold a street car with a motor equal or greater than what you could get in the 911.  Until they started the hybrid cars I guess.

Adrian_Thompson (Forum Supporter)
Adrian_Thompson (Forum Supporter) MegaDork
10/22/20 8:51 a.m.

I know there's a company out there who makes four cyl Boxers using Porsche flat six pistons, jugs, rods and heads with a custom crankcase and cams.  They make way more power than any comparable Porsche four cyl or modified VW based engine.  They are for well healed enthusiasts who want a real hot rod 912.  I'm sure the same thing must be possible to make a flat eight using the same basic idea.  That would be a wild way to recreate this.  

californiamilleghia
californiamilleghia SuperDork
10/22/20 12:41 p.m.
Adrian_Thompson (Forum Supporter) said:

I know there's a company out there who makes four cyl Boxers using Porsche flat six pistons, jugs, rods and heads with a custom crankcase and cams.  They make way more power than any comparable Porsche four cyl or modified VW based engine.  They are for well healed enthusiasts who want a real hot rod 912.  I'm sure the same thing must be possible to make a flat eight using the same basic idea.  That would be a wild way to recreate this.  

Chuck Beck did the first one I saw , he built it for a 12 hour race in his Back 550 Spyder , 

He took a stock case and cut the center 2 cylinders out of it , 

 

 

Adrian_Thompson (Forum Supporter)
Adrian_Thompson (Forum Supporter) MegaDork
10/22/20 1:45 p.m.

In reply to californiamilleghia :

Yup, POLO motors have now (limited scale) productionized them.  Throw a couple of trunk loads of Benjamins at them and I'm sure they'll do the same for a flat 8.  Imagine a flat 8 in a Beck 904!!!

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