180deg V4 better than boxer

[marcel]

Hi All,
I want to know if they ever built a flat four engine that wasn’t a boxer? (180deg V4 engine) I couldn’t find any such motor on the net.
It’s said that a boxer 4 is a perfectly balanced engine see: http://www.e31.net/engines_e.html
I would think that an 180deg V4 would be better than a boxer motor.
Firstly it would have a shorter crank with less flexibility by having a single crank pin for opposing pistons.
Secondly it will be a shorter motor thus lighter motor than a boxer.
The Porsche 917 as well as all the current F1 engines use single pin crank for opposing pistons.
I don’t think that reliability should be a problem with a 2-pin crank flat four as all the F1cars rev up to 18000 RPM’s on the same design.
I am surprised that no one ever build a car using such a motor.

[MINCE]

uhm *cough* isn't a boxer a 180deg V4 anyways?

[Golfmad]

uhm *cough* isn't a boxer a 180deg V4 anyways?

When its less than 180 degrees, its a V, if its 180 degrees, its a boxer / flat no?

[MINCE]

that is my thinking yes!

[alants]

Hmmmm how can it be a V when 180deg is a straight line which ever way you tilt it ?

[MINCE]

I have been reading up on this and there is no indication of anything that is 180 V. The only engine they term is a 180deg V is the Ferrari 12 cylinder boxer motor.
As far as i can tell, there is no 180deg anything
you get inline/V/flat/boxer

[Tom Bishop]

Ford had a ?? degree v4 in the 60s in their Cosair and it was a disaster. It had major bearing problems.

At one time this was the motor to fit in Buggies.

With todays electronics and gizmos almost any piston layout can be made reliable.

[MINCE]

Flat engine
A flat engine is an internal combustion engine with multiple pistons that move in a horizontal plane. Typically, the layout has cylinders arranged in two banks on either side of a single crankshaft and is sometimes known as the boxer, or horizontally opposed engine. The concept was patented in 1896 by engineer Karl Benz. It should not to be confused with the opposed-piston engine, in which each cylinder has a piston at both ends and no cylinder head.

Another widely used form of flat engine consists of a straight engine with two, three, four or more cylinders canted 90 degrees into the horizontal plane, however this is not generally considered significantly different from other straight engines.

Configuration
Flat engines offer a low centre of gravity and thereby may offer a drive configuration with better stability and control. Flat engines lend themselves well to aircraft engines.

Front-mounted air-cooled flat-twin engines were used in Tatra 11 and Tatra 30, by Citroën in their model 2CV and its derivatives, while the GS and GSA. Oltcit used a flat-four and a flat-six was proposed for the Citroën DS but rejected. BMW has used air- or air/oil-cooled flat-twin engines in its motorcycles from 1923 until the present day. Cars such as the Porsche 911 use a flat-engine (in that particular case a six-cylinder) at the rear of the car, where its extra width does not interfere with the steering of the front wheels and there is a weight-saving since no prop-shaft is required.

All versions of the Subaru Impreza, Forester, Tribeca, Legacy, Outback, Baja and SVX use either a flat-4 or flat-6 engine.

True boxers have each crankpin controlling only one piston/cylinder while 180° engines, which superficially appear very similar, share crankpins.

The boxer engine has corresponding pistons reaching top dead centre (TDC) simultaneously.

The 180° V engine has corresponding pistons sharing a crankpin on the crankshaft and reaching TDC half a crankshaft revolution apart. They may use regular connecting rods side by side, or use a master/slave system, or a fork-and-blade system. Flat engines with more than eight cylinders are most commonly V engines.[clarification needed]

Boxer engines must not be confused with opposed-piston engines, which are essentially the inverse, with two pistons compressing a single combustion space. These can be used in vehicles such as tanks.

Boxer engines
Boxer engines got their name because each pair of pistons moves simultaneously in and out rather than alternately, like boxers showing they are ready by clashing their gloved fists against each other before a fight. Boxer engines of up to eight cylinders have proved highly successful in automobiles and up to six cylinders in motorcycles and continue to be popular for light aircraft engines.

Boxers are one of only three cylinder layouts that have a natural dynamic balance; the others being the straight-6 and the V12. These engines can run very smoothly and free of unbalanced forces with a four-stroke cycle and do not require a balance shaft or counterweights on the crankshaft to balance the weight of the reciprocating parts, which are required in other engine configurations. Note that this is generally true of boxer engines regardless of the number of cylinders (assumed to be even), but not true for all V or inline engines. However, in the case of boxer engines with fewer than six cylinders, unbalanced moments (a reciprocating torque also known as a "rocking couple") are unavoidable due to the "opposite" cylinders being slightly out of line with each other.

Boxer engines (and flat engines in general) tend to be noisier than other common engines for both intrinsic and other reasons, e.g., in cars, valve clatter from under the hood is not damped by large air filters and other components. Boxers need no balance weights on the crankshaft, which is lighter and fast-accelerating. They have a characteristic smoothness throughout the rev range and offer a low centre of gravity.

[marcel]

“No” On a boxer engine the apposing pistons are always both in the same position like vw and Porsche 911, each with its own crank pin. On an 180deg V4 the apposing pistons will share the same crank pin like on the flat12/ 917 Porsche all V8/V12 and flat 12’s are like this sharing the apposing crank pin. What I cant understand is why no one experimented using that design on a flat 4 motor.

[Golfmad]

Show us pics of what you mean

[MINCE]

Cool animations of the 3 kinds of motors you get

In-line


V


Flat

[alants]

Ford had a ?? degree v4 in the 60s in their Cosair and it was a disaster. It had major bearing problems.

At one time this was the motor to fit in Buggies.

With todays electronics and gizmos almost any piston layout can be made reliable.

From what I remeber this V4 had serious balance issues ??? - but then I may be wrong !

[Tony Z]

a boxer is not a V and a V is not a boxer.

Simple explanation of the difference:
a V-180 engine has 2 crank throws on each big end journal (2 conrods per journal)
a horizontally opposed engine as a journal for each crank throw (1 conrod per journal)

[Tony Z]

Hi All,
I want to know if they ever built a flat four engine that wasn’t a boxer? (180deg V4 engine) I couldn’t find any such motor on the net.
It’s said that a boxer 4 is a perfectly balanced engine see: http://www.e31.net/engines_e.html thats because each conrod opposes the other so it remains in balance, not entirely true with the beetle engine though because of the lack of counterweights on the crank
I would think that an 180deg V4 would be better than a boxer motor. no way, you would need massive counterweights prob too big to fit in the block to offest 2 sets of conrods and pistons moving the the same direction.
Firstly it would have a shorter crank with less flexibility by having a single crank pin for opposing pistons. not shorter by much, remember longer cranks also absorb vibrations and flexing better than short ones.
Secondly it will be a shorter motor thus lighter motor than a boxer. moving the pistons closer together will reduce the cooling area available and thus will prob lead to overheating - air cooled remember
The Porsche 917 as well as all the current F1 engines use single pin crank for opposing pistons. 12 cylinder, shorter throw, custom built for this - I'll post pictures soon that I took at the Porsche museum
I don’t think that reliability should be a problem with a 2-pin crank flat four as all the F1cars rev up to 18000 RPM’s on the same design. far from the same desing.... 31mm stroke or there abouts, leads to much less inertial forces. Also much lighter conrods and pistons. Needs smaller counterweights and are balaned to be 100% smooth at around 17000rpm
I am surprised that no one ever build a car using such a motor. go for it

[MINCE]

Thanks Tony for clearing EVERYTHING UP. Now I believe we are all on the same page.