can you have an engine block that has 4 cylinders flat like a porsche , and the remaining 4 in a v angle ? ( F-V 8 ) the idea is for a car that has ventury tunnels , the first 4 cylinders that are flat are just ahead of the tunnels, and the remainding 4 (in a v ) are inbetween the tunnels , so by doing this the engine has a very low center of gravity , and the tunnels work with no restritions . can this work ?

That is an interesting suggestion. Every engine designer will say no and yuck, but the quick answer is that it is possible, at worst put a flexijoint of some sort in the crank between the H4 and the V4. I don't think that is necessary.

I would be surprised if the engine had a significantly lower CG than the equivalent V8.

isnt a flat engines cg a lot lower then a V , cams and heads are very heavy , having them sitting 2-300mm in the air has to be worst then flat , only main issue ive got is engine vibrations and weight penalty with 2 lots of heads ( cam gears , cam gears etc )

I think it would be heavier than a V8, but that is not what you asked.

Mightn't most of the potential CoG advantage of an opposed cylinder arrangement in a racing application be lost by having to provide room beneath the banks for the exhausts and ancillaries by raising the crankshaft height? At least with a conventional V and dry sump you can get the crankshaft throws very close to the ground. I wonder how far above the tarmac the big end of the rod is around BDC in a F1 car?

You need to nominate which type or model of V8 to clarify that.

Obviously the superior 2 valve V8 has a lot lower CG than a 4 valve quad cammed, overweight and underpowered V8.

And you didn't mention the higher moment of inertia or is it polar moment of inertia? Always confused the 2.

lol

tell that to porsche and subaru , porsche use the flat engines to great sucsess (lemans) , and subaru (rally), so that says somthing for the flat engine , only set back is aero , the under tray is compramized . so the idea i came up with was put the two togeather .

let us guess the COG height on these two....




in reality, I find it hard to believe that you can better the COG and packaging of a dry sump V8... regardless of the number of valves..

Porsche is an enigma. No one in the recent automotive industry would design a flat, rear engined race or road car. Porsche have done well to refine the design to the point they have. Have you ever driven a 911 by the way? Dangerous POS they are. Have you noticed the Japanese, notorious for doing so, have not made a Porsche copy? Modern Porsches are so darn heavy that the engine layout isn't such a big effective % of the car anymore anyway.

Subaru is not good, just their competition is worse using high GC'ed transverse engines hanging forward of the front axle - wow.

Lancia with their 037 and Delta S4 rally champ winners designed from a clean sheet and without production car nuisances to attend to, used a mid-engine, longitudal inline 4 even though they have vast experience with flat 4's and tranverse layouts - for a lower polar moment of inertia.

I would think a VW 'W' engine may be suitable for your needs.

Azarian

After thinking about it some more don´t you think that the CoG will stay virtually the same?

Letś say that most of of weight or atleast half is central to crank and the rest split evenly between each of two sides of vee, say 90 degrees.

To lay one side of vee flat you will rotate engine 45 degrees about crank center line. No change in height of most of mass. One side of vee will result in lower mass but the other side mass will be raised virtually by the same distance that the lower side was reduced.

Throw in a few things like how do you drain oil from the low side cam/valve box, how do you avoid air pockets in water passages, do you lower heavy accessories and etc??

Then throw in other such things as very few engine/gearbox boltings are symetrical so you will eiither have to make a rotated conversion plate or run the gearbox rotated 45 degrees. Then you have to squeeze the low side headers in to the space.

Good luck for a lot of work for about nil gain!!!!

Regards



Nice first thought but you won find me trying to

why cant you dry sump the boxer engine ?

Exactly.

At some point, whel diameter, drive connectins make raising the bottom of the sump by chaning to a dry sump pointless unless you want to do it for another reason such as windage

As I said in post #3, you probably wouldn't gain much. The crankshaft CL installed in the car will need to be higher than the V8 so the lower CG (relative to the crankshaft) will be mostly lost.

exactly..

also, azarion, you need to package the exhausts and you end up with a very wide engine, which you might interfere with your chassis package and/or underbody aero.
Take a look under a subaru hood... the engine doesn't sit that low anyhow, and exhaust manifold is very hard to get right...
as for the sump.. .I think you need to make the boxer engine dry sump otherwise you have problems with all that oil hitting the pistons all the time..

with a wide V engine you keep the crank at it's lowest (and it is the heaviest part) and raise the heads enough to package the exhausts.. and you end up with a nice compact engine and lo COG..

Stick with the V8. Put Bishop rotary valves on it. More power, lighter, lower CG than your FV8 and cheaper.

renault tryed a wide angle engine in f1 ( 128 ?) , they couldnt make it work . porsche built the 996 gt ( 1996 ? i think ) and it was mid engined flat 6 with 2 turbos , and dominated in the gt championship , distroying the perfict maclaren F1lm .

Because the McLaren was a modified road car and the Porsche was a racing car using the minimum amount of 911 parts. It also helped to destroy what had been a great series. If the flat 6 was so good, why do you want to build a hybrid that probably won't work?

As far as I know the Renault wide-angle engine worked, but not quite as well as a regular V angle. There have been many wide-angle engines, it's not a mystery.

in the end a 2 valve chevy with or without turbos is your best bet..

Ooh! Controversial! But probably correct...

I personally believe that you can not make a engine choice just like that.. first thing is to consider what kind of power and torque characteristics one wants, what is the target vehicle weight , packaging, etc.. Choosing an engine just because it looks or sounds cool is the wrong way imho..

I'm not sure if you are addressing me or azarion, but I agree with you, and I think the original theme of this thread was a bit poinless, but often pointless threads transmogrify into interesting threads - or vice versa...

have a look at my model car youtube azarion supercar photos , and you will see what im getting at , having large ventury tunnels , wait till you see my other engine idea ? hahahaha

ive got a lot of new fresh ideas , there is no harm in asking , can talk about things that alredy exist (boring), or try new things , history shows how new things come out , they may work may not , but you wont know till you arsk .

I was addressing the general idea behind making something just because it looks cool, which I thought was the point behind FV8 engine.. no disrespect intended to azarion.... but I also like these threads, as I like this forum, as it brings up some interesting discussion..

Didn't Renault have torsional stiffness problems with their almost flat vee engine?

yes yes they did , not sure if it was vibrations or installing it , in a moden F1 car . i think arrows had a similer problem with the exteamly small yamaha v10

There seems to be some confusion as to the proposed FV8 engine, this sketch is how I think azarion intends it, but I too may be wrong. This way the front portion has a lower CoG and the rear portion gives more room for the tunnels. I think.

thats it mate , you see how the ventury tunnels can start earlyer ,

Another possibility, making for a much shorter engine, would be to follow the teachings of Bennelli from the early 1950's (if not Anzani from the first decade of the last Century) and go with a fan type layout:
http://v3.espacenet.com/publicationDetails...87687A&KC=A

PJGD

but if it was a V8 the tunnels could start even earlier..

If it was an inline twin and front wheel drive the tunnel could be bigger than the Chunnel!

The possibilities are endless - unfortunately...

Cheers. I was confused.

Also, showoff!

Several years ago Renault split the difference with an F1 V10 built on a 111-degree bank angle. Didn't show any particular advantage whilst creating a lot of problems.

The V8/flat 8 hybrid above would be more heavy and complicated than a conventional V8 with a single bank angle: four cylinder heads instead of two, requiring more fasteners, jacketing, sealing, two sets of cam drives, etc. Lots of downside while the potential upside is debatable at best.

Agree with most of what's already been said - the main killer being any cog benefits are offset by having to raise the whole engine to package the exhaust. From your first post I thought you were proposing something akin to the VW W16 engine. I guess you'd have odd vibrational issues with your suggested layout.

I believe the problem with the Renault V10 was that in an F1 car the engines are fully stressed and the wide V wasn't torsionally stiff enough - which is why renault used (and still use I believe) braces from the monocoque to the rear of the engine.



The wider V design was also heavier, again offsetting the small benefit of lower cog.

Renault quickly kludged up rather cobby looking (at least by F1 standards) tubular braces from the roll structure back to the transmission case to create another load path, though the buzz then was that it was more of a bending stiffness issue than torsional if I'm remembering correctly. The wide V would seem to compromise both compared to a conventional V angle though.

numatic valve , small pistons to operate the valves ,eliminating cams and all the gear to run it , just like the F1 boys , theve ditched cams years ago .

What? Well, I've lost interest...

Tell us more O' wise one.

Yes thats a good point but the problem is that camshafts act as torque compensaters to help offset the twisting force of the crankshaft and when Renault went to the nuumatic valves, eliminating the camshafts, that was the real reason for the extra tubes from the rear bulkhead to the transmission as pictured below, to help fight that extra twist the engine gave. I heard that the first numatic engine actually tried to tear off from the bulkhead on it's maiden test.


When you watch a big American V8 being given a rev you can actually see either the engine or the whole car twist a bit, thats because they only have the one camshaft which doesn't quite have enough torque compensation on it's own compared to the effect DOHC and especially Quad Cam engines can give.

Now Azarion - all you have to do is move the V4 forward till its on top of the flat 4 and Presto - a W8. Does everything you want and is much smaller and lighter.

are you guys talking about pneumatic valves?

Kind of, Nuumatic is a Renault tradmark.

I don't like the numatic valves, I much prefer the oldmatic.

Dramatic valves are OK, when they're not throwing a wobbly, systematics are nothing if not regular, Lavamatics run very clean - which is nice - plutocratics are superior, while pedantics are a bit tedious, although they don't realize it.

as far as i know they replaced the cams , when they strugled with revs over 12,000rpm , the valves would bounce , so the only way round it was numatic ( or what ever is the proper name ) , i think ferrari touched 21,000rpm before the stupid rules came in . but would the hole operating syestem for the numatic vaves weigh , the same as the cam set up ?