E55AMG99

Exactly!

skratch77

blown once again you fail to see what im trying to say.its not about making 100hp/l its about MB making 600hp from an NA v8.its not going to happen.

the frigen mclaren f1 makes 627 NA hp with a 6l v12 and you think a mb NA v8 can make it.

BTW iv heard turner motorsports F1 and let me tell you its sound like a fighter jet.

Not even bmw can make that much power from a v8 and even the new z06 with its 7l v8 is only putting out 500 so please shut up.

Now ill ask you once more please explain to me on how MB is going to get 600 plus hp out of a v8 without using 13.1 compression or even higher.

SoulBladeZA

A petrol engine would detonate at higher than 13:1

BlownV8

Ok, please tell me why a V8 can't make that same hp/liter? I've shown you example of V8 street motors that can make that hp/liter. What is so magical about the V10 or V12 that is an impossible feat for a V8? Heck, a 4 cylinder can do that and so can a 6 cylinder so I guess the V8 is just a big lump of metal with no potential?

skratch77

there are no 4,6,8 or even 10 NA engines making over 600 hp its freaking damn near impossible.

You need more cyl and very high revs to make that much hp(600 hp)NA

Im not talking about 100hp/l im talking about making 600 hp with a v8.

bmw had to make the v10 because the harmonics of a v8 cant rev as high and the fireing order in the upper rpms messes every thing up.

Just sit back and think of what this 6l v8 rumors are saying.As much power as a por/gt with a v8 is just crazzy.

E55AMG99

Back in 1970 in the USA, we saw compression drop from a high of about 12.5:1 down to about 7.5:1. People were saying back then that we would never see high compression street engines again. Well, gasoline today is lower in octane than it was in 1970 and we routinely see 10:1 compression and higher engines that run on 91 octane unleaded just fine.

Again, never say never.

vraa

He didn't say never though

I have a question, can engines be made so they have variable compression?

E55AMG99

Technically, he did not use the words but he was speaking in absolutes.

When it comes to detonation, compression is not the evil fiend that everyone thinks it is. Cylinder pressure is the biggest reason engines ping. I can build an engine with 20:1 compression and make it run on regular unleaded. How? Big cam overlap where the intake and exhaust valves are open at the same time (or leave the exhaust valve open past BDC on the intake stroke). This will lower the amount of air/fuel in the cylinder that has to be compressed. The engine may not run very efficiently but hopefully you understand what is happening here.

Variable valve timing achieves your goal by varying the cylinder pressure with valve timing adjustments.

vraa

Okay, it's kinda coming together. That's what VTEC, Valvetronic / VANOS, and VVT is right?

AMG 5.5L S/C's don't have any of that right? Neither does the M3/M5 (E60)?

E55AMG99

My memory is not what it used to be but one or more of those manufacturers use variable intake ports as a means to altering engine output. This too has an effect on cylinder pressure. Higher velocity intake tract means more A/F is crammed into the cylinder to be compressed.

vraa

So higher velocity also means more compression right?

E55AMG99

First, my appologies for thread hijacking.

NO! Compression ratio is static. It is basically, the volume of the cylinder with piston at BDC in relation to the volume of the combustion chamber. These values are not dynamic.

Imagine the cylinder is at rest at BDC and therefore filled with air at atmospheric pressure (assume 0 psi). When the piston makes it to TDC, the pressure rises (to what level is not important). Now, imagine if you were to put a compressed air hose on that same cylinder at rest at BDC and pressurized it before the piston made its way to TDC. The resulting cylinder pressure would be much greater than the first test becaue you started with more air.

The compression ratio did not change but cylinder pressure did. Make sense?

vraa

I gotcha, it makes sense. And it's my fault that this thread got hijacked. Sorry guys.

So the compression ratio stays the same, but the cylinder pressure and changeable by the valves timings.

Man, cars get complicated fast.

BlownV8

You are the most clueless person that I've ever seen on any car board in my life. Every single V8 NASCAR engine makes over 600 hp and they use a freakin' push rod engine with carburators!

You can get a 600 plus hp small block V8 for $13,000 from these guys:
http://www.badasscars.com/engineprices/chevsb.html

Oops, here is a 340 cubic inch V8 engine that has 600+ hp on 91 octane:
http://www.moparmusclemagazine.com/t.../155_0310_340/

Oh wait, there's more. Here is another article that tells you how to build a 600 hp small block V8 that runs on 92 octane:
http://www.carcraft.com/howto/1004/

Uh-oh, I keep finding more and more evidence that you are clueless about V8's:
http://www.worldcastings.com/docs/03catalog/engines.pdf#search='600%20hp%20small%20block'

Here is a 675 hp small block V8:
http://www.speedomotive.com/675_hp_small_block_4.htm

Here is another 600 hp small block. 600 hp at 6,000 rpm and dirt cheap with off the shelf parts.
http://www.sporttruck.com/techarticles/84258/

Another 600 hp NA V8 that runs on pump gas:
http://www.carcraft.com/techarticles/76858/

I can go on and on and on to show you how easy it is to get power from a V8. For some unknown reason, you seem to doubt that a V8 can be made to produce much power. The above examples us an engine design that is decades old. A new V8 design utilizing multiple overhead valves and cams, variable valve timing, and silica impregnated aluminum bores or aluminum bores that are coated with Nickasil has even more potential to make big power from a naturally aspirated engine. "Freakin' damn near impossible." I don't think so.

reggid

i'm talking increasing bore but reducing stroke to keep the displacement the same. The stroke gives the "leverage" so by incresing the area you will increase the force but if you shorten stroke some if this is undone. Choosing the correct stroke to bore cannot be discussed in this thread as if will take forever and there is no single right answer. one only has to look at an f1 engine with big bore short stroke (to allow more revs) and the kind of characeritics it has and its certainly not bottom end grunt.

Also one also has to look at any production car on the planet that is NA its peak torque is very very strongly governed by absolute displacement. Take 100Nm/L as a good guide and highly tuned good flowing engines get maybe 110Nm/L

reggid

i don't agree with skratch but consider emmissions which i believe was one of the reason MB is leaning towards NA

BlownV8

Here are some other naturally aspirated V8's making above 600 hp and well above 100 hp/liter, enjoy:
http://www.7extrememotorsports.com/transam/stats/

skratch77

BLOWN will you ever give up....IM TALKING ABOUT STOCK RELIABLE POWER omg your so ****ing stupid

I know tuner companies can make that power

wow you brought up nascar that get a engine rebuild 3 times a week good job buddy.

IM SAYING MB WILL NOT PUT OUT A NA V8 making 600 hp

ill bet you 100 bucks it wont be 600hp NA

Kar don

actually saab makes a variable compression engine by using a special headgasket that changes the volume of the combustion chamber.

E55AMG99

So you do know what you are talking about. Increase bore and keep stroke the same is what I was referring to.

E55AMG99

I heard that someone was experimenting with variable compression ratios but I've never seen it in production before. It looks like they varythe angle of the head to do it. Apparently this little motor puts out 150hp per liter with a 2.8 bar (40PSI) boost and as much as 14.0:1 compression! VERY cool!

Thanks for the info Al.

Kar don

no prob, i assume u are an engineer as well?

E55AMG99

Done a lot of things over the years but never been an engineer. I just spent many hours behind the wheel of various race and high performance cars and what feels like even more time staring at dyno charts wondering why the results weren't what I expected.

With all of the advancement in engine technology these days, it is very possible that MB will produce a reliable and drivable V8 making 100hp/liter.

BlownV8

No sir, it is you that is so F#$%ing stupid. For some unknown reason you don't believe that Mercedes can make a 100 hp/liter naturally aspirated engine and you even made the claim that it is damn near impossible to make a V8 with over 600 hp/liter. I gave examples of V8 engines that run on pump gas with over 600 hp to disprove that it is damn near impossible. In fact, it's pretty damn easy with the V8.

Just about every major manufacturer can build a NA V8 with a good bit more than 100 hp/L. Manufacturers use race engines as test beds for their street engines and take the knowledge and apply it to make a car more reliable. With modern engine management systems and variable valve timing, making huge reliable hp is not that difficult.

Yes, Mercedes can make a reliable V8 with over 600 hp. There is no doubt that they could do this. Will they, I don't know. They have surprised me many times with past engines so I wouldn't put anything in the never catagory with them. It is totally assinine for anyone to think that Mercedes couldn't build a reliable big hp NA V8 motor.

skratch77

when have I said MB cant make an 100hp/l engine I said they won't.

do you think that this special 600 hp v8 will last 200k miles and 20 years like almost every mb enigine ever built?

Im sure they could heck BMW in the 70's made a turbo M that had 400Hp/l

800 hp out of a 2.0 l 4 banger.

that car needed a rebuild after everyrace.

its not MB heritage to make a high strung 600 hp v8.They have never came out with any engine near 100 hp/l STOCK and wont

we have 300k miles on our 1983 300 turbo d still runs mint too.