Displacement

[Zenmervolt]

Originally posted by: Summitdrinker
also take into the fact the bigger the cubic inch per cylinder the more ineffeicent it will be burning wise, plus pollution goes up

I would really, really, really need to see some documentation around that.

Smaller cylinders would mean more cylinders for the same displacement, which means vastly greater frictional losses, which means less efficiency, which means more fuel burned for the same power which means more pollution.

Larger cylinders do make it more difficult to get a complete burn of the fuel, but twin plugs can alleviate that issue.

ZV

 

[Zenmervolt]

Originally posted by: Summitdrinker
plus there is other wear too, crank bearing wear, you can only make those bearings so big in a given block

the more cubic inch you make out of that given block along with higher compression too put more load on the bearings

main bearings do wear out

That can be compensated for by simply making heavier-duty bearings. The main bearings in diesel engines for semis don't seem to have problems and those experience a lot more load than the bearings in automotive engines. It's all a matter of engineering to deal with the stresses.

ZV

 

[Demon-Xanth]

Everything has tradeoffs, that's why we haven't "evolved" to one single engine. The 1st gen Chevy Smallblock is the closest anything has come to it. A 16L Cat diesel would crush a Civic, a B16 would fall out of a Kenworth.

 

[Estrella]

Originally posted by: Demon-Xanth
Everything has tradeoffs, that's why we haven't "evolved" to one single engine. The 1st gen Chevy Smallblock is the closest anything has come to it. A 16L Cat diesel would crush a Civic, a B16 would fall out of a Kenworth.

What is that supposed to mean? An engine that large would have probably no more than 50hp but, 50000000000000000000000000lbft of torque. LOL(good deal of exaggeration here)

 

[jagec]

Originally posted by: exdeath
I honestly don't know what the fascination is with revving an engine high to make power if you have to wait all day for it. I just like to blip the throttle off idle and GO, not put my foot to the floor and watch the tach take a leisurely walk to the red line.

I guess some cultures like to impose artificial limits on things to make their lives more challenging than they need to be

It doesn't take all day if the car is light. Take the extreme example: a sport bike. Very little torque, insane gobs of power at high RPM, but if you're riding it right it never feels like you're waiting for the powerband. Torque is for stoplight racing and city driving.

 

[mcturkey]

There are three basic ways to make power from an engine: Displacement, Compression, and RPMs. Most engines balance these in the name of longevity, but then you have sports car engines, which generally employ two or even all three of these methods in heavy doses for a lot of power. The LS7 is a relatively large displacement engine with relatively high compression. It might not rev to 10k, but it doesn't need to. Then you have the S2000 engine, which is low displacement, but has high compression and revs pretty high.

High-revving engines that have pedestrian compression ratios and low displacement make the least power, but do well with fuel economy (ala many Honda engines of the 80's and 90's). High compression engines (eg. diesel) can make decent power with pretty low RPMs and displacement, but require higher octane or special fuels, thus making them less practical in the US. Then you've got big displacement engines that make good power without high compression or high RPMs, but suffer the most in fuel economy. However, when you combine these elements, you wind up with some of the most efficient ways to make power. I'm not talking about miles per gallon so much as horsepower/torque per gallon. I've never come across any good estimates of that, but to me that's a more interesting measure of efficiency than MPG.

 

[dwcal]

Originally posted by: Demon-Xanth
The single biggest factor is laws and racing class displacement rules. The US racing organizations such as NASCAR and NHRA are predominant here while FIA is predominant in Europe. Also, many countries have taxes/laws regarding engines over a specific displacement whereas the US has CAFE. These differences basically caused large engines to be favorable in the US, while high revving engines to be favorable in Europe.

When a racing class only allows for a certain displacement, you end up being forced to go for high revving. When cost is the major factor, displacement becomes attractive.

Demon-Xanth is right. European road racing has a long history of displacement-based formulas. In the 50's and 60's sports car racing used the same cars you could buy for the street (they still do somewhat in production classes), so Ferrari, Porsche and the others built sports cars for the displacement limits of the classes where they raced.

 

[Pacfanweb]

Originally posted by: Summitdrinker
ya, na, ya..the more cubic inch you get from the same block starts to shorten engine life after a certian point, esp if run at higher rpm and or high loads.

big block chevies were a odd motor, atleast they were 20 years ago, one will be powerful and long lived the next one is a dog that dies early

also take into the fact the bigger the cubic inch per cylinder the more ineffeicent it will be burning wise, plus pollution goes up

If you build a larger cubic inch engine, you won't need to turn high rpm's to get more power.

If you try to build more power out of your existing engine without enlarging it, THEN you'll need to turn it higher, run more compression, etc.

I can build a 540 big block with just under 10:1 compression that will make 700 hp and you can drive it across country and back with no worries.

Try doing that with a 454 that makes 700 hp and see where it gets you.

Check this out...555" BBC with 700 hp and 24/24 warranty

540" 695 HP Street engine, 24 month/Unlimited mileage warranty

 

[Summitdrinker]

nascar had a 7 liter (429 ) limit for many years and look at the early to mid 60's that was the biggest engine most american car companies made too

the main bearings on many diesel engines are bigger than car gas engine of the same cubic inch

bigger as in wider and larger diameter

lets go back to old american tractor engines, the johndeere 2 cylinder like th model "a" even up the 730 and 80 etc over 400 cubic inches and 2 cylinders
it was a great motor, but it died. they couldn't get any more horsepower out of it

reason why? it wouldn't burn completely, esp if reved any higher. ya twin plugs would helped some, but not that much

twin plugs? now add more cost to the engine too, plus more maintence and repair cost

 

[exdeath]

Originally posted by: jagec

Originally posted by: exdeath
I honestly don't know what the fascination is with revving an engine high to make power if you have to wait all day for it. I just like to blip the throttle off idle and GO, not put my foot to the floor and watch the tach take a leisurely walk to the red line.

I guess some cultures like to impose artificial limits on things to make their lives more challenging than they need to be

It doesn't take all day if the car is light. Take the extreme example: a sport bike. Very little torque, insane gobs of power at high RPM, but if you're riding it right it never feels like you're waiting for the powerband. Torque is for stoplight racing and city driving.

I live in a city with lots of straight north-south and east-west roads with stoplights and stop signs

Thats actually how most all American cities are set up. Contrast with the twisty roads of Europe I can see how they would never really get a chance to open it up on a straight and feel the rush that raw torque gives.

 

[Zenmervolt]

Originally posted by: Summitdrinker
nascar had a 7 liter (429 ) limit for many years and look at the early to mid 60's that was the biggest engine most american car companies made too

the main bearings on many diesel engines are bigger than car gas engine of the same cubic inch

bigger as in wider and larger diameter

lets go back to old american tractor engines, the johndeere 2 cylinder like th model "a" even up the 730 and 80 etc over 400 cubic inches and 2 cylinders
it was a great motor, but it died. they couldn't get any more horsepower out of it

reason why? it wouldn't burn completely, esp if reved any higher. ya twin plugs would helped some, but not that much

twin plugs? now add more cost to the engine too, plus more maintence and repair cost

I'm with you, sort of. We're not arguing cost or complexity, only displacement. If you can get a complete burn and if you don't have vibration issues (like a large 2 or 4 cylinder would), then, all else being equal, an engine with fewer cylinders will have less friction and therefore more power. This does have to be balanced by appropriate engineering accommodations (larger main bearings, etc, as I mentioned in my previous post and as you repeat).

Twin plugs don't add much extra complexity at all. You don't even need a special distributor or coil, just run two plug leads off of each distributor cap terminal. All you need is a different distributor cap. I don't see how that translates into more maintenance/repair cost. Yes, you have twice as many spark plugs, but they're around $1.50/each. It's such a tiny amount of money that it doesn't matter.

ZV

 

[Pacfanweb]

Originally posted by: Summitdrinker
nascar had a 7 liter (429 ) limit for many years and look at the early to mid 60's that was the biggest engine most american car companies made too

Engine technology, especially cylinder head tech, has come a LONG way since then. The 350's they use in Nascar today make several hundred more HP than the big blocks did back in the 60's and 70's....then again, the rules are different, too.

The heads on the engines they have now are ported beyond belief, and they flow better than the big block heads they had back then............but not the big block heads they have NOW.

I'd love to see them reinstate the 7.0 limit for a season and see what kind of power they could make, now that engine builders would have
A: far superior head tech
B: far superior bottom end components that could withstand higher rpms

They'd have 1000 horsepower cars if they went to work on the big blocks now.

And your old JD tractor engine....again, the technology wasn't there. If that engine was still being used now, they'd be light-years ahead of where it used to be in power.

 

[Pacfanweb]

Originally posted by: Zenmervolt

I'm with you, sort of. We're not arguing cost or complexity, only displacement. If you can get a complete burn and if you don't have vibration issues (like a large 2 or 4 cylinder would), then, all else being equal, an engine with fewer cylinders will have less friction and therefore more power. This does have to be balanced by appropriate engineering accommodations (larger main bearings, etc, as I mentioned in my previous post and as you repeat).ZV

Interesting to note that many of the NHRA Pro Stock motorcycles now use the Harley V-Twins, as they've equaled or surpassed the 4 cylinder rice bikes in power output.
Didn't take long after someone started using them to catch up, either. I remember seeing the first one in competition just a few years back, and its performance wasn't even close.
Now they are prevalent in racing.

 

[jagec]

Originally posted by: Pacfanweb

Originally posted by: Zenmervolt

I'm with you, sort of. We're not arguing cost or complexity, only displacement. If you can get a complete burn and if you don't have vibration issues (like a large 2 or 4 cylinder would), then, all else being equal, an engine with fewer cylinders will have less friction and therefore more power. This does have to be balanced by appropriate engineering accommodations (larger main bearings, etc, as I mentioned in my previous post and as you repeat).ZV

Interesting to note that many of the NHRA Pro Stock motorcycles now use the Harley V-Twins, as they've equaled or surpassed the 4 cylinder rice bikes in power output.
Didn't take long after someone started using them to catch up, either. I remember seeing the first one in competition just a few years back, and its performance wasn't even close.
Now they are prevalent in racing.

90 degree or 35 degree?

My bike's a 90 degree V-twin, and it's a sweet engine. I hear there are non-trivial balancing issues with a 35 degree engine, though?

 

[Estrella]

So, basically, I gather the differences are directly related to restrictions placed by w/e racing association/organization that the manufacturers cars most commonly appear in(exceptions being any form of drag racing where one goes all out, high displacement, forced induction, tech, and some fuel ending in -ol). Rev high, rev low, one can make power.

 

[Zenmervolt]

Originally posted by: Estrella
So, basically, I gather the differences are directly related to restrictions placed by w/e racing association/organization that the manufacturers cars most commonly appear in(exceptions being any form of drag racing where one goes all out, high displacement, forced induction, tech, and some fuel ending in -ol). Rev high, rev low, one can make power.

That, and use. European cities are set up more centrally and are closer together, there's much less need for extended highway cruising.

I've had both high-revving sportscars and big V8 yachts. On an extended trip, a car with a big V8 that's only spinning 1,500 RPM at 70 mph is much nicer to cross a continent in than a smaller car running at 3,000 RPM.

The prevalence of extended road trips in America favors larger engines that don't need to rev as much.

Yes, smaller engines revving more do just fine and there's no real longevity advantage, but it's still more peaceful on a long trip to have a car with a slow-revving, large, V8.

ZV

 

[Summitdrinker]

ya americanies like big cars, will they used too, I guess I am old school, because I still do, nothing like a big V8 RWD car for the highway and pulling boats

i drive a yacht to this day

 

[Eli]

It's also to change or maybe more accurately go with the desired persona of the car.

A 2.8L V8 that has a 9,000RPM redline would be much more fun to drive than a 5.0L V8 with a 5,000RPM redline, IMO.

 

[Summitdrinker]

some euros like big american iron too
as you will see here:
http://www.tottis-inn.de/

 

[GoatMonkey]

I'd like to see a racing series that limits the car's fuel instead of its displacement. In racing they are constantly reducing the maximum displacement of the engines to limit the speed. If you limit the amount of fuel cars can use to run the entire race it's going to force the teams to make more efficient engines/cars. They should be allowed any displacement, turbos, hybrids, whatever. Just as long as you finish the race using the original amount of fuel.

That's technology that we need to trickle down to street cars.

 

[Demon-Xanth]

In think they actually did that in CART.

 

[Fenixgoon]

Originally posted by: GoatMonkey
I'd like to see a racing series that limits the car's fuel instead of its displacement. In racing they are constantly reducing the maximum displacement of the engines to limit the speed. If you limit the amount of fuel cars can use to run the entire race it's going to force the teams to make more efficient engines/cars. They should be allowed any displacement, turbos, hybrids, whatever. Just as long as you finish the race using the original amount of fuel.

That's technology that we need to trickle down to street cars.

honestly, that's a pretty interesting curveball. however, it is very sensitive not only to engine efficiency, but driver input as well. so the race might be more like a crawl, relatively speaking

 

[GoatMonkey]

Originally posted by: Fenixgoon

Originally posted by: GoatMonkey
I'd like to see a racing series that limits the car's fuel instead of its displacement. In racing they are constantly reducing the maximum displacement of the engines to limit the speed. If you limit the amount of fuel cars can use to run the entire race it's going to force the teams to make more efficient engines/cars. They should be allowed any displacement, turbos, hybrids, whatever. Just as long as you finish the race using the original amount of fuel.

That's technology that we need to trickle down to street cars.

honestly, that's a pretty interesting curveball. however, it is very sensitive not only to engine efficiency, but driver input as well. so the race might be more like a crawl, relatively speaking

It depends on how it's done really. The idea is to still keep the race exciting, so it wouldn't be one of those 1 gallon to drive 500 miles or something. More like 50 gallons for 100 miles. Then if they go too fast for the race safety guys, the next race they only get 40 gallons. Or something like that.

 

[marincounty]

Originally posted by: Pacfanweb

Originally posted by: Zenmervolt

I'm with you, sort of. We're not arguing cost or complexity, only displacement. If you can get a complete burn and if you don't have vibration issues (like a large 2 or 4 cylinder would), then, all else being equal, an engine with fewer cylinders will have less friction and therefore more power. This does have to be balanced by appropriate engineering accommodations (larger main bearings, etc, as I mentioned in my previous post and as you repeat).ZV

Interesting to note that many of the NHRA Pro Stock motorcycles now use the Harley V-Twins, as they've equaled or surpassed the 4 cylinder rice bikes in power output.
Didn't take long after someone started using them to catch up, either. I remember seeing the first one in competition just a few years back, and its performance wasn't even close.
Now they are prevalent in racing.

Complete BS. NHRA rules for Pro Stock motorcycles allow the Harley based bikes to use up to 160 cubic inches engines and the Suzukis are limited to 101 cubic inches. The Harleys and Suzukis are both subject to a 615 pound minimum weight, Buell 625 pounds.
Yeah that sounds fair to me, the Harleys get a 60 % displacement advantage.In addition the Suzukis have been forced to use old two valve engines from the '80's. I think this year or next they will finally be able to use 4 valve heads which have been used on streetbikes since the early '80's. The Vrod uses a 4 valve head.
Text
Following a review of recent performances in the Pro Stock Motorcycle category, NHRA has announced that the minimum weight for all Buell-powered motorcycles is increased 10 pounds, from 615 to 625 (minimum weights include the rider).

The change is effective June 7, 2007, Harley-Davidson V-Rod (160 cid) and Suzuki (101 cid) remain at 615 pounds

As for stock bikes:
A Harley-Davison V-Rod, with just 1130cc of displacement, shreds it in the quarter-mile: the V-Rod running 11.31 seconds at 114.95 mph while a stock 2006 Suzuki GSXR 1000 does the quarter in 10.09 at 143 mph. The Kawasaki ZX14 does the quarter in 9.65 seconds at 153 mph.

So you can see that the "rice" bikes are still much faster than Harleys, and it is only through the manipulation of the rules that Harley has any chance whatsoever.
Suzuki kicks ASS.