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Cotton
Cotton Dork
10/25/12 3:41 p.m.

I should throw some HP/liter bike numbers out just to stir the pot ...lol.

chaparral
chaparral HalfDork
10/25/12 4:15 p.m.

I'll spare you the trouble, Cotton.

Aprilia RSA125, 125cc (6 1/4 cubic inches), 53.9 horsepower, for 440 hp/l.

For four-strokes, it's rare to get past 135 hp for a 600cc, for 220 hp/l with 150cc cylinders.

RossD
RossD UberDork
10/25/12 4:16 p.m.

I wonder whats happening in the "Good God Almight!" thread...

Keith Tanner
Keith Tanner MegaDork
10/25/12 4:18 p.m.

You guys know that specific output usually drops with engine size, right?

I'm looking forward to getting my hands on one of these, although there is going to be definite confusion due to the name choice. The old big block LS3 was a long time ago, the LT only went out of production 15 years ago and was pretty high profile. Dumb.

tuna55
tuna55 UberDork
10/25/12 5:10 p.m.
Keith Tanner wrote: You guys know that specific output usually drops with engine size, right? I'm looking forward to getting my hands on one of these, although there is going to be definite confusion due to the name choice. The old big block LS3 was a long time ago, the LT only went out of production 15 years ago and was pretty high profile. Dumb.

Yes, some of us do.

bravenrace wrote: In reply to racerfink: HP/liter is independent of the number of cylinders.
Tuna55 wrote: But it is NOT independent of cylinder size. A smaller cylinder will always produce more power per displacement than a larger one. Obviously, once the pistons starting getting the size of thimbles, this stops being true, but for all normal sized applications it's right. Comparisons per displacement are pretty irrelevant anyway, since other than specific racing classes, nobody could possible even notice. If tomorrow you found out that there had been a huge mistake and that the BMW V8 was actually 6.2L and the LS3 was actually 4.4L, would it matter to anyone? No.
stuart in mn
stuart in mn PowerDork
10/25/12 6:22 p.m.
wvumtnbkr wrote: There was actually a pretty good thread about exactly this topic a few weeks ago. If you search for OHC, you will probably find it.

I think there have been about 8,000 threads on this subject...

novaderrik
novaderrik UltraDork
10/25/12 6:28 p.m.

the original LT1 engine had only been out of production for 20 years when the used that code on the new Corvette engine in 1992.. how dare they...

Ford started putting a 5 liter version of their DOHC engine in Mustangs- and putting the iconic "5.0" badges on the fenders- only 15 years after the last 5.0 Windsor was put in a Mustang.. how dare they..

why does everyone get all bent out of shape over the option codes they use to name their new engines? in GM terminology, the "L" codes mean "engine"- it's just the option code that goes into the computer that tells the factory people which parts go where.

would it be better if they had used something like LG4, L69, or L05? maybe they should come out with a turbocharged version and call it the "LC2" just to rile up the GN guys..

Keith Tanner
Keith Tanner MegaDork
10/25/12 7:09 p.m.

It's because it will cause lots of confusion. The LT1 was a pretty common swap. It would be useful if they could be easily distinguished. What if you're trying to buy LT1 parts at a swap meet, or advertise a car with an LT1 swap? I know I'd pay a whole lot more attention if it were the new engine, not the old one. I forsee much confusion in my future talking to customers, as we will likely be putting LT1s in Miatas before too long. No, not that LT1. The other one. Yes, that one's been put in Miatas too.

Reusing the LS1 and LS3 names wasn't brilliant, but the sheer production volume made it easy to tell which was. It's possible that this one is an LTx because T follows S, but by that logic the 1997 LS1 should have been an LU1.

Ford's 5.0 is just marketing. There's still a way for gearheads to distinguish the engines,either by referring to a 302, a Windsor or a Coyote.

z31maniac
z31maniac PowerDork
10/25/12 7:24 p.m.
HiTempguy wrote:
alfadriver wrote: ((also kind of sad that so few appreciate better fuel economy and emissions performance vs. a minor improvement in power- for street cars, how much is enough? So very few use the power they have already))

While I don't condone hooning on the streets...

If I were to buy a new car, I want it to lay a patch in 3rd gear. That requires a fair chunk of torque.

Of course, topping any modern car out in 2nd gear is usually 0-"mandatory court date" in about 5.0s, so I do see your point.

Gonna need some skinny tires or ludicrous levels of power. My new mustang with 3.73s instead of 3.31s will "scratch" third, but not lay black marks.......and that's with only sticky 255s.

Knurled
Knurled SuperDork
10/25/12 7:33 p.m.
Cotton wrote: I should throw some HP/liter bike numbers out just to stir the pot ...lol.

My co-worker has a liter bike that makes something like 170hp.

I looked at the engine's specs. Besides drooling over the ITB arrangement with stangted injectors (port injectors for idle, airbox injectors for power, allegedly 48mm but other places say otherwise) the valve sizes and cylinder bore are the same as your average 2 liter engine. It just has half the stroke.

There's a guy in the UK who, quite plainly, will tell you that an engine's HP potential can be condensed down to intake valve curtain area. Everything else just either supports that (head design, valve shrouding, combustion efficiency) or tells you what RPM is needed to utilize the flow (displacement).

So, again, 170hp from a 2 liter is downright common. Cut the stroke in half, rev it twice as high.

The guy in question (Dave Baker of Puma Racing) also has rules of thumb for engine efficiency - 2-valves tend to make X ft-lb/liter, 4-valves can make maybe 10% more, etc.

What I find interesting is that one of the engines people keep ragging on as a turd, the Chevy 2.2, has 44mm intake valves, which are something that 8v VW guys would stomp their puppies in order to get. They also have beautiful intake ports. Shame the engine is hampered by a crappy bottom end and no real aftermarket. Cam it up, put quad 48-50mm throttles on it, gets some compression and a stout bottom end in it, and it should be a riot.

81cpcamaro
81cpcamaro HalfDork
10/25/12 7:34 p.m.
Keith Tanner wrote: It's because it will cause lots of confusion. The LT1 was a pretty common swap. It would be useful if they could be easily distinguished. What if you're trying to buy LT1 parts at a swap meet, or advertise a car with an LT1 swap? I know I'd pay a whole lot more attention if it were the new engine, not the old one. I forsee much confusion in my future talking to customers, as we will likely be putting LT1s in Miatas before too long. No, not that LT1. The other one. Yes, that one's been put in Miatas too.

We will just have to get used to saying Gen 1, Gen II or Gen IV in reference to LT1s. Not ideal but we do what me must.

novaderrik
novaderrik UltraDork
10/25/12 8:59 p.m.
Keith Tanner wrote: It's because it will cause lots of confusion. The LT1 was a pretty common swap. It would be useful if they could be easily distinguished. What if you're trying to buy LT1 parts at a swap meet, or advertise a car with an LT1 swap? I know I'd pay a whole lot more attention if it were the new engine, not the old one. I forsee much confusion in my future talking to customers, as we will likely be putting LT1s in Miatas before too long. No, not that LT1. The other one. Yes, that one's been put in Miatas too. Reusing the LS1 and LS3 names wasn't brilliant, but the sheer production volume made it easy to tell which was. It's possible that this one is an LTx because T follows S, but by that logic the 1997 LS1 should have been an LU1. Ford's 5.0 is just marketing. There's still a way for gearheads to distinguish the engines,either by referring to a 302, a Windsor or a Coyote.

do you have the same problem telling the differences between the different variations of the LT1 that they used from 92-97? the Y, F, and B bodies all had their own different parts that distinguished them from each other- heads, cams, blocks, etc. and they even changed the distributors in the B bodies in 94 and then in the F and Y bodies in 95..-but they were all called "LT1".

Knurled
Knurled SuperDork
10/25/12 9:36 p.m.

To be a pedant, there is only one LT1 (well, one series of LT1). The new engine hasn't come out yet and the 1970 engine was the LT-1.

IIRC, the LT-1 was just the DZ302 with .48" more stroke, after the SCCA allowed destroking down to the 5 liter displacement limit.

Keith Tanner
Keith Tanner MegaDork
10/26/12 12:04 a.m.
novaderrik wrote:
Keith Tanner wrote: It's because it will cause lots of confusion. The LT1 was a pretty common swap. It would be useful if they could be easily distinguished. What if you're trying to buy LT1 parts at a swap meet, or advertise a car with an LT1 swap? I know I'd pay a whole lot more attention if it were the new engine, not the old one. I forsee much confusion in my future talking to customers, as we will likely be putting LT1s in Miatas before too long. No, not that LT1. The other one. Yes, that one's been put in Miatas too. Reusing the LS1 and LS3 names wasn't brilliant, but the sheer production volume made it easy to tell which was. It's possible that this one is an LTx because T follows S, but by that logic the 1997 LS1 should have been an LU1. Ford's 5.0 is just marketing. There's still a way for gearheads to distinguish the engines,either by referring to a 302, a Windsor or a Coyote.

do you have the same problem telling the differences between the different variations of the LT1 that they used from 92-97? the Y, F, and B bodies all had their own different parts that distinguished them from each other- heads, cams, blocks, etc. and they even changed the distributors in the B bodies in 94 and then in the F and Y bodies in 95..-but they were all called "LT1".

Ah, but you're an engine nerd. Apparently I did not know that - to me, the LT1 is the temporary jump between the classic SBC and the LS generation(s). So how DO you distinguish? Or is it like the difference between an LSA and an LS9, mostly just trivial?

I'm looking at it from the outside. I use GM engines. I don't live and breathe the casting numbers and that sort of thing, which I think makes me more typical than atypical. And for people like me, there is going to be some confusion between LT1 (LT-1, whatever) and LT1.

bravenrace
bravenrace PowerDork
10/26/12 5:51 a.m.
tuna55 wrote:
Keith Tanner wrote: You guys know that specific output usually drops with engine size, right? I'm looking forward to getting my hands on one of these, although there is going to be definite confusion due to the name choice. The old big block LS3 was a long time ago, the LT only went out of production 15 years ago and was pretty high profile. Dumb.

Yes, some of us do.

bravenrace wrote: In reply to racerfink: HP/liter is independent of the number of cylinders.
Tuna55 wrote: But it is NOT independent of cylinder size. A smaller cylinder will always produce more power per displacement than a larger one. Obviously, once the pistons starting getting the size of thimbles, this stops being true, but for all normal sized applications it's right. Comparisons per displacement are pretty irrelevant anyway, since other than specific racing classes, nobody could possible even notice. If tomorrow you found out that there had been a huge mistake and that the BMW V8 was actually 6.2L and the LS3 was actually 4.4L, would it matter to anyone? No.

Thanks for correcting me (twice) about something I didn't say.

novaderrik
novaderrik UltraDork
10/26/12 6:30 a.m.
Knurled wrote: To be a pedant, there is only one LT1 (well, one series of LT1). The new engine hasn't come out yet and the 1970 engine was the LT-1. IIRC, the LT-1 was just the DZ302 with .48" more stroke, after the SCCA allowed destroking down to the 5 liter displacement limit.

look at a build sheet for a 1970 (add the "1/2" if you feel you must continue the "pedant" theme..) Z/28, and it will say "LT1" in the box that says "engine"... not "LT-1".

then in 71or 72 they way toned the LT1 down with less compression and a (gasp) hydraulic cam and with an optional (gasp) automatic trans. but they still called it LT1, because that's just the option code for the particular engine that went with that particular option package.

i guess what i'm saying is don't get caught up in what it's called and just be happy that we all live in a time when a big company is going to be mass producing an engine family like this instead of trying to build trucks that get 40mpg and have no cargo hauling capabilities.

tuna55
tuna55 UberDork
10/26/12 6:47 a.m.

In reply to bravenrace:

touchy touchy...

novaderrik
novaderrik UltraDork
10/26/12 7:41 a.m.

check out the video of the test stand where they put this engine thru it's paces. GM puts all their engines in rigs like this and holds them at WFO for hundreds of hours at a time before letting them get mass produced...

http://www.foxnews.com/leisure/2012/10/25/2014-chevy-corvette-high-tech-v8-revealed/?intcmp=features

Knurled
Knurled SuperDork
10/26/12 7:45 a.m.
novaderrik wrote: i guess what i'm saying is don't get caught up in what it's called and just be happy that we all live in a time when a big company is going to be mass producing an engine family like this instead of trying to build trucks that get 40mpg and have no cargo hauling capabilities.

Those 40mpg trucks are what allows them to make engines like this in the first place. You can't have, say, a Trailblazer SS without a couple HHRs to balance out the MPG sheet.

When I was investigating the 2.2, I was first curious if the bore center was the same as the LS1-based engines. (It's not.) Then I noticed that the head actually looked PDG.

novaderrik
novaderrik UltraDork
10/26/12 8:27 a.m.
Knurled wrote:
novaderrik wrote: i guess what i'm saying is don't get caught up in what it's called and just be happy that we all live in a time when a big company is going to be mass producing an engine family like this instead of trying to build trucks that get 40mpg and have no cargo hauling capabilities.

Those 40mpg trucks are what allows them to make engines like this in the first place. You can't have, say, a Trailblazer SS without a couple HHRs to balance out the MPG sheet.

When I was investigating the 2.2, I was first curious if the bore center was the same as the LS1-based engines. (It's not.) Then I noticed that the head actually looked PDG.

i disagree- it's the ability to make engines like this that allows them to build smaller engines that get better fuel economy.

which 2.2 are you talking about here? the good old reliable pushrod motors that last forever and get awesome fuel economy with respectable power for what they are or the new overly complicated DOHC Ecotec that dies a premature death without warning when a small speck of crud blocks an oil passage in the timing chain tensioner?

Knurled
Knurled SuperDork
10/26/12 12:10 p.m.
novaderrik wrote: i disagree- it's the ability to make engines like this that allows them to build smaller engines that get better fuel economy.

Automakers have to have a corporate average fuel economy of X mpg. If they make a vehicle that gets less than that average, they need to balance it out with a higher economy vehicle. They will also charge more for the low-economy vehicles so that fewer people buy them, and sell the high-economy vehicles at a loss to entice people to buy.

which 2.2 are you talking about here? the good old reliable pushrod motors that last forever and get awesome fuel economy with respectable power for what they are or the new overly complicated DOHC Ecotec that dies a premature death without warning when a small speck of crud blocks an oil passage in the timing chain tensioner?

The former, although the latter last a good long time if you bother to change the oil every 3k.

alfadriver
alfadriver PowerDork
10/26/12 12:38 p.m.
novaderrik wrote: check out the video of the test stand where they put this engine thru it's paces. GM puts all their engines in rigs like this and holds them at WFO for hundreds of hours at a time before letting them get mass produced... http://www.foxnews.com/leisure/2012/10/25/2014-chevy-corvette-high-tech-v8-revealed/?intcmp=features

FWIW, everyone does. Hours at HP, and then hours at TQ peak. Sometime at stoich the entire time. It's one of the reasons that new engines cost so much to make. New, as in clean sheet.

sobe_death
sobe_death HalfDork
10/26/12 6:44 p.m.

You should see when we put our 460mm bore engines on the tilt table. Quite impressive

Teh E36 M3
Teh E36 M3 Dork
11/27/12 8:24 a.m.
pinchvalve wrote:
Ranger50 wrote: Complete artist cutaway:

David Kimble is superhuman.

No kidding. You see the comparative valve sizes? The intake has to be twice as big (diameter) as the exhaust. Also, there was mention about 4 valve heads- there is a company (Hot Dock) that builds 4 valve pushrod heads for sportsters. I'm sure it's possible for OHV V8's, but it'd be an engineering challenge, for sure.

Edit: How the hell did I resurrect a thread from a month ago when it was on the front page?

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