Louie83

iTrader: (3)

And it's bigger and heavier than an LS2 or LS7.

engineermike

Hey guys! I finally caught on to black_knight's posts! If, "Higher HP from constant displacement takes L out of the equation. HP/L without changing L just equals HP."

Based on that, PSI is not a valid unit of measure. I mean, higher force (lbs) from a constant area takes in^2 out of the equation! PSI without changing in^2 just equals lbs! I can't wait to go to work tomorrow so I can tell all the other engineers that they shouldn't be using PSI in their calculations!

"How much tire pressure do you want?" Oh, I dunno, about 70,000 lb.
"What was the compression in that motor?" I got 1900 lb based on piston area.
"How much boost are you running?" Crap, this is going to get complicated.

I think it's funny how all the engineering and driveline development-types see the value in the metric "hp/liter", but black_knight and a couple other die-hard GM guys don't...

I never really thought about this, but I own a Chevy (turbo 388 Z28), Ford (Lightning with "gasp" a missed-the-boat mod motor), a Kawasaki (ZX-10R), Yamaha's (YZ250 and IT175), a Honda (MB5), and a Sea-Doo (RXP). The only one with pushrods is the Chevy. I guess ALL the others (which were ALL designed for high performance) got it way wrong according to some of you.

I agree with DanO. I'm glad you guys aren't in engine development (like him).

Mike

FieroZ34

iTrader: (1)

But obviously the 4.6 was good enough that they still sold, quite well in fact, quite better than your Godly equipped F-body's.

And just the other day I got my *** royally handed to me by a 4.6l Mustang. And this wasn't in my V6 that nobody cares about, this was in my 12.8 second SS Camaro. And he didn't just walk me, we started at 4,000 in 2nd, and by my shift to 3rd, I couldn't even hear him anymore. And that car was f*cking loud. He raped me. Rolled to a gas station, his mod list was cut outs, a smaller pulley, and a tune. He ran an 11.2. Show me an LS1 that will pull an 11.8 with under $1000 in mods, in a heavier car.

Correct me if I'm wrong, but didn't the 3.8 Camaro's outsell the V8s as well? If the LS1 was so cheap to produce, and such a goldmine for GM, you'd think it'd keep selling. Nope, cut after 4 years. ****, my DOHC Lumina lasted longer than that!

Louie83

iTrader: (3)

You didn't lose because you have a pushrod engine. You lost because he is supercharged.

FieroZ34

iTrader: (1)

However if I had a DOHC engine, whose heads could actually flow, I could use my extra 1.1l to an exponentially greater proportion, and he would've gotten his *** beat.

Explain to me why my 3.4l DOHC, when it wasn't turbocharged, could beat a 3.8l supercharged. It's got a half liter of displacement less, and doesn't have 10psi force feeding it. Because my heads don't suck, that's why. But it's a good thing he had so much low end torque, even though my 60' was still 2 tenths faster.

Louie83

iTrader: (3)

If you had a 5.7L DOHC engine, it would be sticking out of your hood.

Look idiot, people like Engineering Mike and Dano can see that OHC and OHV engines both have their uses in various situations. You on the other hand, can see nothing but HP/L. HP/L is important in performance engines, but so is size, weight, and cost.

If I could fit a 7L DOHC engine with 5 valves per head, and have it be the size and cost of a 7L OHV engine, I would. Something you don't understand is that there are trade-offs that engineering teams have to take into consideration.

Someone could use your same argument and say they beat a Cobra with their LS7 engine they put in an F-body. The LS7 weighs less and is smaller and does not have a supercharger, and it STILL makes more power. We could go in circles like this forever, but the point is that you did not lose because the Cobra is DOHC.

To everyone: Picking random examples and comparing them based on whatever criteria benefits you most is a pointless exercise that can go on forever.

78novacaine

iTrader: (2)

apples to monkeys comparison

FieroZ34

iTrader: (1)

How come my 3.4 DOHC engine doesn't stick out of my decklid? In fact, using the exact same engine mounts as the stock 2.8, the highest point of the engine only sits 3/8" higher than that of the 2.8l OHV engine. So I gained 100+hp, lost 40lbs, and the engine is not any higher. Why can't the same be done on an LS1?

But I can't? I drive and enjoy pushrod engines (3), on a daily basis, and as a matter of fact, drive them much more frequently than my DOHC. Maybe you should try reading before making ignorant remarks.

I went from a 2.8l OHV, which was already tight in the engine bay, to a 3.4l DOHC, with a turbocharger and air:water intercooler. The space is there, it just takes some good engineering to make it work.

But my car doesn't have an LS7, nor was it offered with one. In fact, an LS7 engine costs more than my entire car did.

Louie83

iTrader: (3)

I have no idea about either engine, but it sounds like you picked a good one. I don't care about random examples of specific engines. I do not have a problem with OHC at all.

You drive them daily and bash them hourly.

I don't care about your car. The point being made is that OHV's are in general more compact and lighter. That is their main advantage and why engineers use them.

Are you dense? You were comparing the supercharged 4.6 to a NA 5.7 LS1. We aren't arguing Firebirds and Mustangs, we are arguing about DOHC and OHV. The point is, if you are going to be dumb enough to say DOHC is better because a 4.6 supercharged DOHC engine makes more power than a NA 5.7 engine, then I'll bring up the fact that the LS7 is smaller, lighter, and makes more power than the supercharged 4.6.

So stop doing this:
The reason why I am picking on you and not Engineering MIke is because you bash LSx engines, anything OHV, and GM (well, maybe they deserve it). HP/L is important, but from every single post you have made in this thread, it seems to be your only criteria to base engines on.

All I want is for you to see that OHV's can be impressive from a performance standpoint just like DOHC's. OHC's have benefits and OHV's have benefits. If this were not true, then engineering teams would not use both designs.

Please read this: http://www.cheersandgears.com/forum...topic=15551&hl=

dakkrin

technically you can put 35000 psi in 2 in^2 which would be 70000 lbs
or 10000 psi in 7 in^2 which would be 70000 lbs

just saying

black_knight

iTrader: (1)

I don't disagree with anything that you said. So I must be coming across wrong. I qualified my statements, and the contexts they were meant to apply to, but that was like a bazillion pages ago and of course I am being slandered left and right by Mike so I could see that it might get lost in the wall of noise.

Don't worry Dan; I know those things.

black_knight

iTrader: (1)

Exactly correct!

black_knight

iTrader: (1)

For the exact reasons that Krom listed. Nothing to do with the engine.

Pulley? Oh, so you left out the detail that it's a Terminator. Where we were talking about contemporaries of the LS1 and LT1. What exactly are you trying to pull?

black_knight

iTrader: (1)

How's that? I said that since you are talking about increasing "hp/L" without changing L, then you are simply increasing HP. The "per liter" thing is totally redundant in that phrase. Null value.

engineermike

. . . and by that line of thinking, if you are talking about increasing "pounds per square inch" without changing "square inches", then you are simply increasing "pounds". The "per square inch" thing is totally redundant in that phrase. Therefore, "PSI" is a null value and just ricer math.

Also, look up the definition of "slander".

Mike

black_knight

iTrader: (1)

Well, I'm not talking about pounds per square inch.

/smartass answer

Fact is, you're playing word games. Dishonest ones.

DanO

I dont know.. but im a moron..

germeezy1

I was done but I still can't believe someone would compare a basically one off engine that came in one obscure limited production car in the US to the LS1. The 5.4 DOHC N/A made less hp than the LS6 and thats with a parts list of internals that reads like the who is who of engines.

This is not about displacement...vs displacement...I know that DOHC heads flow better and make more hp per liter usually. If GM can fit 5.7 liters into a package well under the size and weight of a 4.6 liter that sounds like great engineering and its ridiculous to knock the LS1 because of that.

As I have said before my C5 is the first pushrod car I have owned in a long time, I actually bought my Cobra because of the 32V engine and have owned many N* Cadillacs (love that engine!) My hats off to GM for evolving the pushrod motor into something that has no problem revving as high and a much better powerband in a smaller space than most DOHC engines.

Why not have your cake and eat it too? My dream engine would combine big cubes and high revs and two power adders! Mercedes has always done a good job at there OHC engines and they are not afraid of displacement. There is something to be said for the feel of a car with a good powerband.

germeezy1

With new technologies such as VVT for OHV its only a matter of time and development before most of the trade offs for OHV are eliminated. For those of you that forget...pushrod engines do high revs and peaky powerbands too.

mzoomora

iTrader: (36)

What kind of car are we talking about here? A heavy FWD Grand Prix? Regal? Monte Carlo? Park Avenue? There are other things to consider, like mods, weight, driver, tires, etc.

Also keep in mind that the 2.8 you are talking about is rather large for its displacement. So much so that they ended up being 3.1 and then 3.4, so in essence you put a 3.4 where a 3.4 could have been.

How much wider was your 3.4?