Bench Life of different car engines available?

When did i say anything about quarter mile times of the 3800 V6? whoops, i misread. Examples?

The biggest thing i can think of without knowing the cars you’re talking about is gearing and driver skill. Either can make a huge difference. And are we talking about quarter mile times or track times or what?

And yes, 450HP out of an 8.0litre V-10 is sad. An engine that size should make much more horsepower.

Agreed, area under the curve is THE most important thing. But there’s 2 ways to look at area, by increasing the y value (increasing torque and HP) or increasing the x value (making power available across a greater rev range, or some combination of both.

That’s another advantage of DOHC engines, they can spin much higher. Even in Nascar, they can only go to 9000RPM (elite pushrod engines), which some production cars can do. Compare to F1 or Cart (elite DOHC engines), where they can spin to 16000RPM :eek: Obviously the cart engine will have much more area under the curve because it revs almost 2x higher.

NASCAR engines are often limited to extremely small a 4v carb

And yeah it smacks them on the track! less rated HP in a heavier car but still quicker 1/4 mile times. Even with some mods on the imports!

There are some fast imports, but they usually have tens of thousands of dollars in mods.

1/4 mile gives a good idea of real power based on weight and MPH

What imports are you talking about man? I still don’t know what cars you’re talking about! How can I answer?!?!

i wish we could edit.

I’ve nemed amny engines that are smaller, naturally aspirated, yet make the same or more HP than the supercharged 3800.

I’ve named several engines that also have forced induction, but are still smaller, and they make from 60-80 MORE horsepower than the SC 3800 V6.

I’ve named many engines that are significantly (47%) smaller, yet make almost the same HP, and in one case more.

re:9000RPM and 16000RPM

pushrods are limited to about 9000RPM because of their valvetrain. Even the first engine i built (a 4a-ge) could spin to 10000RPM (did it by accident, but took it to 9000 regularly).

something clever-I’m surprised that you can talk about the Supra using nitrous and racing gas, but in your next point you hold up Top fuel drag cars as an example of good pushrod motors. It’s just funny in an ironic way.

about point 3. If pushrods make the most power, why don’ we see them in Cart? F1? IRL? Le Mans? WRC? In any racing series that doesn’t mandate them? I did ask first after all.

Again, IANARacing geek, but i think either the rules in nascar mandate against DOHC motors, that or else no one has tried to run one yet. Situation one-when/if DOHC cars are allowed to race in Nascar, within 5 years (giving myself some room here) all the competitive teams will be using them. Situation 2-once a team starts winning with a DOHC engine, within 5 years they will dominate and all teams will use them.

B&I-again, i wish we could edit, I’ve given you many examples of engines that i think smack the 3800 around, you have only given your own assertions that the 3800 is better. Please give me some examples.

I didn’t even touch the N/A performance of the 3800, that would be way too easy.

B&I-again, i wish we could edit, I’ve given you many examples of engines that i think smack the 3800 around, you have only given your own assertions that the 3800 is better. Please give me some examples.

I didn’t even touch the N/A performance of the 3800, that would be way too easy.

And the pushrod dominance in Top Fuel isn’t indicative of overall engine performance. It’s such a limited style of racing, it would be like saying “a is a much better basketball player than b because he can jump 4 inches higher.” What about all the other aspects of engine performance (like being able to last for more than a quarter mile race :o )

The reason NASCAR engines don’t rev as high as F1 or CART engines is because they have a longer stroke. The piston speeds are much higher in the NASCAR engine because it has farther to travel for each turn of the crank.

Also, for production cars that don’t have a displacement limit like F1 cars do, power/displacement doesn’t mean a thing. What matters is power/weight. For that reason, plus the tuning of the engines (A 300ZX is a sports car, tuned for all out performance, whereas a Pontiac with a 3.8L is tuned more for making your commute.

Area under the torque curve? maybe. I like to think about it in terms of “average horsepower” during the run. When you shift into 2nd, your RPM’s better not drop into a low HP rating for a second or else your average HP will drop, and your time will increase. Same thing pretty much.

Making power across a greater rev range? My Suzuki GSX-R has a smaller rear sprocket, so 1st gear goes all the way to 59mph. THis causes terrible low RPM power, but you know what? That doesn’t really matter because when i am taking off, the bike never sees those low RPM’s because i rev it to 7 or 8k and clutch it off the line. THen the gears are so close together, it never ends up connecting at lower than 8 or 9k. So, in my case, the power is across a very small rev range, but doesn’t really hurt the time because my bike has a great clutch and is geared correctly (and because it has a good rider).

The 2003 Viper has 500 HP from 8.3l… that’s a little better than 450 from 8.0l. THe reason it has such weak numbers is compression ratio is relatively low, 9.6:1. Speaking of comp…

THe honda S2k has 11:1 Compression Ratio, that’s another reason it has so much power besides just timing. (Torque=compression*Displacement, right?)

about 30 points or so

in 1987 the turbo 3.8l v6 was rated 245hp and 355ft-lb tq

it put that much to the wheels. in 1989 the same motor was rated 250hp and 360ft-lb tq… it put about 305 to the wheels. the 1989 turbo trans am was the fastest (still is) trans am ever made… and it was a 3.8l v6. busch grand national race cars back in the 80s made ~600hp out of a naturally aspirated 3.8l v6.

the reason they dont do it today? no one wants that! its adequate as it is… hell a stock v6 camaro is still faster than a stock civic SI (any of them) and a camaro weighs a hell of a lot more…

how many people will change the pulley on a sc 3.8? probably more than can afford a 75,000$ luxury car…

almost every newer pushrod motor has a roller valvetrain. its no big deal. and its definitely more complicated, have you seen the head on a dohc v8 compared to the heads on a pushrod v8? they are massive.

i never said vvt was a bad thing.
gm designs new engines that are pushrod, because theres nothing wrong with them. two cams for more valves to improve airflow, not because four cams are better.

um actually people race tractor trailer trucks that are diesels. rpm doesnt matter if you have low rear end gears… big blocks dont usually turn high rpms but they dont need to… dont put a 4.10 gear in one and you’ll be fine… keep it numerically low and you’ll keep the rpms down and therefore keep it near the power band.
you keep comparing the very economical 3800 to expensive as hell motors. you keep saying OH BUT NO ONE WOULD DO THAT YOU HAVE TO COMPARE STOCK TO STOCK. well guess what when you have a sports car you do all the little things from the factory that aftermarket people would do. gm cant port and polish, mill the heads and up the compression ratio, then tell everyone use premium gas or you’ll blow it up, etc for every single 3800. they make too many.

top fuel engines dont last very long because they burn nitromethane. i dont think you realize how explosive it is. if they ran gasoline they would last much longer however they wouldnt make 8000hp. also… if you were to try to idle your engine on nitro, you would crack the block.

you compare apples to oranges.

the 3800 v6 to a bmw motor… okay how about the 3.8l v6 in MY car…? i run 23psi of boost on pump gas. how about that? 8.0:1 compression and the car makes about 300hp at the wheels at around 4500rpm, torque output is around 450 at around 2400rpm. how about that? is that good enough for you? oh yeah its got 135,000 miles on it tooo… and it gets 26mpg on the freaking highway, with a 4 speed transmission and a 2800 stall converter.

oh yeah and its pretty much stock, nearly anyone can do this to their turbo 3.8, and most do way way more.

if youre gonna compare a freaking race car, compare a race car. i have an article posted in turbo magazine comparing your beloved mclaren to … dumpa dumm… a stage II turbo v6 buick built for the silver state classic… its a high speed run… the car puts out 967hp and has a top speed of about 244mph or so, it outdoes the mclaren in every aspect including handling (about 1.2g on good tires)…

im going to sleep but i cant wait to hear what you have to say :slight_smile:

[rant]OMG, this so frustrating. It’s not even that we’re arguing in circles, we’re not. And it’s not even the fact that my points are being ignored that bothers me. What bothers me is people putting words into my mouth, and raising ridiculous and ludicrous arguments.

When did I compare the 3800 to a $75000 luxury car engine? Did the Accord, 350Z and BMW 3 series triple in price on me? When did I compare the 3800 V6 to a race car engine? Did the Accord and the 3 series change from family sedans to race cars overnight? The closest thing to a race car I compared it to is the VQ engine in the 350Z. Never mind the fact that the VQ is available in the Altima, yet another inexpensive family sedan. Never mind that I’m GIVING the advantage to the 3800 by comparing a forced induction motor to naturally aspirated ones.

If you’re talking about the Supra and the 300ZX, then fine, I guess those are “race cars.” Unfortunately, there are no other forced induction 6 cylinders I can think of. I guess it’s okay to give the advantage to the 3.8L, but as soon as I compare forced induction engines to forced induction engines it’s unfair.

People say I’m comparing apples to oranges, and they’re right. I’m comparing supercharged 3.8L to naturally aspirated engines. Funny thing is, the DOHC N/A engines still win, even though they don’t have the advantage of forced induction. When compared to other forced induction motors, the SC 3.8 gets slaughtered, but for some reason that’s unfair. And apples to oranges? A camaro and a Civic are about as different as they get. Ironic humour.

Since when is a tractor a race car? Just because people race it doesn’t make it a race car. Next thing you know, someone will call a lawnmower a race car because after all, there are people that race them. And somehow I’m supposed to be surprised that a car with 300 more HP has a higher top speed? Somehow a Buick GN out-handling a McLaren F1 means the 3.8L is a better engine? Somehow saying it IN ALL CAPS LIKE THIS makes it true?

You talk about your car, but when did I say that they weren’t moddable? Several posts ago I said that pushrods were more easily modified for the dollar. You use the word “economical” to describe the 3800 V6. I said the exact same thing, except I chose the word “cheap.” You say “the 3.8L can do this, can do that,” but I never said it couldn’t. I said a modern engine can do it better. The way my words are getting twisted is absolutely ridiculous.

You yourself realize that Top Fuel drag engines have nothing to do with anything remotely resembling a production car engine, but this is one of your 2(!) examples of a good pushrod engine. Again, funny in an ironic way.

And I just realized last night B&I, that I’m talking about engines, not cars. I just listed something like 3 import engines that either produce the same or slightly more horsepower, without forced induction and with smaller displacement. I listed a couple of import engines that make significantly more horsepower with forced induction, and smaller displacement. I listed 4 import engines that make nearly the same amount of horsepower with 40 fricken 7 percent less displacement. What’s the reply? “Well imports always lose on the track.” Well dear, we have nothing but your word. Besides, it’s not the engine that loses, it’s the car. You said that the 3800 smacks around import engines. Engines is the key word. Off the top of my head I listed 9 import engines that smack around the 3800. With some actual thought I could probably name 9 more. I’d ask you to tell me what engines the 3800 is better than but I suspect that there would be no worthwhile reply. There hasn’t been one yet. [/rant]

My only point, which I’ve brought up numerous times but which nobody is addressing is this:

For any two engines of the same displacement, the DOHC engine will produce more power and likely be more fuel efficient. For any two engines of the same power levels, the DOHC motor will have less displacement and likely be more fuel efficient.

You talk about 300 HP to the ground, that’s great. But there are plenty of guys doing that with two litre four cylinders. Again, my point holds true, for a given power level, a modern engine will need less displacement. I’ve given nine examples of this. No one has challenged it. No one can because it’s true. Name a pushrod engine in a current production car, and I’ll give at* least *2 examples of current production DOHC engines that either make more power with the same or even less displacement or else make the same power with less displacement.

What import engines does the 3.8L smack? I ask, but no one answers. Besides cost, what is the advantage of a pushrod engine? I ask, but no one answers. If it offers better or equal performance for less cost, why is the pushrod engine nearly obsolete as a production car engine? I ask, but no one answers.

Instead of being given reasons why a pushrod is better, I’m getting nitpicked. Instead of serious replies, I get tractor racing (tractor racing! The mind boggles!). Instead of actual facts, I get personal assertions. I say an engine is old, i get told about the great things it did 10-20 years ago. I say DOHC engines are more expensive, i get told that they’re expensive as hell.

<sigh> I don’t know whether to :rofl: or :cry:

and the link to the xv8 doesn’t work BTW.

I got my figure from here. I guess I shouldn’t believe the first thing I read on teh intraweb! :stuck_out_tongue:

The short answer is yes on the compression part. On the timing part, it’s not the timing really, it’s the cams.

no, torque has to do with twisting power. In engine applications, it’s a mathematical truth that hp=(torqueRPM)/5252. re-arranging that, torque=(HP5252)/RPM

On chassis dynos, the first formula is the one they use to calculate HP. They actually measure torque and extrapolate the HP from there. I don’t know if that means anything to you.

As a measure of efficiency it does mean something. HP/L for an engine is like shooting percentage for a basketball player. If there 2 players (say shooting guards) who both score 30 points per game, who is more impressive, the player that shoots 25% from the field or the one that shoots 45%? 30 points is nothing, anybody can score 30 points if they take enough shots. It’s the same thing for engines. A 287 HP naturally aspirated 3.5 litre engine is more impressive than a 240HP supercharged 3.8 litre. It’s smaller and doesn’t have a power adder, but it still makes more power. Anybody can make 240HP if the engines big enough and you add a supercharger to it. It’s not the horsepower that impresses me, it’s how they get their horses.

OK, who wants to help a Mod out and explain precisely what the remaining General Question(s) is/are?

Umm, yeah. I don’t even remember what the OP was :o

Apologies to fuel for participating in the total and complete hijack of the thread.

Pure: everyone knows that HP=Torque*RPM/5252. What i was saying is that the Torque variable is calculated by measuring the displacement and compression of the engine and multiplying them, (not sure on the units of measurement though).

Think about it guy. What you said is mathematically and logically ridiculous. You can’t get the torque of an engine from it’s horsepower and RPM and constant! There is a formula within a formula here. Although, I am not 100% sure about my disp.*comp=torque, it was something i vaguely remembered and seems logical…

The prevailing question still stands for anyone who knows: Any bench test results out there in the open for any car/truck engine?

TO be more specific, dispcomp6+mods=torque. That’s a really crude formula that i came upwith a while ago for normal units. Camshaft and timing are afterthoughts compared to these variables.

Fuel: Sorry man, I misunderstood your meaning. If that’s what you meant by formula to arrive at torque, then I can’t help. That formula (AFAIK) is only good for any specific point. Cars are only my hobby, and I’m no physicist either.

AAANY-WAYS, <trying to redeem myself for the hijacking here> no, I don’t know of any bench test results of automotive engines.

I’ll just echo what someone else said and say that I’d be surprised if they didn’t exist somewhere, but they’re probably guarded secrets. No manufacturer would want it to become public knowledge that their engine won’t last as long as a competitors.

I’ve not heard of any, but you might want to talk to the oldest mechanics still working that you can find. One I knew told me that back in the 60s there was a slant six Mopar engine that he noticed rarely ever came in for repairs, so he sat down and started going through the records to see what the numbers were. He could still remember the exact figures when he told me, but I’ve since forgotten them, but it was a ludicrously low number in comparison to all the other engines that they worked on. You might get lucky and find someone who’s done similar research at their shop, or you could just go around at various shops and ask their opinions on the matter to see if you get a consensious on the engines. Not terribly scientific, but better than nothing, I suppose.

Pure, I wrote a nice reply but it never made it to the MB.

I have not read any replies since a day or two ago. I’ll get back when I have more time but the jest of it was

When I see the imports come to the line at the track that are considered so hot I watch them run. Various Acura’s, Honda’s, Toyota’s, Nissan’s, BMW’s, and the WRX’s that only run, like the others, a mid 15 second 1/4 mile. AND most of these cars have mods! I have seen one Supra and one 300Z run fast - both h-i-g-h dollar modded cars.

Bone stock 3800 II N/A cars are running 16’s. All I am saying is that when one considers modifications and the fact that these 3800 cars are 3,900 #'s!!! I find it hard to accept the awesome reputation of most of the imports.

Also, if we are to include modified cars, the old 3.8 turbo cars smack the hell out of the imports.

Cite? To hell with your cite - I actually go and race at the track and I know what I see. When tracks like MIR sponsor events like WWIII, import vs domestic, one has the opportunity to watch hundreds of imports race - the pushrod engines, for some reason, WIN!

I know that the OHC engines have more potential, great hemi style heads etc, but for some reason, they don’t seem to be realizing that theoretical potential for the most part.

My appoligies. Me and others have turned this in to a GD thread.

Knowledge is good.