V6 vs V8

-
318willrun

318willrun

Utube channel 318willrun
FABO Gold Member
Joined
Sep 13, 2013
Messages
22,005
Reaction score
29,088
Location
I'm here
Just going to throw a thought out there...... Why do we see more and more V6's in modern day cars pushing 285-320 net horsepower without boost, and most of these are 3.6L or smaller, and yet to get 350-375 gross horsepower out of a 318, or even a 360, we have to accept the rough idle cams that only work well with steeper gears and 3000 stall converters? There are a lot of cubic inches in difference, and we have the ability to get great street heads, compression, and anything else that may be the influence factor on the new V6 performance. So why shouldn't it be average thought to grab a 318 and say I want 350 hp, smooth as glass idle, 2000 stall, and no long tube headers? And have a set up like this work 100%? Just asking? I mean, you would be working with about a 100 more cubic inches, isn't that HUGE??? your opinions please........
 
Not to hijack...but seeing this reminded me of a claim I saw years ago....that "v" engines are inherently more torquey than inlines.....any documented proof? Sorry for the hijack, now back to your regularly scheduled programming....
 
inkjunkie said:
Not to hijack...but seeing this reminded me of a claim I saw years ago....that "v" engines are inherently more torquey than inlines.....any documented proof? Sorry for the hijack, now back to your regularly scheduled programming....
Click to expand...

I've always heard the opposite... Idk?
 
Probably a few little items like DOHC, 4 valves per cylinder, variable valve timing, EFI, variable intake volume, and let's not forget computer control to make it all work...
 
The internal combustion engine has been around for more than 100 years. Why it's still here is anybody's guess. Big oil conspiracy? Lack of technology to move on? Pick one. The reason is irrelevant, really.

More than 100 years though, is a long time to improve on the basic design. From the block down is really pretty much unchanged, except for things like durability, better operating angles and such.

Where the real progress has happened is in the cylinder head and induction department. From flatheads to overhead valves, to overhead camshafts, to multiple overhead camshafts and more than two valves per cylinder.

Throw in all of the electronic advancements such as the modern ECM and EFI and it's easy to see how it's accomplished. I would love to see someone do a 440 in a modern EFI package just like the factory might have done it. EFI can calm a rowdy camshaft right on down.

I remember when I worked for the local Chevy dealer, I was at the GM training center in Atlanta for a drivability course. The instructor had a pretty basic GM 5.7 on a run stand. Basic except that it had no camshaft. The valves were operated by electronic solenoids tied into the EFI system. He could program them just like changing a camshaft. One minute it had a smooth stock idle the next he could reprogram it to sound like a top fueler. Really interesting stuff.

EFI can calm a rowdy camshaft right on down
 
RustyRatRod said:
except that it had no camshaft. The valves were operated by electronic solenoids tied into the EFI system.
Click to expand...
I still don't understand with all the advancements we've made, we are "still using cams." Of course there IS VVT

Even THAT is not "new." I can remember someone --aftermarket performance parts-- was making a centrifugal based cam drive in the ? 60s ? which never really went anywhere.
 
grumpuscreature said:
Probably a few little items like DOHC, 4 valves per cylinder, variable valve timing, EFI, variable intake volume, and let's not forget computer control to make it all work...
Click to expand...

Ding Ding!! Winner. My 5.7 hemi does almost exactly as you say, idles smooth, runs great, lots of power and hopefully some economy too. The base of the 318/360 is still "old technology" so although there are great parts avail these days for power/performance and driveability we are still adapting these parts to a much older product, and topping it off with a very low tech distributor and carb...

JOE
 
inkjunkie said:
Not to hijack...but seeing this reminded me of a claim I saw years ago....that "v" engines are inherently more torquey than inlines.....any documented proof? Sorry for the hijack, now back to your regularly scheduled programming....
Click to expand...

Inlines are actually more torquey.

That's why the old Mopar Flathead 6 was so popular and was produced all the way into the late 1970's (even after it had been replaced the Poly/LA/B/RB/Hemi/Slant 6). They only produced between 80 and 200hp at 3,600 RPM... Yet at the same time they produced their max torque (numbers varied greatly depending on engine size/application) at 1,600 RPM. YES 1,600 RPM, that's roughly 400 - 600 rpm above idle.

That's diesel type torque (in terms of rpm) out of an engine design that is 80+ years old. And is the reason they were still manufactured into the 70's for Industrial Applications.
 
67Dart273 said:
I still don't understand with all the advancements we've made, we are "still using cams."
Click to expand...
Last I read, a few years ago, the solenoids to actuate an all-electric valve train were not durable enough to live long in the harsh environment inside an engine. It sounded like they could be made, but were so expensive that they were just not going to go into production. Nobody was going to pay the price.
 
Knock sensing allows various fuels to be used and keeps ignition advance at optimum regardless of engine operating situation.

RE: In-line engine torque. IMO there is a relationship between the length of the connecting rod and torque potential. The torque-ier engines tend to have long con rods.
 
I get that VVT is a plus. I don't think the heads on most V6's outflow magnum heads with a mild port job. I also don't think EFI is a huge performance enhancer. If so, most 8, 9, and 10 second cars would be running EFI and I don't think it's money either, not when a lot of these cars have 20k in them. I found when I lived in the high altitude, FI cars did not fair in performance as well as carbs. Better valve timing VVT and computer controlled ignition timing would be a plus. However, you are trying to make up the difference of approx 100 cubic inches. I just find the thought interesting....
 
Don't forget about the tuned intake manifolds on the new engines. Even though some of the old engines used these as well, think the Chrysler 413 with the long crossram intake manifolds.
 
The exhaust manifolds flow way better than 1960's pieces. Who wouldn't love to have a cast iron exhaust manifold that fit an A body and flowed almost like a set of headers.
 
We do not have to have a ruff idle cam. Have it ground on a 112 or smother 114.

To get a 318 to 400 HP is a snap. It's just most peoeple will point to a magazine article where they use a certain parts list and that becomes the bassis on which everyone assumes is needed for the task at hand. And while there is a certain amount of truth to it, it is only because of the parts used. Basically, it is the cheapest way to do it with the results, AKA, choppy idle that 99% of the people want, that have the engine/car acting the way it does.

Now getting it done cheap is what everyone jumps up and down about and if you don't, Then you get ridiculous taunts. So to avoid them and feeling foolish, you copy the magazine build.

Next time you (actually anybody) tries a build, and cheap is not the motto to follow, spend money on the heads for superior flow and choose a split duration roller cam on a 112 or 114 for that smooth idle and add a nice F.I. System. Then spend again on a quality torque converter in a overdrive trans, not the OE 3spd.

Do note the modern engines use very small roller cams with heads that seriously flow some air. Take a good look at how Detroit is getting it done. Then copy as best as you can.

The modern machines have a lot of advantages over the old ones designed in the late 50's. You can incorporate many of the modern systems but not all of them. You can still do a danm good job at it. It'll just cost you 2-3 or maybe even 4X's times the money.

Then You'll have to live with some jass hole yanking your chain about spending 3X's the amount for a cam only when his Summit cam was only $79.
 
VVT allows for higher compression ratio's to be used in conjunction with EFI and the ability for a feed back system to control spark timing and cam timing you can do wonderful things. Add refinements to EGR (i.e. rebreath, a befit added by VVT), computer flow analysis of combustion dynamics, Port flow, and direct injection.

Advancements in technology make it better but also make it more complicated and more complicated to modify.
 
JGC403 said:
Don't forget about the tuned intake manifolds on the new engines. Even though some of the old engines used these as well, think the Chrysler 413 with the long crossram intake manifolds.
Click to expand...
Very true, the intake is where it all comes in....
 
bobscuda67 said:
The exhaust manifolds flow way better than 1960's pieces. Who wouldn't love to have a cast iron exhaust manifold that fit an A body and flowed almost like a set of headers.
Click to expand...
Much agreed! If you bring it in, it must go out!
 
Rumblefish360, much truth on the technology in the cam. I also agree with you, that the cam of equal function can be installed in a 318/360...... but it will cost $$$$.
 
dano said:
VVT allows for higher compression ratio's to be used in conjunction with EFI and the ability for a feed back system to control spark timing and cam timing you can do wonderful things. Add refinements to EGR (i.e. rebreath, a befit added by VVT), computer flow analysis of combustion dynamics, Port flow, and direct injection. Advancements in technology make it better but also make it more complicated and more complicated to modify.
Click to expand...
Yep, it all plays a roll! (and more complicated it is). I think the 318/360 magnums could have "yet again" been reworked! When they went from the LA to the magnum, they gained about 50 ponies. I think with some of the "mentioned above" topics, I think we could have easily seen the 5.9 go from, lets say, a magnum to a super commando. I think they could have redone the heads, cam, intake, add VVT, PCM enhancements, and pulled 450 ponies, and perhaps the 5.7 hemi would have never been needed.... then we would have really had some bolt-ons for our classic cars... not that I mind the Hemi, but.... just a thought....
 
That is true. They just didn't want to push the old engine into today's standards. To match the HEMI's double quench is one thing you can do buy a new head casting. The double plug could prove troublesome in a LA. I don't think the factory wanted any part of that.

The way Chrysler does the VVT would also require a new block casting to the LA block.
 
318willrun said:
Yep, it all plays a roll! (and more complicated it is). I think the 318/360 magnums could have "yet again" been reworked! When they went from the LA to the magnum, they gained about 50 ponies. I think with some of the "mentioned above" topics, I think we could have easily seen the 5.9 go from, lets say, a magnum to a super commando. I think they could have redone the heads, cam, intake, add VVT, PCM enhancements, and pulled 450 ponies, and perhaps the 5.7 hemi would have never been needed.... then we would have really had some bolt-ons for our classic cars... not that I mind the Hemi, but.... just a thought....
Click to expand...

I kinda disagree, there's a good reason almost nobody makes a modern engine with wedge chambers and 2-valve heads except for GM and we all know how resistant that company is to trying new ideas. There's so much more potential for overall efficiency in the design of the new Hemis. Like rumblefish said the way to go for OEMs is to use short-duration roller cams with good lift and heavily R&D'd computer-designed ports that flow massive amounts of air even at low valve lifts. That's why a new Hemi will gain 100+ HP with just a cam swap. Combustion efficiency has also improved that's why you now see factory 10.5:1 engines that are made to run on regular or mid-grade gas.

Remember the LA was designed as a quick & dirty lightweight replacement for the poly engines back in 1964. 50 years is an eternity when you're talking about technological advances. BTW of all the new tech features mentioned in this thread 4-valve heads are BY FAR the most significant efficiency improvement over the years. VVT, variable intakes etc. are secondary they actually don't do a whole lot on their own.
 
It all comes down to head flow (remember 6 cyl needs 33% more air flow per port than an 8 cause of 2 less ports to make same power). Take the new Hemi from the flow numbers I've seen 5.7 flow about the same as a stock W2 and 6.1 as ported ones. The 5.7 hemi is basically a 318 with a 360 crank and W2 heads it wouldn't take too much duraration to build big hp numbers. We tend to under heads our engines, take a 340, X heads probably flow enough for 440 hp unported but you would need a lot of Cam and Compression even stock 318 heads probably could do 350 plus but they wouldn't be very streetable, pure race only.
 
318willrun said:
I get that VVT is a plus. I don't think the heads on most V6's outflow magnum heads with a mild port job. I also don't think EFI is a huge performance enhancer. If so, most 8, 9, and 10 second cars would be running EFI and I don't think it's money either, not when a lot of these cars have 20k in them. I found when I lived in the high altitude, FI cars did not fair in performance as well as carbs. Better valve timing VVT and computer controlled ignition timing would be a plus. However, you are trying to make up the difference of approx 100 cubic inches. I just find the thought interesting....
Click to expand...

With EFI it's all about the tuning, (and so any advances have been made in aftermarket EFI in the last 5 yrs more racers are using it, and will continue to switch) Typically aftermarket EFU systems haven't adjusted well to altitude or barometric changes, but many systems now operate just as well as factory EFI at elevation.

Also remember the 9 sec and 10 sec cars you talk about are mostly tuned with wide-band O2 for optimal performance. And yes a carb will easily keep up with a EFI system for WOT pulls if both are tuned appropriately, (which is all a drag car truly does). But change variables or conditions (like idle, gear, load, altitude, or temp and a EFI system can more accurately provide fuel and correction with those changes. Especially a EFI system that has spark control with a knock sensor as mentioned.

That is exactly why the "v6" you refer too has the power of the 318 and all the other great characteristics you desire.
 
You must log in or register to reply here.
-

Back
Top