BEAR-AvHistory

Yeah thats true but what do you want from a truck engine? Toyota seems to be down on power with their DOHC engines. The LFA Super Car has only 553BHP out of a 4.8L engine.

Have a great idea they already have an engine deal with BMW for some DOHC engine cars so why not extend it & get the 5 series 4.4L (268 CI) V8 @ 617bhp DOHC engine? Cut 400CC (25CI), 2 cylinders & add 64BHP. Then order a BMS JB 4 & get 694WHP & 693FT LBS for $900. At the crank with a 15% loss factor thats 798BHP. Enough to drive a 4370lb 4 door luxury sedan with finger tip shifting to a no muss no fuss at 10.3 seconds @ 136mph 1/4 mile

If you look close you can see the C7 in the outside rear view mirror.


Car & Driver 2018 M5 pure stock road test summery
It harasses supercars with its 2.8-second rip to 60 mph. At 10.9 seconds and 129 mph in the quarter-mile, the 4288-pound M5 is only one-tenth of a second slower than the half-a-million-dollar Ford GT.

jefnvk

But what specifically about higher RPM = better?

If I can get the HP and torque out of lower RPM, why do I need to wind the engine up?

BEAR-AvHistory

Urban legend. For street occasional fun car there is zero reason to wind the car up. As technology moves forward there are always people who bitch its human nature for people who are comfortable with what is now. Power steering was going to kill people because it was to easy to turn, Power brakes have no feel. A/C is unnecessary just open the window, computers in cars are too complicated & on & on since cars were invented remember, "Just Get A Horse".

M5 Stock Rated power 600BHP @ 5700RPM Torque 553FT LBS from 1800 to 5700RPM
M5 JB4 Rated power 694WHP @ 5590RPM Torque 693FT LBS @ 4,820RPM almost flat from 3,000RPM to 5000RPM 500ftlbs @ 2000RPM

Transparency item. Beta tested JB4 & COBB units for the 335IS 3.0T 7DCT coupe series back when I have the 2011.





Still have a JB4 on one of my cars the other has the factory MPPSK tune as did the one that replaced the 2011 car.

jefnvk

Doesn't that bolster my argument? Why is more RPMs a good thing in and of itself if you have a engine that can deliver the same power lower?

BEAR-AvHistory

Yes you are correct the 4.4L DOHC Turbo M5's lower RPM maximum output looks good against the 6.1L 2V Supercharged Z06.

The M5 JB4 is delivering 694 horsepower at 5590 RPM & the Z06 delivers 650 at 6400RPM.

My comment was geared towards the threads general claim that a DOHC sucks if it can't be reved up. They can & do run more revs as some of the pure race F1 engines are running as much 15,000RPM but its a myth that they have to run high rpm's to compete with a 2V in generating usable horsepower.

Sorry if I misunderstood your comment.

Warp Factor

It's not that it sucks, just that there is little to no advantage if the high rev capability isn't taken advantage of, and some disadvantages.

JD_AMG

Your using displacement again like its something relevant for comparison. That 4.8l is HUGE.

Quote:

Have a great idea they already have an engine deal with BMW for some DOHC engine cars so why not extend it & get the 5 series 4.4L (268 CI) V8 @ 617bhp DOHC engine? Cut 400CC (25CI), 2 cylinders & add 64BHP. Then order a BMS JB 4 & get 694WHP & 693FT LBS for $900. At the crank with a 15% loss factor thats 798BHP. Enough to drive a 4370lb 4 door luxury sedan with finger tip shifting to a no muss no fuss at 10.3 seconds @ 136mph 1/4 mile

If you look close you can see the C7 in the outside rear view mirror.

I love that you cherry pick the $100K+ BMW M5 to compare to a base ~$50K stingray, and ignore that the $80K Z06 will match or beat that 1/4 mile time but more importantly SMOKE the BMW on a roadcourse - again this is what matters to sports car, not 1/4 mile times.

But if you want to pick 1/4 mile times at least compare apples to apples

JD_AMG

Remember who you are talking to, he has a massive reading comprehension problem.

Warp Factor

What's the difference between those engines, and the Toyota which only puts out 471 horsepower? Both are overhead cam, so that's probably not it. Shoot, Toyota's dual overhead cam engine doesn't even make more power than a pushrod LT1!

Oh, I wonder if it might be because the LT1 and Toyota are NA, and the BMWs are running very high turbo boost?
Have you noticed some of the turbo LT pushrod engines on this forum making 800-1000 horsepower?

Nah, you're too busy messing around in your underpants.
Your overhead cam superiority argument fails again!

jschindler

I've had seven Corvettes. Six of them since I have been on this forum. I sold my last, a 2009 Z06 about seven years ago because it was sitting while I rode my motorcycles. Look at my Avatar....member for something like 18 years and 26,000 + posts

BEAR-AvHistory

Yeah Toyota seems to be having a little trouble getting it right thats why they buy 3.0L BMW engines for their new small sports car. BTW nice try on that BS distorted V10 Toyota 4.8L picture. The Lexus LFA V10 is shorter than a typical V8 & lighter than a typical V6.

WOW a whole 800-1000BHP for the pushrod 6.2 liter Chevy. If thats the key horsepower number for greatness Mark Gearharts 5.0L 302 COYOTE with a Wipple supercharger looks like a winner with a 1028BHP average. Peak pull was 1042BHP. Spotting the 6.2 liter engine 1.2 liters. 1.2 Liters, nice size motorcycle engine or small economy car engine.

Did you know that supercharged COYOTE's are small enough to fit into the COBRA replicas under the stock hood? No need to cut a stupid hole in it. Quote a few on the FFR sites.




Hot Rod magazine did a nice series with Mike on building bullet proof 1000BHP Coyotes.

BTW he has a really slick Factory Five Cobra with a 5.0 COYOTE engine.

BEAR-AvHistory

DUH Missed that. Only have have has a few Corvettes last purchase was a 1967 Coupe that I kept into the 1990's. Have been kicking around a C7 or C8 thats my reason to be here. Was mostly interested in a C8, like the whole concept of the car. Think the front mounted engine chassis is a far as it can go as a successful top tier sports car.

Getting to be too much of an old fart to ride the bike a lot have a Yamaha V Star 650 that goes out once in a while.

Warp Factor

Uh oh, you must have gotten me confused with some other poster.
No, that's not anything close to a peak or "key" horsepower number for an LT pushrod motor. Heck, one can even buy LT-powered turnkey cars with 1000 horsepower.
http://www.thedrive.com/news/24279/t...at-dealers-now
Cobra replicas are a cool old-school deal, but not anything I'm interested in right now. I'd be much more interested in a 1950's Ford pickup with a modern chassis and drivetrain. Unlike the Cobra, I wouldn't even need to drill holes in the floor in case it rains.

BEAR-AvHistory

Must have been your alter ego whats his name, JD?

So based on the link its not a 1000BHP for a 6.2 Chevy & for only $67,000, not including the car, sounds like the deal of the century.

Interesting they had to push the Chevy out to 6.8 liters (415 CI) from 6.2 liters (378CI) to make 1000BHP while the COYOTE still does it with only 5.0 liters (305CI). Takes The Chevy 110 more cubic inches to make the same power as the COYOTE you can't see any superiority in the COYOTE.

Think for around $70,000 I would take the 700+ horsepower 5.2 liter VOODOO & the GT-500 car that comes with it for free.

To me pickup trucks are to move stuff & go hunting with. Might get tempted to put a COYOTE in my 1998 Ranger 4X4 if it ever decides to die on me. So far no issues other then a clutch replacement & a transfer case shift motor a few years ago. But its engine is running fine & looks like the day I brought it home 20 years ago. Driveway is getting too full, really need to gravel in the spot for the Ranger.

Warp Factor

If you prefer, you can do it for $14,000 instead.
EV 1150 C7ZO6 Power

Let's see what all had to be done to that Coyote engine to make similar power:
https://www.hotrod.com/articles/buil...us-horsepower/

Holy cow, look at the size of that muthah, and it doesn't even have the blower on yet:

JD_AMG

Its not distorted, its literally the display piece Lexus put up. And its not shorter than a V8 or lighter than a typical V6, nice try.

Aw look at you champ, comparing displacement like its something relevant again. The Coyote has to use double the valves, 4 times as many cams and a much bigger engine to make the same power the "old tech" pushrod engine makes, thats embarrassing for Furd.

800-100hp is NA territory for LSx's...




And still smaller than a Coyote...


Did you know the LS/LT fits better and is lighter, making the car perform all around better? Yea neat.
You know the old saying, how do you make a Ford fast? Put a Chevy engine in it...

JD_AMG

Sucks for the Coyote that the 6.8L V8 is still smaller and lighter than a 5L V8. Displacement is irrelevant, quit being a ricer.

Coyote is the perfect truck engine being a big heavy V8. Leave the lightweight small pushrod V8s for sports cars where they belong.

jefnvk

Ugh, I guess my ridiculous use of a Toyota pushrod went over some folks head. Racing engines have about zero relevance to street engines. They are two different usages, engineered, built, and tuned for two different purposes.

Again I ask in a pointed manner: if GM is getting the power it needs out of a pushrod, what exact benefits are gained from a change to DOHC?

Darion

Possibly more control over future emission regs. Seems like a waste of time in a way. With all the trend pointing to Electric this is just wasted energy and resources, GM just needs to jump straight to camless. lol

PC

BEAR-AvHistory

Would seem to most people that spending over a billion $ for development, tooling & production facilities at Bowling Green KY for a DOHC engine that GM did not feel they are getting everything they need from a push rod engine otherwise they would continue to use one.

The power might be OK but its failing in other areas or they would not be spending all that money to replace it. If it ain't broke don't fix it. They must have considered it broke or else they are defrauding the stockholders by pissing away billions of dollars on a boondoggle.

If someone was really interested in GM's decision process they could look for any tech papers produced by GM. My two guesses is that they can't meet future emissions or CAFE standards with the current 2V engines. Also marketing a 2V engine in a 4V supercar world is not a great plan.

When Hot Rod did a build a less then $10,000 engine build a few years back the Chevy beat the COYOTE F150 556HP to 510HP. Steve Brulé of Westech Performance who ran the test also stated that with equal displacement the COYOTE would have developed 631HP. Comment was:

" there’s no question about it. That four-valve head is superior to a 2-valve head”

That was done a few years ago with a Generation 1 truck engine since then the COYOTE has had some head & cam upgrades to Generation 3. The off the shelf base Corvette 2V 378CI is 455BHP engine & the base Mustang 4V 305CI is 460BHP. Think thats what GM brass sees in the market place. A car with a base price of $35K out powering their Corvette base priced at $56K by $21,000. Also looking at their own produce line the $38K Camaro SS also runs the same 455HP engine as the Corvette.

What is the case for the $56K Corvette when you have a power & weight overlap with a $38K car from the same manufacturer running the same power system.

Going forward they will be able to knock out a say 5.5L DOHC @ 550 or so power in a base configuration & make a case that the Corvette has joined the present.


To reverse the question why would GM be canning the push-rod engine if it was giving them everything the need?

BTW JD last time we looked the Chevy was 12lbs lighter ready to run. Like many others looking forward to the big heavy DOHC in the C8 Corvette.