Michael Johnson wrote in news:zfydnXhW7ticaJ3anZ2dnUVZ snipped-for-privacy@giganews.com:
There's hope yet! ;)
Michael, in a warped kind of way way you are making my point by going with the 427 in your LX. :)
Then why are you planning on that 427??? ;)
If I had my druthers I would LOVE to stuff an '03/'04 Cobra motor with a Kenne Bell blower on top into the engine bay. The 427W is easier and less expensive but, make no mistake, the Cobra motor would bitch slap it with ease.
Michael Johnson wrote in news:5tadnSuZy5qzbZ3anZ2dnUVZ snipped-for-privacy@giganews.com:
Discussing which makers underrate and overrate will always be suspect unless we take said vehicles out to the dyno.
See below.
Take a look at the Ford 5.4, Chevy 5.3 and 6.0 Vortecs, and the Dodge 5.7. I don't see the Ford as a clear winner at all. At best it's in the ballpark, considering it's a 3V motor.
Take a look at the '08 Dodge 4.7 SOHC numbers below. Not too shabby. And it's only 2V. ;)
Just like GM and Chrysler have done with their OHV motors.
I doubt they'll be able to hit that mark, but we will see. I still say Ford talks a lot more than they do...
It still remains to be seen. Reality shows us that the OHC is not that much better (if at all) than the OHV.
OK, here are some specs taken from each maker's web site:
Ford 4.6L SOHC 3V HP - 300 @ 5750 TQ - 320 @ 4500
Ford 5.4L SOHC 3V HP - 300 @ 5000 rpm TQ - 365 @ 3750 rpm
Dodge 4.7L SOHC (2008) HP - 302 @ 5650 rpm TQ - 329 @ 3950 rpm
Dodge 5.7L OHV HP - 335 @ 5000 rpm TQ - 375 @ 4000 rpm
Dodge 6.1L OHV HP - 425 @ 6000 rpm TQ - 420 @ 4800 rpm
Chevy 4.8L Vortec OHV HP - 295 @ 5600 rpm TQ - 305 @ 4800 rpm
Chevy 5.3L Vortec OHV HP - 315 @ 5200 rpm TQ - 338 @ 4400 rpm
Chevy 6.0L Vortec MAX OHV HP - 367 @ 5500 rpm TQ - 375 @ 4300 rpm
Chevy 6.0L LS2 OHV HP - 400 @ 6000 rpm TQ - 400 @ 4400 rpm
Chevy 7.0L LS7 OHV HP - 505 @ 6300 rpm TQ - 470 @ 4800 rpm
Interesting numbers, to say the least. If anything pops out, it's that Ford doesn't have a n/a motor over 300hp. ;)
Michael Johnson wrote in news:MJedndjfXtgL5pzanZ2dnUVZ snipped-for-privacy@giganews.com:
technology
stainless
potential
Well, of course it would! And that brings us back to the SN65. Remember that thing? Awesome...
Ford 6.8L SOHC 3V(2005 & up) HP - 362 @ 4750 RPM TQ - 457 @ 3250 RPM
Rob
Mike,
HP/liter means absolutely nothing. There isn't any tax for using extra displacement. Weight and external size of the motor is what's important.
Patrick
So take away their strong point to make your point? How about remove the 4.6s OHVs and it's just a small displacement motor.
Yes, a $4K upgrade can do wonderful things.
Patrick
Much like many of the older [high-compression] 4.6 Cobras did after their owners added blowers.
Again, your comparisons are not very good.
Patrick
The SRT10 viper and the normally aspirated 'stang both had 9.6:1 CR stock. In 2007 the standart viper had 9.2:1. In 2008 the SRT10 goes to
10.2:1The 2008 SRT10 8.4 liter Viper puts out 600 HP normally aspirated for
74.5 HP per liter at 6250 RPM. It puts out 560 ft lb of torque, or almost 67 ft lbs per liter.If you boosted this engine to 7psi ((same as Stang) you would see almost 100 HP per liter, and torque in the 90 ft lb per liter range, with CR down around 8.5:1
The GT500 supercharged 5.7engine has 8.4:1 native compression ratio . It makes 500 hp at 6000 RPM. That's almost 88 HP per liter. It puts out 480 ft lbs on 150% of atmospheric pressure at the intake. That/s just over 84 ft lbs per liter.
Not really. I was going to post about how many modified LS powered GM cars there are in my neck of the woods... errr beach. In fact I talked with one of the guys just this morning. He has an '02 Trans Am with Z06 heads, cam and exhaust. I don't know what else he's done, but there's no blower or juice and he's running low 11s at around
120.
GM has been under-rating since the LS1 came out.
Even comparing stock to stock the hp/liter
Ford's "truck engine" [family] powered their flagship Ford GT.
Chrysler's flagship engine also powered a pickup. The SRT-10.
But, again, none of this matters because HP/liter doesn't matter.
Patrick
I don't think anyone today is over stating hp numbers. If anything they are slightly under rating them. For Chevy to squeeze another 100 hp from their OHV Vette motor they had to increase the displacement. That tells me they are close to maxing out the engine while keeping emissions viable and reliable. Otherwise they would keep the displacement at 6 liters for the Z06.
Ford isn't producing a high performance N/A 5.4L engine at the moment. They did several years ago and put it into the Cobra R. It made an under rated 385 hp and in reality probably made close to 400 hp with 5.4 liters of displacement. Ford produced this engine seven years ago and Chevy needs 6 liters to hit 400 hp with their base Vette engine. The current GT500 (and Ford GT) engine is basically a Cobra R engine with a blower and stronger internals.
The Mustang's 4.6L is Ford's only N/A high performance engine at the moment. The after market tuners are getting another 30-40 hp from them with tuning tweaks and these cars still pass all the emissions tests. Ford could do the same from the factory but don't need to because the car has no immediate competition. Getting 340 hp from 4.6 liters is better hp/liter numbers than the Z06 of Viper engines. Ford could easily give the 4.6L another 1000 rpm up top and push it to 400 hp, IMO. Heck, nearly 17-18 years ago Ford was offering an OHC SHO engine in the Taurus that made better hp/liter numbers than today's Z06 or Viper OHV engines.
I never said OHV engines aren't reliable. ;)
With 5.0L displacement they can do it easily. With 4.6L displacement it will take some new design features like maybe four valves per cylinder and a 7,000+ redline.
The only reason Ford doesn't have one is because they refuse to build it and/or have no use for it at present. They produced a 385-400 hp 5.4L N/A OHC engine for the Cobra R so we know what they can do it even with seven year old engine technology. Remember the ZR1 Corvette? It had a DOHC 350 ci V-8 that made 405 hp from 5.7 liters back in the early
1990s. The OHV engine is just catching it in power production. Think what hp levels they would see if they put all that R&D into the ZR1 engine. Chevy should have kept the ZR1 and ditched the OHV engines. That engine, IMO, should have evolved into the base engine for the Corvette.
That engine would make a Yugo sweet.
If there is more power left in the base Corvette engine then why did Chevy have to raise the displacement of the Z06 engine to 7 liters to get 505 hp? ;)
I think most all manufacturers under rate there performance engines nowadays. None of them want to get caught shorting the buyer.
Maybe not for ETs or lap times but it does give an idea of an engine's hp efficiency and effectiveness of its design regard power production.
My point is the OHC engines have other ways of making hp than just increasing displacement. For instance improved airflow from a multi-valve head in conjunction with high rpm capability can produce very impressive hp numbers. Sure you can do the same with an OHV engine but low end power suffers and the cost of machining the engine to tight tolerances is cost prohibitive for a mass produced engine. GM and Chrysler have gone the displacement route to overcome the inherent weaknesses of the OHV design. The OHC engines don't have these weaknesses and this, IMO, make them a superior design.
It's not the $4k. It's the blower. I just love forced induction and don't know why it isn't used more often. There's absolutely nothing wrong with 150+ hp/liter engines. They are light, small and run like hell.
Can the Viper engine take 7 psi of boost with no internal engine modifications? The Mustang's 4.6L can take 9 psi with no modifications.
The GT500's engine isn't even breaking a sweat at 500 hp. Ford slapped an inefficient Roots blower on it and detuned it. A Kenne Bell twin screw kit on a GT500 will make nearly 700 rwhp on pump gas. That equates to 150 hp/liter and you can fill up the tank at Sunoco. This is also done without removing the valve covers or oil pan from the engine.
I wasn't talking about the N/A Cobra engines. My comparisons are between today's Viper and Mustang engines. Ford builds more headroom into their modular V-8s. Can a Viper engine handle a 50-60% increase in power output without removing the valve covers or oil pan? I know the Mustang's OHC engine can.
HP/liter means something when talking about an engine's power production efficiency. A Viper engine weighs in at about 650 lbs. and a Z06 at about 460 lbs. The 4.6L weighs in at around 440 lbs. The Ford Triton V-10 weighs in at 635 lbs. fully dressed. I will give you that the external size of OHC engines are greater than OHV engines. The weight looks to be nearly equal.
It wasn't a Ford engine, though. It was a Yamaha. And the Duratec V6 isn't a "Ford" engine either. Yes, they build it, but the block is a Porsche design, and the heads are Cosworth. ANd it is a royal pain to work on, and DOES require more work than lower output pushrod engines.
>
And NONE of this has anything to do with where the camshafts are located.
The "blower" mustang starts with lower CR out of the box than the non blower engine.
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