ccwebb

I've been reading...and reading...but so far have yet to find a concise description outlining the pros of the modern fuel injected, OHC engine vs. carbureted, pushrod engines.

i.e. what does the naturally aspirated Coyote do better than an modern NA 351W?
I'm guessing that the Coyote's Ti-VCT also plays here.

Anyway, it seems the 351W variants produce great numbers, including huge amount of torque throughout RPM range, albeit at lower RPMs.

So if I had the choice why wouldn't I want a carb'd pushrod engine vs. the Coyote?

Thanks!

jz78817

Idle.

I'm serious. the Coyote makes 420 horsepower from 5.0 liters. It makes 420 hp all day, every day. It idles smoothly, has great throttle response across most of its RPM range, and has a fairly broad torque curve.

a 420 hp carbed 351W (5.8 liters) would need a hot cam and probably a single plane intake, so it would barely idle at all, would have little low-end pull, and would be a huge pain in the *** to drive on the street. oh, and if you have power brakes you'd probably need an auxiliary vacuum pump to make up for the lack of manifold vacuum. nobody would put up with a rough idle like in a modern car.

ccwebb

Hi JZ,
Thanks for your reply and video.

Sincere question: So the crate engines from Ford can't achieve their rated numbers in a streetable manner?
That seems odd but maybe true. I wouldn't know. I've never driven anything other than the 302 and the Modulars.

The HP achievable with the Coyote from Ford is fine by me... the Coyote Aluminator XS is rated North of 500 HP but the downer is torque... 386 ft lbs.

I'm more concerned with torque.

Thanks again!

jz78817

Keep in mind the "351" crate motors offered by Ford Racing Parts are actually punched out to 427 cu. in. but yeah, they have aggressive cams and the "recommended intake" Edelbrock Super Victor is single-plane. Single plane intakes are generally used for mid- to top-end power, and you trade off low end.

Horsepower= (Torque x RPM)/5252. If you have a carbed V8 and fixed cam timing/profile, you've got to decide what kind of engine you want. If you want low-end torque, you're going to need a calmer, shorter-duration cam and a dual-plane intake, with fairly small primaries on your carb. You'll make good low-end torque but your peak horsepower will not be that high. If you want a high-rpm circle track engine, you want a single-plan intake, a long duration/high lift cam, and a high-cfm carb. It'll make big hp numbers, but low end performance will be crap and it'll be a pain in the **** to drive around town.

When you have fuel injection, variable cam timing, and variable intake manifold geometry, the sky is the limit.

yeah. see, that's the thing about torque/hp peaks; if you push the torque peak up to a higher RPM, your peak horsepower goes up (see the equation I wrote above.) The simple fact that the Aluminator makes the same peak torque as a stock 2012 5.0 but almost 100 more horsepower guarantees that the hp peak occurs at a higher RPM.

actually, put it this way:
2012 5.0 Mustang: 412hp, 390 lb-ft
2012 F-150 5.0: 360hp, 380 lb-ft
Aluminator XS: 500hp, 386 lb-ft.

Kind of interesting, eh? They all make about the same peak torque. The key difference is in how the engines are tuned; e.g. where in the RPM range those peaks happen. The F-150 makes that 380 lb-ft at a lot lower RPM than the other two, so the peak hp is a lot lower at 360.

ccwebb

JZ,
Oh yeah I forgot to mention: Nice Notchback! I dig the 408. Is this yours?

ccwebb

Ahh, bummer. I'm looking to keep low to mid torque...basically a big fat torque curve.

I know that the Coyote is probably enough HP and Torque but you know how it is...if we were all satisfied then there would never be a supercharger sold.

I just prefer NA vs FI but want more torque and would like to do something fun like run Carb'd engine in my S197.

jz78817

eh, physics pretty much says that the Coyote is capped at about 400 lb-ft when naturally aspirated (go read up about BMEP if you want to know more.) Once you go forced induction, that's a new set of rules...

I wish. Just some video I found on youtube.

pascal

Well, the power is in the heads basically.
The Coyote has a DOHC and it's a huge advantage over the old school 351.
But despite that, the 351 has the extra cubic inches and with good aftermarket flowing heads like AFR or Trick Flow (185cc) and good intake like an air gap or Victor Junior Edelbrock with matching roller cam you will match the Coyote hp and have more torque without going for a stroker kit.
Now a well built 408 out of a 351 block will spank the Coyote mill with no problems and still be easy to drive on the streets.


So OP, if you're looking for good torque naturally aspirated, the 351 will be better but make sure your State doesn't have the yearly inspection.

ccwebb

Yeah 390 ft lbs torque seems to be about it, though Stang TV features a custom built Coyote using a Livernois block that laid down 624.9 horsepower recorded at 7,800 rpm. Peak torque of 462.3 lb-ft came at 6,200 rpm. The engine developed over 400 lb-ft of torque by 4,700 rpm. But the build and tune was radically different than a factory or even a factory reworked engine.


Thanks Pascal. That's what I'm looking to achieve. It's less money that a new car...and in just about every instance a lot more fun. A civilized 408 would be the cat's ***.


You mean like California?
My Mustang turns 7 this year so I think I will have to get it smogged. I believe new cars are exempt for the first 6 yrs.

All of this seems to add up to why superchargers are so popular.

jz78817

I think this is the first time I've seen someone recommend a single-plane intake for an engine to be "easy to drive on the street."