Roush VS. Ford Racing Engines

[Don]

The specs for the 2006 Z06 Corvette 7.0 litre, 427 CI engine indicate the pistons are cast aluminum:

http://www.corvettemuseum.com/specs/2006/LS7.shtml

The 505 HP is at 6,200 RPM

[scottj]

Originally Posted by Don

The specs for the 2006 Z06 Corvette 7.0 litre, 427 CI engine indicate the pistons are cast aluminum:

http://www.corvettemuseum.com/specs/2006/LS7.shtml

The 505 HP is at 6,200 RPM

but... what does it tell you when Chevy builds 50 "performance" LS7s for a special project and the only difference between the production engine and the "performance" engine is that the performance engine has forged pistons.

[Mr427]

OK, you can have cast pistons, with their advantages, like tight fit, light weight and so on, but then you must also have knock sensors and high tech ignition management systems that ensure ignition retard, fuel mixture changes and a whole lot of other functions that are either unattainable or too costly for the average backyard hot rodder ...... just another 2 cents ..

[Don]

The C6 Z06 427 engine is hand assembled at a separate GM facility, which does not assemble the standard Corvette engine:

http://www.superchevy.com/technical/...09sc_assembly/

" Just as interesting as the LS7's specifi-cations is its assembly process at the new GM Performance Build Center (PBC), in the industrial 'burbs of Detroit. A single technician builds each engine by hand. It's a process that marches 180 degrees away from GM's typical mass-production methods.

The V-8 plant at St. Catharines, Ontario, for example, will produce thousands of engines in a day; the PBC might build 100. Indeed, it's a more intimate procedure, with a small, hand-selected group of experienced enthusiasts performing the assembly duties.

We toured the facility recently to watch--and help with--the assembly of an LS7 engine. At 100,000 square feet (and not all of it currently utilized), the PBC's shop floor is downright miniscule compared to other GM large-scale manufacturing operations. While we've been through other GM plants, and were surprised by the cleanliness and brightness of the assembly area, the PBC ratchets those qualities up several notches. It's more like the setting of a high-end Indy car or NASCAR race shop.

You'll see the LS7's build process unfold in the accompanying photos, but here's a quick rundown of the overall assembly procedure: Each engine is hand-assembled by a single technician who builds it from start to finish. (There's even a plaque with the builder's name affixed to the engine after the final inspections are completed.) He or she starts with a bare, cleaned block and begins the build by installing bearings--just like you would on an at-home build. "

[Don]

Another article on the special assembly of the C6 Z06 427:

http://www.popularhotrodding.com/tec..._build_center/

[Anthony]

Originally Posted by Mr427

Ford´s early 429 engine is a case in study of how to do things right. =====. It could take more ignition advance than ANY comparable engine of its time and it did all this, reaching high compression and power with flat top pistons.

I generally thought that the more advance in timing an engine could take means the greater the combustion inefficiency, a bad thing.

[Mr427]

Ford got it right with this engine although it has been overlooked for over 40 years. I was fortunate enough to get my hands on a mint 1970 Cyclone GT with this engine, early on. To contardict myself a little on this issue, I can state that in stock form this motor was not a match for the 428Cj that it replaced as medium street performance engine. BUT, it is structurally a MUCH stronger engine and no matter how hard I drove it, it never caused any problems and it would run well past 6000 rpms on mediocre gas with the ignition highly advanced WITHOUT detonation. That was the missing point from my previous message. The other issue on the excellent breathing this engine has, it will not start to protest taller cams until you go past circa 225-228° @ ,050 valve lift. I know of no other engine that can match that.

The combustion chambers are "closed" (72cc) for lack of a better term, with a large squish area, taking up almost 45% of the bore area. That is pretty darn good thinking for its design time frame, around 1965, which according to some in the know, over on the 460 forum, was the time Ford did serious pre-production testing on these engines.

This is really a subject for a new post on this forum. I did not intend to hijack this post for an off topic issue. Still,

There are several people running this type of 385 engine WITH these cylinder heads, fully ported, with flat top pistons and otherwise 1970-ish tecnhology, deliveriing in excess of 700 horsepower with a single carburetor. The only drawbacks these engines have are due to two issues:

1. Everyone in Detroit KNEW in 1966 what was going to come from Washington in the next few years. That is why Ford designed higher emissions efficiency into this engine than some would have liked.
2. The exhaust ports on all of the 385 series engines were bent downwards at an angle so severe that after they reach ,300 on the lift scale, they start to suffer reverse flow. This was done for one reason only. Without this change, this engine would never have been installed by the factory into Cyclones, Torinos and most importantly the 1971 Mach 1.

When they win as they do often, the Chevy crowd reportedly gathers in the pit area to explain this novelty away, saying: "Yeah, but you have spread bore ports"

As for the combustion chamber design efficiency, this engine speaks for itself. It delivers excellent hp in stock form. The reason you can advance the ignition to up to 42° total is because you have no heat spots in the chambers or on the pistons. It has no valve shrouding problems because of its
huge bore and piston speed is relatively low because of its small blockish stroke.

(See this and other superior discussion on this and other fabulous Ford stuff, by the top Ford people in the country at www.460ford.com and on this fine forum CLUB COBRA)

[cobrashoch]

Interesting thread that got hyjacked. Regarding forged cranks, I know of only
a couple of crank makers that make forged cranks for 385's and they are expensive. There is some talk about scat and eagle importing some, but even with that they are scarce. I've used both and I've never seen one ioata of difference between the two practically, they both have performance advantages and disadvantages. Usially, the failure of cranks is due to main cap walk or oil issues, but keep in mind the stock high noduar iron 385 crank will take over 800 horsepower, so the build is everything. Been there, done that and many times too. Currently, I know of no-one that is building crate 385's with forged cranks, that's in the realm of custom builders such as Kaase or K. Craft. And that brings up the point stated above, custom engine builders (more often than naught) will build better engines than any crate motor you can by, often cheaper too.
Keep in mind there is other engine builders out there that build custom engines we normally do not think about too.Take Jasper engines for example. They are the largest aftermarket engine remanufacturer, and they have the largest warranty network out there. Did you know that they have a custom engine (read; racing) department? And that warranty network will except these custom built engines? Kinda gives one something new to think about now doesn't it, esp. when you are looking for a zero deck, fully clearanced engine at a certain price point.
cobrashock

[JayBar]

Timely subject. I was at a All Ford Car Show at a local dealer, this weekend. I won't use names but was speaking to a Cobra Dealer. I asked if he bought crate engines from that dealer, he said "a few" but he now uses Roush mostly.
He told the last two 392's they installed went bad. The first one the customer drove home 58 miles taking car to be "gentle" on the new engine, and pulling into his drive a rod went through the oil pan. They replaced that engine with the second one they had in stock (bought from the same Ford Dealer) an at 59 miles the engine developed a major "noise". This is not the first crate engine that went bad. A rep from that same dealer said they experienced about a 25 percent failure rate on these engines. Now is Roush worth the money, maybe. I would think a complainant local guy could build an equally good engine. The parts are available, after all Roush does not have any secrete metals like "kryptonite". My engine was done locally with an Eagle forged crank, H beam rods, AFR heads, dart block. If they were put together correctly with care I can't see why a Roush built engine would be better.

[Don]

First time I noticed in an auto magazine the two page ad regarding the 1st quarter 2007 availability of the Boss 302, block only:

http://www.fordracingparts.com/jumppages/boss.asp?x=1

[CobraNV]

I'm not an engine guy, so I don't understand all of the internals or intricacies of engine building. In many discussions about engines and HP, one question always comes up...What are you going to use the car for? For me, the answer is this: I will use it 99% of the time on the street for both short and long drives. Occasionally, I may want to take it on a track to open it up just for fun. I also want to be able to kick the $*#! out of the Vetts and the Vipers on the street.

Here's the hijacking back to the original post: The Ford Racing 460 puts out between 500 - 550 hp with 495 - 535 ftlbs of torque. The Roush 427R puts out similar numbers. They claim the Roush motors are complete up to the clutch. The Roush 427R is between $14K - 15K. The 460 Crate is around $6K. About how much would it cost to add the components necessary to get the 460 to the same stage of readiness for installation as the Roush? For what I'm looking to do with the car, is the Roush really worth twice as much? Do you generally get the difference back when you sell it?

[RNT]

CobraNV..I purchased the Ford Racing 460 with SCJ aluminum Kaesse heads (the best I hear) and am completely happy. Powerful and looks great when you open the hood. 2000 miles so far and not a burp. Roush makes a fine engine but I could buy two FR 460's for one Roush.

[CobraNV]

Originally Posted by RNT

CobraNV..I purchased the Ford Racing 460 with SCJ aluminum Kaesse heads (the best I hear) and am completely happy. Powerful and looks great when you open the hood. 2000 miles so far and not a burp. Roush makes a fine engine but I could buy two FR 460's for one Roush.

That seems like the logical thing to do, however, this entire endeavor is not one that dictates logic as a prime driving force

Does anyone else have experience with either engine?

Thanks.

[SPF1061]

CobraNV,
I can not tell you which to buy or even recommend one over the other, to each their own. I can tell you that I have a Roush 427R in my SPF and I could not be more satisfied. I have about 6000 street, track and strip miles on this motor without the first hickup. It runs 11:60s/125+mph 1/4 mile on Yoko Avids w/32lbs air pressure. It feels like a runaway freight train going down hill from off idle to rev limit. That's all I know.