are sb 427's really 427 c.i.'s

[Dangerous Doug]

Originally Posted by patrickt

In all honesty, one should say "It's a small block 427 -- it's not like the ones they originally used." I think you have to go the "extra distance" in answering this question truthfully because anyone that would ask it obviously knows next to nothing about engines since they can't tell the difference between a BB and a SB.

Unless the hood is down when they ask...

DD

[Streetwize]

To compare what you can build either motor at 427", a stroker smallblock wins hands-down.

2 words....Modern Technology.

Take a motorsports block and put on a set of CNC'ed CHI heads and at 427", there's no way an FE can even come close in terms of horsepower. The last few EngineMasters motors have been small blocks with CHI heads that can flow close to 400cfm or enough for 800hp.

You have to compare Apples, cube for cube, aluminum block/head to the same. On paper and with a lot of $$$ you can build an all-aluminum FE that can make awesome power but at 427 cubes it won't make the power or torque of a 427 Smallblock with an 1800G bobweight. Since NASCAR went to 358" in the mid 70's the vast majority of high dollar technology was applied to improving the small block platforms of the big 3. And once the 5.0 hit the streets in the 1980's it became the 55 chevy of this generation and small block technology for very stout street use grew leaps and bounds while the 352-428 FE platform was (sad to say) ignored. The other reason the FE was not furrther developed was the packaging, 428's in mid-late 60's Mustangs were tightly packages and VERY NOSE HEAVY....once the boss 351 hit the street it became to motor of choice and today the Cleveland/Windsor hybrid with race blocks capable of supporting over 470 cubes are now the normally aspirated powerplant of choice.

The FE is great for the purist approach and I admire the ones that build a true replica that honor the originals; but the in line/narrow angle wedge head and horizontal runner angles just can't compete with a canted valve, raidsed port NASCAR Technology modern head in terms of breathing, and breathing means more power and RPM potential. But fact of business...the Cobras that actually won FIA championship and Daytona were all small block powered and the better overall weight distribution and better cooler running packaging make it a slam dunk in terms of Volumetric efficiency and a broader powerband. By the time the 427 S/C came out is was really obsolete because the racing technology and aerodynamics had advanced and the chassis though significantly reinforced over the 289 still suffered from torque flex.

I love FE's, I've been working on them for over 30 years but in a bang for the buck type evaluation, they just don't compare anymore. Just like a Harley, they still have a mystique, but not really the perfomance numbers to still compete head to head because modern technology driven by marketing/packaging/Performance Acceptance caught up.

[cobrarkc]

[quote=Streetwize;915156]To compare what you can build either motor at 427", a stroker smallblock wins hands-down.

2 words....Modern Technology.

Take a motorsports block and put on a set of CNC'ed CHI heads and at 427", there's no way an FE can even come close in terms of horsepower. The last few EngineMasters motors have been small blocks with CHI heads that can flow close to 400cfm or enough for 800hp.

You have to compare Apples, cube for cube, aluminum block/head to the same. On paper and with a lot of $$$ you can build an all-aluminum FE that can make awesome power but at 427 cubes it won't make the power or torque of a 427 Smallblock with an 1800G bobweight. Since NASCAR went to 358" in the mid 70's the vast majority of high dollar technology was applied to improving the small block platforms of the big 3. And once the 5.0 hit the streets in the 1980's it became the 55 chevy of this generation and small block technology for very stout street use grew leaps and bounds while the 352-428 FE platform was (sad to say) ignored. The other reason the FE was not furrther developed was the packaging, 428's in mid-late 60's Mustangs were tightly packages and VERY NOSE HEAVY....once the boss 351 hit the street it became to motor of choice and today the Cleveland/Windsor hybrid with race blocks capable of supporting over 470 cubes are now the normally aspirated powerplant of choice.

The FE is great for the purist approach and I admire the ones that build a true replica that honor the originals; but the in line/narrow angle wedge head and horizontal runner angles just can't compete with a canted valve, raidsed port NASCAR Technology modern head in terms of breathing, and breathing means more power and RPM potential. "


You know most people would have to agree with you about modern technology and the canted valve heads but I'll bet 90% of the people that brag about their small blocks are running in line/ narrow angle windsor heads with that same old technology of the FE head.

[Streetwize]

Rich,

I think you may be right regarding the head/valve layout but even considering that these days 427" is really the realm of the big inch small block, much lighter rotating mass (my bobweight is like 1830G), guys are building small blocks in the 470 and even 480 cube range these days. 1 7/8" and 2" header sizes that weren't even dreamed of 15 yrs ago for smallblocks, now they're common place. And I do agree most of the Windsor stuff is still a traditional wedge, however the port angles and lighter valvetrain mass (especially in that 280-320CFM headflow range) is still an advantage at higher RPM (above the torque peak)over say the Edelbrock FE head.

Another thing about packaging is that for a given HP output there is a lot more room in the Cobra engine compartment for a smallblock to dissipate heat and when you are hot lapping a car around the track or even around town heat soaking of the intake manifold/heads and carb will absorb a fair amount of net power (as the fuel charge loses density onthe way to the hole)to the wheels in the real world as a opposed to the controlled conditions of the engine dyno.

I run an iron block aluminum head 351 based 427 with a scattershield, the weight balance of the car is nearly perfect and the power to weight and the HP/torque curve is virtually identical to a real deal FE as delivered in 1965-66....that's really what matters to me, does it feel like a 7 litre motor from behind the wheel.....also to me a smallblock offsets some of the weight penalty of the heavier fiberglass body, to build an iron block glass bodied car you're going to wind up a bit heavier than the real thing....yes some of us can and will afford the high dollar dove aluminum block and more power to them.....I don't have the Dust to go that route butit's not to say I wouldn't if I could. As I said, I love the old FE, it's quirky intake/head configuration, all that stuff....but at the 500-600hp level, I like the smallblocks.

BTW....PatrikT...That is an Awesome looking cobra you have !!!!

[cobrarkc]

Originally Posted by Streetwize

Rich,

I think you may be right regarding the head/valve layout but even considering that these days 427" is really the realm of the big inch small block, much lighter rotating mass (my bobweight is like 1830G), guys are building small blocks in the 470 and even 480 cube range these days. 1 7/8" and 2" header sizes that weren't even dreamed of 15 yrs ago for smallblocks, now they're common place. And I do agree most of the Windsor stuff is still a traditional wedge, however the port angles and lighter valvetrain mass (especially in that 280-320CFM headflow range) is still an advantage at higher RPM (above the torque peak)over say the Edelbrock FE head.

Wize
I quess you don't know that Keith Craft stage II heads flow 320+ cfm and stock Tunnelport heads flow 350cfm and there are couple people manufacturing SOHC heads that flow 400cfm and they are making kits for complete engines now. On the FE forum Ohio George was just telling everyone how he ran his SOHC motors to 8k+ back in the 60's. As you stated it costs big money but the old saying still holds true. "There is no substitute for cubic inches".
Small blocks are fun as you can see I have one, but there is nothing like that kick in the pants you get from a BIG BLOCK!

[Streetwize]

With respect....I think I know a pretty good amount about most of the heads that are out there, and I know a better than average amount about BIG BIG BLOCKS (ex: I run Chapman CNC'ed 380+ heads on a 700+hp 517" street car) ....but with big blocks proportionally big cross section ports will want either (big cubes to make torque) or Lots of RPM to make the ports work. The really trick "go fast" stuff for big blocks all have farily large (to really large) port cross-sections as they are designed primarily to work with todays modern BIG (typically 480+ cube) Big blocks. The really big stuff flows 465+ cfm and state of the art pro stock 500" stuff is well over 500.

If you build a 427" FE and a 427" 9.2 to 9.5" deck height smallblock with similar head flows (take your pick as long as you go Apples to Apples) compression, cams, induction and exhaust, I'd put my $$$ on the small block making more power, and fromthe driver's seat the smallblock (by virtue of a more efficient port (smaller valve, longer stroke, better port angle and smaller port cross section) it would make more torque out of the basement and then up top by virtue of a MUCH LIGHTER bobweight and valvetrain mass will rev faster and higher and make more power up top. Maybe not much more, but definately measureably more. So I think you can attain both more peak power and better average torque through out the powerband, so at 427" I think the "Nothing kicks like a big block" doesn't really hold up any more.

Remember....To compare fairly you have to build both to the same size and parameters. A smallblock reaches a practical limit at around 450-460 cubes, (4.155 x 4.17-ish), but even potentially bigger with a 400M deck block. compare that to maybe 410 only 10 yrs ago. Beyond that you are pretty much in the Big block realm.

The topic is 427 cubes (and ONLY 427 cubes).....7000 cc's.......for Fords (my .02 cents) the best power packages at that displacement or below are small blocks in terms of average torque and Hp per cube. Again....It's primarily due to the tens of millions of dollars invested over the years in NASCAR small block (358") technology that has trickled down to the hot hodding world.

[patrickt]

Originally Posted by Streetwize

BTW....PatrickT...That is an Awesome looking cobra you have !!!!

Thanks, you just made my day. She's tucked away until spring in a CarBag with a few bags of desiccant, StaBil in the tank, and an extra 10lbs of air in the tires. My December to April maintenance involves nothing more than pushing the car forward and back in the bag once a month.

[Got the Bug]

Originally Posted by patrickt

Thanks, you just made my day. She's tucked away until spring in a CarBag with a few bags of desiccant, StaBil in the tank, and an extra 10lbs of air in the tires. My December to April maintenance involves nothing more than pushing the car forward and back in the bag once a month.

Take that poor car out of its bag.

Your winter maintenance schedule should include a couple of drives.

Who drives their Cobra in the cold weather?

[patrickt]

Originally Posted by Got the Bug

Your winter maintenance schedule should include a couple of drives.

Who drives their Cobra in the cold weather?

Well, I will say that driving a Cobra on snow has a certain allure to it. The problem is that we don't have much snow -- we have salt. Salt on the roads, salt on the cars, salt everywhere. Salt, salt, salt. The colors of all the cars look the same because they're covered in a layer of salt -- it looks kind of like a color TV's picture tube before it finally gives out for good. There's so much salt you have to wash the dog's paws if she goes for a walk in the street. It's terrible. And it won't go away until we get a couple of really hard, soaking rains in late March or April. You know, like the rains that fixed FatBoy's leather seats....