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"454 is better in every way except, possibly, nostalgia."
That statement makes me realize you have no clue about what you're talking about.
There is nothing special about 427 cubic inches. It’s entirely nostalgia. All else equal, a 454 will make more power and torque and it’ll do it at a lower RPM.
Those are facts born out from decades of engine builders all over this country...not bench racers worrying about irrelevant factors.
A 427 will hook up faster and generate more hp at higher RPMs and that's just for starters.......
Please do your homework. 454 isn't called a stump puller for no reason and agreed it's not all negative.
More HP on the big end is better than the bottom end unless your pulling stumps.
I DONT WANT TO HAVE TO SIT HERE ALL NIGHT AND SCHOOL YOU
A 427 will hook up faster and generate more hp at higher RPMs and that's just for starters.......
Please do your homework. 454 isn't called a stump puller for no reason and agreed it's not all negative.
More HP on the big end is better than the bottom end unless your pulling stumps.
I DONT WANT TO HAVE TO SIT HERE ALL NIGHT AND SCHOOL YOU
Please guys. Your arguing two different things. Street performance is all about low end seat of your pants torque. Racing is all about high rpm horsepower. The two cross at 5250 rpm. Build your engine for where it will live. You don’t see many high rpm street machines for a reason.
Please guys. Your arguing two different things. Street performance is all about low end seat of your pants torque. Racing is all about high rpm horsepower. The two cross at 5250 rpm. Build your engine for where it will live. You don’t see many high rpm street machines for a reason.
Race engines are all about high RPM specifically because displacement is typically limited by rules. In classes where displacement is not limited, big displacement is the norm.
Only when you start pushing absurd RPM and/or displacement does the large engine start seeing any kind of disadvantage (like the 1006 cubic inch, 8000 RPM, 2100 HP Sonny Leonard “big block”).
Your point is well taken but your example is too extreme.
I have owned both 71 BBC 4spd and a 69 427 BBC 4spd. The 427 was faster, had more leftover 5,000+ rpm. just a better driving experience for all the reasons I mentioned.
Further, I have driven a 71 LT1 SB which I believe was 11:1 compression. high rpm car. a blast to drive, GM may disagree with you on the low rpm high torque model.
Any way you look at it. A 427 hooks up faster and keeps pulling over 5300 rpm as I watch a 454 stump puller in my rearview. I'll take 427 all day long over a 454
Ask yourself why Carroll Shelby went to the 427 in the 64 Cobra. An astonishingly fast and valuable car. I think he knew a little more than us.
A 454 is a poor mans 427 BB
I love a 427...still have mine sitting on an engine stand in my shop. I flogged it for 20 years in several cars. Ran low 11's on motor and high 9's with a 200+ hit of N20. At the time I never worried about 454's. As mentioned...the 427 in street trim often got out of the hole better without too much wheelspin drama and then pulled like crazy as it gained RPM. Like for like, the 454 will make 30-45 more HP and TQ maybe in street trim. Throw some real serious compression and fuel in them and they will surprise you.
As far as rev ability....my 555" will spin to the moon even with its 4.250" crank...actually higher than I ever spun the 427 and has been doing it for 20 years also. I shift at 7600-7800 and cross the line at 8000 RPM. Sure piston speed is higher...but that helps cylinder filling too.
A 6000 RPM 496 with some 3.08-3.36 gearing will be a blast!
Problem is a 427 block that needs work is at least 3k not worth it. Last one I saw had 2 sleeves, front headbolt threads were boogered etc.
You can buy a new 454 block for a grand +-
I dont know how an engine size has anything to do with hooking up.
Kinda like saying a 327 will always woop a 350 cause it has 1/4" less stroke. Or a 383 is only a low rpm torque engine;ironically same stroke as a 427
Theres good enough parts you can make just about any engine do what you want
Short stroke engines are fun to wind up but whats even more fun is winding up a larger one .
Your point is well taken but your example is too extreme.
I have owned both 71 BBC 4spd and a 69 427 BBC 4spd. The 427 was faster, had more leftover 5,000+ rpm. just a better driving experience for all the reasons I mentioned.
Further, I have driven a 71 LT1 SB which I believe was 11:1 compression. high rpm car. a blast to drive, GM may disagree with you on the low rpm high torque model.
Any way you look at it. A 427 hooks up faster and keeps pulling over 5300 rpm as I watch a 454 stump puller in my rearview. I'll take 427 all day long over a 454
Ask yourself why Carroll Shelby went to the 427 in the 64 Cobra. An astonishingly fast and valuable car. I think he knew a little more than us.
A 454 is a poor mans 427 BB
1971 saw power drop across the board at GM with lower compression ratios...so not sure why you think that’s a valid comparison.
The 1971 LT1 had 9:1 compression. Again, compression dropped across the board in 71. It was also slower than the LS6 and the LS5 (by a smaller margin) 454 in the quarter mile. So again, displacement wins.
Shelby went with the biggest Ford motor he could get his hands on to replace the 289. So...yeah, that again supports my point, not yours. (Also, Ford built the engine at that displacement because it was a common limit among multiple race series).
Another part of the equation.....if I do go hydraulic roller, I know that in my 406 SBC, it was cheaper with a factory roller block. I see GM is selling new blocks with that option, as well as mechanical pump (which is must have) and clutch bosses (must have). Also,....will roller rocker arms fit under factory style 69 Big Block covers......I bet not....so I guess I uses factory rocker arms, or valve cover spacers??
The intake and exhaust manifolds will be the restriction in an out...so I wouldn’t go nuts with anything...
The tri power unit and exhaust manifolds that 632C2 were EXTENSIVELY a worked over by him....and he is a rocket scientist...literally.
I mean you can still make 500hp or so with stock manifolds and the hood restriction with some carefully detailed work but....intake selection will be critical.
All depends on how much you want to spend and how serious you want to get.
Normally I would always say go the biggest you can on the motor but....since it’s going to be butt plugged with stock manifolds and intake, I can’t see going bigger then a 454 unless you are going to do a lot of porting/extrude honing etc. Otherwise it’ll just make stupid torque and roll over by 5000-5200.
There are a lot of 500hp stock appearing builds out there. Do your research. And you can never go wrong having Mark Jones build it for you. If anyone can make power with it, he can....
A few years ago I built something similar to what you are wanting for our 65’, it was a 396 (408”) and ended up a 441hp/435 tq.....through stock manifolds. I was a little disappointed in it and we spent a lot of money on that motor.
You guys can all make your case for the stump puller till hell freezes over, I know the 427 is better, faster, rarer, more sought after, and a legend when it comes to BB's.
The 454 can't until it can and its time has passed. Everybody hates what they can't have.
I'll take the legendary 427 over a 454 Slug regardless of price. Did you say free? No thanks.
mic drop...........
This thread has gone as far as it can go... The history books have shown, the 427 Reigns Supreme
LONG LIVE THE KING OF BB'S.
Depends on how sneaky you're willing to be. You're thinking right in that you have to be able to feed it. The fact that you plan on keeping RPM down...I'm guessing 5500-6000 max helps a lot.
I'd build a 496, install ported oval port iron heads or some nice aluminum Brodix/AFR with some disguising. The cam choice will depend on heads...but a hyd roller makes a lot of sense and I doubt it would be a single pattern. I'd add some exhaust duration to help the limited exhaust potential. I'd port the heck out of the ex manifolds.
CK out 632C2 here on the Forum....he has a 548" with iron manifolds and a tripower that makes about 700 RWHP and runs high 9's in the qtr. Way past what you're doing....but the point is he's doing all that through manifolds. They have 3" pipes bolted to them and use little 12 point nuts on the studs...but they work!
JIM
I agree, and also use stock manifolds on all street builds. Headers are a pain on the street IMO. If you at least port the manifolds to be as big as the exhaust port it helps a lot, and grind the big bump cast in for air injection tubes completely out of the way that helps even more. Corvette manifolds are not that bad actually.
If you go with a rec port head you can run an aluminum LS-6 intake that will clear a factory BB hood, and although not ideal, they also work pretty good. I have built numerous BB Vettes over the years, and they all get a 496 or bigger usually.
Also just a side note, the splash shield on the LS-6 intake will not clear roller lifters, and has to be removed.
Last edited by centuryoldracer; Dec 4, 2020 at 08:47 PM.
You guys can all make your case for the stump puller till hell freezes over, I know the 427 is better, faster, rarer, more sought after, and a legend when it comes to BB's.
The 454 can't until it can and its time has passed. Everybody hates what they can't have.
I'll take the legendary 427 over a 454 Slug regardless of price. Did you say free? No thanks.
mic drop...........
This thread has gone as far as it can go... The history books have shown, the 427 Reigns Supreme
LONG LIVE THE KING OF BB'S.
There is no replacement for displacement. Its like arguing a 327 is better than a 350 power wise
Another part of the equation.....if I do go hydraulic roller, I know that in my 406 SBC, it was cheaper with a factory roller block. I see GM is selling new blocks with that option, as well as mechanical pump (which is must have) and clutch bosses (must have). Also,....will roller rocker arms fit under factory style 69 Big Block covers......I bet not....so I guess I uses factory rocker arms, or valve cover spacers??
If you have a good block already its almost the same for a retro roller set up. Scorpion Roller rockers are the lowest profile I have seen, and they will fit under a stock VC. I always add a thicker gasket just to be safe, but I also like to use stock chrome covers.
