Big Block vs. Small Block

1320stang said:

Yeah, mine has heavy old TRW 12.7:1s in it, but with the bigger chamber of the '69 heads, I'm guessing it's about a point off. Mine sounds GREAT!! but that's with open headers. My buddy describes the sound of a properly tuned Ford motor as kernaling (sp?). I've heard several motors that are tuned right with this sound, when mine started making the sound and he said something about it, made me pretty proud. It sorta sounds like my drum roll, I'm not very good at it and my left hand is slower than the right, so the right catches up to the left and they're hitting at the same time, then it passes the left and its back to the way its supposed to sound, then back to catching up. That's the only way I can describe the sound.

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Yep mine has the heavy old trw 12.7s in it also. Our engines must sound very similar.

TRICKFastback said:

Daddy's money? Let's take your motor for instance. 429 T-Jet/ 372 hp/ 490 ft lbs. Then, you take my motor. 351W/ 460 hp/ 495 ft lbs. Dont get me wrong, but to me it looks like a smaller motor (not to mention lighter) with more horsepower and more torque.

And if I remember correctly the 429 T-Jet stock should produce 360 hp. You are only 12 hp on that? That tells me you must have changed either the exhaust or maybe the intake? just a secret between you and me, your not going to a win a race that way.

So if you think I spent "Daddy's money" it looks like I spent "that wisely huh?

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Trick: sorry I got up in your face about what you worte. Long day. Your engine reads pretty sweet. Did you dyno it during buildup? Desktop, engine or chassis dyno?


everyone else: since we have hijacked an exhaust thread into a big vs bigger (not 1.6L rice burner engines), and handling; please take the poll I started earlier today.

Buzz my small block stroker will tear your big block a new one. lol

Yeh and don't be ratting on the 1.6L motors, I've got one in my car and it's... yeh ok it's crap. lol

as far as weight the is concerned you have static weight as well as polar weight. ALL weight is bad. but polar weight is worse ....the wider the weight is from the center of the car the worse he effect is on handleing. but on a v engine it's better to have a "v" than a "V" as far as a motor is concerned

weight in front of the rear wheels is bad as well as weight behind the rear wheels

last gen rx7's I think had to be the best engineered car on the street other than the rotory not produceing much torque but the motor is behind the center of the front wheels.



did anyone read this month's hotrod mag? they tested a pair of same inch chevys one a smallblock the other a bigblock the smallblock beat the bigblock! yes if I had my choice of a fe 427 vs a windsor 427 the windsor would be in my car...unless I wanted a show car or a resto.

if I was building a drag car it would be a lima motor I think that a 460 based motor is a smarter motor than a fe but I sure do like my bbc 502 in my motorhome

Do you mean in front of the front wheels and behind the rear wheels?

have any of you all read how the boss 302's were faster than the boss 429's on the strip?

1320stang said:

I think the big reason for going away from the BB motors is in many cases, they're not needed due to the diesel motors that are out there. Now a 7.3 is a BB really. A V10 motor is 6.8, but the cylinders are the same size as the 5.4, is the 5.4 a SB?

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Alright, well I'm going to keep this to V8s for the most part. The only V10 put in performance cars are the Viper V10 (which, if it wasn't for the fact that the V10 is part of its image, would have lost the V10 already... DC wanted to move it to a smaller V8 with similar power but it did not get good press), and the BMW M5 and Lambo Gallardo (both of which have V10s in the 5-6L range, still small block displacement).

I consider any V8 that was designed with 250-375ish cid to be a small block. It depends more on the engine family than the greatest displacement you can get out of a family. You may point out that there were 400 SBCs and 400 Ponchos... those were just V8s from families meant for smaller displacements stroked out due to the muscle car age. Hell, a lot of people would prefer a 350 SBC to a 400 due to better bore-stroke ratio, etc. The block itself is the same as the small block, hence its a small block. You may also point out that Dodge is coming out with a 6.1L Hemi and rumor has it that the next z06 will get a 7L V8. My thoughts on this are A) its doubtful and B) the block for that LS7, 427 cid, 7L motor would still be derived from a small block still, and it would still be a small block.

I consider the 5.4L a small block (Even thought it is big). It does not fit neatly into conventional categories because it is a OHC motor and inherently has different design constraints, but the closest you can get from its family of engines is a small block.

1320 Stang: The difference between a stock dressed out 351W and a 427FE is about 120#.

I'm planning on doing a Cobra kit in the near future to both drag and autocross, and I am having no second thoughts about my plan to go with a big block.

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Well, being that it is a 2000 lb car designed to handle, your car will handle relatively well. Carroll Shelby did, however, prefer his 289 Cobras because they handled better... he actualy referred to the 427 powered ones as "pigs."

Anyway, everyone keeps bringing this up. Alright, that figure is true. But ask anyone who does anythign that requires handling of any sort, and they'll tell you that 120 lbs is HUGE. Our cars, even with aluminum headed 302s don't have great weight distrubitions. With big blocks, its almost impossible to even approach decent.

The main reasons that small blocks are around in performance vehicle are many. Big blocks don't get the gas mileage that small blocks can. Second is driveability... all that torque and weight imbalance of a big block can seriously hamper day to day travels. Third I'd put down the handling issue, being that in a performance car these days, people look at handling every bit as much as straight line power. This isn't the 60s, and big blocks have a huge disadvantage here. Finally though... small blocks, with all the modern bells and whistles, can provide all the power one would need. An LS2 is capable of taking a 3500 lb car into the 12s stock. They still respond well to mods. Same with a Hemi, and in a few years the 4.6L will be there too. They create more usable power, with a lot of science behind their power curves so that the cars can actually utilize most of it (and all of you guys with late 60s mustangs and big blocks know what I mean there... sure, spinning is great, but actually going somewhere is better).

I'm not going to be a ricer and pull up specific output arguments. I know those are BS. I"m not saying that smaller motors are better either. I think small block displacement V8s are an optimal performance configuration for a mid weight car. Everyone knows that huge motors have more power potential. But after a point, that extra size doesn't help until you're trying to run 7s.

Sorry for the book.

SadbutTrue said:

Everyone knows that huge motors have more power potential. But after a point, that extra size doesn't help until you're trying to run 7s.

Sorry for the book.

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Good post. I just didn't want to quote the whole thing. One other thing about the big vs. small block logic is this: the same logic applies to 460 vs. 390. Why run a 390, when a 460 will make more power, doesn't weigh much more, etc? If the logic worked, everyone should be running stroked and overbored 500+ ci monsters in their cars. However, mostly quarter milers run them.

I do think big blocks are neat and fun for street rods. I hope to have one someday. Just the rarity makes them interesting to me.

Good post SBT. I'll also point out that you could move the BB back a couple of inches and change the weight ratio a bunch (can do the same with the SB).

It all depends on what your trying to accomplish I guess. For instance, in Hack's FE vs. 385 logic (a 385 weighs about another 80 lbs. over an FE), I'm building a stroker 390 for my '63 Fairlane. I'm hoping to bore my 390 block (4.05" bore stock, mine's .060" over at 4.11") out to the 428 bore (4.13") and still have .125" cylinder walls left. The block will be Hardblocked up to the water pump holes and this will be a Tunnel Wedged, aluminum headed (new Blue Thunder high risers hopefully), Scat cast 4.25" stroked, solid roller, T&D rockered, 6.7 BBC rodded drag only motor that will be 455" in size and hopefully make about 600/600 at the rear wheels in front of a Jerico 4-speed. The reason for the FE when my little 289 ought to take the car into the 10's at 2600# is that the class (Nostalgia Super Stock) I'm trying to make it legal for requires a period correct motor. In the 60's, the Super Stocker Ford's ran the FE series motors, and besides, what is going to look more at home in that Fairlane?

I used to go to Road America all the time for the vintage races. This is a 4 mile road course with three very long straights. The 289 Cobras consistantly beat the 427/8 powered ones. The extra weight is huge.

I have owned powerful 302s, 351s, a 393 stroker, some 390s and a well built 428. I like em all in their own way, but I would have to say I am happiest with the 393 stroker. It is the best of both worlds to me.

67GTA-FB429 said:

Trick: sorry I got up in your face about what you worte. Long day. Your engine reads pretty sweet. Did you dyno it during buildup? Desktop, engine or chassis dyno?


everyone else: since we have hijacked an exhaust thread into a big vs bigger (not 1.6L rice burner engines), and handling; please take the poll I started earlier today.

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Don't sweat it!!, this is a Forum, and everyone is here to learn from everyone else whether a mistake or knowledge. I feel I know alot about the car, but have never claimed to know everything.

As far as your question though, nope I have never had it on a dyno to check RWHP yet. I did however have it dynoed on the engine itself and at the fly is pulls 464hp. I hope to get it on a dyno this summer and check the RWHP. there are a few other things I want to do to the motor before doing so. Not to mention the rear end need alittle TLC to handle the HP/ Torque.

I had posted that hotrod did the write up...it's in car-craft nov 2004 the sbc 454 made 556 pounds of torque @ 4,700 rpm while the bbc made 545 @ 4,900

the hp was 574 @6300 for the sbc and 567 @ 6200 for the big block


I wish that I had scaled my 331 motor.
it's set up with a set of afr 185 aluminium heads
aluminium intake-edelbrock rpm air gap
aluminium water pump

it would be cool to see what series of motors weight in real life

the radiator is aluminium as well and the battery is in the trunk to move weight back

Wow a 77# crank! People are just starting to bring the fe as close to current as possible. The 351w is waaayy more developed and if I had a choice it would be my choice. not to mention if you get serios you can go with neal or yates heads.

Yeah, but that's for a steel crank, a cast crank weighs a bit less. A 390 crank which is the same stroke as the 427 crank is 65#.

427 weighs 687 or something, I could pick it up! With my bare hands. Well, maybe not, but I can deadlift closed to that weight. Who needs a engine hoist. I have thought about he engine thing too. I would be easy to get my hands on a 351W but I am trying to make a replica and would like to go for a 428 down the road. I guess I would take what ever came available when I start the engine stage.

I wouldn't take a stroker though, they wear out faster than a regular motor.

Yeah, don't get me wrong about big blocks, they are a ton of fun. My friend has a 455 4 speed 70 Buick GS, and the car is a rediculous amount of fun, even in nearly stock form. But I do think that the small block is a better all around configuratoin.

1320stang said:

http://tc.ne13.com/FordEngineWeightsV1.html

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Wow! Cool information, thanks!

I see that my 250 probably weighs about 389 pounds, whereas the 351C I want to put in will weigh closer to 600. I think I'll just keep the straight six.

.. Well maybe not.

TRICKFastback said:

Don't sweat it!!, this is a Forum, and everyone is here to learn from everyone else whether a mistake or knowledge. I feel I know alot about the car, but have never claimed to know everything.

As far as your question though, nope I have never had it on a dyno to check RWHP yet. I did however have it dynoed on the engine itself and at the fly is pulls 464hp. I hope to get it on a dyno this summer and check the RWHP. there are a few other things I want to do to the motor before doing so. Not to mention the rear end need alittle TLC to handle the HP/ Torque.

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I wish I had aluminum heads...CJ heads at that...but my cast iron stock ones do for now.

Keep the faith and make em fast and loud.