SBC vs. BBC

[Turbo231]

I know people that insist a big-block Chevy is always superior to a small-block Chevy, even if they are running the same cubic inches. I can see this being the case if for say, we built both to 400 cid and only use factory parts, due to the better heads on the BBC. I am not sure how this would play out if we start modding the engines. Of course the SB weighs less but if built comparably, can it be equal in power production with same cid?

[hondo383]

BBC=bigger valves/csa in port,canted valves,bigger bore,bore spacing, bigger cam tunnel etc
all things the aftermarket has moved towards for small block stuff...400 inches with factory parts BBC is a landslide win hp wide

They could be made equal obviously but the effort/$ will need to be more for the small block

[englertracing]

The bbc doesnt have the pushrod pinch, but it does have half the ports turning the wrong way....

Ford 385 for the win

[DanE1]

The bbc doesnt have the pushrod pinch, but it does have half the ports turning the wrong way....

Ford 385 for the win

You make me grin, and I feel the same way.

[Newold1]

If we look at the evolution of OHV, push rod, normally aspirated V-8 engines from let's say the 1950's to present day you will see that all these engines have migrated and evolved into one basic configuration. That is one with symmetrical design, with higher oval intake port entries, better straighter intake port shapes, charge shaped combustion chambers, flatter valve angles and such, regardless of the OEM maker. Back in the what we now call the "early" days of V--8 pushrod OHV engines the designs were very varied in these areas and hence there tended to be a few that produced better power potential than others. There was something else at play and that was QUANTITY! Lots of SBC's and BBC's out there to used.. so the result was that the aftermarket was rich with parts and use to make both the great horses of their day. The bigger cubic inches of the BBC and the high rpms of the SBC's. Gave both engines a great place in the evolving high performance arenas. One can show so many great examples of both that the argument that one was better than the other is like arguing about the weather! Ford and Molar had some great designs and results over the years, but as time goes on they all pretty much have migrated into a more singular design and levels of NA performance. JMO

[Stan Weiss]

Yes I know they are not the same ci's.

So at the very top of N/A development, Pro Stock. Just many more HP per ci is the 500 ci BB making over the 400 ci SB?

Stan

[pdq67]

Poking AND stroking are fine, but as for myself, I'd rather be blown!!

Wasn't the little, (I think??), 305"/328"(??), sized 917-30 engine equipped with a couple of, "hair-driers"???

They beat up on the big 494"/510" CanAm V-8's, didn't they..

pdq67

[JoePorting]

I've often wondered about this subject because I've seen some 427 SBC's that made more power than 427 BBC's. Yes the 427 SBC's I'm thinking of had more money in them than the BBC's, but you'd think a junk BBC would still make more power than a SBC. Makes me wonder if the large exhaust port of the BBC actually hurts power since that's the major difference between the two.

[Jim2527]

How much does the bore/stroke ratio come into play?

427 BBC = 4.250 X 3.76
427 SBC = 4.125 x 4.00

[desoto30]

quite a bit I would imagine

[pdq67]

How much does the bore/stroke ratio come into play?

427 BBC = 4.250 X 3.76
427 SBC = 4.125 x 4.00

Then use a W/P's small block that will bore to 4.200" or even 4.250" and go. Or is it the Dart block??

pdq67

[plovett]

I would say the SBC has had more development after it's design, than probably any other gas powered 4 cycle engine in history. I think cylinder heads flow well more than double the originals, for instance. So, it could compete with or beat the BBC at some displacements. At 400 cid, I would guess the SBC with state of the art heads would beat a BBC.

JMO,

paulie

[Turbo231]

Let me throw one more Chevy engine in this mix. How about an LS based engine? If we had the same amount of money and were limited to 400 cid and NA, which engine has the most horsepower potential? And what do you think the horsepower potential is? From my standpoint, if we are NA, it is definitely all about the heads.

[swampbuggy]

Look at the 1960's Chevy S.B.C. 327/365 HP w/carb 327/375HP w/F.I. I believe this was the highest HP/CI in the early days of GM engines. These numbers in spite of crude cyl. heads. I think this says something about Bore/Stroke ratio (and) the S.B.C. overall. MPO= My Personal Opinion. Mark H.

[psychomotors]

My memory sucks but I believe Hot Rod or more than likely Car Craft did this several years ago with what I believe was a 408 ci bbc and sbc and dynoed them. Then they actually put them in a car and run them through the quarter to find out which was better." IF " I remember correctly (again , memory sucks) the sbc edged it out slightly in hp but the bbc won in the car. They used the same car for both engines to minimize variables.