Interested in going supercharged...SBC or BBC ???

[DRJDVM's '69]

I'm already thinking about going a different route with the motor in my car. I'm really interested in going supercharged or turbo (probably not turbo becasue of cost but maybe)...

The motor I have right now really wouldnt be up to running much boost without changing alot of stuff, so I figure I would be best starting from scratch. That way I can really maximaize the potential of supercharging rather than just slap one on but be limited to pretty low boost levels....that seems like a waste to me.

So if I'm going to start from scratch, I'm debating SBC vs going BBC. I have alot of nice accessory stuff for the SB ( headers, oil pan, dampner, etc etc) and the mounts, clutch linkage, front springs etc are all for SB and pretty new, so I would have to change all that too.

Alot of guys seem to be building small blocks for supercharging rather than big blocks.... Scott G for example....... why is that ???? Is it based mostly on cost ???? I know BB are usually more expensive to build but not that much. I guess I'm debating whether all the of the extra stuff to convert form SB to BB is going to end up costing me alot more in addition to the difference in cost of the motor etc.

[XcYZ]

Ned, I've always been a small block guy. All my experience, race and street, has been with small blocks, so that's the direction I went with my build.

There IS a replacement for displacement, it's called boost.

[Blown353]

Personally, I'd go for SBC just because of size/weight issues. Lots more room under the hood, more header options and less header clearance issues, less weight on the nose. The only BBC setup I would consider would be an all-aluminum setup as Jody did with his last car, but things get out of hand in a hurry in the cost and parts department (raised cam, spread pan rails, the cost of the block itself, etc.)

One thing to keep in mind with either engine is displacement. While I can't remember the specifics, the guy that helped me with my Procharger setup built a couple of nearly identical procharged big blocks earlier this year. I believe one was 472, and one was 540. The 540 held the edge in torque up to about 3000 RPM and then the 472 left it behind, making quite a bit more HP. He attributed this to increased frictional losses in the larger engine. This phenomenon would also apply to "big inch" small blocks. While more displacement is beneficial up to a point, at some point the increased displacement will start having negative effects from too much friction caused by the increased stroke, less favorable rod length/stroke ratio resulting in higher side loads on the piston, greater surface area from the larger bore, etc. I can't say what the point of diminishing returns is on this subject as I don't have the experience and haven't built enough engines to find it out for myself, but the issue is a real one.

You can get quite a bit of power out of a boosted small block, either turbo or supercharged. The choice of which to go with in your car IMO is pretty clear cut since you already have a lot of SB stuff-- I would stick with an SB. Just for an example, Don's 69 Camaro runs a Procharged 406 small block, and on pump gas and no intercooler it made 691 hp / 634 ft/lbs at the WHEELS. Figuring in drivetrain loss that's about 800hp at the crank. While I haven't dyno'd my combo yet I'm expecting >625 rwhp out of my car.

Boost is a wonderful equalizer for a street engine, as the combo will be quite tame when off boost as a cam for a boosted application is usually fairly mild. Keep your foot out of it and you can cruise around town with the A/C on with no bad behaviors of a high-HP, big cammed N/A car. However, put your right foot down and things get out of hand in a hurry.

Money and difficulty being no issues I would go turbos, but you can get outstanding results out of a supercharged combo with a lot less packaging issues. Personally, I don't think you can go wrong with either way. My car would have the Banks kit on it had it been available 2 years ago when I first decided to go boosted. I've thought about making the switch, but the Procharger works so well I've decided its not worth the hassle and cost for me to change over to turbos... at this time. The car already moves out pretty good, it needs paint far more than it needs a new form of forced breathing.

Again, I'm more than willing to make the short drive down there and let you have a look-see at my setup and take you for a demo ride (once I get a few more miles on my new rear gears, don't want to go abusing them quite yet.) Just don't poke fun at the rust holes in the bottom of my front fenders. For that matter, don't poke at them either, they might get bigger. :p

Troy

[jonny51]

All I have to say is that this site is contagious

[hotwheels]

i too would go with the small block.......if you find yourself in a spot where you can afford to go turbocharged, i would do it.....if you plan on driving the car, there is no comparison to the feeling you get from the torque from turbocharging........not sure the full price on the banks systems, but there are alot of turbo companies making kit's these day's that are getting more affordable.........hotwheels

[touring67]

K, I had a really long post here and for some reason I must not have been logged in and it didnt let me post it so I'll summarize it. Build the small block turbo, the big block is likely too much in reality. Think of what you intend to do with this car and ask yourself if you 'need' that much. I know you likely 'want' it and I can guarantee that I want more power too but keep it within your limits. I personally have the same question raging in my head and as much as I hate to realize it the small block is where you should invest. You already have it, its lighter, parts are cheaper, you have other accessories and you can still make plenty (unoptimized can easily push 650 hp and torque) of hp and torque with a blown setup. I definately agree with hotwheels on the turbo issue, if you have ever driven in a turbo car there is nothing that will give you that seat of the pants rush when the boost comes in. I also have a love affair with turbos and believe they are well worth the money in gains and the long run. Its really not the turbo that costs, its the packaging. If I even get started on them this post will be three times the length it already is if not more so I'll just stop with them here. Superchargers are quicker, easier and cheaper to install in many cases but in reality do you need 1000 hp?

With all that moral stuff outta the way I'd say go with the blown BBC.

[hotwheels]

but in reality do you need 1000 hp?

yes



hotwheels of turborides

[jonny51]

Originally Posted by hotwheels

yes



hotwheels of turborides

No you need 1100 hp

[touring67]

Why stop there? I asked the question, and I expected no less of you guys! Thats why I suggested the BBC, WE CRAVE POWER!

[jeff sledge]

I am a new member to this sight and thought i would post a reply to the bbc dilema.I just sat a 427bbc with a vortec blow thru box in my 69 camaro.Kinda wished i would have put a turbo but i have had 5 superchargers in the past and thought i would stay with that.I also switched from sbc to bbc and kinda wished i wouldnt have (didnt realize the cost).Its in now and going to try to start it this weekend.I guess if i had to do it over i would have done the same thing again because it looks pretty cool in the car.