Weird Science

I'm still in the planning/dreaming phase of my project.

I understand the cost issues and know what it takes to get a BBC into my original sb car.

I guess my main question is how noticable will it really be in regards to the cars handeling? With Aluminum heads and Water pump, how much more will it weigh? I want the ride to handle very nice on windy mountain roads but have no desire to auto-x it.

So, guys that have conerted, could you really tell a difference and how bad was it? I don't want a straight-line only car.

Another question is HP. How hard is it to get a reliable, streetable 500HP. I don't mind a mild lump to the idle, but I don't want it shaking my fillings out.

I've studided small blocks for years bit I am considering going big on this project.

I'm thinking 496 with oval port alum heads, roller cam.


[Modified by Weird Science, 1:10 PM 6/20/2003]

BB73Chris

As far as streetable 500hp, the Edelbrock gets 540hp 539tq with just 9.5:1 on a 454, and it's supposed to have good vacuum at idle and be relatively smooth... :chevy

and as far as handling, all the guys with C3's at the SOVREN races have big blocks (though many of them are aluminum, except the 68s).

Corey_68

The handling on a Big Block is MUCH better than some may have you believe. It's not that bad believe me.

And 500hp out of a 454 or 496 is cake, a monkey can build that. :D All it takes is a decent set of heads, cam and intake, and it would still be VERY streetable.

The money issue aside, I think the choice is obvious. :thumbs:

Corey_68

Why is that? :confused:

BB73Chris

because in that series they have to run what the origional race cars would/could have had, and there were no ZL-1's until '69... so the '68s are limited to Aluminum heads (Like a L-88).

Chuck Harmon

Weird Science,

I've made the change from sb to bb myself. the answer to your question really depends on what you want when it's finished. It is easier to get 500 street able horse power out of a bb, but there is a fair amount of stuff you need to change to make the swap. Nothing bad or difficult, but more than simply pulling out and sticking bb in. If you have a large brass radiator, you can probably get by with it. My 350/350 had a big radiator that probably would have worked ok, but I went with a larger aluminum BeCool radiator for weight and the ability to handle the high hp numbers my engine makes. Brackets, pulleys, exhaust make up most of the changes needed.

Yet a bb will make much more torque than you sb so you need to consider all the parts that need replacing to handle the power instead of getting stranded on the road at the worst time with a broken "whatever".

What kind of personality do you like in an engine? A real 400 horsepower 6500-7000rpm sb is a very potent engine that will blow many unsuspecting bb cars into the weeds. But you have to know how to drive the car. You must shift to take advantage of the engine's upper range abilities. With a bb you just mash the throttle and the locomotive like torque just pulls. Most bb's run out of breath by about 4500-5000 rpm, just about where a sb is really beginning to shine.

I wanted the best of both. The L88 gives me the high rpm of a sb along with the torque of a bb. A bit edgier personality than the marvelous LT1, but not greatly unlike its personality. But you really feel the extra 150-170 rwhp of the L88. Less extreme bb's will still run 6500+ and easily outrun a sb car. Les' 65 gorgeous blue bb is such a car and will walk away from my ZO6. Very street able car, very impressive!

There may be more mystique to a bb, but you pay for it. Aluminum heads, radiator, water pump and other items bring the weight penalty of the bb down to numbers not really noticeable to any but the most qualified professional drivers. I doubt if there are more such drivers on this forum than you could count on one hand. I think you might even have a few fingers leftover.

My advice to you would be to build the car for what you want, don't build it for someone else! Whatever you do, if done well it will be a great source of pride and the object of admiration for many.

Chuck

Weird Science

Thanks for the replies.

Chuck- I'm getting new exhaust anyway, so that's not much concern. I also have a be-cool aluminum radiator, so I think cooling is ok. I do understand all it takes for the swap. Thanks fro giving a heads up on what I might actually notice in terms of handeling. I think a 6000 redline would make me happy.

How important is it to really upgrade all the drivetrain when I'm only running street tires? Without slicks, wouldn't the tires break loose before a u-joint says goodbye?

I want to smoke the tires at will. I do not want to build an enigne, and then wish I built more power down the road. Streetability is why I am considering Big Block. I know I could build the power I want out of a SBC, but not one I would want to drive every day.

Another note- I ofund a site with a guy that retrofited late model LT1 style serpentine setup for brackets and pulleys. I'd probably copy that.

467-Ratman

When I built my 454 motor 2 years ago, I was impressed by the numbers and once it hit the street I had this smile that will not go away! My combo is good for about 500hp at around 6k, it has a real mean idle and gets respect everywhere I go. I normally get around 5mpg around town but who cares. Also when you open your hood people will stand back and just say wow! I replaced many things in my swap, including u joints, drive shaft new springs up front and a BeCool radiator with twin Spal fans. I have 255-60's on my car and they break loose so quick I am not worried about breaking the expensive parts! Go Big and you won't be sorry, no offense to my SB brothers and sisters!

Fevre

If you have some good small block heads a 406 would give you the monster torque you want and cost less than a full blown bb swap. If you want to see some eyes pop tear it up with a 406 torque monster then open the hood to show a little mouse. :eek: 'How'd you do that with that little thing?'

Me, I am going with a super charged FI 383. Figure with a 5 speed I'll can put out 500+ hp and torque while knocking down 20+ mph on the e-way. :steering:

73 LS-4

Don't worry, big block cars can be made to handle very well. You just have to put them on a bit of a diet and setup the suspension for the weight balance of the car.

:cheers:
Pat Kunz

Bearcat

When I converted my 68 to a big block, I upgraded the suspension too. I used the 550# front springs, and a 340# rear fiberglass spring. I realize the 32 pounds I saved on the rear spring threw the weight bias off a little, but the weight savings is fairly significant, and the handling's better. I also threw on some urethane suspension bushings and engine mounts, and Bilstein high pressure gas shocks. The Corvette handles very well. The limitation is not the chassis. The limitation is not being able to put good enough tires under it. However, I'm going to try the Pirelli Scorpion 255/60VR-15 tires out. Might be a night and day improvement.

The car weighed in at 3325 lbs curb weight, with a full tank of fuel. Not bad, really, for a big block car.