What does it take to build a BBC 496?

[Bandit]

How to build a 496 stroker motor from a standard 454 MK IV block? Is it just a matter of boring the block, installing new pistons and crank or is there more cost and machine work involved?

I am trying to get 550-600 EASY, streetable hp from a rebuilt BBC. I am not going to go with a crate motor at this point since I already have a lot of parts left over from my 402 that I want to reuse, like the hyd. cam. I have Brodix race-rite heads with 115 cc combustion chambers that I want to use.

Would it make more sense to just bore the 454 block and build a 468 with the stock 454 crank? Or maybe use my 402 block and make it into a 427 with a 454 crank? Can I bore the 402 big enough to do this (it's already punched out .060 over)?

[69rs633]

A 496 requires a 4.25 stroke. You will have to notch the block for the extra 1/4inch stroke. I'm partial to more cubic inches but the 468 or 496 should be fairly easy to obtain 550-600hp.

[Bandit]

A 496 requires a 4.25 stroke. You will have to notch the block for the extra 1/4inch stroke. I'm partial to more cubic inches but the 468 or 496 should be fairly easy to obtain 550-600hp.

I guess it's a matter of perspective, but 496 cubes is a BIG motor in my world. And 600 hp is a LOT of power. Keep in mind this is a car that I will drive to work in nice weather, and likely cruise cross-country from time to time. Not a balls-out racer. Plus I need to keep the cost down. So no new 540 for me at this time.

Can any competent machine shop prepare the block with the required notching for the longer stroke? Any ideas on where to get a good balanced rotating assembly for the 496?

[Adam's 55 Chevy]

If you are on a budget I would build a 468 if the bores are good. There is no reason why you can't get your power requirement from this ci. Perhaps some of the money saved can be spent on a roller cam set up.

[Bandit]

I forgot to mention, I want to reuse the hydraulic roller cam that I already have from my 402. To build a 468 you just bore it out and use the stock 4" stroke crank, right?

[Adam's 55 Chevy]

Your 402 block in in effect a +.030 396. You have from what you say gone a further = .030?

The 427ci was a 3.76" stroke 4.250 bore engine.

I think your 402 block will take a maximum bore of + .95 to bring it to 4.250 which is stock a 427/454 bore. With a core shift check some 396ci blocks can take a + .125 but it does compromise cylinder wall thickness.

Also you would have to revive the block for the bigger stroke if you wanted to install a 4" crank at the bottom of the bore as your 3.76" stroke block does not have the cut outs a 454 block does. This brings the work very close to water jackets and there is a risk you could hit one.

Personally if you want a 427ci start off with a 454 block and use your 3.76" crank. In the long run it will save you both time, money and grief.