Can someone tell me how you get 496ci out of a 454ci?:D
Can you just bore it, or do you have to stroke it with another crank?:confused:

Bore .060" Stroke to 4.250. No other way to do it with a stock 454 block

A 496 engine has a 4.31" b x 4.25" s = 496".

.060" overbore 454 block with a 1/4" longer stroke and use at least 1/4" longer rods to make balancing it easier!

pdq67 and my 496.

Common method is to overbore to 4.31 and use a stroker crank that's 4.250.
Or 4.250 bore with 4.370 stroke.

So I would have to use a after market crank and rods?
Or just a different crank and 454 rods?

Sorry for all the questions but I know nothing about BBC'c.

Pardon me for jumping in but also would the OP need special pistons to go along with the stroked and rodded engine, like the 383 uses? I am asking because I am considering a similar mod.

When GM built the "482 Turbo-Marine" (Stock bore, +1/4" stroke) engine for offshore boat racing in the late '60's, they used a tall-deck block, the 4.25" crank, special longer rods (6.405" if I remember correctly) and off-the-shelf 454 pistons in a dome size that made the appropriate compression.

The taller block, longer stroke, and longer rods, in combination, allow standard 454 piston-pin height to be used.

That said, the common 496 uses the passenger-car deck height, 6.385 rods, and pistons made with a different pin height that works with the longer stroke.

You don't HAVE to use longer rods--but--without them there isn't enough material on the counterweights for proper balance. It costs a bunch extra to get the thing to balance. You might as well spend the money on the rods (and a crank made to accept the longer rods) than to pay for all the Mallory metal.

Thanks Shurkey, I was hoping to get by without having to buy a $2100, stroker kit.

Oh well, Speed Cost Money, How Fast Do You Want To Go?

Thanks Shurkey, I was hoping to get by without having to buy a $2100, stroker kit.

Oh well, Speed Cost Money, How Fast Do You Want To Go?

How fast can you AFFORD to go?

F14Tomcat,
A cheapie 496 stroker kit is $1300.....the better ones start at $1800 and you can spend lots more pretty easily.....

Thanks, George.
Is there any work has to be done to the block to get all the rotating parts to clear, like on a 383?

Please consider forged rotating kits from;

Speed-O-Motive; and

Ohio Crankshaft Company.

Buy one unbalanced and mock it up, then have a GOOD Machine Shop check everything out and finally balance it!

Should be cheaper than what you mentioned, imho.

pdq67

Is there any work has to be done to the block to get all the rotating parts to clear, like on a 383?
Just like the 383 ,it'll depend on the rods you use.
Stock type require more clearancing than I-beam or H-beam rods.

My '75 454 P/U block swallowed my thumb-rod 496 rotating assembly w/ NO grinding whatsoever!

But I did have to cam-cut the crank counterweights and then h-m balance her. It was a wash between doing that or at least install 1/4" longer custom rods in price back then.

pdq67

Can someone tell me how you get 496ci out of a 454ci?:D
Can you just bore it, or do you have to stroke it with another crank?:confused:

I suspect your question is more than anwered but
.060" overbore is 467", mine is .070" and is 469" that is about as far as the guys like on the 4 bolt block, for some strange reason the 2 bolt blocks have a bit more metal and can go a bit bigger (.090"?)

I know of a 454 in a jet boat that's been bored to 482--I'm thinking + .120.

Whatever it was, the machinist said the bore could have gone bigger; the block wasn't at it's max yet. (no, not an aftermarket block--ordinary passenger-car/light truck 454.)

SOME of the 454 blocks will withstand a huge overbore. Clearly, you'd want to sonic-test the cylinder walls first!

To my knowledge, since 2-bolt and 4-bolt blocks sometimes used the same casting, there's no difference in cylinder wall thickness based on how many bolts hold the main caps on.

I was going to say some can bore an 1/8" over.

pdq67

I was going to say some can bore an 1/8" over.

pdq67

My understanding was a 2 bolt main block may go 1/8th but the 4 bolt is thinner

My understanding was a 2 bolt main block may go 1/8th but the 4 bolt is thinner
The blocks are exactly the same, the only difference is the main caps.
Why would a performance 4-bolt block have thinner cylinder walls than a 2-bolt? GM put 2-bolt caps on some, 4-bolts on others with the same casting numbers.
Gen 6 blocks are supposed to be thinner but I haven't seen any scientific tests.

i was thinking there are some 750 dollar 496 stroker kits on ebay. but they need balance

i was toying with the idea of building more cubes for my next engine build. trying to stay on the cheap side.

You can do a 4.250 stroke on a 454 block using the 454 rods, flex plate and damper. You need new pistons made for the standard length rod. Balancing is then done external. 4.250 bore, 4.250 stroke = 482 Cubic Inches
OK for a square low budget grocery getter.
Squido

When you say the engine needs to be balanced internally, does this mean all the pistons need to weigh the same and all the rods need to weigh the same?
Does the crank need to balanced on a machine, or do they normally come completely balanced?

One more question, PLease, If you bore the 454 .060, put a 4.25 stroke crank, and use the factory 454 rods, and get the after market pistons because you used the factory rods, does this make 496ci?

Thanks Shurkey, I was hoping to get by without having to buy a $2100, stroker kit.

Oh well, Speed Cost Money, How Fast Do You Want To Go?

Cast rotating assembly for a 496 (10:1). - $879.95

Stroker1 (http://www.competitionproducts.com/prodinfo.asp?number=CK496D-60) - Competition Products

Cast rotating assembly for a 496 (10:1). - $895
Stroker2 (http://www.ohiocrank.com/chevbb_rotate.html) - Ohio Cranshaft

Should be good easily for 500 hp. You don't have to spend $2100 unless you want all forged parts. My forged rotating 496 cost about $1800.

E.

When you say the engine needs to be balanced internally, does this mean all the pistons need to weigh the same and all the rods need to weigh the same?
Internal OR external--the parts need to weigh the same!

Does the crank need to balanced on a machine, or do they normally come completely balanced?
Yes, it has to be done on a balance machine. The crank will be set up to be ""close" but the manufacturer is guessing on the weight of the parts used with their crank. If YOU choose parts that weigh a good bit more--or less--then what they've guesstimated, there could be a bunch of lightening or heavy metal required.

One more question, PLease, If you bore the 454 .060, put a 4.25 stroke crank, and use the factory 454 rods, and get the after market pistons because you used the factory rods, does this make 496ci?
The only thing that matters is the bore and the stroke. The rods and pistons have to match each other and the crank, but they don't affect the displacement. So--YES. A 454 + .060 used with a 4.25 crank = 496.

Cast rotating assembly for a 496 (10:1). - $879.95

Stroker1 (http://www.competitionproducts.com/prodinfo.asp?number=CK496D-60) - Competition Products

Cast rotating assembly for a 496 (10:1). - $895
Stroker2 (http://www.ohiocrank.com/chevbb_rotate.html) - Ohio Cranshaft

Should be good easily for 500 hp. You don't have to spend $2100 unless you want all forged parts. My forged rotating 496 cost about $1800.

E.
Why build a 500 horse 496 unless you're going for a tow-truck engine?

Snip...

Why build a 500 horse 496 unless you're going for a tow-truck engine?
Schurkey,

Good or bad, that's what I did. 500hp/585 torque 496. Iron heads, mild cam. The bottom end is forged, so it gives me room to grow when I get new heads and a roller.:D

The comment was directed to a reliable 500 hp engine on cast parts. :)

My $.02.
E.

AGAIN.

".060" overbore 454 block with a 1/4" longer stroke and use at least 1/4" longer rods to make balancing it easier!"

AND

"My '75 454 P/U block swallowed my thumb-rod 496 rotating assembly w/ NO grinding whatsoever!

But I did have to cam-cut the crank counterweights and then h-m balance her. It was a wash between doing that or at least install 1/4" longer custom rods in price back then."

Notice that you have to cam-cut the crank counterweights and then heavy-metal balance it b/c the stock 6.134" long rods like I used are too short for this application!

Piston pin bosses will hit the counterweights at BDC!!!

Thats why you need to install AT LEAST 1/4" longer rods!!

Been there, had to do it in my truck rod 496!

pdq67

OK, I hate to beat a dead horse(Texas Saying) , but.............
If I cut the cylinder bottoms for clearance myself, make all the pistons weigh the same, make all the rods weigh the same, use the 1/4 longer rods, do I still have a machine shop balance the crank with all the parts?
I am just trying to do as much as possible myself to save some bucks.

I don't have a problen porting the heads myself, been there... done that.

OK, I hate to beat a dead horse(Texas Saying) , but.............
If I cut the cylinder bottoms for clearance myself, make all the pistons weigh the same, make all the rods weigh the same, use the 1/4 longer rods, do I still have a machine shop balance the crank with all the parts?


YES unless you have your own balance machine!

Ok, then, thanks.

Can I save any money if I buy a balancing machine to do my crank? LOL
Hey, and then I could do all of yall's balancing work for FREE.