496 guys. What is different?
Thread Starter
Safety Car
Joined: Oct 2000
Posts: 4,282
Likes: 172
From: Lake Wylie, South Carolina
496 guys. What is different?
I was sitting here thinking about camshaft changes again tonight and started wondering about the difference between 496's and 454's. What make a 496 from a 454? Are the pistons different or just the rods and the crank?
Melting Slicks
Joined: Mar 2005
Posts: 2,838
Likes: 10
From: Austin TX
454 = 4.00" stroke.
496 = 4.25" stroke, bored .060
Rods are usually the same. Piston is a function of desired compression and how much the block has been bored out.
Everything else, including camshafts, are the same.
496 = 4.25" stroke, bored .060
Rods are usually the same. Piston is a function of desired compression and how much the block has been bored out.
Everything else, including camshafts, are the same.
Le Mans Master
Joined: Apr 2007
Posts: 7,353
Likes: 72
From: Graceland in a Not Correctly Restored Stingray
Not only are the pistons a larger bore (4.310"), but they also have different compression heights (the distance from the wrist pin CL to the piston deck) due to the combination of the longer stroke and 6.385" (0.250" long) rods typically used with the 4.25" stroke.
FYI, to calculate comp height, subtract rod length and 1/2 stroke from block deck height, then add or subtract desired piston deck height.
FYI, to calculate comp height, subtract rod length and 1/2 stroke from block deck height, then add or subtract desired piston deck height.
Thread Starter
Safety Car
Joined: Oct 2000
Posts: 4,282
Likes: 172
From: Lake Wylie, South Carolina
Thanks guys. So it would not be as simple as replacing the crank. I was just kicking around the idea but if I have to change more than 1 peice of the rotating assembly I cannot justify the cost of a switch now sense crank and pistons are new and the rods have already been polished resized and balanced with arp bolts.
Man I need to get this thing back together so I will stop obsesing about changes.
Man I need to get this thing back together so I will stop obsesing about changes.
Race Director
Joined: Jan 2000
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From: Corsicana, Tx
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There you go...you're now officially hooked!
Soon you'll be rationalizing how it makes more sense to just build a 540 or larger!
A 496 *can* be built with a stock rod and some tricky piston machining. Look for some old Lingenfelter articles where he whacked the deck on some 454 pistons like .110-.120 or so and used that to make up for deck height instead of decking the block.
The long rods help get pistons away from the crank at the bottom of the stroke. Balancing one of these is tricky since counterweights aren't that large to account for the heavy pistons.
JIM
Soon you'll be rationalizing how it makes more sense to just build a 540 or larger!
A 496 *can* be built with a stock rod and some tricky piston machining. Look for some old Lingenfelter articles where he whacked the deck on some 454 pistons like .110-.120 or so and used that to make up for deck height instead of decking the block.
The long rods help get pistons away from the crank at the bottom of the stroke. Balancing one of these is tricky since counterweights aren't that large to account for the heavy pistons.
JIM
