Lets build the best stroker 454 for the $$$
01-15-2003 | 09:18 AM
#11
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Hello Guys,
I have built several 496's with stock length rods. If you have the 3/8" bolt, low performance rod, I would not use them in a 496 boat engine. If you have the "dimple" 7/16" rods, they are fine. If you are going to use a stroker crank, you must buy pistons and/or rods anyway. On a budget, I would use the good GM rod and Keith Black pistons. These, when properly installed, are extremely durable. READ AND FOLLOW DIRECTIONS, especially about RING GAPS that come with the PISTONS. If your engine has been run for almost any length of time, you really must make sure it hones out true and round WITH A DECK PLATE INSTALLED.
Besides, you must buy the pistons anyway and the larger bore and maybe a bore notching will really help power!!
I have built several 496's with stock length rods. If you have the 3/8" bolt, low performance rod, I would not use them in a 496 boat engine. If you have the "dimple" 7/16" rods, they are fine. If you are going to use a stroker crank, you must buy pistons and/or rods anyway. On a budget, I would use the good GM rod and Keith Black pistons. These, when properly installed, are extremely durable. READ AND FOLLOW DIRECTIONS, especially about RING GAPS that come with the PISTONS. If your engine has been run for almost any length of time, you really must make sure it hones out true and round WITH A DECK PLATE INSTALLED.
Besides, you must buy the pistons anyway and the larger bore and maybe a bore notching will really help power!!
01-15-2003 | 11:04 AM
#12
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Joined: Dec 2002
Posts: 31
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From: Fond du lac, WI
Mcollinstn,
Were probably splitting hairs but if you compare two 496's, one with 4.25 bore and 4.375 stroke, the other with 4.31 bore and 4.25 stroke, the longer stroke engines rings sweep more surface area than the shorter stroke engine. The numbers I calculated are 58.4 sq. inches / cylinder for the long stroke and 57.6 for the short stroke. Should translate into more friction loss assuming comparable cylinder pressures regardless of where in the stroke you are. Maybe you're saying that the larger diameter top rings would transmit more of the cylinder pressure through the rings to the cylinder wall. I haven't really thought much about this effect. Maybe.
Tom
Were probably splitting hairs but if you compare two 496's, one with 4.25 bore and 4.375 stroke, the other with 4.31 bore and 4.25 stroke, the longer stroke engines rings sweep more surface area than the shorter stroke engine. The numbers I calculated are 58.4 sq. inches / cylinder for the long stroke and 57.6 for the short stroke. Should translate into more friction loss assuming comparable cylinder pressures regardless of where in the stroke you are. Maybe you're saying that the larger diameter top rings would transmit more of the cylinder pressure through the rings to the cylinder wall. I haven't really thought much about this effect. Maybe.
Tom
01-15-2003 | 11:35 AM
#13
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Hello 'bago Baja and Mcollinstn,
The ring drag you are talking about is an insignificant number. Even though one travels farther and one has a larger furface area, the ring drag should not be much of a factor with today's rings and cylinder wall finishes. The main improvement between the combinations is the air flow improvement with the bigger bore.
The ring drag you are talking about is an insignificant number. Even though one travels farther and one has a larger furface area, the ring drag should not be much of a factor with today's rings and cylinder wall finishes. The main improvement between the combinations is the air flow improvement with the bigger bore.
01-15-2003 | 06:43 PM
#16
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Dyno!!
You cannot get any size engine just from rods. Rods have NO AFFECT on displacement. That said, you must change the crank or bore the block or both. Most common is 4.310" bore-that is .060" overbore, and a stroke of 4.25"-that is a quarter inch longer than the 4.00" standard 454 crank. You can get that with the stock 6.135" rod, but 6.385" rods, even in a short deck motor, is my preference. This is just one of countless combinations, but the most common.
Hope this helps. If you need more, just ask!!!!!!!!
You cannot get any size engine just from rods. Rods have NO AFFECT on displacement. That said, you must change the crank or bore the block or both. Most common is 4.310" bore-that is .060" overbore, and a stroke of 4.25"-that is a quarter inch longer than the 4.00" standard 454 crank. You can get that with the stock 6.135" rod, but 6.385" rods, even in a short deck motor, is my preference. This is just one of countless combinations, but the most common.
Hope this helps. If you need more, just ask!!!!!!!!
01-15-2003 | 07:18 PM
#17
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I just built my motor last year with a 4.25 crank, 6.385 H-beam rods, and Keith Black pistons. Every thing went together great with no clearence problems at all. Can't say how rods with nut and bolt fastener fits but the capscrew rod is the way to go. Rods and pistons are much lighter than stock sith is a good thing. The 6.385 rod keeps rod to stroke ratio close to stock.
01-15-2003 | 08:53 PM
#18
Thread Starter
Charter Member #655
Joined: Dec 2000
Posts: 4,939
Likes: 1
From: Holland, Michigan
What the heck????I was on FlatLander Racings web page tonight and they offer no less than 700 different combinations of stroker motors and not one of them is good enough for Kaama!!!!!Mark you smokin Crack again???? The self proclaimed Kahuna of Cubic Inch is loosing it!You know I love ya Man but your off your rocker this time!!!I'd fill you all in but I've been sworn to secrecy...Stay tuned to the Kaama (Kahuna of Cubes) goes bizzzerk Show!!!!
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01-15-2003 | 10:14 PM
#20
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Joined: Sep 2001
Posts: 5,769
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From: tn
Aw C'mon!
I want to get back to splitting hairs...
I think the short stroke motor makes more power cause it has less pumping losses inside the crankcase. Since the bores are bigger, the air moving around inside the cases is not as restricted as the air is in the smaller bore motor.
Whatcha think?
I want to get back to splitting hairs...
I think the short stroke motor makes more power cause it has less pumping losses inside the crankcase. Since the bores are bigger, the air moving around inside the cases is not as restricted as the air is in the smaller bore motor.
Whatcha think?
