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hsutton
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Joined: 20 Sep 2006
Posts: 5
274.48 points
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 Posted: Thu Jan 07, 2010 6:33 pm Post subject: |
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| Big Dave wrote: | 496 is a 454 that has been 0.060" over bored, and fitted with a 1/4" longer than stock stroke of 4.250". The 496 is a street motor not a Pro Stock motor. The 502 is an 1/8" over bored 454 that retains the stock length stroke forged steel crank. The bores are so large that they are Siamesed (touching) just like in the case of a SBC 400. A 540 is a 0.030" over bored 502 block with another 1/4" added to the crank. My 582 is a 5.060" bore with a 3/8" stroker crank (the longest that will fit between the oil pan rails of a standard deck height block without grinding away the sides of the block). Painted orange it looks just like a 396/454 though the decal on the breather claims 402.
As I stated earlier a longer stroke engine builds more torque than a similar bore shorter stroke engine. The only thing that keeps the longer stroke engine from reving as high and as fast as the shorter stroke motor is the reciprocating mass and added parasitic losses due to the pistons rubbing a greater distance and pushing harder upon the cylinder walls. If you are willing to strengthen the bottom end with stronger parts, run smaller piston skirts with lighter pressure on your piston rings, you could build a motor that would rev as fast and as high as the shorter stroke motor; it just would not live very long; and it would burn oil (a bad thing in a pump gas motor because it causes detonation in the combustion chamber beating up your light weight ring pack).
As I told you in my first reply to your question of which is the best BBC engine; the 540 has the best of both worlds (bore and stroke) that fits within a standard deck block. I also said to go large as soon as you decide to use a tall deck block, because every tall beck motor you see is at least a 632, with about half being a 705 cid or larger (you have to assume they are at least or they will eat your shorts).
Big Dave |
Just for reference, the 502 has a 4.47 bore. If you bore it to 4.500 it is a 509. |
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Big Dave
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Joined: 04 Dec 2005
Posts: 2437
Location: Tampa Florida
111706.68 points
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| Posted: Thu Jan 07, 2010 9:48 pm Post subject: |
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Sorry about that I have no idea what I was thinking when I stated a 5.060" bore.
My motor has a 4.600 inch bore (Dart Big M block) with a 4.375" stroke Callies 4340 forged steel crank, with Ross forged pistons, Howard rods and a Lunati solid roller cam.
Big Dave |
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FRITODAVE
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Joined: 05 Sep 2007
Posts: 166
Location: Victoria, KS
5170.64 points
1969 Plymouth Barracuda
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| Posted: Fri Jan 08, 2010 1:59 am Post subject: |
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After a year lay off from smokemup, big dave you still sound the same! Post a pic of your dyno and I will tend to believe you. Till then, your antiquated book knowledge is pass'e. Knarley is correct in that rod length plays a very small part. Countless hours of dyno tests have shown very small gains in power only with high rpm high end engines. Bore and stroke ratio is truly determined by the application it is applied to. Power to weight ratio is everything. More weight more stroke.
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If you learn from your mistakes, then I must be a freaking genius! |
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af2
Member
Joined: 01 Sep 2003
Posts: 5258
Location: grassvalley, ca
62454.74 points
1933 Willys Coupe
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| Posted: Sat Jan 09, 2010 1:03 am Post subject: |
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Frito, you move from Bakersfield to KS and you get an attitude?
Give it a break. If everything was set in stone we would all run in the 9's and have 800 hp small blocks.
Glad you're back.  |
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FRITODAVE
Member
Joined: 05 Sep 2007
Posts: 166
Location: Victoria, KS
5170.64 points
1969 Plymouth Barracuda
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| Posted: Sat Jan 09, 2010 8:30 pm Post subject: |
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I was having a bad hair day. It is very windy here  .
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If you learn from your mistakes, then I must be a freaking genius! |
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