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Re: compare 496 b & 499 rb
[Re: 68roadrunner]
#1134997
12/15/11 10:46 PM
12/15/11 10:46 PM
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Joined: Nov 2003
Posts: 6,293
Rock Springs
Bob_Coomer
master
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master
Joined: Nov 2003
Posts: 6,293
Rock Springs
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Just curious what block your using for a 4.31 low deck build?? Unless these engines are all out 7500 rpm's id say there isnt much diff power wise, even then would be little measurable amount. 
[color:"red"]65 Hemi Belvedere coming soon [/color]
[color:"#00FF00"]557" Indy engine 1.07 60ft 144mph in the 8th 2100 lbs package [/color]
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Re: compare 496 b & 499 rb
[Re: viperblue72]
#1135000
12/16/11 03:59 PM
12/16/11 03:59 PM
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Joined: Nov 2004
Posts: 1,745
Maryland
340_Dart
top fuel
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top fuel
Joined: Nov 2004
Posts: 1,745
Maryland
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Quote:
The rotating weight would be too negligible to matter. Bigger bore would help unshroud but would matter only a little. Id say the only difference that would matter is the 400 block is stronger and would be better that it isn't .060 over.
Where is the 400 block in this post? i see either a 496 based off of a .060+ 383 block or a 499 based from a 440 block...
I agree though that i doubt you see any real difference in performance based on the 2 engines mentioned using the same top end components.
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Re: compare 496 b & 499 rb
[Re: 340_Dart]
#1135001
12/16/11 04:06 PM
12/16/11 04:06 PM
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Joined: Nov 2007
Posts: 1,600
Alberta Canada
StrokerAspen
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top fuel
Joined: Nov 2007
Posts: 1,600
Alberta Canada
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Quote:
Where is the 400 block in this post?
 For a big block stock block biuld, the 400 is my #1 choice...
-Kenny
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Re: compare 496 b & 499 rb
[Re: 68roadrunner]
#1135002
12/16/11 04:08 PM
12/16/11 04:08 PM
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Joined: Aug 2003
Posts: 43,096
Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,096
Bend,OR USA
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I like the 4.25 stroke with the BB Chevy rod sizes  I have bought a 4.15 crank and had it offset ground to 4.300 stroke with the BB chevy rod journal size, 2.200  I also had the mains and counterbalnces ground down so I could put it in a 400 block, that made my 518 C.I. pump gas street motor
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: compare 496 b & 499 rb
[Re: moparacer]
#1135006
12/16/11 05:43 PM
12/16/11 05:43 PM
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Joined: Jan 2003
Posts: 9,982
Frostbitefalls MN (Rocky&Bullw...
gregsdart
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master
Joined: Jan 2003
Posts: 9,982
Frostbitefalls MN (Rocky&Bullw...
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also go to the 440Source home page, and read up on blocks. It is an eye opener, and for a race piece, only a 400 block with either the best or second best web sizes above the main bearing saddles is good enough to put to use making race hp. The best combo to date is the 512, 4.375 bore x 4.25 stroke. Cheap, light, and big.
8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
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Re: compare 496 b & 499 rb
[Re: 68roadrunner]
#1135007
12/16/11 07:13 PM
12/16/11 07:13 PM
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Joined: Jul 2010
Posts: 2,091
Delray beach, Florida
Performance Only
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Joined: Jul 2010
Posts: 2,091
Delray beach, Florida
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the force is applied to the piston. the larger the piston, the more force is exerted on the crank. for the purpose of the engine combo's listed, bobweight has at best a negligble effect on actual horsepower.
keep adding port cross section and flow ability and the difference between the two combo's grows. limit port and flow and the difference is little at best. there's a lot more that could be added to this but all it would do is create confusion for the most part.
lighter rotating assemblies have the ability to make more power, but in many cases people tend to negate those gains because they make poor choices in other areas of the build,IMO.
machine shop owner and engine builder
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Re: compare 496 b & 499 rb
[Re: gregsdart]
#1135008
12/16/11 08:27 PM
12/16/11 08:27 PM
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Joined: Apr 2011
Posts: 319
jonestown,pa
dmking
enthusiast
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enthusiast
Joined: Apr 2011
Posts: 319
jonestown,pa
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i my self found the 440 block made late with the same thick mains ans the wide supports under the jugs as the 400s (but not the monster thick ones) it has to be better than the stock 440 block. i am not leagle to go faster than 10.s so i just hope this one does not crack. some day i will do one of these combos.
Last edited by dmking; 12/16/11 08:33 PM.
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Re: compare 496 b & 499 rb
[Re: 68roadrunner]
#1135009
12/16/11 11:29 PM
12/16/11 11:29 PM
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Joined: Jun 2009
Posts: 877
ky
68roadrunner
OP
super stock
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OP
super stock
Joined: Jun 2009
Posts: 877
ky
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yes,yes,yes the block will break we all know that if i had a 400 laying around i would be looking at that.(but i was not smart enough to buy any up) maybe to make the rotating weight less, use alum rods. will alum rods fit in the 4.25 stroke 383? it might not be a fair comparison but a comp eliminator motor makes good hp with small cubes. but does turn alot of rpm. okay  on
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Re: compare 496 b & 499 rb
[Re: 68roadrunner]
#1135010
12/17/11 12:34 AM
12/17/11 12:34 AM
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Joined: Oct 2007
Posts: 4,205
New York
polyspheric
master
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master
Joined: Oct 2007
Posts: 4,205
New York
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The B has 2 minor advantages:
1. shorter cylinder wall = stronger and stiffer
2. shorter pushrods are much stiffer in the same diameter and wall thickness
Boffin Emeritus
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Re: compare 496 b & 499 rb
[Re: Performance Only]
#1135012
12/17/11 05:10 AM
12/17/11 05:10 AM
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Joined: Feb 2007
Posts: 1,025
Las Vegas, NV
dodgeboy11
super stock
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super stock
Joined: Feb 2007
Posts: 1,025
Las Vegas, NV
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Quote:
Quote:
The B has 2 minor advantages:
1. shorter cylinder wall = stronger and stiffer
2. shorter pushrods are much stiffer in the same diameter and wall thickness
if #1 is true, how come i consistently see the same amount of distortion in the cylinders of the low deck blocks as i see in the RB blocks when a honing plate is installed?
re; #2 buy stiffer pushrods for the taller engine if needed.
#1 because the deck's are the same so the distortion you see is the same. But, the length of the cylinder is shorter so the strength of the cylinder will be stronger, thickness being equal between the two blocks.
I agree with your response to #2.
But, to continue, the 383/400 block is stronger downstairs due to the smaller main housing bore as well as it being a slightly more compact setup because of the shorter deck. The lower rod ratio will increase the bottom end and the added stroke will offset the smaller bore difference. BUT you can get a super victor intake for a 440 with a dominator flange that you can't get for a B deck block. Some builders feel it gains more to add a spacer/adapter to get a dominator to fit though so I'm not really sure of the real advantages of this.
To put it in a different perspective, I have dyno'd both combos with similar heads and cam specs. They both made right around 570 hp on pump 91. The RB had an eagle crank that hit the bottoms of the pistons with the counterweights (I really don't like eagle crankshafts). I had to grind a bunch more material out of the RB because of the larger rod journals too. I don't care if you want the RB block, go with the 2.2 journals and save some headaches. For that matter, run the 4.375 stroke and get 520ish inches.
To sum it up, if you have a 383 block, build the 496. 440, go 493 (.030 440). If you have both, decide which one is better based on a packaging standpoint: weight, clearance, etc...
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Re: compare 496 b & 499 rb
[Re: Performance Only]
#1135013
12/17/11 11:11 AM
12/17/11 11:11 AM
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Joined: Oct 2007
Posts: 4,205
New York
polyspheric
master
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master
Joined: Oct 2007
Posts: 4,205
New York
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buy stiffer pushrods for the taller engine if needed
Wow, thanks, you're the first one who thought of that.
Boffin Emeritus
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Re: compare 496 b & 499 rb
[Re: dodgeboy11]
#1135014
12/17/11 11:28 AM
12/17/11 11:28 AM
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Joined: Jun 2009
Posts: 877
ky
68roadrunner
OP
super stock
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OP
super stock
Joined: Jun 2009
Posts: 877
ky
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The lower rod ratio will increase the bottom end and the added stroke will offset the smaller bore difference. that is what i was getting at. so you are saying the extra stroke 4.250 over 4.150 will help overcome the bore difference of .065 . would a different cam and head port size help the smaller bore fill better. would you use a smaller faster port or not 
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Re: compare 496 b & 499 rb
[Re: polyspheric]
#1135015
12/17/11 03:54 PM
12/17/11 03:54 PM
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Joined: Jul 2010
Posts: 2,091
Delray beach, Florida
Performance Only
top fuel
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top fuel
Joined: Jul 2010
Posts: 2,091
Delray beach, Florida
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Quote:
buy stiffer pushrods for the taller engine if needed
Wow, thanks, you're the first one who thought of that.
right, the only problem here, other than your sarcastic attitude, is that you make it sound like the extra 3/4" is a really big deal. it's not. given the same spring pressures in either scenario, the same thickness pushrod would work in either.
your great with the math, but i get the feeling you have very little practical hands on experience with this stuff.
as far as the cylinder walls being stronger because they're shorter, that's more myth than fact. we aren't talking about a machined tube here, it's a cast iron cylinder wall with imperfections all over the outside cast wall.thick and thin area's exist in both B and RB blocks. if you have a thin wall in the middle of the B block cylinder, it's a weak area just like it is in a RB cylinder. the only true advantage to the B block is the stronger bottom end.
in the 35 years i've been building these engines i've yet to see more than a handful that actually had thick symmetrical bores on all 8 cylinders. if you could actually find one, then i'd say THAT particular block would be stronger. we don't work in the theoretical world though.
in response to the block distortion from a cylinder head or honing plate, there's no difference in the strength there either. the deck is connected to the cylinder walls. if you torque the fasteners on either block they both distort the same amount. if the cylinders were stronger in one vs. the other, that wouldn't happen. the distortion shows up in the bore as well as the deck.
machine shop owner and engine builder
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