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Re: hughes engines sb stud girdle
[Re: humpty]
#1743357
02/01/15 10:27 PM
02/01/15 10:27 PM
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Joined: Jan 2005
Posts: 12,419
Kalispell Mt.
HotRodDave
I Live Here
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I Live Here
Joined: Jan 2005
Posts: 12,419
Kalispell Mt.
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I would not run the 4 bolt mains unless it was a magnum block and the bolts were wider so they could get into the extra meat in the pan rails.
I think the girdle could help keep the mains from deflecting to the front and back of the block, it is not going to do much up/down motion.
I am not causing global warming, I am just trying to hold off a impending Ice Age!
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Re: hughes engines sb stud girdle
[Re: Porter67]
#1743358
02/01/15 10:47 PM
02/01/15 10:47 PM
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Joined: Dec 2003
Posts: 22,696
Bitopia
jcc
If you can't dazzle em with diamonds..
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If you can't dazzle em with diamonds..
Joined: Dec 2003
Posts: 22,696
Bitopia
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You mention "harmonics", first time I've that issue addressed with a girdle. I don't know that it could not address that issue, but suspect it's more by accident then design. All my reasoning would have me agreeing Ryan. If I was asked to design a way to connect all the cap studs together with as much flexibility as possible, with 1/4" plate, this is the design I would use. If however connecting just the two studs together on each cap with 1/4" was the goal, it probably does a decent job, if that is the crux of the problem. However back to the first point here, harmonics can be solved many ways, but only best thru a lot of controlled expensive testing when using a design as complex as a SB running across a broad rpm range. And if that is the case, the OEM's likely just fix the original problem rather then band aid it. I say we have a classic case of: "In psychology and cognitive science, confirmation bias (or confirmatory bias) is a tendency to search for or interpret information in a way that confirms one's preconceptions, leading to statistical errors." 
Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.
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Re: hughes engines sb stud girdle
[Re: HotRodDave]
#1743359
02/01/15 11:18 PM
02/01/15 11:18 PM
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Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Quote:
I would not run the 4 bolt mains unless it was a magnum block and the bolts were wider so they could get into the extra meat in the pan rails.
I think the girdle could help keep the mains from deflecting to the front and back of the block, it is not going to do much up/down motion.
I have 1 block(stock) with 4 bolt mains.. been a very
strong block for years.. it started out in the roundy
round stuff then I bought it
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Re: hughes engines sb stud girdle
[Re: mopar dave]
#1743361
02/02/15 03:33 AM
02/02/15 03:33 AM
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Joined: Nov 2006
Posts: 733
jacksonville,FLORIDA
slammedR/T
super stock
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super stock
Joined: Nov 2006
Posts: 733
jacksonville,FLORIDA
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 I have had one since they first came out whne I first built my 408 stroker from my factory magnum block. Stock main caps and 8rpm with ZERO signs of cap walk and my main bearings are always perfect looking on disassemble. I don't suggest doing 4-bolt splayed caps in a magnum block because if you look at the main webbing it doesn't have alot of meat there as it is. You got doing 4-bolt caps and you are just removing more meat from the webbings. Then you are adding the stress into the webbing area that is alredy the weak point of the block. I machined my main caps to sit the girdle down on them tight and the girdle also acts as a crank scraper. I have been spraying the piss out my 408 for shoot 8 years now, same crank,rods,pistons just new top end and rings/bearings. Never had to turn the crank once and I first built this motor back in 2004.
2000 Dakota R/T, 408 magnum, 727, Indy heads 1000cfm 4150 carb, 93 octane fuel. motor; 10.258 @ 132.78 200 shot; 9.262 @ 144.69 racemagnum
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Re: hughes engines sb stud girdle
[Re: mshred]
#1743366
02/02/15 07:30 PM
02/02/15 07:30 PM
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Joined: Jan 2005
Posts: 3,635
Oakland, MI
dizuster
master
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master
Joined: Jan 2005
Posts: 3,635
Oakland, MI
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I think there is some misconception out there on how the girdle works, and what it's engineered purpose is.
The girdles intended purpose has NOTHING to do with resisting forces in the vertical direction. As correctly mentioned the 1/4" or 5/16" thickness will easily bend from the attachment points (same goes for a big block to a lesser degree).
What it is intended to do, is to prevent the caps from moving fore/aft in the block. As the crank is pushed down against the caps, they want to "splay" forward and rearward because of the bending forces from the crank. The girdle ties the caps together in a fore/aft manner preventing this from happening. This helps prevent that bending force from being transferred up the main webs and into the bulkheads also... meaning the benefits are not limited only to the cap/block interface joint.
The splayed caps only help the block/cap interface joint by increasing clamping, but do not prevent the bending forces from getting up/through the bulkhead in the block.
If you mill the tops of the cap down, and shim accordingly, it can also slightly increase the cap strength by "strapping" across the top of the cap.
Now there is a lot to debate here because all of these blocks were built long before FEA and computer modeling to review stresses, but in my opinion the proof is in the pudding with guys visually seeing differences in their teardown inspections after adding them.
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Re: hughes engines sb stud girdle
[Re: dizuster]
#1743367
02/03/15 12:26 AM
02/03/15 12:26 AM
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Joined: Oct 2003
Posts: 7,506
Az
Crizila
master
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master
Joined: Oct 2003
Posts: 7,506
Az
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Quote:
I think there is some misconception out there on how the girdle works, and what it's engineered purpose is.
The girdles intended purpose has NOTHING to do with resisting forces in the vertical direction. As correctly mentioned the 1/4" or 5/16" thickness will easily bend from the attachment points (same goes for a big block to a lesser degree).
What it is intended to do, is to prevent the caps from moving fore/aft in the block. As the crank is pushed down against the caps, they want to "splay" forward and rearward because of the bending forces from the crank. The girdle ties the caps together in a fore/aft manner preventing this from happening. This helps prevent that bending force from being transferred up the main webs and into the bulkheads also... meaning the benefits are not limited only to the cap/block interface joint.
The splayed caps only help the block/cap interface joint by increasing clamping, but do not prevent the bending forces from getting up/through the bulkhead in the block.
If you mill the tops of the cap down, and shim accordingly, it can also slightly increase the cap strength by "strapping" across the top of the cap.
Now there is a lot to debate here because all of these blocks were built long before FEA and computer modeling to review stresses, but in my opinion the proof is in the pudding with guys visually seeing differences in their teardown inspections after adding them.
Interesting - Concept. I've been through one teardown since going with my 4 bolt splayed caps and haven't visually seen any problems? Actually used the main bearings over again. Then again, I'm not running a rubber crankshaft.
Fastest 300
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Re: hughes engines sb stud girdle
[Re: Crizila]
#1743368
02/03/15 06:25 AM
02/03/15 06:25 AM
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Joined: Nov 2006
Posts: 733
jacksonville,FLORIDA
slammedR/T
super stock
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super stock
Joined: Nov 2006
Posts: 733
jacksonville,FLORIDA
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Quote:
Quote:
I think there is some misconception out there on how the girdle works, and what it's engineered purpose is.
The girdles intended purpose has NOTHING to do with resisting forces in the vertical direction. As correctly mentioned the 1/4" or 5/16" thickness will easily bend from the attachment points (same goes for a big block to a lesser degree).
What it is intended to do, is to prevent the caps from moving fore/aft in the block. As the crank is pushed down against the caps, they want to "splay" forward and rearward because of the bending forces from the crank. The girdle ties the caps together in a fore/aft manner preventing this from happening. This helps prevent that bending force from being transferred up the main webs and into the bulkheads also... meaning the benefits are not limited only to the cap/block interface joint.
The splayed caps only help the block/cap interface joint by increasing clamping, but do not prevent the bending forces from getting up/through the bulkhead in the block.
If you mill the tops of the cap down, and shim accordingly, it can also slightly increase the cap strength by "strapping" across the top of the cap.
Now there is a lot to debate here because all of these blocks were built long before FEA and computer modeling to review stresses, but in my opinion the proof is in the pudding with guys visually seeing differences in their teardown inspections after adding them.
Interesting - Concept. I've been through one teardown since going with my 4 bolt splayed caps and haven't visually seen any problems? Actually used the main bearings over again. Then again, I'm not running a rubber crankshaft.
same for me, I have only put three sets of main bearings in this motor since I built in 2004. First set were clevites and i didn't care for them, second set were King's that i like and after using them twice I bought another set. I'm still running on them today(third re-use) I will prolly change these next time I crack the seal just cause I don't wanna re-use them more than three times.
2000 Dakota R/T, 408 magnum, 727, Indy heads 1000cfm 4150 carb, 93 octane fuel. motor; 10.258 @ 132.78 200 shot; 9.262 @ 144.69 racemagnum
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Re: hughes engines sb stud girdle
[Re: Crizila]
#1743369
02/03/15 07:54 PM
02/03/15 07:54 PM
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Joined: Jan 2005
Posts: 3,635
Oakland, MI
dizuster
master
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master
Joined: Jan 2005
Posts: 3,635
Oakland, MI
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Quote:
Interesting - Concept. I've been through one teardown since going with my 4 bolt splayed caps and haven't visually seen any problems? Actually used the main bearings over again. Then again, I'm not running a rubber crankshaft.
Just to be clear, I'm not saying the 4-bolt caps don't work, or aren't an improvement. I'm just saying that they are doing a different thing then the girdle does.
The 4-bolt cap certainly does a good job keeping the cap clamped to the block which is a good thing. It also helps distribute the load across a wider section of the bulkhead which is also good. In a way it helps tie more of the main bulkhead back to the pan rail through mechanical fastening.
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