Do I need a main stud girdle or not?

Scott Kiger

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I just bought an RB block that has been machined to run billet caps with the cross bolts added through the side. Would running a main girdle be overkill on this engine or is it needed like on all the other race engines I have built? Will be a 500” stroker bracket engine with all the best parts when built.
 

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it needs to be line honed also,
with the 2 middle studs on each main cap
(3 center main caps) torqued down in place
if you go with a girdle, it's part of the girdles' support
IMO It can't hurt, if your budget can handle it
it's not that expensive either,
IMO cheap insurance
(unless you have a good aftermarket block, that was designed for
& came with 4 or 6 bolt main-caps
)
It just helps, to tie 'all the bottom end together'
the block, sides/oil pan-rails & mains
so the main studs/main bolts aren't acting
'like a flag pole, waving in the wind'

the weakest part of an RB block,
especially an OE factory 2 bolt main block

is the 'main journal webs' undercuts just above the mains
 
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Scott Kiger

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it needs to be line honed also,
with the 2 middle studs on each main cap
(3 center main caps) torqued down in place
if you go with a girdle, it's part of the girdles' support
IMO It can't hurt, if your budget can handle it
it's not that expensive either,
IMO cheap insurance
(unless you have a good aftermarket block, that was designed for
& came with 4 or 6 bolt main-caps
)
It just helps, to tie 'all the bottom end together'
the block, sides/oil pan-rails & mains
so the main studs/main bolts aren't acting
'like a flag pole, waving in the wind'

the weakest part of an RB block,
especially an OE factory 2 bolt main block

is the 'main journal webs' undercuts just above the mains

Thanks. I was thinking I would run the girdle. Just didn’t know if it would be redundant or not. It’s an OE block that has been side drilled and machined like a Hemi block.
 

33 IMP

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If you have the maincaps tied into the side of the block,, like a hemi, and IF the machine work was done properly, you shouldn't need a girdle. A girdle is just a cheap and easy way to duplicate what has already been done to yours.
 

Scott Kiger

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What's your target power range?

I don’t really have one. It’s going to be a 500” inch engine with Stage VI max wedge port heads. Heads have been CNC ported and worked. Will be full roller. Going in a tube chassis bracket car.
 

451Mopar

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Sounds like the aftermarket cross-bolted mains would tie the block together like a girdle.
I have the aluminum main caps and 1/2" thick steel girdle from BCR and it seems to work good for me.
I don't know how stiff the 1/4 steel girdles are. I may use one on a new 512" 440. The extra 1/4" space will make the molded 4.15" stroker windage tray/gasket easier to clear the 4.25" stroke crank.

FWIW, the molded 4.15" windage tray will clear some 512 stroker combinations, but it is really close.
 

33 IMP

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Sounds like the aftermarket cross-bolted mains would tie the block together like a girdle.
I have the aluminum main caps and 1/2" thick steel girdle from BCR and it seems to work good for me.
I don't know how stiff the 1/4 steel girdles are. I may use one on a new 512" 440. The extra 1/4" space will make the molded 4.15" stroker windage tray/gasket easier to clear the 4.25" stroke crank.

FWIW, the molded 4.15" windage tray will clear some 512 stroker combinations, but it is really close.
I really like that BCR setup, especially for a stroker. If your gonna put a girdle on, use a nice thick one!
 

biomedtechguy

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I have the aluminum main caps and 1/2" thick steel girdle from BCR
I really like that BCR setup, especially for a stroker. If your gonna put a girdle on, use a nice thick one!
THAT exact setup was what I was going to use IF I was using a factory block.
The technical description of that kit's benefits are undeniable IMO.
Instead, I got a new Bill Mitchell aluminum block.
 

451Mopar

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It's pretty easy to have over $1,500+ into the caps and girdle when you include the machine work to install them.
I haven't bought an aftermarket block yet, but I think if I was going to do a power adder then I would start with an aftermarket block.
 
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