Big Bird WS6

iTrader: (9)

hey is it possible to get a 408 out of an lt1? friend just broke a piston and has to bore it .020 over to take out nick. so if we have to bore more that is fine. but what stroke and bore do i need to get a 408?

thanks

Ray@Nitrous Outlet

is there a particular reason you want 408cid.....????

383 or 396 is the more common stroker discplacements for the LT1.

Big Bird WS6

iTrader: (9)

just what friend wants.

but i will tell him to do either of those. just what bore and stroke and rod lenght do i need?
thanks

grn95t/a

iTrader: (10)

http://eaglerod.com/products/Chevy/s...ssemblies.html

Big Bird WS6

iTrader: (9)

so 12113 will work in a LT1 block?

1SlowFormula

you can do a 408 and I have been debating on it, the only downfall is most cranks are made for a 6" rod and this puts the CH of the piston at about an inch which is getting kinda short and tothe limit of what's not recommended...

It would be a 4" stroke crank to get you above 400" in an SBC/LT1...

This is what I was thinking about using, if I wanted off the shelf parts, and decking the block to 9" flat...

Eagle 435340006000 1pc, 4" stroke crank
Eagle CRS6000BST rods are already cam clearanced for the 4" stroke
You can use Diamond street/strip (8cc dome) 23* pistons (11710 - .030, 11711 - .040, 11712 - .060)
or Diamond Race (12cc dome) 23* pistons (11925 - .030, 11926 - .040, 11927 - .060)

The other thought is go with a custom piston and a 5.85 rod to gain a little more CH on the piston and maybe move the bottom ring away from the pin...

something like...
Eagle 435340006000 1pc, 4" stroke crank
Eagle CRS5850BST rods, again they are already cam clearanced for the 4" stroke
and a custom piston that will top out depending on the least material I can take off the block to get it straight. lets asume I can get it straight with a .005 machined off (most LT1's are between 9.025 and 9.030 from the factory) bringing the deck to 9.020ish then the CH height of the piston could be a slightly more desirable 1.170", anything under 1" starts to wobble in the bore and wear the bore out quicker and break ring lands, not to mention have the oil ring in the pin channel...


So yes, a 408 LT1 is possible, but if you want it to be safe and reliable it will add the cost of custom pistons and a shorter rod, plus the extra for ballancing because of the custom stuff since you would have to shave the counterweights for the shorter rods to not allow piston to crank contact at BDC according to the tech guy I talked to at Eagle...