Thule

one of the things i cant stop thinking about is to sell my new 346cid motor complete, and start building a new and bigger one. instead of stroking my 346 to 383

i always wanted a aluminium block, but i can hardly overlook the price of the lq9 block, its almost 1k under the ls3 block that i want.

and i must admit that the 418/421cid kits do sound interesting,

but as the lq9 builds are really common here i would really like to hear from you guys about them.

are there any downsides on the 418/421 compared to 402/408?


i would most likely purchase PRC stage 3 head/cam package. or AFR's and the tsp 244/248 cam,

what kind of rwhp's could i expect from a set up like this?

all info about lg9 builds gladly accepted.

best regards
ivar

bww3588

iTrader: (49)

I would start with the 408 because the longer stroke will lead to oil consumption and longevity issues in The long run. The 4 inch stroke engines have a slight problem with this but anything over 4 inch and the piston starts to really rock at the bottom of the bore And the rings lose their seal ever so slightly letting oil by.

JC70SS

iTrader: (7)

the 418 is a 4" stroke in the LS3 block. 416 is a 4.1" stroke I believe in a LS2 or iron block.

bww3588

iTrader: (49)

there is a 416 and a 421. the 421 both have 4.125 cranks. the 416 uses the LS2 block, and the 421 uses the LQ block.

The 418 is a 4.00 stroke LS3/L92

Thule

yes it is a 4.125 crank.

interesting to hear about these oil problems, how are the 454 motors doing then?

FlamingTA

iTrader: (8)

You are going to get some ppl that are not going to like the 4.125 stroke. In the past, yes, the 4.125 stroke engines did use oil. Now they have the piston design down alot better. If it is built by a good shop you won't have anything to worry about. I have a LS2 based 421 built by ERL. I dont' have alot of miles, only 2k or so, but no oil usage so far. These will be NA use only, or maybe a small shot of n2o.

ERL Performance

The piston design is much better now. The sleeve length is the other big issue. Our sleeves actually have a 5.800 length and longer in certain applications but that is key because that longer cylinder keeps more of that pistons up in the cylinder when using the longer stroke cranks like the 4.125 and keeps the piston from rocking as much and causing oil consumption.

Thule

i have checked out the ERL homepage and really want a short block from there,

but the only reason i am thinking about a iron block set up is because you can get a ballanced stroker kit+ the block for under 3k and buy a real good set of heads and cam and still be under 6k

my goal for a long time where to stroke my 346 to 383. but building a big cube motor is just something a want much much more. and if i would do it i would want as big cubes as i could and run it N/A

Thule

damn.. that ERL superdeck block is just awesome, 443cid with a 4.000" stroke. add a set of all pros or AFR's on that and what a engine you would have

Jason 98 TA

iTrader: (4)

We have 408 & 418 short-block iron engines in stock currently. I typically lean towards 4" stroke, but the 4.100" stroke is a option for someone looking to stay n/a. Give us a call & lets discuss options. I believe discussing your goals over the phone is probably the best way to determine what best fits your goals.