so i'm kicking the idea around about building a stroker motor, and looking at a few different options....

how tight of a fit would a 4 inch stroke crank be in a production 1989 L98 block? i have a roller block sitting here that i'd like to use. i want to avoid going to a tall-deck block if at all possible.

a 4 inch stroke with a 4.030 bore would put me at just a hair over 408 cubic inches.

i found a rule sheet for the latest engine masters challenge in the june 04 phr magazine, and they specify a production height block must be used. aftermarket blocks are ok, just that they must be production height. they specify a 410 ci limit, if it specs at 410.1, you're disqualified.

this brings me to my next question. the lighter a part is, the easier it is to spin faster, correct? i want to have the lightest possible rotating assembly.

yes, i'm aware of the expense.

yes, i'm probably crazy.. any insight?

 

It would be damn near impossible. The only way to do it would be to severly grind into the water passages by the oil pan rail and weld or expoxy them up. You would also have a really hard time finding pistons with the pin deep into the ring package.

So in short with a GM production it isn't going to happen, but it you had a Dart block them maybe. I will guarantee it will work with a tall deck block though!

 

Ok, it's late, but i will have a crack at what i [i]think[i] is going to happen. First, you will need 6" rods so the pistons clear the crank. With that in mind, here it goes:

2" for the stroke (the radius of the stroke, or center of the crank to the rod journal)
6" for the rod

2+6 = 8. You have aobut 1" for compression height otherwise the piston will poke out the block on a factory deck.

 

the more i thought about it today, it's going to be obscenely expensive if not impossible to accomplish.

i think it's going to be easier to build a large-bore (400-type block) as opposed to trying to stroke a 350 block.

i sat and did some math earlier today. a .040 over 400 block with a 3.75 stroke crank will bring me to 408.7 cubes. plus, 400-type pistons are much more readily available from what i've seen compared to the custom 350 stroker application i was looking for.

i know crower makes a lightweight crank that specs out anywhere between 38-45 lbs, based on mains and stroke.

how light of a rotating assembly is too light? i can realistically say i'd like to spin this engine up to 6500 rpm.

opinions? insight?

thanks guys!