royslsbry

who knows what crank and rods that are used to turn a 350 into 408 stroker

Sonix

iTrader: (1)

I believe that can be done with a 4" stroke crank. You'll need custom pistons.
I don't even think you can do that with a stock block, you'd need an aftermarket block.
There's a reason why no-one is doing that. Just find a 400cid block, and use that - it'd be a heck of a lot cheaper in the long run.

crazywill

a 406 can either be made out of an ls1 or a 400 but a good aftermarket block like world can go all the way out to 454ci

88bracketT/A

Yes a 30 over 350 block with a 4" stroke crank will give you a 408 but it can not be done with a stock block because there isn't enough room for the 4" crank. If you don't want to go with aftermarket block just build a .40 over 400 and that will give you a 408. If you can fork out the money for the aftermarket block then you would better off getting one with the 400 bore and that would give you a 434, more cubes and a better bore to stroke ratio. Just my 2 cents.

Formula for finding CID: (bore) X (bore) X (stroke) X (# of cyl) X .7854 = CID
4.030 X 4.030 X 4.00 X 8 X .7854 = 408

Bradlyj8Z28

iTrader: (2)

go to StrokerMotor.com, they do a good job expaining how you get the differant ci.

sofakingdom

iTrader: (1)

A "408" is USUALLY a 4000 that's been bored out .040". No stroking is required.

This business of giving motors a new name based on having had routine scheduled maintenance performed is amusing to me. Not sure where that came from.... this "355", "406", etc. kind of stuff.

It's one thing when you're creating a whole new displacement by mixing & matching or altering parts, to a size that the factory DIDN'T produce; like a 383, a 434, etc. But maintenance doesn't really count as a "mod". I don't give my engine a new name because I changed its air filter, either.

Incidentally, a 400, in its native state, doesn't really have 400 CID, anyway; it really has almost 402. We don't call it a "402" though.

The other MUCH RARER possibility for coming up with a 408, the 4" crank in a 350 block, DOES deserve a new "name", since that's a totally non-factory combo. It's also all but impossible to produce in a stock block. There's just not enough room in there to move everything in the crankcase out by ¼", and not have to grind so far that you hit water or something. But with the right choice of rods and some SERIOUS luck, it can occasionally be done. You'll also find that generally, a plain common ordinary stock-dimension 400 with whatever routine maintenance might be required, will outrun it; and best of all, FOR A FRACTION OF THE COST. The only reason to do the other is if class rules or the like put a limit on block choice. For general street-strip type use, it is GROSSLY economically inefficient (a waste of money).

//<86TA>\\

iTrader: (14)

i have a 408 stroker, factory roller block, it is possible. got if from T and L engine development in NC.

88bracketT/A

Well I stand corrected. I was always told that 3.875 stroke was the max unless the roller blocks have more room in them. Do you know what rods they used in it ?

//<86TA>\\

iTrader: (14)

they are h-beams, but as far as length or mods, i dont know

AlkyIROC

The hardest part about overstroking a SBC is the cam height and the deck height.

There's only so much bore inside a stock block. To get more stroke, you need shorter pistons to allow them down farther into the cylinder and still keep the skirts inside the bores. There's a practical limit as to how far a piston can go into the cylinder. Also related to this is the area under the piston which needs to clear the balance weights on the crankshaft when the piston is at BDC. Normally this means pistons that move the wrist pin up into the oil control ring for longer rods.

The distance between the crankshaft centerline and the camshaft centerline doesn't allow a great increase in stroke before the crankshaft (con rods) hit the camshaft. A small base circle cam helps but an aftermarket block designed for a 4+" stroke usually has a raised cam position. Aftermarket blocks can also have a higher deck height, distance from the crankshaft centerline to the top of the deck. A taller deck allows for more stroke without having the piston go down into the bottom of the cylinder.

A 4" stroke will also need to have the block clearanced along the pan rails and at the bottom of the cylinders to clear the con rods. Most factory blocks don't have enough metal to shave off.

If you want a "big" SBC, it's better to use an aftermarket block as well as everything else aftermarket.

royslsbry

the reason i asked about this 408 is because t@l engines offers this and it is one bad motor my friend recently purchased one from them and man is his car fast and runs well on pump gas i asked him how they built it he wasnt sure. I can say one thing its mean. I guess i need to quit trying to figure out how to build it and just buy one from t@l can anyone help donate to my cause

Sonix

iTrader: (1)

Interesting. I'd be curious to know what T&L uses. Perhaps Hard-blok, then grinding? What pistons and rods? That stuff is usually quite expensive...

But a long stroke shorter bore is generally better at warding off detonation, compared to the same cubes made by a larger bore and shorter stroke.

//<86TA>\\

iTrader: (14)

you could always call T and L, ask for lloyd as ask what they do, though i do believe its a secret

as for being fast, the thing is a beast!