SPANKY LS1

iTrader: (24)

4.125 stroke + 4.010 bore= 417cid
4.125 stroke + 4.020 bore= 419 cid
4.125 stroke + 4.030 bore= 421 cid
4.125 stroke + 4.040 bore= 423 cid

Will these combos work better/worse than a 4" stroke motor? (404cid, 406cid, 408cid, 410cid respectively). Are they too "out of square"? I am building a iron blocked 4xx motor, would these 4.125" combos produce more or less power than the 4.000" combos, and would it affect the powerband in the same way that a "traditional stroker" (382/383) does, meaning peaks way lower and generally does not rev as high as a 346. Would a 420 produce signifigantly more power/tq than a 408? What would the tradeoffs/negatives be, if any?

Thanks, Shawn

kumar75150

The only issue I have had with my 4.125 stroke is having to add a quart of oil ever 3000 miles.

I spin my motor to 7000 and have spun it to 7200 before hundreds of times and its still running fine.

GMCtrk

iTrader: (23)

I'd don't think you would have to be worried about anything until you go to 4.250 stroke (oil consumption)

antz01ta

iTrader: (3)

i'm running a 4.125 stroke on a 3.905 bore 395ci. i dont have any oil consumption issues and my motor turns to 7000. just make sure you get standard tension rings, and not the low tension rings that everyone uses.

ktmrider

Good suggestions, all. The longer stroke will apply more side-loading to the piston and rings which is the usual culprit of the oil consumption. But, a really good blueprinting and centerline hone will usually take care of the oil issues.
The longer stroke will give ya more low for a trade on revs. Again, good quality parts and setup will overcome the differences in revs.
Good luck, let us know how things work out!

FASTONE

Good question!How much room do you have in a 6.0 block with a 4.125 stroke?Would it clear aluminum rods?Maybe a little grinding?

strokedls1

iTrader: (1)

I have a 4.060 bore with 4.075 stroke and it runs great. No major oil consumption issues. The motor has reved to 7000 a couple times, but I keep my shift points at 6500rpm. I use regular tension rings from je. No machine work to clearance for the crank was needed with carrillo rods.

SLED28

iTrader: (7)

Aluminum rods with a 4" stroke are tough to get to fit, let alone a 4.125 stroke. You have to notch the block, modify the windage tray and notch the pan, but with a 4.125 stroke the pan won't be able to get notched enough, it will hit the rack
Dave
GMPerf

antz01ta

iTrader: (3)

if this is a street driven application why would you even consider using aluminum rods?