GIGAPUNK

iTrader: (2)

All I ever see around are the 402s and 408s with the 4.0" strokes in the LS2. Are the stock sleeves not deep enough for 4.1" or 4.125". I know that 4.250" stroke is reserved for the realm of resleaved blocks with their deeper sleeves. A lot of guys are already going into the oil control ring with 4.0", so if it isn't going to pull the piston out of the bottom of the cylinder I don't see what's holding people back from going a little bigger.

SLED28

iTrader: (7)

I will be building a few 4.125 stroke LS2 motors soon in the next few weeks, they are torque monster 415 cubers. It is a nice combo and different. I use a little longer rod at 6.200 and that helps keeping the piston up in the bore and not pull out like everybody thinks. I have built a 4.250 stroke motor before with no problems.

Randy WS6

iTrader: (69)

I buint a LS2 418 4.030" bore & 4.100" stroke & 6.125"rods, Hope to put it in next weekend

Beast96Z

iTrader: (21)

You can do 4.250 on a stock sleeve. It's been done, just not the most desirable set-up.

Dragaholic

iTrader: (180)

Just curious, but why is it not desirable? What are your thoughts on a 4.100" stroke? Do they even make 4.125", 4.150", 4.175", etc. etc.?

SLED28

iTrader: (7)

You can get 4.100, 4.125, 4.185, 4.250's

Randy WS6

iTrader: (69)

As far as i know Eagle is the only ones out there making the 4.100" stroke forged crank , but i like it a little bigger than a 4.00" stroke and a little smaller the the 4.125 and the cost between the 4.100 and the 4.125 around 600.00 to 800.00 differance i just cant see that much money for .025" and four cubic inches. 418 cid.4.100" 4.030" bore & 4.125"stroke, 4.030 bore. 422 cid.

Blown04Z06

if either of these ***418 cid.4.100" 4.030" bore & 4.125"stroke 4.030 bore. 422 cid.*** were even offered to me as options i would have gone with one of them. if i dont like the results from my 403 i think i will have it pulled to go with a 418 or a 422

i think this would be the best option without spending an additional $2300-$2500 to go to a 427.

i think the idea behind a 402/403 is the motor is square having a square motor supposedly makes it more balanced, durable and will last longer

Blown04Z06

ill be looking forward to seeing your results to see if my thought process is correct or not. the 418/422 combo should break into the 525/525 with out running a huge cam or building a max effort motor.

my car will be done saturday LS2 403 minus headers, so im not expecting to even break 470 without long tubes. i just needed to get it running now that i dont have a 2nd car. i havent drove the car in 9 months and 14 days.

Blown04Z06

oh and regardless notching or clearancing the block will be required with 4"+ crank. they had to clear mine for the eagle H-beam rods. on mock up the rods hit the inside of the block. i cant remember how many 1000ths had to be removed but it was done. so if there is only a $600 difference in cost to do it, i would do it if i had a second chance. hard decision im sure your going through trying to decide. find an engine builder that is comfortable with the build that you want and move on it.

GIGAPUNK

iTrader: (2)

Anybody have a profile pic of one of the 4.100" + stroke pistons that they put in a stock (minus rod clearance) LS2 block. I'm curious too see how close to the 2nd piston ring the pin is. What kind of compression height does that come out to with a 6.200" rod?! (just bein lazy)

PS. SLED I'm glad you chimed in.
PPS. Randy, that is a thing of beauty.

Randy WS6

iTrader: (69)

On a 6.125 rod, The wrist pin is up in the piston ,They use a shorter wrist pin and i had to use a ring support for the lower oil scraper ring to rest on . and to get my compression down to 12.5.1 my pistons were cut .005 down in the hole ,flat tops not dished, with .055 thick LS2 head gaskets, 59cc chambers and the pistons are very light 382 grams and no less than .055 clearance piston to counter weight, and the block will need to be clearance for the rod bolt at least .060" I just used a die grinder to notch the block ,very easy ,and the F-Body oil pan will need clearance up front for the front #2 rod ,rod bolt to clear .and will need to shim the windage tray 3'16" to clear the counter weights ,The wurst thing is ,I had to have the reluctor ring turned down .030" to cleat the pistons and the pistons were notched also ,The pistons were notched so deep that there were only .060" between the rector ring and the spiral locks .Ross made these pistons for me and they work perfectly with no clearance problems at all ,After turning the reluctor ring down i had to do some modification to the crank sensor to move it closer to the crank a minus of.020" besides all that every thing when pretty smooth. all the clearance problem done in one full day. this is what i had to do to build a 418cid. These motor are so new that there are very few of these like 10 maybe 15 that exist (Shier Dicky) is the man that help me with all this you see and he builds them for customers.

SLED28

iTrader: (7)

Here is a 412 LS2 piston/rod pic. 4.100 stroke x 6.125 rod x 4.00 bore. CH is 1.065". You can see there is quite a bit of meat there, good for a 250+ shot. i used to run a 1.060 CH in my LT1 years back with a 400 shot no problem. ALso the pistons used have a 1/16 1/16 3/16 ring package, which has more ring width then metric ring packages. One reason I like the Wiseco's, and 2nd, they clear the reluctor out of the box. (always double check though).

Beast96Z

iTrader: (21)

My wiesco's didn't have the problems Randy was talking about either. I have a 4.185" stroke in mine and have had problems. Just the normal stroker clearencing.

Dragaholic

iTrader: (180)

Would this apply to the L92 block as well? Would you be able to use a longer rod for more stroke?

SLED28

iTrader: (7)

When you go longer rod or stroke, your losing piston thickness... But at 4.125 stroke x 6.125", there is still good piston thickness. I would assume its the same for the L92 block.

GIGAPUNK

iTrader: (2)

Maybe I should post this question in NO2, but...

What do you guys consider a minimum piston thickness?
Measured as compression height or distance to the first ring land?
Let's say and still be strong enough to never have to worry about a 200 shot, and still using a standard ring pack. Can you get away with a CH of less than 1.050"? Less than 1.000"?

SLED28

iTrader: (7)

I've run 300 shots on .975 CH pistons in LS motors. Its the top ring land that needs the meat.

Dragaholic

iTrader: (180)

Is a 4.125" or even a 4.100" a standard stroke crank for LSX based motors? In other words, is it a shelf item or has to be custom made?

Can anyone verify if its possible to use a bigger stroke than a 4.00" in a L92?

GIGAPUNK

iTrader: (2)

Eagle makes really affordable 4.oo and 4.100
Lunati and others make 4.00, 4.125, 4.250, and pretty much anything else you're willing to pay for.

I've never heard mention of any differences in the depth of the sleeves in the L92. The deck ht is the same as the LS2, it just has a .060" bigger bore and DOD.