Narrowing down my new LS engine combo.. - Page 2 - Lateral-g Forums

**Steve1968LS2** · #11 01-04-2010, 04:20 PM

Quote:

Originally Posted by tobenk

I would think around 440 or 450 but when u get cubic inches with stroke u run out of room. The only place to get it with the same rod length is pin heigth. Then u start messin with piston strength.

In this case it's mostly happening through bore size.. which normally can't happen with an LS engine to any real degree.

Original plan was a 4.125 bore and 4" stroke for a 427, but if I can get more displacement (safely) then I will.

I will know more once I talk with my piston rep.

ProdigyCustoms · #12 01-04-2010, 05:48 PM

Quote:

Originally Posted by Steve1968LS2

I should probley talk with Carl.. I know enough but I'm no "expert"..

.

You should talk to him for entertainment value if nothing else. He has got some stories and has "A WAY" of puttng things that makes me laugh all the time!

Van B · #13 01-04-2010, 08:59 PM

Quote:

Originally Posted by ProdigyCustoms

You should talk to him for entertainment value if nothing else. He has got some stories and has "A WAY" of puttng things that makes me laugh all the time!

I can tell you stories. I spent the better part of a year with Carl and my dad at the shop when I was a kid (mid 70's) and they were working on the Pro Stock car they ran together. Carl has never been afraid to tell anyone what's on his mind... An incredibly smart man.

I seem to remember talking to Dan from Wegner's and if you go with too much stroke in these things and the piston travels too far out the bottom of the cylinder bore and rocks back and forth. I do not have a good mind for these things so I don't remember what that number was.

**Steve1968LS2** · #14 01-04-2010, 09:29 PM

Quote:

Originally Posted by Van B

I seem to remember talking to Dan from Wegner's and if you go with too much stroke in these things and the piston travels too far out the bottom of the cylinder bore and rocks back and forth. I do not have a good mind for these things so I don't remember what that number was.

I know.. that's why I built the 402 and not something bigger (ie, longer stroke)

piston rock at BDC is a bad thing. BUT, with the new Darton sleeves it's now really a problem since the cylinders can be made a bit longer. I'm going to try and stay with a 4" stroke, hopefully the bore size will cooperate..

**DFRESH** · #15 01-04-2010, 09:54 PM

Steve, what kind of RPM's will the motor be seeing---with those cam specs---looks to be around 6600 or so? Piston speed with that longer rod should be a consideration---but maybe I am still stuck in the old SBC world. I think you are right---clearance on you pan could be an issue with that size rod---didn't you have to clearance it once already for the current motor due to same issue?

Van B · #16 01-04-2010, 10:05 PM

Quote:

Originally Posted by Steve1968LS2

I know.. that's why I built the 402 and not something bigger (ie, longer stroke)

piston rock at BDC is a bad thing. BUT, with the new Darton sleeves it's now really a problem since the cylinders can be made a bit longer. I'm going to try and stay with a 4" stroke, hopefully the bore size will cooperate..

I saw your post at PT about the sleeves after I had posted that. Makes sense. Like I said, my memory was sketchy.

There is no replacement for displacement...

**Steve1968LS2** · #17 01-04-2010, 11:04 PM

Quote:

Originally Posted by DFRESH

Steve, what kind of RPM's will the motor be seeing---with those cam specs---looks to be around 6600 or so? Piston speed with that longer rod should be a consideration---but maybe I am still stuck in the old SBC world. I think you are right---clearance on you pan could be an issue with that size rod---didn't you have to clearance it once already for the current motor due to same issue?

I think my peak power is around 6,300 (now) but it still makes good power even up over 6,700.

My rev limiter is set right now at 6,900.. mostly so I can hold a bit longer before shifting if I need to.

Yea, the rods slapped the stock f-bod Canton pan so we welded in a section for more clearance. That's why I want to stay with a 4" stroke and know that even adding .125 could mean more pan mods and maybe mods to the windage tray.

You can see the 402 build (and the clearance issue) in the story here:
http://www.camaroperformers.com/cama...ade/index.html

tobenk · #18 01-04-2010, 11:23 PM

Steve i would stay with the 4" stroke then just less hassle. No pans modes
and such. I think u good use a little more tq. U said the car could take a little more power but i think torque good help u in the autocross better than horsepower. Either way both motors sound like good combos.