booboo37

iTrader: (43)

I picked up a nice Lsa short block and wondering about a few things...

Thinking of selling the rotating assembly and keeping the block and building a stroker....

Should i only stick to 415--416ci. or can i go bigger with this Lsa block...???...no power adder ...all motor....so I'm thinking higher compression...

i do have GMPP cnc Ls3 821 heads..Ls3 Super Vic 4500 carb. intake manifold with Prosystem 4500 carb...

Has anyone taken the oil squirters out and put set screws in ??

redtan

iTrader: (5)

While you can make a 427 out of it by stroking it more, the general consensus is that a 4" stroke is the limit on these in terms of longevity and reliability. The same goes for the bore, anymore than that is pushing it.

gnx7

iTrader: (28)

You could run Katech squirters and keep that nice engineering marvel; however they are $$$

slogo

Redtan, can you explain why more than 4"
stroke cuts down on reliability, longevity.
I have a 4.100 stroke and wondering how much
I screwed up by going that route. I have asked
before and just wanting more opinions. Thanks

showdog75

iTrader: (8)

This is a interesting video. He explains why he doesn't like long stroke ls engines.

slogo

Thanks showdog, that is a good watch.

booboo37

iTrader: (43)

I like the set screw idea better lol..

slogo

Is there a reason you cannot use the factory ones? did they have to come out for some reason? I have never seen them before if that is a stupid question.

redtan

iTrader: (5)

The liners on most LS based engines are short and do not support a long stroke well (exception being the LS7) and when you increase the stroke, you pull the piston further down in its bore. If it's not long enough, the bottom of the piston is pulled out past the liner and thus it starts to rock and become unstable due to not having the support necessary.

Piston manufactures have gone a long way in designing pistons for long strokes in stock liners and have greatly improved on this issue...but the liner length still remains a limiting factor. 4" strokes have been ok for lots of miles in plenty of applications. Past that though it starts to get less and less reliable over the long term, especially with 4.1" and 4.125" strokes.

It's not the end of the world with a 4.1" stroke, it's just that you'll burn more oil and probably wear out some engine parts quicker than the same engine but with a sub 4" stroke.

booboo37

iTrader: (43)

If you go to a longer stroke the pistons will hit the oil squirters...


<a href="http://s51.photobucket.com/user/bigcowl-imp/media/ls9%20block%20002_zpsjjylya90.jpg.html" target="_blank"><img src="http://i51.photobucket.com/albums/f393/bigcowl-imp/ls9%20block%20002_zpsjjylya90.jpg" border="0" alt=" photo ls9 block 002_zpsjjylya90.jpg"/></a>

slogo

Thanks for the picture I have not
Seen that, that's a bummer you can't use
Looks like a good thing

Mechanic a

according to GM max stroke on a lsa block is 4.5



this is out of the 2014 gm performance parts catalog

redtan

iTrader: (5)

And the LS7, which has the longest sleeves in all mass produced blocks (not counting the LSX stuff) can only do 4.100? Seems odd.

Mechanic a

Doesn't really make sense to me either, especially since in stock form it's only 3.622 stroke, unless the designed it with the aftermarket world in mind because of what the engine is put into. But I do know GM wouldn't say it's possible unless it is.

KCS

iTrader: (20)

Well it's not possible, not as they come from GM at least. The stock sleeves just are not long enough to support that much stroke. It's probably just a typo.

Mechanic a

The 2015 and 2016 catalog both say the same. LSA and LS9 max stroke of 4.50. Block part numbers 12623968 lsa and 12623969

KCS

iTrader: (20)

Then those catalogs have typos too.

dogsballs

More dramas than its worth. Lsa have stronger crank than a ls3 as well

Yonerton

iTrader: (-1)

I would never run more than a 4" stroke personally but that's just me. Them oil squirters tho!

booboo37

iTrader: (43)

What about a Ls7 block ?? I think the biggest i seen was 442ci. ...i think....i wonder if guys ever make a 455ci.. with the Ls7 block and 4.250 stroke....??