Gen IV LS3 build elements

[carbuff]

Originally Posted by 71RS/SS396

and good venting on the valve covers and valley through a catch can.

Tim,

Do you have a preferred catch can that you suggest/use? There are so many different styles, and as such, a lot of marketing hype for each...

[Jay Hilliard]

Bryan,

Petersen and DSE cans seem to be the ones used a lot.

[Sieg]

Thanks for the input gentlemen, very much appreciated.

What are the basics to improve valvetrain reliability?

[carbuff]

Originally Posted by Jay Hilliard

Bryan,

Petersen and DSE cans seem to be the ones used a lot.

I wasn't aware that DSE sold one. After looking at the picture on their site, that sure looks like the Mike Norris can, which is the one I already have. Thanx...

[PTAddict]

Originally Posted by Sieg

What are the basics to improve valvetrain reliability?

No easy answer there. Every combination known to man has broken for somebody at some point, and you'll see even very highly regarded builders swearing by completely opposite strategies.

Basically, you see variations on two schools of thought. One school emphasizes valvetrain stability - minimize flexure, resonance and valve bounce through light weight hollow stem or titanium valves and beehive springs. That is also the factory GM approach. The other school goes for brute force - solid stainless valves and high pressure dual springs.

Katech, a highly regarded builder who does a lot of research for GM and built all of the Vette endurance racing engines for a number of years, goes for school #1, and they have lots of Spintron data to back it up.

Lingenfelter, on the other hand, goes for big dual Ferrara springs.

I myself think approach #1 makes the most sense from an engineering perspective, and its worked for me for 50ish track days over 10 years. But YMMV, and as I said there is no absolute 100% reliability on any motor used repeatedly to its limits.

BTW, no reason to replace stock rockers - they have very low "effective tip mass" and are reliable.

[Sieg]

Good answers.....Thank you.

[Solid LT1]

Originally Posted by Sieg

So 550 - 575 at the crank is a reasonably safe target?

What are the LS3's common stress related failures?

Throw the connecting rods away, forged pistons, some valve train components and mods to oiling system passages. I haven't built a lot of LS motors but, my friends machine shop has, including his sons kick ass KOH off road buggy engine. If your going drag racing, it's one thing but, if you plan on hitting a road course for 20 minute lapping sessions and extended high RPM running, cooling systems upgrades would come into play in my book.

When building my GS Vette LS3 I went with Mahle pistons, Manley forged rods (lighter than the GM powder metal crap rods) hand ported the heads, changed valves for hollow stem stainless stuff (but the OEM LS3 intakes are pretty nice and light) I drilled the plastic lifter guides for better oil drain back, used better lifters, pushrods, valve springs, and most importantly looked at all the poorly intersecting holes in the oil passages of the block/oil pan and ported/smoothed the transitions as I anticipate extended high RPM operation of my build. You won't find the deficiencies of the LS oiling system in a drag racing environment but, take that same modified motor to a track and you will. After all I went through on the LS build, I think I should have just called up Donvon Engineering and ordered an aluminum GEN1 block. In my opinion the oiling system of an LS motor isn't as good of a set up as a GEN1.

[Vega$69]

The GM Performance LS3/525 is a great motor as is. If looking for 550-575 crank there is no reason to start throwing away bottom end parts. With long tubes and good tuning you'll be likely at the 550 mark without changing a thing

Lots of guys run stock rotating assemblies up to 800 HP without any issues at all.

The GM hot cams are easy on the valve train with their relatively low .525 lift and longer durations.

[ErikLS2]

http://www.hotrod.com/how-to/engine/...g-bang-theory/

[Sieg]

Originally Posted by ErikLS2

http://www.hotrod.com/how-to/engine/...g-bang-theory/

Well that was interesting