Chevrolet LS series mechanical roller valve train

[user-17438]

Help me begin my education of the LS engines mechanical roller valve train.

Questions:

*considering the LS3/L92 rectangular-port head.What is required for valve springs and rockers to accommodate adjustable rockers and .750" range lift?

*This engine will spin in the 7800 RPM range and make around 700 horse. It will be carburated with a powerglide, dedicated, trailered, serious drag race package.

I am not interested in a non-adjustable, hydraulic valve train.

Valve spring choice has more to do with what lobe and rocker ratio you are using. I have spun 7800rpm with oem hydraulic rollers without problem using hardly any spring pressure. And I have spun 9000rpm using almost the same spring pressures with a solid roller. You need to talk to the cam grinder, work with him on your valve weights and rocker ratio.

How dedicated are you? Change valve springs every 10 passes kind of guy? Is .750 the maximum lift for a reason? Too many variables. Call LSM, Mike Jones, Bullet. And see what they say. If I tell you from my past experience and you chose a different component from why worked for me could be catastrophic for you.

[user-17438]

Racepak shows rpm drops back to about 6200-ish after a 7800 shift.
No Dyno.

Give it more converter.

[user-17438]

Oh and for the adjustble, vs non adjustable. I like non adjustable myself. It's all preference.

[Dragsinger]

MTEngines

I do have some experience, this is one of my builds.

http://classracer.com/classforum/showthread.php?t=54442

[D.B.O.]

Racepak shows rpm drops back to about 6200-ish after a 7800 shift.
No Dyno.

Give it more converter.

Next item on my to-do list

[RW TECH]

A while back I posted some Spintron results on Class Racer- see post ID 20 at this link:
http://classracer.com/classforum/showth ... 898&page=2

The rocker arms were Jesel aluminum with no lightening, in a kit that is made to fit the LS3 cylinder heads. Valves were Manley stainless, pushrods were 7/16" x .165" tapered, cam was a Bullet solid roller (.450-ish lobe height/.775"-ish lift) with their branded Morel solid roller lifters. Retainers were light-weight tool steel and locks were Ti. Timing chain & gear were stock LS3 except cam gear was stock LS7.

Customer brought all of this in along with some PAC 1335 springs, and what wound up running cleaner/higher RPM was a PAC 1238X spring that has significantly lower spring force and costs a lot less.

All said & done this ran smooth above 9K RPM during spin testing.

Don't get too carried away with spring force.

[bill jones]

-I'm curious as to what fasteners are being used for most rockers or shaft mounted rocker arms?

-is everybody still using the stock 8mm size or going to something other?
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-and---what about where the intake fastener holes are ground away up inside the intake ports----to where the intakes can suck oil---what procedures are being used to stop that oil flow into the intake ports?
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-I've only seen the T&D rocker arm bedplates for one LS engine that apparently has GM over the counter only CNC ported heads where the sides of those bolt holes are machined wide open----and that deal still uses 8 mm fasteners.

-it has leaked to where we decided to chamfer the top and underside of the bed plates to install O-rings top and bottom---wasn't really any big deal but they had to be pretty precise O-ring recesses as the bed plates aren't very thick.