Chevrolet LS series mechanical roller valve train

[Dragsinger]

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.

[CGT]

Look at Manley 221422-16

[Dragsinger]

Thank You about the Manley spring.

For future reference, the LS series has many options and all the parts and modifications we are accustomed to with the generation 1 SBC are also available for the LS series. Mechanical, link bar roller lifters, adjustable & shaft rockers, valve springs to accommodate.750" lift. Also, Brodix, Dart, and GM offer a number of race head packages.

[V Remian]

Pac 1335 spring. TD rockers. Machine rocker mounting pedestals around .100 to restore geometry.

[D.B.O.]

I tested last weekend, made 7 passes between 9.001 and 9.102; 149.80 and 150.78, testing various theories. 2600lb Camaro, powerglide, cast single plane and 4500 Dominator. 7800 shift, 7500 lights. 416ci LS3. But with a hydraulic roller. How fast are you wanting to go? Going solid roller this summer, also interested in responses.

[CGT]

I tested last weekend, made 7 passes between 9.001 and 9.102; 149.80 and 150.78, testing various theories. 2600lb Camaro, powerglide, cast single plane and 4500 Dominator. 7800 shift, 7500 lights. 416ci LS3. But with a hydraulic roller. How fast are you wanting to go? Going solid roller this summer, also interested in responses.

Id be interested to know some details on your 416.

[Dragsinger]

D B O,

the performance you posted is excellent and in the range of what I expect. My build will be about 2900 with driver so a 5.85 1/8 is a good expectation.

Tell us about your LS 3 heads.

[Dragsinger]

I am considering a 4.065 bore x 4.00 stroke, is that what you have?

[D.B.O.]

Yes, 4.070 x 4.00. K1/Wiseco rotating assembly. +5 dome, 14.13cr, OEM 5364 Ls3 castings, REV 2.165 intakes, Ferrea 1.60 exhausts. Gavin @ SPS Cyl. Heads ported them. BTR .685 springs/retainers. 3/8 pushrods, Jesel 1.8, 254-266 .658/.639 111+5.(needs more lift, I know). CID intake, untouched, 1050 dominator converted to 2 circuit.
The 7 passes were with 1.5” spacer to get my scoop to seal to carb plate, though with that large of a plenum, don’t know if it hurt or helped or made zero difference. I do know that Racepak said I only had 4” of vacuum, so I need to look at that. I also know the converter is about 500rpm too tight, again based on Racepak graph.
What else?

[CGT]

Yes, 4.070 x 4.00. K1/Wiseco rotating assembly. +5 dome, 14.13cr, OEM 5364 Ls3 castings, REV 2.165 intakes, Ferrea 1.60 exhausts. Gavin @ SPS Cyl. Heads ported them. BTR .685 springs/retainers. 3/8 pushrods, Jesel 1.8, 254-266 .658/.639 111+5.(needs more lift, I know). CID intake, untouched, 1050 dominator converted to 2 circuit.
The 7 passes were with 1.5” spacer to get my scoop to seal to carb plate, though with that large of a plenum, don’t know if it hurt or helped or made zero difference. I do know that Racepak said I only had 4” of vacuum, so I need to look at that. I also know the converter is about 500rpm too tight, again based on Racepak graph.
What else?

Very cool. Still using gm lifters? Im building a 4.070x3.622 currently, 10cc dome. 4500 carb. Your 416 is pretty similiar to the direction Im going minus the stroke.

[D.B.O.]

Actually, just took out the OEM valves and lifter not long ago. Using Johnson 2110r lifters now, though the LS7’s have seen 7800 many times

[randy331]

I tested last weekend, made 7 passes between 9.001 and 9.102; 149.80 and 150.78, testing various theories. 2600lb Camaro, powerglide, cast single plane and 4500 Dominator. 7800 shift, 7500 lights. 416ci LS3. But with a hydraulic roller. How fast are you wanting to go? Going solid roller this summer, also interested in responses.

Your car runs good.

What's stall speed ?
Been on a dyno ?

Randy

[D.B.O.]

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

[randy331]

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

Flash at starting line ?

Care to share what the current cam is ? the lobes etc.

Randy

[D.B.O.]

Launch at 5000, rpm instantly climbs to 6200, then converter lugs to motor down to 6000 and then climbs to shift point.
EPS designed cam with Cam Motion lobes. 254-266 @ .050 .621/.604 w/1.7 rockers, but I have 1.8 shafts. I set up preload 1/4 turn after zero lash, cold. 111LC installed on 106