PTV clearance and .030 quench question

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Jul 14, 2006 | 12:35 PM

Stroker2112

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From: Nebraska

PTV clearance and .030 quench question

Predator Z and/or anyone who has experience with this setup:

I've been trying to finish the top end of my new 408, and am having some confidence issues confirming the ptv clearance . I've done the light spring and clay excercise several times, but not real confident with in my results ...

My set up is:

-15cc dished Diamond pistons
.010 out of the hole
2 degree advance (111) on a Torquer2 (.595/.598 lift @.050)
4.030in bore
4.000in stroke (6.125 rods)
62cc head chamber (ls6 243s, stock valves)
.040 Cometic head gaskets
Patriot Gold dual springs with .600 lift

With the measurements above, can I be confident in my ptv? Or should I continue to test and possible modify the hydraulic lifters to get exact reading?(not sure this is needed when using light springs)...

...I realize my quench is pretty tight at .030... so this is my concern. Reading the many other posts in LS1tech regarding this issue, it seems my setup is pretty close to other successful owners' top ends.

Last edited by Stroker2112; Jul 14, 2006 at 12:47 PM.

Jul 14, 2006 | 12:37 PM

GFORCE1320

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From: Wichita, KS

You should be fine with the quench, what did the clay results give you?

Jul 14, 2006 | 12:38 PM

Uthinkso

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Joined: Jan 2004

Posts: 633

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From: Detroit,MI

6.125 stroke??? I think you meant 6.125 rods and a 4.000" stroke with 4.030 piston.

P-to-V needs to meausred for sure. What measurements are you coming up with so far?

Jul 14, 2006 | 12:45 PM

Stroker2112

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From: Nebraska

Yes, 6.125 rods...4.000 stroke ...and 4.030 bore...thanks.

I'm getting imprints that measure approx .0625 (or 4/64ths) ... mostly in the exhaust valve.

Jul 14, 2006 | 01:03 PM

PREDATOR-Z

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Joined: Mar 2004

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From: BFE

Just measure the depth in the clay from deepest imprint part to piston contact.\

IMO, you are fine.

Man that motor is gonna make sick,sick trq.

~11.49 SCR and 8.79 DCR, 93 +octane recomended.
.030 quench will be a ++

Jul 14, 2006 | 01:12 PM

GFORCE1320

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From: Wichita, KS

.060 is my comfy zone, you'll be fine.

Jul 14, 2006 | 01:25 PM

Stroker2112

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Joined: May 2006

Posts: 308

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From: Nebraska

Predator Z

Thanks! Would you recommend modifying the Hydraulic lifters for complete accuracy .. or just relying on the light checker springs to do the job?...I plan to measure the clay again tonight for hopefully the last time...looking for a .080 clearance on the intake and .100 on the exhaust.

...the rest of my setup is a 90TB, LS2 intake, 44#injectors, true dual exhaust (flowmasters) with long tubed headers, ported oil pump, K&N air filter, and at some point in the future...probably a new transmission! If it makes as much torque/hp as I think it will (maybe 450-500?)...I'll need to figure out how to get it all back to the wheels on my 2000 Silverado.
Best Regards,

2112Stroker