Only made 357whp on 346ci LS1, whats killing my power??
11-30-2010, 11:23 AM
#21
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What is reccomended lifter preload these days, 50 thou?
I've had a few 346-348 cid engines, and yes the headers hurt, but unless you plan to run cutouts what can you do. My 11:1 engine had TFS heads, LS2 intake, 240/244 Vengeance cam, and made 420rwhp thru an 8" converter.... went 10.9@123 mph NA @ 3300 raceweight. That's stock water pump and 1.75 headers.
I've had a few 346-348 cid engines, and yes the headers hurt, but unless you plan to run cutouts what can you do. My 11:1 engine had TFS heads, LS2 intake, 240/244 Vengeance cam, and made 420rwhp thru an 8" converter.... went 10.9@123 mph NA @ 3300 raceweight. That's stock water pump and 1.75 headers.
11-30-2010, 11:31 AM
#22
What is reccomended lifter preload these days, 50 thou?
I've had a few 346-348 cid engines, and yes the headers hurt, but unless you plan to run cutouts what can you do. My 11:1 engine had TFS heads, LS2 intake, 240/244 Vengeance cam, and made 420rwhp thru an 8" converter.... went 10.9@123 mph NA @ 3300 raceweight. That's stock water pump and 1.75 headers.
I've had a few 346-348 cid engines, and yes the headers hurt, but unless you plan to run cutouts what can you do. My 11:1 engine had TFS heads, LS2 intake, 240/244 Vengeance cam, and made 420rwhp thru an 8" converter.... went 10.9@123 mph NA @ 3300 raceweight. That's stock water pump and 1.75 headers.
11-30-2010, 01:16 PM
#23
That intake has to be killing your power as well. It looks like the majority of the air feeding your engine is coming straight off your headers. That's well over 100*F air temps, not good for power at all. I guarantee if you get that intake rearranged so your motor's getting fed clean fresh cold air you'll see very noticable improvement.
11-30-2010, 03:06 PM
#24
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Thanks for the replies guys!
I have now made my intake re-routed towards the headlight, huge Improvement! Later today I will check lifter preload with my friends adjustable push rod length checker. Hopefully I have INCORRECT preload lol, because I think I should be at 380whp at least...
Also... I re-routed the air flow meter further instream toward the throttle body. Much better drivability now at low rpm high loads! No more surging.
I have now made my intake re-routed towards the headlight, huge Improvement! Later today I will check lifter preload with my friends adjustable push rod length checker. Hopefully I have INCORRECT preload lol, because I think I should be at 380whp at least...
Also... I re-routed the air flow meter further instream toward the throttle body. Much better drivability now at low rpm high loads! No more surging.
11-30-2010, 06:20 PM
#26
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Ok just checked lifter pre-load on a valve.
We went to 0 lash, and it took 1 1/4 turns to seat the rocker back down. We figure approximately .060 preload.
Any other ideas?
We went to 0 lash, and it took 1 1/4 turns to seat the rocker back down. We figure approximately .060 preload.
Any other ideas?
11-30-2010, 07:27 PM
#27
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Well take 357rwhp and then add in 20rwhp for your smaller than stock exhaust... You are at 377rwhp. I think your numbers make sense. I made 375rwhp with h/c/ls1 intake thru a locked A4 11 years ago... similar cam.
11-30-2010, 10:01 PM
#30
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I run those ls7 lifters around 30thou seam to hold on better up top, i ran them as low as 15-25 with no issues and dead quiet. You don't need to run 80 thou preload, Geez don't even see that in ol' SBC with aftermarket cams, they go quarter of a turn and lock out. Which would be 30 thou tops. When I ran them at 80 thou I had bad pump up and I was losing tq quickly up top.
11-30-2010, 11:39 PM
#31
What about camshaft timing? (Degree) Do LS7 lifters have the heavy duty retaining clips? I don't think I would run much preload at all if they did. The oil pumps in ls engines are amazing I would think pump up would be more common in them.
11-30-2010, 11:58 PM
#32
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I run those ls7 lifters around 30thou seam to hold on better up top, i ran them as low as 15-25 with no issues and dead quiet. You don't need to run 80 thou preload, Geez don't even see that in ol' SBC with aftermarket cams, they go quarter of a turn and lock out. Which would be 30 thou tops. When I ran them at 80 thou I had bad pump up and I was losing tq quickly up top.
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