Reasonable pushrod length?
Thread Starter
Teching In
Joined: Mar 2014
Posts: 38
Likes: 1
From: Paris, KY
Reasonable pushrod length? Hello,
I have a 2005 5.3 L33 from a 2005 Silverado going into my '82 S10 truck, currently on the engine stand while I reassemble it. Today I measured for pushrod length using the Comp pushrod check tool, and I want to know if what I measured seems reasonable, since this is my first LS build (everything else I've touched had adjustable rockers).
The Comp. cam tool (6.800 length) came out to 11 turns on the intake and exhaust both, on both heads, checked several times, to get to zero lash. That looks to be 6.800 + (.050*11) + .075 = 7.425 pushrod length. When I ordered the cam Cam Motion said to measure it but expected that stock pushrods would probably be where I ended up.
This was measured with the Cam Motion valve springs that shipped with my cam installed.
The engine: 5.3 L33 long block is all stock, no machine work that I know of (used engine but as far as I can tell I'm the first to disassemble it). Stock 799 heads fresh from the machine shop, where they were cleaned/pressure tested/valve job and they said they did a .005 cut to clean up the deck. Original GM rocker arms rebuilt with Straub bushing kit. Head gaskets are GM MLS 12498544. GM LS7 lifters. Cam is a custom grind Cam Motion cam (224/234 111.5 +3, about .600 lift).
Does this seem reasonable?
Also, I was considering ordering a larger-than-stock diameter pushrod (and possibly larger wall thickness) but have not yet decided what will fit. Any thoughts here are greatly appreciated as well.
Thanks,
I have a 2005 5.3 L33 from a 2005 Silverado going into my '82 S10 truck, currently on the engine stand while I reassemble it. Today I measured for pushrod length using the Comp pushrod check tool, and I want to know if what I measured seems reasonable, since this is my first LS build (everything else I've touched had adjustable rockers).
The Comp. cam tool (6.800 length) came out to 11 turns on the intake and exhaust both, on both heads, checked several times, to get to zero lash. That looks to be 6.800 + (.050*11) + .075 = 7.425 pushrod length. When I ordered the cam Cam Motion said to measure it but expected that stock pushrods would probably be where I ended up.
This was measured with the Cam Motion valve springs that shipped with my cam installed.
The engine: 5.3 L33 long block is all stock, no machine work that I know of (used engine but as far as I can tell I'm the first to disassemble it). Stock 799 heads fresh from the machine shop, where they were cleaned/pressure tested/valve job and they said they did a .005 cut to clean up the deck. Original GM rocker arms rebuilt with Straub bushing kit. Head gaskets are GM MLS 12498544. GM LS7 lifters. Cam is a custom grind Cam Motion cam (224/234 111.5 +3, about .600 lift).
Does this seem reasonable?
Also, I was considering ordering a larger-than-stock diameter pushrod (and possibly larger wall thickness) but have not yet decided what will fit. Any thoughts here are greatly appreciated as well.
Thanks,
Length doesn't sound unreasonable for the pushrods. With stock heads, the Manton 11/32" pushrods will probably work without further work to the heads. 3/8" straight pushrods will typically not fit. The 3/8" double taper "might" fit but they are more money than the 11/32" and you need to test them prior to installation. I got my 3/8" double taper from Trend. Larger OD pushrods is a very good idea as they will greatly increase the valve train stability at higher RPM.
Joined: Aug 2007
Posts: 24,241
Likes: 89
From: Turnin' Wrenches Infractions: 005
That looks to be 6.800 + (.050*11) + .075 = 7.425 pushrod length.
Does this seem reasonable?
Also, I was considering ordering a larger-than-stock diameter pushrod (and possibly larger wall thickness) but have not yet decided what will fit. Any thoughts here are greatly appreciated as well.
Thanks,
Does this seem reasonable?
Also, I was considering ordering a larger-than-stock diameter pushrod (and possibly larger wall thickness) but have not yet decided what will fit. Any thoughts here are greatly appreciated as well.
Thanks,
https://www.ebay.com/itm/Manley-LS-P...dVf21r&vxp=mtr
Thread Starter
Teching In
Joined: Mar 2014
Posts: 38
Likes: 1
From: Paris, KY
Hello,
I measured 11 turns on the tool, so that's 6.800 + (0x50 * 11) = 7.350. I added .075 for preload to get to 7.425.
I called Manton on Monday and ordered a set. They suggested the 11/32 pushrods, and he added (I think, I don't have the number handy) .015 to adjust for the measuring tool method vs. the method they use.
$218.97 shipped to my door.
I measured 11 turns on the tool, so that's 6.800 + (0x50 * 11) = 7.350. I added .075 for preload to get to 7.425.
I called Manton on Monday and ordered a set. They suggested the 11/32 pushrods, and he added (I think, I don't have the number handy) .015 to adjust for the measuring tool method vs. the method they use.
$218.97 shipped to my door.
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Sound just fine to me. I've had best luck at .060" to .080" with the LS7's to keep them nice and quiet.