Lq9 with 823 heads
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Joined: Jan 2012
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From: Post Falls, Id
Lq9 with 823 heads anyone out there that has built a lq9 6.0 and installed 823 rectangle port heads, using stock rockers and a LS9 head gasket? was there an issue with pushrod length? if so what did you do to for changes?
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From: Dade City, Fl.
I didn't have one either but bought one when I was putting together my LQ9. It was under $20 and I bought a 8" caliper for $25 . Well worth the cost to have the lifter preload set optimally
Thread Starter
9 Second Club
Joined: Jan 2012
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From: Post Falls, Id
i have done all the preload math but too me it just seems off, which it is coming out to .055 on the preload. and when i run the motor it acts like it has an vacuum leak which I have tested for a external vacuum leak numerous times with no change in the idle and when it comes to the fueling side of things having a fairly high cyl airmass which when tuning SD makes me have to crank up the values on the ve table. so it makes me think that my valves aren't fully seated. not to mention that under light driving it acts like a miss fire and the motor is back firing into the intake randomly. not i have gone through all the cam and crank and everything is dead on zero so I know that is good, im fairly sure that its not in the hp software/tune cause no matter how much it tune the same problem persists.
There are lots of variables at play here, to determine pushrod length. Head gasket thickness, milled heads, decked block. Diameter of camshaft base circle, type of lifter, etc. You really have two choices...guess at it, or buy the tools and do it correctly. You’ll spend way more guessing at pushrod lengths over and over, at $80-$100 each set, than simply buying the tools. You don’t need SnapOn calipers. Go to Harbor Freight. The adjustable pushrod is under $30 from Summit.
Thread Starter
9 Second Club
Joined: Jan 2012
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From: Post Falls, Id
all my parts are a stock gm part, cam, valve springs and head gaskets are all LS9 gm parts, heads and rockers are stock 823 , pushrods and lifters are stock lq9, the only thing in or on my motor that are not stock parts is the pistons, rods, intake, throttle body and injectors
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all my parts are a stock gm part, cam, valve springs and head gaskets are all LS9 gm parts, heads and rockers are stock 823 , pushrods and lifters are stock lq9, the only thing in or on my motor that are not stock parts is the pistons, rods, intake, throttle body and injectors
Are you asking me? I measure overall adjustable PR length, and then tell Manton how I measured. I use a digital 12” caliper. I personally don’t like the “count the overall turns” method. It works, but I’d rather measure.
as long as the pushrod maker knows exactly how you measured the adjustable pushrod, it works great.
