LS7 Lifters and Pushrod Length
#1
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I used some LS7 lifters in a recent round of mods on my 94 Formula. Yhey said direct replacement, and they were cheaper so it seemed like a good choice. They were not direct replacement. Yeah they fit in the bores, but they are a lot shallower then OEM LT1 lifters.
I used them in conjunction with the .026" Victor Rienz head gaskets and some GMPP 1.6 rrs, Comp 983 dual valve springs, Ti Retianers and locks, as well as some new stock valves (nothing fancy just stock replacements). My block is not decked, nor were my heads milled. However when I put it all together with 7.2 pushrods it ran like it had a massive cam in it. Not in the good way either. Granted having 6 month old gas in it could have played a part, but not entirely
Knowing something was wrong, I opened it back up and checked the valvetrain geometry. It was all messed up. The rocker tips were way to far over on the valve. I measured for the correct pushrod size, and turns out I needed a 6.881 pushrod for the rocker tip to stay centered on the valve.
I dunno bout you all, but that is a pretty big jump from 7.2 pushrods to me! I'm actually kinda baffled. I haven't tested the new pushrods yet (putting them in this weekend), but I did check one after I measured, and the geometry looks right now. Because its such a huge jump in size it has me questioning...we will see this weekend.
Any similar situations?
I used them in conjunction with the .026" Victor Rienz head gaskets and some GMPP 1.6 rrs, Comp 983 dual valve springs, Ti Retianers and locks, as well as some new stock valves (nothing fancy just stock replacements). My block is not decked, nor were my heads milled. However when I put it all together with 7.2 pushrods it ran like it had a massive cam in it. Not in the good way either. Granted having 6 month old gas in it could have played a part, but not entirely
Knowing something was wrong, I opened it back up and checked the valvetrain geometry. It was all messed up. The rocker tips were way to far over on the valve. I measured for the correct pushrod size, and turns out I needed a 6.881 pushrod for the rocker tip to stay centered on the valve.
I dunno bout you all, but that is a pretty big jump from 7.2 pushrods to me! I'm actually kinda baffled. I haven't tested the new pushrods yet (putting them in this weekend), but I did check one after I measured, and the geometry looks right now. Because its such a huge jump in size it has me questioning...we will see this weekend.
Any similar situations?
#3
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Mine is using 7.200 pushrods with LS7 lifters, geometry checked out fine with the rollers centered on the stems
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#8
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iTrader: (35)
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The difference between lengths can't be right, definetly isn't that much of a difference if a difference. When I measured my geometry with the stock lifters, .026 Reinz, milling of the heads, etc. etc. I ended up with a 7.100" pushrod. I swapped the lifters for LS7's and came up with the same length.
#9
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The difference between lengths can't be right, definetly isn't that much of a difference if a difference. When I measured my geometry with the stock lifters, .026 Reinz, milling of the heads, etc. etc. I ended up with a 7.100" pushrod. I swapped the lifters for LS7's and came up with the same length.
#10
11 Second Club
iTrader: (35)
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Thats very strange since the cup is noticeably more shallow then the OEM lifter. Several people have measured it to be a .1 difference. So for you to have swapped OEM LT1 Lifters with a LS7 lifter that is .1 taller it should have thrown your geometry off since you are running a longer pushrod.