.1" offset rockers on cammed LT1? Valvetrain guys come in.
#1
.1" offset rockers on cammed LT1? Valvetrain guys come in.
Hey guys-
I just picked up a set of rockers for my hot rod build for quite a steal, but I'm unsure of how the geometry is going to work out. I didn't realize this possible issue until I already had them "in the bag".
They're Scorpion 1.6 rockers, 7/16" stud, .1" offset. The motor (LT1) is a cam only build, stock heads/stock block (original, never been cracked open). I don't have pushrods, springs/retainers/locks yet. I do have ARP 7/16" studs and Trick Flow 5/16" guideplates.
Cam specs are 224/236 .565/.565 110 LSA.
I've been doing a bit of reading, and it seems that there are some guys with .15" offset rockers that aren't having any issues. Conversely, there are some claiming that this is a huge mistake. It almost seems like a matter of opinion when dealing with a small offset.
What are the potential issues for this? What do I need to look out for?
Thanks-
-Brett-
I just picked up a set of rockers for my hot rod build for quite a steal, but I'm unsure of how the geometry is going to work out. I didn't realize this possible issue until I already had them "in the bag".
They're Scorpion 1.6 rockers, 7/16" stud, .1" offset. The motor (LT1) is a cam only build, stock heads/stock block (original, never been cracked open). I don't have pushrods, springs/retainers/locks yet. I do have ARP 7/16" studs and Trick Flow 5/16" guideplates.
Cam specs are 224/236 .565/.565 110 LSA.
I've been doing a bit of reading, and it seems that there are some guys with .15" offset rockers that aren't having any issues. Conversely, there are some claiming that this is a huge mistake. It almost seems like a matter of opinion when dealing with a small offset.
What are the potential issues for this? What do I need to look out for?
Thanks-
-Brett-
#3
heres what i would suggest...if you have them..and an adjustable push rod/ push rod measuring tool. i would put them on and check the sweep on the top of the valve with sharpie method. If you get a good sweep... i would do it.
#5
Looks like they'll end up being for sale soon, and needing to find some regular 1.6's. Dammit.
#7
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I run .450 offset shaftmounts (rockers) with .180 offset lifters. The offset is a lateral shift so that you can gain room from the pinch area of the intake ports. I dont see a problem with a .100 offset with a stock setup . The roller on the valve remains in the same location the pushrod cup is shifted over the .100.
Last edited by Z8'S; 10-06-2011 at 05:10 PM. Reason: added picture
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#11
i wouldnt see a problem with that as long as you can get the torqued down and in the right spot.
#14
PRs don't need to be perfectly up and down, the slight offset wont hurt anything - but like stated, you will need adjustable guideplates to compensate. Hell, some BBC heads need the pushrods at all sorts of crazy angles. Mine are offset quite a bit as well.
Those DRE too? They have awesome customer service - quick shipped me a new trunnion shaft when I F'd one of mine up installing it. Got it in 2 days .
I run .450 offset shaftmounts (rockers) with .180 offset lifters. The offset is a lateral shift so that you can gain room from the pinch area of the intake ports. I dont see a problem with a .100 offset with a stock setup . The roller on the valve remains in the same location the pushrod cup is shifted over the .100.
#15
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PRs don't need to be perfectly up and down, the slight offset wont hurt anything - but like stated, you will need adjustable guideplates to compensate. Hell, some BBC heads need the pushrods at all sorts of crazy angles. Mine are offset quite a bit as well.
Those DRE too? They have awesome customer service - quick shipped me a new trunnion shaft when I F'd one of mine up installing it. Got it in 2 days .
Those DRE too? They have awesome customer service - quick shipped me a new trunnion shaft when I F'd one of mine up installing it. Got it in 2 days .
#17
Killer deal, Crane Golds are pretty expensive new.
#18
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thats a great deal and a much better way to go.......regardless of whether it will "run" with a non-parallel geometry in the valvetrain it will be better straight.........thats one of the things i make sure of on every engine i build........i check my valvetrain geometry and make it straight before i order rockers and pushrods.......im not too keen to the idea of angled pushrods when they dont have to be
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All push rods run at an angle eccept possibly at ONE point in the lift cycle--it does't matter if they run slightly sideways EXCEPT with individual stud mounted rockers you need something to keep them aligned on the TIP of the valve---this can be as simple as slots in the head, a valve tip that strattles the valve tip , or guide plates---
If its on an aftermarket or performance head where the valve location has been moved to get larger valves in the chamber, most of the times both valves will have been moved---
Sometimes its to have a bigger intake port in the head and to spread the pushrods--
If the pushrod end of the rocher is what is relocated/offset, then you can do it with guide plates---you do not want to open/offset the BOLT holes in the guide plates as most likely both valves/rockers won't be offset the same as stock
There are guide plates available that are slotted boltholes that are adjustable/slotted for adjusting the spread/offset for the pushrods.
If its on an aftermarket or performance head where the valve location has been moved to get larger valves in the chamber, most of the times both valves will have been moved---
Sometimes its to have a bigger intake port in the head and to spread the pushrods--
If the pushrod end of the rocher is what is relocated/offset, then you can do it with guide plates---you do not want to open/offset the BOLT holes in the guide plates as most likely both valves/rockers won't be offset the same as stock
There are guide plates available that are slotted boltholes that are adjustable/slotted for adjusting the spread/offset for the pushrods.