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VALVE LIFT LIMIT

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JERSEYJOE View Drop Down
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    Posted: Dec/08/2022 at 9:22pm
What is the valve lift limit with factory bridged pivot rockers?  I'm thinking less than .500 so like .480?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Trader Quote  Post ReplyReply Direct Link To This Post Posted: Dec/09/2022 at 3:09am
Most will say 0.500", including myself. Erson states 0.510":
Not all the stamped bridge rockers are the same, so caution is in order if going to the limit. And never reuse aluminum bridges!

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Post Options Post Options   Thanks (0) Thanks(0)   Quote ericdowneast Quote  Post ReplyReply Direct Link To This Post Posted: Dec/09/2022 at 9:25am
I wonder what the lift limit is for the new Scorpion lifters?  Probably about the same I would guess.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Sonic Silver Quote  Post ReplyReply Direct Link To This Post Posted: Dec/09/2022 at 9:33am
Originally posted by ericdowneast ericdowneast wrote:

I wonder what the lift limit is for the new Scorpion lifters?  Probably about the same I would guess.
The Scorpion pedestal rockers say they are good to .950 lift and 950 lbs. open spring pressure. Sounds like a lot to me, but that is what their literature states.
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Post Options Post Options   Thanks (1) Thanks(1)   Quote merr6267 Quote  Post ReplyReply Direct Link To This Post Posted: Dec/09/2022 at 10:30am
On the factory bridged setup I've been running what is allegedly a .488 cam on a haphazardly assembled, worn out junkyard motor with mismatched bridges and rockers for almost 20 years.  

It's been WOT for minutes at a time at 5000+rpm without an issue related to the valvetrain.  Now, the rockers had wear marks in them before I ever assembled it, and I didn't intend on keeping the engine together for any length of time so I just assembled it.  It was obvious that the rockers had to skip, or jump over their wear pattern, but I just went with it.  They were noisy at first, then I stopped paying attention.  I eventually upgraded the valve springs to avoid float at 4500 and they still looked in fair condition.  That was 18 years ago, but the poor old Jeep has been mostly parked awaiting another restoration for the last 12.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote ericdowneast Quote  Post ReplyReply Direct Link To This Post Posted: Dec/09/2022 at 5:58pm
Yes it does seem like a lot.  I read the specs too but was wondering if some one knew more about it from experience.  I guess they are pretty new to the market so maybe we don't know that answer yet.

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Post Options Post Options   Thanks (0) Thanks(0)   Quote Trader Quote  Post ReplyReply Direct Link To This Post Posted: Dec/10/2022 at 9:06am
Scorpion bridge mount rockers have different lift and spring pressure limits:
Realistically, anyone building an engine with valve lift over 0.550" is not going to be using bridge rocker heads as is, if at all. The heads would need professional porting just to support the flow for that lift. Your getting into race motor territory and money will be spent on better components for longevity and specific goals.
IMO, these support the gap between 0.500" and 0.550" lift that stamped bridge rockers are not made for. They can also be used at lower lifts, but not necessary. 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Heavy 488 Quote  Post ReplyReply Direct Link To This Post Posted: Dec/10/2022 at 9:49am
If you're going to a high lift cam, are you going to trust a stamped piece of tin to be an actual 1.6 ratio?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Trader Quote  Post ReplyReply Direct Link To This Post Posted: Dec/10/2022 at 10:37am
Up to 0.500" lift, have for many years with no issues.
Highly doubt "tin" is the best description as the OEM ones can be cleaned up and reused and show little wear after tens of thousands of miles if proper maintenance is done. 
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