windage tray questions, LS5 454
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Intermediate
Joined: Feb 2005
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From: GA
windage tray questions, LS5 454
During engine teardown of my 72 LS5 454 I noticed that there is a pop-in valley pan that spans the complete intake valley. When I flipped the original cast iron intake over to look at the underside I noticed four small bolt holes where I believe some sort of shield belongs. Later I discovered cracks in the intake (unrelated to the shield issue) and I have since sourced another one with similar date code (hasn't arrived yet). However, I noticed in my searching that most original intakes do have a small shield that is afixed to the underside of the intake with some sort of bolts that have a nurled-like thread pattern (almost as if they are hammered in).
So clearly I've been running without this shield on the underside for years. Was I really missing something here? Did the large valley pan that spanned the valley come original or was it placed there because the intake shield on the underside was missing? Lastly, did guys learn to remove the shield from the underside due to concerns these "bolts" might back out and find there way in the moving parts of the motor on the way down? Basically, should I remove the pan on the replacement intake or leave them in? I dropping a boatload on the motor---this is a one-time long-awaited project.
Thoughts?
thanks.
So clearly I've been running without this shield on the underside for years. Was I really missing something here? Did the large valley pan that spanned the valley come original or was it placed there because the intake shield on the underside was missing? Lastly, did guys learn to remove the shield from the underside due to concerns these "bolts" might back out and find there way in the moving parts of the motor on the way down? Basically, should I remove the pan on the replacement intake or leave them in? I dropping a boatload on the motor---this is a one-time long-awaited project.
Thoughts?
thanks.
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From: North of Toronto - Ontario
The four small holes were for the rivets that held the original pan/heat shield. ok if missing, just runs slightly hotter under the carb
The large pan is an aftermarket item and performs the same function. Frequently called "Lifter Valley Heat Shields" and are supposed to help keep hot oil off the underside of the intake (cooler charge, etc)
(forgot the original ???)
Yes I run the full pan, mainly because the intake I'm using (GM aluminum) had the original pan removed and they left the rivets in. I could machine them out but have that "what if they fall out" worry I just don't need.
M
The large pan is an aftermarket item and performs the same function. Frequently called "Lifter Valley Heat Shields" and are supposed to help keep hot oil off the underside of the intake (cooler charge, etc)
(forgot the original ???)
Yes I run the full pan, mainly because the intake I'm using (GM aluminum) had the original pan removed and they left the rivets in. I could machine them out but have that "what if they fall out" worry I just don't need.
M
Last edited by Mooser; Apr 12, 2014 at 12:53 PM.
Race Director
Joined: Apr 2011
Posts: 11,183
Likes: 3,336
From: North of Toronto - Ontario
Moroso and a few others also make them but don't seem to be as heavy a gage.
Some of the modern (cough cough) ones have them from the factory and they act as the anti-rotation guides for the roller lifters (I believe)
M
Thread Starter
Intermediate
Joined: Feb 2005
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From: GA
Mooser, your photo shows the exact valley pan (lifter valley heat shield) that was sitting in the valley under my intake. Sooo, if I reuse this lifter valley heat shield and the replacement intake I have ordered has the tin pan riveted to the underside of the intake...will they both fit at the same time?
And do you think I should have the machine shop pull the rivets and small tin pan off the underside of the intake? Is there any history of these rivets falling out?
Much appreciated Tim/Mooser, this was a big help to understanding their purpose.
And do you think I should have the machine shop pull the rivets and small tin pan off the underside of the intake? Is there any history of these rivets falling out?
Much appreciated Tim/Mooser, this was a big help to understanding their purpose.
