Question About Rocker Arm Geometry?
Thread Starter
Safety Car
Joined: Aug 2000
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From: Clymer PA
Question About Rocker Arm Geometry?
This is probably a dumb question but I am constantly running different ideas through my mind and had a question concerning this one. I watched the video about establishing a 90 degree relation with your rocker arm to figure out what the appropriate pushrod length should be (thank you to Straub Tech for that video, very interesting stuff). My question is, wouldn't it be even easier to establish 90 degree rocker arm geometry with shaft mounted rocker systems? Wouldn't you just move the rocker arm till it touches the valve stem and then measure from there to figure out pushrod length....or is there more to it?
I ask this because I am pondering using shaft mounted rockers.
I ask this because I am pondering using shaft mounted rockers.
Last edited by bence13_33; Feb 1, 2018 at 02:07 PM.
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From: Corsicana, Tx
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Pretty close. Shafts are a lot easier.
Still need to ck them to be sure stands are correct for what you have. Some heads are still a little wonky with angles.
JIM
Still need to ck them to be sure stands are correct for what you have. Some heads are still a little wonky with angles.
JIM
Thread Starter
Safety Car
Joined: Aug 2000
Posts: 3,909
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From: Clymer PA
What do you do if the stands are too low, shim them up? What do you do if they are too high, have them milled down? I'm just trying to visualize this process because I think strength wise they would be a nice upgrade. Added to the fact that they seem simpler to setup (which is right up my alley lol).
Team Owner
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
What do you do if the stands are too low, shim them up? What do you do if they are too high, have them milled down? I'm just trying to visualize this process because I think strength wise they would be a nice upgrade. Added to the fact that they seem simpler to setup (which is right up my alley lol).
How much shim can I use under the stand to get my geometry correct?
Included in most rocker sets is 0.090” of shim. That is the maximum we recommend. T&D offers custom stands with extra height starting with +0.100” so it is very simple to get more height if necessary.
http://tdmach.com/
Team Owner
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From: Southern Cal Ca
St. Jude Donor '22
raising rockers may cause interference with valve cover.
as far as pushrod length
some places have rods that expand and contract
by twisting them, they are like a turnbuckle to
make it simple.
so, get a good estimate, use adjust rod find
length that gives proper wear of dye applied to
valve tip.
measure length of adjust rod.
look for rods at that length.
may then use minimal shims under your
fancy rocker setup.
sometimes you get lucky and find a rod at proper
length and need no shims.
other method is find a speed shop that will loan you
some pushrods at guessed length and try
a few different lengths to get a ball park and then
look for them and shim.
good luck
as far as pushrod length
some places have rods that expand and contract
by twisting them, they are like a turnbuckle to
make it simple.
so, get a good estimate, use adjust rod find
length that gives proper wear of dye applied to
valve tip.
measure length of adjust rod.
look for rods at that length.
may then use minimal shims under your
fancy rocker setup.
sometimes you get lucky and find a rod at proper
length and need no shims.
other method is find a speed shop that will loan you
some pushrods at guessed length and try
a few different lengths to get a ball park and then
look for them and shim.
good luck
