Setting Rocker Wipe Pattern - Experts Please!
Thread Starter
Drifting
Joined: Oct 2006
Posts: 1,724
Likes: 23
From: Minnesota
Setting Rocker Wipe Pattern - Experts Please!
When setting wipe pattern is it necessary or even desireable to use the method where special light weight springs are utilized and the rocker is measured using a dial indicator as outlined in this thread:
http://forums.corvetteforum.com/c5-t...e-pattern.html
Or is it better to set the wipe pattern utilizing the method outlined by YellaTerra in the following video:
The reason I ask is because it seems that with hydraulic lifters a majority of the time the lifters aren't pumped up and even at high RPM the lifters aren't likely to be fully pumped at maximum lift (spring pressure and acceleration against that spring pressure will/should ensure this).
So basically, why would YellaTerra publish a video of how to properly set wipe using the hydraulic lifters and manually rotating the engine if this wasn't the right way to do it?
It seems far easier to use the method of using light weight springs and dial indicator than it does using the YellaTerra method (since its a PITA to rotate a fully assembled engine in the car).
Or, is it a situation where using the in car method is good enough in that testing the full pattern (dial indicator method) isn't going to yield much different results?
Thanks for the advice!
http://forums.corvetteforum.com/c5-t...e-pattern.html
Or is it better to set the wipe pattern utilizing the method outlined by YellaTerra in the following video:
The reason I ask is because it seems that with hydraulic lifters a majority of the time the lifters aren't pumped up and even at high RPM the lifters aren't likely to be fully pumped at maximum lift (spring pressure and acceleration against that spring pressure will/should ensure this).
So basically, why would YellaTerra publish a video of how to properly set wipe using the hydraulic lifters and manually rotating the engine if this wasn't the right way to do it?
It seems far easier to use the method of using light weight springs and dial indicator than it does using the YellaTerra method (since its a PITA to rotate a fully assembled engine in the car).
Or, is it a situation where using the in car method is good enough in that testing the full pattern (dial indicator method) isn't going to yield much different results?
Thanks for the advice!
Last edited by reactor2; Apr 11, 2014 at 09:39 PM.
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
Your reference is my thread. I find it much easier and accurate to use the check springs. You also have to adjust the shim height to get it correct, which involves removing/re-installing the rockers. I have had the rockers off since that thread (for the thread on pushrods) and the wipe pattern can be seen on the valve stem if you shine a light at the right angle. It is spot on. My patch width was 0.045". Their calculation for pre-load is not correct either.
I also don't like the way they torque the rockers, it should be done (IMO) with each rocker pair on the base circle of the cam to prevent loading up the bolts especially if you are running aftermarket valve springs.
I also don't like the way they torque the rockers, it should be done (IMO) with each rocker pair on the base circle of the cam to prevent loading up the bolts especially if you are running aftermarket valve springs.
Last edited by vettenuts; Apr 12, 2014 at 10:52 AM.
Thread Starter
Drifting
Joined: Oct 2006
Posts: 1,724
Likes: 23
From: Minnesota
Your reference is my thread. I find it much easier and accurate to use the check springs. You also have to adjust the shim height to get it correct, which involves removing/re-installing the rockers. I have had the rockers off since that thread (for the thread on pushrods) and the wipe pattern can be seen on the valve stem if you shine a light at the right angle. It is spot on. My patch width was 0.045". Their calculation for pre-load is not correct either.
I also don't like the way they torque the rockers, it should be done (IMO) with each rocker pair on the base circle of the cam to prevent loading up the bolts especially if you are running aftermarket valve springs.
I also don't like the way they torque the rockers, it should be done (IMO) with each rocker pair on the base circle of the cam to prevent loading up the bolts especially if you are running aftermarket valve springs.
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
I used the supplied shims and some thin washers to figure out what the thickness was I needed. Mine were AFR heads so I needed a rather thick shim. If you have stock heads, you may find the supplied shim is adequate. I bought mine at McMaster-Carr.
Thread Starter
Drifting
Joined: Oct 2006
Posts: 1,724
Likes: 23
From: Minnesota
I have dart pro 1 205 heads
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
I would try the shims in hand. Unless the Darts have been worked they should set up similar to stock. If the shim isn't think enough, try some washers or shim stock to establish the required thickness.
Le Mans Master
Joined: Mar 2002
Posts: 5,955
Likes: 161
From: PNW
Maybe I missed it in the video, but if you have to add shims or mill the rocker pedestals to raise or lower the rocker arm assy to get the right valve stem wipe pattern, wouldn't you then also have to reassess the correct push rod lenght for the relocated rocker arm height.
Thread Starter
Drifting
Joined: Oct 2006
Posts: 1,724
Likes: 23
From: Minnesota
Maybe I missed it in the video, but if you have to add shims or mill the rocker pedestals to raise or lower the rocker arm assy to get the right valve stem wipe pattern, wouldn't you then also have to reassess the correct push rod lenght for the relocated rocker arm height.
I want to check my pushrod length again anyway, I'm running .08" preload which I think is too much causing my valvetrain to be louder than it needs to be. My cam isn't that big 228/232 .571/.573 112 but my valve train is a lot noisier than I would like. It sounds "loose" to me. Maybe I need more preload? I don't know. They say .06-.09". But I think stock is a lot less than that.
Last edited by reactor2; Apr 12, 2014 at 04:31 PM.
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Safety Car
Joined: Aug 2011
Posts: 4,439
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From: Portland OR
Hyd lifters certainly bleed down when the engine isn't running. My guess is they won't all bleed the same either.
So using checking springs makes sense to me.
Vettenut has it down pat.
As far as bleeding down while running, I sure hope not. Unless you bought Rhodes variable duration lifters......remember those?
Ron
So using checking springs makes sense to me.
Vettenut has it down pat.
As far as bleeding down while running, I sure hope not. Unless you bought Rhodes variable duration lifters......remember those?
Ron
Thread Starter
Drifting
Joined: Oct 2006
Posts: 1,724
Likes: 23
From: Minnesota
Hyd lifters certainly bleed down when the engine isn't running. My guess is they won't all bleed the same either.
So using checking springs makes sense to me.
Vettenut has it down pat.
As far as bleeding down while running, I sure hope not. Unless you bought Rhodes variable duration lifters......remember those?
Ron
So using checking springs makes sense to me.
Vettenut has it down pat.
As far as bleeding down while running, I sure hope not. Unless you bought Rhodes variable duration lifters......remember those?
Ron
I'll give YellaTerra a call on monday to see what they recommend.
Last edited by reactor2; Apr 12, 2014 at 07:21 PM.
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
Not with the shaft mount rockers, stud mount yes. The shaft mount such as stock or Yella Terra is a fixed mount and the wipe pattern is set by the bolted installation height unlike the stud mount where the pushrod sets both preload and geometry (wipe).