LS1TECH - Camaro and Firebird Forum Discussion

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-   -   Yella Terra's and Trickflow's (https://ls1tech.com/forums/generation-iii-internal-engine/1191650-yella-terras-trickflows.html)

larrygto Oct 14, 2009 09:55 AM

Yella Terra's and Trickflow's
 
OK I'm setting my wipe pattern on my valve stems, using the shims that come with the yella terras. 2 leave me a hair to the intake side 3 leave a hair to the exhaust side. So I come up with .125 be the size shim that I need.
I know every set up is different, but is this in the ballpark of others who have a similar set up?
Also where are you guys getting shims?
Thanks!

JPH Oct 14, 2009 07:14 PM

Favor the intake side. Use or make your own shims for your perfect/ideal pattern!

SOMbitch Oct 14, 2009 08:43 PM


Originally Posted by JPH (Post 12364666)
Favor the intake side. Use or make your own shims for your perfect/ideal pattern!


Why favor intake side JPH???? Because the valve is heavier???

BTW haven't seen you on here in a while, glad you're back:D

vettenuts Oct 14, 2009 08:59 PM

I ended up with 0.125" as well on my AFR's. You will definitely need to clearance the valve covers, including the bosses on the coil bracket fasteners. I got my shims from McMaster-Carr. I have a post on here somewhere with the part identification as it is a close SAE size to metric. If you can't find it, let me know and I will do some searching.

larrygto Oct 15, 2009 07:38 AM


Originally Posted by JPH (Post 12364666)
Favor the intake side.

Why favor the intake side? I'm a n00b when it comes to this stuff, But from what I can see the roller travels towards the intake side as it depresses Using that logic won't favoring the exhaust side give you a more centered wipe?
Also you would think Trickflow a company that requires you to use roller rockers would design their head to have enough clearance for the valve covers?

vettenuts Oct 15, 2009 11:30 AM


Originally Posted by larrygto (Post 12366730)
Why favor the intake side? I'm a n00b when it comes to this stuff, But from what I can see the roller travels towards the intake side as it depresses Using that logic won't favoring the exhaust side give you a more centered wipe?
Also you would think Trickflow a company that requires you to use roller rockers would design their head to have enough clearance for the valve covers?

I usually try and center and narrow the pattern as much as possible.

I believe what JPH is referring to, and he can correct me if I am wrong, is to set the pattern little shifted to the intake side of the valve stem. The reason is the rocker moves from the intake side to the exhaust side during valve opening. As the valve opens, the valve spring force increases because it is depressed more. At full open, a slight intake bias at what is also the highest spring force will reduce the side loads on the valve guide.

Russ K Oct 15, 2009 12:21 PM

Always check the wipe pattern with valve springs, not checking springs. On my 215 Trick Flow heads & 1.7 Yella Terra rockers, no shims were needed.

Russ Kemp

SOMbitch Oct 15, 2009 12:25 PM


Originally Posted by vettenuts (Post 12367631)
I usually try and center and narrow the pattern as much as possible.

I believe what JPH is referring to, and he can correct me if I am wrong, is to set the pattern little shifted to the intake side of the valve stem. The reason is the rocker moves from the intake side to the exhaust side during valve opening. As the valve opens, the valve spring force increases because it is depressed more. At full open, a slight intake bias at what is also the highest spring force will reduce the side loads on the valve guide.


Makes sense...

larrygto Oct 15, 2009 04:26 PM


Originally Posted by Russ K (Post 12367861)
Always check the wipe pattern with valve springs, not checking springs. On my 215 Trick Flow heads & 1.7 Yella Terra rockers, no shims were needed.

Russ Kemp

Thanks, Dead center with no shims!

vettenuts Oct 15, 2009 05:08 PM


Originally Posted by Russ K (Post 12367861)
Always check the wipe pattern with valve springs, not checking springs. On my 215 Trick Flow heads & 1.7 Yella Terra rockers, no shims were needed.

Russ Kemp

Russ,

Think we have had this discussion before. If you use the full spring without a solid lifter, how do you ensure full lift is achieved without compressing the plunger in the lifter?

racer7088 Oct 16, 2009 01:05 AM

Yes the pattern will always look good with a hydraulic lifter bled down since you have like barely half the lift you will really have. Don't know what is being said really but you need a solid lifter to see the real pattern that gives you full lift at the rocker and valve like when the lifters are pumped fully up.

vettenuts Oct 16, 2009 04:49 AM


Originally Posted by racer7088 (Post 12371354)
Yes the pattern will always look good with a hydraulic lifter bled down since you have like barely half the lift you will really have. Don't know what is being said really but you need a solid lifter to see the real pattern that gives you full lift at the rocker and valve like when the lifters are pumped fully up.

I have been using check springs with a dial indicator and actuating the rockers by hand (Fixed base rockers such as stock or Yella Terra). This allows you to check the wipe without the lifter coming into play. Only issue I have had is the light check springs don't do a very good job of removing the Sharpie from the valve stem. Have done a number of motors this way and several thousand miles later when you remove rockers, the wipe pattern can be seen on the bare valve stem in the right light. I haven't seen a difference.

BRD-PREY Oct 16, 2009 06:25 AM

Eric can you send me one solid lifter when you mail my motor?
Ed
P.S. were you able to get a front cover? (never mind just read my email)

24 Tooth Reluctor is what I need

larrygto Oct 16, 2009 12:05 PM

Thanks guys! I went ahead and made some solid lifters and double checked wipe looked good with out shims. Measured my Pr length it came to 7.425 which if my math is correct is right on the money considering the heads are milled to 62cc and I'm using LS7 lifters. Correct me if I'm wrong please!
Again thanks Larry

JPH Oct 16, 2009 12:32 PM


Originally Posted by vettenuts (Post 12367631)
I usually try and center and narrow the pattern as much as possible.

I believe what JPH is referring to, and he can correct me if I am wrong, is to set the pattern little shifted to the intake side of the valve stem. The reason is the rocker moves from the intake side to the exhaust side during valve opening. As the valve opens, the valve spring force increases because it is depressed more. At full open, a slight intake bias at what is also the highest spring force will reduce the side loads on the valve guide.

Your right and you da man Bob! :) Ya, also like everyone says I hope your using checking springs also, if not not solid lifters?

vettenuts Oct 16, 2009 06:52 PM


Originally Posted by larrygto (Post 12372744)
Thanks guys! I went ahead and made some solid lifters and double checked wipe looked good with out shims. Measured my Pr length it came to 7.425 which if my math is correct is right on the money considering the heads are milled to 62cc and I'm using LS7 lifters. Correct me if I'm wrong please!
Again thanks Larry

OK, I am confused. How were you checking before? If you went from needing 0.125" shims to no shims what changed? Were you using hydraulic lifters and the actual valve springs (not check springs)?

larrygto Oct 16, 2009 07:13 PM


Originally Posted by vettenuts (Post 12374362)
OK, I am confused. How were you checking before? If you went from needing 0.125" shims to no shims what changed? Were you using hydraulic lifters and the actual valve springs (not check springs)?

I was using checker springs with the heads on a bench. I was having a hard time getting my dial indicator set up so I was pretty much guessing at the lift.
Once I put the heads on the engine I checked both with checker springs and actual springs using a solid lifter. Both springs centered the wipe with no shims. I'm sure I was doing something wrong on the bench.

vettenuts Oct 16, 2009 08:57 PM

The tip moves from the intake side to the exhaust side, so if you weren't opening the valve enough the wipe pattern would tend to stay towards the intake side. Adding the shims would move it outwards more towards the exhaust side, assuming the lift was the same each time. Since the rockers are fixed in place, it shouldn't really matter what springs are used as long as the lift (valve motion) is accurate. The trouble with the actual valve springs is they will depress the hydraulic plunger such that the lift decreases and the pattern will be towards the intake side again giving the appearance of requiring a shim. Also, on the bench, the head must be lifted off the bench otherwise the valve will hit the bench without fully opening. I usually set the heads on some 2X4's so that the valves have several unobstructed inches of motion. If you were doing this on the bench with the head flat on the bench, this could have also lead to the appearance of requiring shims because the valve wouldn't have been able to open to the required lift anyhow due to contact with the bench surface.


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