Yella Terra Ultralites vs. Comp Dual 921 springs.
03-12-2008, 07:39 PM
#1
Yella Terra Ultralites vs. Comp Dual 921 springs. Just ordered a set of the Yella Terra Ultralites. Will it matter if I have the dual Comp 921 valve springs? I have the Comp 921 duals springs and just wanting someone to confirm if the new Yella Terra's are going to work. with a dual spring setup. I really don't know ... sorry.
03-12-2008, 08:02 PM
#2
Just ordered a set of the Yella Terra Ultralites. Will it matter if I have the dual Comp 921 valve springs? I have the Comp 921 duals springs and just wanting someone to confirm if the new Yella Terra's are going to work. with a dual spring setup. I really don't know ... sorry.
03-12-2008, 08:11 PM
#3
I have a 347ci LS6 with AFR 205's and Comp 921 dual springs ... just not sure if there is a difference between installing the Yella Terra Ultralites with single springs vs. dual springs.
It likely sounds like a rediculous question, but, the YT rocker set is for either, right? They don't make a different set for a dual sping setup than for a single spring setup, do they?
It likely sounds like a rediculous question, but, the YT rocker set is for either, right? They don't make a different set for a dual sping setup than for a single spring setup, do they?
03-12-2008, 08:23 PM
#4
I have a 347ci LS6 with AFR 205's and Comp 921 dual springs ... just not sure if there is a difference between installing the Yella Terra Ultralites with single springs vs. dual springs.
It likely sounds like a rediculous question, but, the YT rocker set is for either, right? They don't make a different set for a dual sping setup than for a single spring setup, do they?
It likely sounds like a rediculous question, but, the YT rocker set is for either, right? They don't make a different set for a dual sping setup than for a single spring setup, do they?
03-12-2008, 08:49 PM
#5
Well, I've been reading about 'wipe pattern' and now you're talking about shimming. You think I should get a performance shop to install mine? I do stuff like intake swaps, header installs, change calipers/drums/rotors, etc. I'm too hot on internal engine work. I think if I install them myself, I'll mess it up, bad.
03-13-2008, 03:12 AM
#6
TECH Fanatic
iTrader: (2)
Join Date: Nov 2006
Location: Aztec, NM
Posts: 1,360
Likes: 0
Received 0 Likes
on
0 Posts
The Yella Terra Ulralights on my cousins Vette clears a 1.535" dual valve spring with pleanty of room. It looks like to me that they could clear a 1.55" or maybe a 1.56" OD spring. Your 921's are only 1.3" OD.
03-13-2008, 04:31 AM
#7
Since it looks like the YT Ultralites will work with my dual spring Comp 921's, I now have to decide to do it myself or not. I'll use the search feature and see if I can set the 'wipe pattern' and shim them, myself.
If anybody has any advice, links, or pics, I'd sure appreciate anything you could help me with.
If anybody has any advice, links, or pics, I'd sure appreciate anything you could help me with.
Trending Topics
03-14-2008, 12:02 AM
#8
TECH Fanatic
iTrader: (2)
Join Date: Nov 2006
Location: Aztec, NM
Posts: 1,360
Likes: 0
Received 0 Likes
on
0 Posts
Here is some copied info out of the "cam guide" LS1 internal section. You will have to read through the following link b/c the pics didn't make it through the copy & paste method. https://ls1tech.com/forums/generation-iii-internal-engine/327734-cam-guide.html
B. Pushrods
What they are:
What they do: transfer the motion of the cam to the rockers
What to look for:
- New pushrods aren’t absolutely necessary but they are highly recommended.
- The pushrod was never designed to be a fusible link in the valvetrain. Several years ago we even had a member (might have been in the old LS1.com days) that was an engineer from Jesel (don't recall his ID) and he was adamantly opposed to the notion that the LS1 pushrods were designed to break in the event of a mechanical over-rev. The job of the pushrod is to accurately transmit the motion of the cam lobe (via the rocker arm) to the valve. If it’s flexing under load, then its simply not doing its job.
Look at it this way; you CAN mechanically over-rev any engine - pushrod, OHC, rotary, or otherwise - and cause damage. There is nothing unique or special about the LS1 pushrods making them fusible.
This is like saying that you broke your ring gear on a missed shift so therefore everybody should continue using the weak 10-bolt rear ends. Just a silly, backwards argument IMO - especially when you're considered an aggressive cam with heavier valve springs (Fulton 1)
- Pushrod Calculator here
How To Verify Proper Valve Train Geometry
from Holly.com
The following is a method of verifying proper valve train geometry. After you have estimated the required pushrod length using a Pushrod Length Checker, use this method to verify that the valve train geometry is correct (using the rockers you are using in your engine):
1
The first step is to install a solid lifter and an adjustable pushrod. Mark the tip of the valve with a marker
2
Install your rocker arm and set it up with zero lash.
3
Rotate the crankshaft clockwise several times. Remove the rocker arm. The contact pattern of the rocker tip will be where the marker has been wiped away from the valve tip. The pattern should be centered on the valve tip, and as narrow as possible. If it is not, experiment with varying the pushrod length to yield the best pattern.
4
Pushrod Too Long: Notice how the pattern is wide, and shifted to the exhaust side of the valve tip.
5
Pushrod Too Short: Notice how the pattern is wide, and shifted to the intake side of the valve tip.
6
Pushrod Length Correct: Notice how the pattern is narrow and is centered on the valve tip.
C. Rockers
What they are: HS 1 / 2, Comp Magnums, Comp Shaft, Crane, SLP 1.85
What they do: transfer the cam motion along from the pushrods and accentuate the valves to open
What to look for:
- New rockers are also an optional choice during a cam install.
- The stock roller tip rockers have been known to loose there bearings but it’s not an overly common occurrence.
- One problem people have experienced with the HS and YT rockers are valvetrain issues at high RPM's due to the added weight of the rockers, coupled with heavy dual springs with undesirable harmonics.
A good alternative is to run the stock rockers retro-fitted by Nasty Nate. They are stock rockers which keep the weight down but the trunion bearings have new C-clips which prevent the needle bearings from spilling.
- Adjustable rockers allow you to adjust lifter pre-load; a must for Comp R's (875's)
- Higher ratio rockers can be used to increase lift (see cam lift for more info). Along with increasing the valve lift adding higher ratio rockers also nets you an extra degree or two of duration at the valve and increased overlap.
- Jesel SS Shaft Mount: INSTALL GUIDE
D. Others
- It’s a good idea to install a new timing chain as well. The stock ones are notorious for having a lot of slack in them
- You can either get a single (JWIS) or double (my rollmaster)
the most economical route is the LS2 chain pt# 12586482 ordered from SDPC
- The double chains come with the needed spacers to clear the oil pump
- 98-00 cars should also factor in a new oil pump
- A new chain and oil pump should run you about 200 dollars
III. HOW TO INSTALL
- JMX is the muthafuckin man, that’s all you need to know
- Install Guide
- I along with countless others have followed that guide for cam installs (among other things). If you can turn a wrentch, have some basic knowledge, and follow that guide you can do your own cam install.
IV. Tuning
- Factor in tuning from the get go. If you cant afford tuning then just hold off on the install until you can. Its not going to kill you to wait a bit to save up the 350-500 for the dyno tuning.
1) This is especially true when installing big cams, the bigger the cam the harder it is for the stock PCM to compensate.
2) Smaller cams can get away with stock tuning longer then bigger cams but even so all cams can benefit from tuning
3) A DYNO IS A TUNING DEVICE; NOTHING MORE, NOTHING LESS
4) Tuning is more then just looking for more HP. It makes your car more livable and drivable by dialing in your a/f ratio, deleting codes, helping with hot and cold starts, getting your idle set straight, ect.
- Of course if you have your own copy of hptuner/flashscan/editor/predator you can do the tuning yourself.
--------------------------------------------------------------------------------
Last edited by jrp : 05-29-2005 at 08:51 PM.
B. Pushrods
What they are:
What they do: transfer the motion of the cam to the rockers
What to look for:
- New pushrods aren’t absolutely necessary but they are highly recommended.
- The pushrod was never designed to be a fusible link in the valvetrain. Several years ago we even had a member (might have been in the old LS1.com days) that was an engineer from Jesel (don't recall his ID) and he was adamantly opposed to the notion that the LS1 pushrods were designed to break in the event of a mechanical over-rev. The job of the pushrod is to accurately transmit the motion of the cam lobe (via the rocker arm) to the valve. If it’s flexing under load, then its simply not doing its job.
Look at it this way; you CAN mechanically over-rev any engine - pushrod, OHC, rotary, or otherwise - and cause damage. There is nothing unique or special about the LS1 pushrods making them fusible.
This is like saying that you broke your ring gear on a missed shift so therefore everybody should continue using the weak 10-bolt rear ends. Just a silly, backwards argument IMO - especially when you're considered an aggressive cam with heavier valve springs (Fulton 1)
- Pushrod Calculator here
How To Verify Proper Valve Train Geometry
from Holly.com
The following is a method of verifying proper valve train geometry. After you have estimated the required pushrod length using a Pushrod Length Checker, use this method to verify that the valve train geometry is correct (using the rockers you are using in your engine):
1
The first step is to install a solid lifter and an adjustable pushrod. Mark the tip of the valve with a marker
2
Install your rocker arm and set it up with zero lash.
3
Rotate the crankshaft clockwise several times. Remove the rocker arm. The contact pattern of the rocker tip will be where the marker has been wiped away from the valve tip. The pattern should be centered on the valve tip, and as narrow as possible. If it is not, experiment with varying the pushrod length to yield the best pattern.
4
Pushrod Too Long: Notice how the pattern is wide, and shifted to the exhaust side of the valve tip.
5
Pushrod Too Short: Notice how the pattern is wide, and shifted to the intake side of the valve tip.
6
Pushrod Length Correct: Notice how the pattern is narrow and is centered on the valve tip.
C. Rockers
What they are: HS 1 / 2, Comp Magnums, Comp Shaft, Crane, SLP 1.85
What they do: transfer the cam motion along from the pushrods and accentuate the valves to open
What to look for:
- New rockers are also an optional choice during a cam install.
- The stock roller tip rockers have been known to loose there bearings but it’s not an overly common occurrence.
- One problem people have experienced with the HS and YT rockers are valvetrain issues at high RPM's due to the added weight of the rockers, coupled with heavy dual springs with undesirable harmonics.
A good alternative is to run the stock rockers retro-fitted by Nasty Nate. They are stock rockers which keep the weight down but the trunion bearings have new C-clips which prevent the needle bearings from spilling.
- Adjustable rockers allow you to adjust lifter pre-load; a must for Comp R's (875's)
- Higher ratio rockers can be used to increase lift (see cam lift for more info). Along with increasing the valve lift adding higher ratio rockers also nets you an extra degree or two of duration at the valve and increased overlap.
- Jesel SS Shaft Mount: INSTALL GUIDE
D. Others
- It’s a good idea to install a new timing chain as well. The stock ones are notorious for having a lot of slack in them
- You can either get a single (JWIS) or double (my rollmaster)
the most economical route is the LS2 chain pt# 12586482 ordered from SDPC
- The double chains come with the needed spacers to clear the oil pump
- 98-00 cars should also factor in a new oil pump
- A new chain and oil pump should run you about 200 dollars
III. HOW TO INSTALL
- JMX is the muthafuckin man, that’s all you need to know
- Install Guide
- I along with countless others have followed that guide for cam installs (among other things). If you can turn a wrentch, have some basic knowledge, and follow that guide you can do your own cam install.
IV. Tuning
- Factor in tuning from the get go. If you cant afford tuning then just hold off on the install until you can. Its not going to kill you to wait a bit to save up the 350-500 for the dyno tuning.
1) This is especially true when installing big cams, the bigger the cam the harder it is for the stock PCM to compensate.
2) Smaller cams can get away with stock tuning longer then bigger cams but even so all cams can benefit from tuning
3) A DYNO IS A TUNING DEVICE; NOTHING MORE, NOTHING LESS
4) Tuning is more then just looking for more HP. It makes your car more livable and drivable by dialing in your a/f ratio, deleting codes, helping with hot and cold starts, getting your idle set straight, ect.
- Of course if you have your own copy of hptuner/flashscan/editor/predator you can do the tuning yourself.
--------------------------------------------------------------------------------
Last edited by jrp : 05-29-2005 at 08:51 PM.
Last edited by 1997bird; 03-14-2008 at 12:06 AM. Reason: Sorry the pics didn't make it!
03-14-2008, 06:34 AM
#9
Dang! And my engine builder went with Comp R 850's ...
I read the sticky long ago and forgot it exisited. Thanks for pulling my head out of the clouds.
I'll be getting them installed soon. I have a shop wanting to do a baseline dyno run with the current stock rocker setup. After the YT Ultralites are in, the car would be given time to cool down and then re-ran.
Of course, there is the chance I might attempt the install myself to save a few hundred dollars just don't want to end up paying 2-3 times that if I 'f' it up ... doesn't look like there's much to mess up, though. Maybe the worst thing would be a poor wipe pattern, but, that could be corrected easy enough (I think).
I read the sticky long ago and forgot it exisited. Thanks for pulling my head out of the clouds.
I'll be getting them installed soon. I have a shop wanting to do a baseline dyno run with the current stock rocker setup. After the YT Ultralites are in, the car would be given time to cool down and then re-ran.
Of course, there is the chance I might attempt the install myself to save a few hundred dollars just don't want to end up paying 2-3 times that if I 'f' it up ... doesn't look like there's much to mess up, though. Maybe the worst thing would be a poor wipe pattern, but, that could be corrected easy enough (I think).
03-14-2008, 09:42 AM
#10
There are much easier ways to set the wipe pattern, something you should check. Just don't bolt them in. These are nice rockers, but also make sure you check the clearances between the pushrod and the valve spring retainer. The order of setup is:
1. Set wipe
2. Measure pushrod
Don't use the shims to set preload, the shims are used to set wipe. The instructions that come with them are very mis-leading in that they are common to the fully adjustable set as well. Note also the LS1howto doesn't do this correctly either.
Here's a link to when I set mine up on the work bench: Link
1. Set wipe
2. Measure pushrod
Don't use the shims to set preload, the shims are used to set wipe. The instructions that come with them are very mis-leading in that they are common to the fully adjustable set as well. Note also the LS1howto doesn't do this correctly either.
Here's a link to when I set mine up on the work bench: Link
03-14-2008, 05:38 PM
#12
If you have a set of checking springs, swap them out and then move the piston down the cylinder a tad. Set up a dial indicator (or use a ruler) to measure how much you move the valve and then install the rockers, use some Sharpie on the valve stem and then move the rockers through the lift of your cam with your hand. You should be able to figure it out fairly quickly and its very easy to do. Only thing is if you shim and have your pushrods already, the pushrods may need to be changed for a different length.
03-14-2008, 08:01 PM
#16
TECH Addict
iTrader: (1)
There are much easier ways to set the wipe pattern, something you should check. Just don't bolt them in. These are nice rockers, but also make sure you check the clearances between the pushrod and the valve spring retainer. The order of setup is:
1. Set wipe
2. Measure pushrod
Don't use the shims to set preload, the shims are used to set wipe. The instructions that come with them are very mis-leading in that they are common to the fully adjustable set as well. Note also the LS1howto doesn't do this correctly either.
Here's a link to when I set mine up on the work bench: Link
1. Set wipe
2. Measure pushrod
Don't use the shims to set preload, the shims are used to set wipe. The instructions that come with them are very mis-leading in that they are common to the fully adjustable set as well. Note also the LS1howto doesn't do this correctly either.
Here's a link to when I set mine up on the work bench: Link
03-14-2008, 08:16 PM
#17
TECH Addict
iTrader: (1)
Anyway, after I tore it down, I believe that this may be a (The?) major reason that it has burned so much oil from day one. Since it makes good power, and gets good mileage for a motor this size, I have a hard time believing that it is the rings or valve guide seals.:
03-15-2008, 07:49 AM
#18
Sorry, I guess you could read it that way. What I meant was that he should check clearance of the rocker between the retainer and check the clearance between the rocker and the pushrod for the entire motion of the rocker (full closed to full open and return). This will ensure no interference between the rocker and any of the other parts. There have been a couple of guys who ran into problems with clearance (Yella Terra instructions will point out where to look) and the rocker was pushing on the retainer and damaging it.
