Valve Springs replacement

[Steve Wood]

Don't believe I said that at all

Also, No one said that 3E had less tension on it.  3E tends to spin slowly as compared to the others.  That makes it more susceptible to wear.  It happens because the number 3 exhaust lobe on the cam sits almost directly centered under the lifter bore hole so that the lifter  is right on top of the lop instead of being set with the lifter base center on the edge of the lobe which causes it to rotate (due to a small taper across the lobe fore and aft and the convex bottom of the lifter.

There is no factory spec.  I was referring to the usual shift point from the factory which was around 4800 rpm as delivered.  When we install non factory cams with more duration, we often shift 5400-5800 depending upon the cam and the power band we have.  There was nothing wrong with the valve springs as delivered from the factory on the factory cam other than they wore out frequently between 40-50,000 miles of driving.

We install slightly stiffer springs of better quality to last longer and give us a bit more stable operation around 5000-5400 rpm if we are trying to get the best performance out of the factory cam or we are putting higher boost than stock into the engine which means the boost is trying to push the intake valve open as it overcomes the spring pressure holding the valve closed except when adding fuel/air at the proper time.

If you are unsure as to how to change the springs, the best idea would be to find some one local to help you.  Otherwise there should be a number of good videos and articles on line showing how it is done.

[Steve Wood]

Here are the factory valve spring pressures.  1.727" is the normal installed height with the valve closed.  If you reduce that height there will be more tension on the spring and the pressure would be slightly greater depending upon how much shorter the installed height becomes.  If a spring spec shows 1.700 as the installed height, and you install it at 1.727", then it will have a bit less tension installed than that shown in the specs for that particular spring.

[gnonyx]

Don't believe I said that at all

Hi Steve, Please understand my last thread was not about you, and trust me I have a great deal of respect to you.

[gnonyx]

Here are the factory valve spring pressures.  1.727" is the normal installed height with the valve closed.  If you reduce that height there will be more tension on the spring and the pressure would be slightly greater depending upon how much shorter the installed height becomes.  If a spring spec shows 1.700 as the installed height, and you install it at 1.727", then it will have a bit less tension installed than that shown in the specs for that particular spring.

Steve, I have been reading and doing a lot of research, as this is a learning experience for me. I have been doing my own mechanical work on my GN since day one and that is going on 33 years of owning it.
I learned a lot from my father at younger age, but some learning do slip away like trying to learn how to rebuilt a older caddy tranny in the winter on the driveway, and no it was fun trying to learn that.
The photo shown; will this comp cam 981-16 spec is okay use?
Thanks, Julio

[Steve Wood]

All 981 springs have the same spec. I would ignore everything written on the box. I would remove the current springs, one at a time and install a 981 spring in its place. I would not measure any thing. I would not use any shims. I would simply install a spring and damper (the inner spring looking device), put the retainer on and install the keepers. Then I always put a large socket on the retainer and give it a tap with a hammer to make sure the locks are located correctly in the retainer and won't jump out. When I finish a side, I pour oil over them so the don't start dry and get hot on the first start.

Only the intakes get a seal.

You will most likely need a valve spring tool made for a Buick turbo to get in to the rear passenger side. I bought mine from Cotton. I think most vendors sell them.
.

[Steve Wood]

I would use new matching retainers and locks if I did it to make sure everything fit just right.

Steel Retainers:728-16  /   750-16
Tool Steel Retainers:1750-16

[gnonyx]

All 981 springs have the same spec. I would ignore everything written on the box. I would remove the current springs, one at a time and install a 981 spring in its place. I would not measure any thing. I would not use any shims. I would simply install a spring and damper (the inner spring looking device), put the retainer on and install the keepers. Then I always put a large socket on the retainer and give it a tap with a hammer to make sure the locks are located correctly in the retainer and won't jump out. When I finish a side, I pour oil over them so the don't start dry and get hot on the first start.

Only the intakes get a seal.

You will most likely need a valve spring tool made for a Buick turbo to get in to the rear passenger side. I bought mine from Cotton. I think most vendors sell them.
.

Check all over for a good price of parts and gasket and the only was RockAuto
Intake manifold gasket:  FEL-PRO MS96033
Intake valve guide Seal: FEL-PRO SS72623
GM TBI Fuel Line O-Ring Kit; Dimensions - Inches: 1/4, 3/8"; Contents: 2 O-Rings
Already got the valve spring tool from Cotton's Performance a while back and if you go to his site now there is nothing there since there is a message on his site:

Welcome to Cotton's Performance's new website!

Big Changes are happening here at Cotton's Performance! With almost 30 years servicing the race car and automotive industry, Jack Cotton has retired and has passed down the business, his expertise and experience to his son Brian Cotton!
I replaced just about all gasket except the biggest one, the Intake manifold gasket. Once I remove the intake manifold, and pass. valve cover I will finally be able to reach the ground wires behind the heads. I will clean bolt together with #8 wire to relocate on top of intake manifold once I put in back.
Thanks Steve for your help and I will post again once I finish or run into trouble:) Julio

[gnonyx]

I would use new matching retainers and locks if I did it to make sure everything fit just right.

Steel Retainers:728-16  /   750-16
Tool Steel Retainers:1750-16

WOW, I can't believe the price for both of these items
Is it possible to still use the existing retainers?

[Steve Wood]

I believe these springs are very slightly larger in diameter than factory springs so they will rub in a different place on the retainer than the factory springs did.

I am sure many have reused the original retainers, but, personally, it makes me nervous to put 35 year old parts on top of new parts and I would wait until I could at least get the retainers and preferably the locks as well.

BUT opinions will vary and I would see what Brad, Ed, and Jeremy or others think.  My feeling is that dropping a valve might cost a whole bunch more than the price of the new parts.  I am old and hard headed. That does not necessarily mean I am right LOL

[gnonyx]

I believe these springs are very slightly larger in diameter than factory springs so they will rub in a different place on the retainer than the factory springs did.

I am sure many have reused the original retainers, but, personally, it makes me nervous to put 35 year old parts on top of new parts and I would wait until I could at least get the retainers and preferably the locks as well.

BUT opinions will vary and I would see what Brad, Ed, and Jeremy or others think.  My feeling is that dropping a valve might cost a whole bunch more than the price of the new parts.  I am old and hard headed. That does not necessarily mean I am right LOL

would these be okay
 Comp Cams 750-16 10 Degree Hardened Steel Valve Spring Retainers

[Steve Wood]

Look at the comp cam catalog online and see if they are an option

[gnonyx]

Look at the comp cam catalog online and see if they are an option

Go choice Steve, I looked at Comp cam site and hopefully this what I need: I'll call them to confirm

https://www.compcams.com/single-outer-valve-springs-1-254-o-d-880-i-d.html

https://www.compcams.com/10-steel-retainers-1-250-spring-dia.html

Just realize I don't need 16 being out TR is only a 6 so only need 12 valve springs and 12 steel retainers
and their price is good compare to other places

[gnonyx]

I would use new matching retainers and locks if I did it to make sure everything fit just right.

Steel Retainers:728-16  /   750-16
Tool Steel Retainers:1750-16

Hi Steve, I called Comp Cam and asked about:
981-12 (V6) Single Outer Valve Springs: 1.254" O.D., .880" I.D.
Steel Retainers 750-12: 10° Steel Retainers: 1.250" Spring Dia.
Steel Retainers 742-12:  7° Steel Retainers: 1.250" Spring Dia.
During the conversation I asked what is the between 7° & 10° for our V6, but got cut off, redial but on waited too long for connection. Unless you know which degree I can use.
Anyway, I started disassemble the intake manifold and valve cover, it may be slow for others but it took me about 3.5 hrs. to remove both.
The real P.I.A. was the last pass. intake bolt that was hided behind the tranny dip tube. I had to remove the tranny bolt that hold the tranny dip tube in order to remove the intake manifold bolt. I tried to keep as much on the intake as possible, leaving the fuel rail on, Throttle Body vacuum block, twin heater tubes that connected together, Throttle cables bracket, and all sensors. I found out for me to remove the intake manifold was to raise the rear intake first in an angle and keep the front intake lower, and then sliding the intake backwards. This was to avoid the return fuel rail without bending out of it's original shape. Now I have a lot of time for cleaning the intake manifold, engine valley, and it looks like I might have to remove the intercool in order to rotate the engine since I'm using the rope method of replacing the valve springs.
Thanks

[Steve Wood]

 I am pretty sure the factory used 7 deg locks and retainers.  10 degs are stronger but I don't think they are needed for 90 lbs springs.  I suspect ten degree units are more expensive but I have not looked at prices.

[gnonyx]

I am pretty sure the factory used 7 deg locks and retainers.  10 degs are stronger but I don't think they are needed for 90 lbs springs.  I suspect ten degree units are more expensive but I have not looked at prices.

Both retainers Prices:
https://www.compcams.com/7-steel-retainers-1-250-spring-dia.html   - 742-12 - $55.95
https://www.compcams.com/10-steel-retainers-1-250-spring-dia.html - 750-12 - $55.95
Would it make a difference if using a 7 degs or 10 degs?

According the comp cam site spec:
742-12
COMP Cams­® Part# 742-12
Includes 12 Retainers
Chevrolet V6 and Small Block, Buick V6
7° Lock Angle - 11/32" Valve Stem Size - 1.250" Spring Diameter

 COMP Cams­® Part# 750-12
Includes 12 Retainers
Super Lock™ Retainers
10° Lock Angle - All Valve Stem Sizes - 1.250" Spring Diameter

 I think after reading the 742-12 might be a better choice, what do you think?