Author Topic: valve springs  (Read 18159 times)

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Offline Shimy87

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valve springs
« on: June 17 2016, 10:16:10 AM »
I will be changing these, from my reading seem like 2 popular choices, 980's and 981's.  Which is the better option for my combo...see sig

Thanks!!
87 GN, K&N cold air, gutted cat, TT 5.7 chip, AFPR, 340 Walbro w/ hotwire, 60 LBS injectors, 981 valve springs, 206/206 Cam, RJC Powerplate, LS1 MAF & translator, Vacuum brakes, Hellwig rear sway bar, Energy suspension poly bushings, Razors Alky, Pypes exhaust, 5931 turbo, CK9.5 converter

Offline Steve Wood

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Re: valve springs
« Reply #1 on: June 17 2016, 11:04:58 AM »
These days, I think I would go with the stiffer of the two
Steve Wood

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A lot of broken parts does not make you a racer; it makes you a slow learner.

Offline larrym

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valve springs
« Reply #2 on: June 17 2016, 11:10:22 AM »
Yes 981s where what I used ion my flat tappets the 980s are pretty mushy after you spin it high a couple times.
86 white T type with t tops and blackout trim. 60lb injectors Gen 2 with Extender Chip TR6 ignition 212/206 roller cam Turbonetics BB CPT 61 CAS V4 Intercooler Cobbled together Alky Injection 4 inch MAF pipe with integral sensor
2800 stall lots of fun with a little 6 banger!
Best ET 11.36

Offline Shimy87

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Re: valve springs
« Reply #3 on: June 17 2016, 11:37:50 AM »
Thanks guys!!
87 GN, K&N cold air, gutted cat, TT 5.7 chip, AFPR, 340 Walbro w/ hotwire, 60 LBS injectors, 981 valve springs, 206/206 Cam, RJC Powerplate, LS1 MAF & translator, Vacuum brakes, Hellwig rear sway bar, Energy suspension poly bushings, Razors Alky, Pypes exhaust, 5931 turbo, CK9.5 converter

Offline Scoobum

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Re: valve springs
« Reply #4 on: June 17 2016, 05:05:08 PM »
981's and don't spin the engine past 5500. I agree with Bison. Most don't  run near enuf valve spring pressure.


A lesson I learned. If you ever overboost an engine...be sure to swap in a new set of valve springs when you're changing the head gaskets.


I ran across a post from Dusty Bradfiord a while back. When he was racing these 231's back in the day...he was swapping valve springs 3 times during the race season.
Hard work pays off, dreams come true. Bad times don't last, but BAD GUYS do!

RIP Scott Hall AKA Razor Ramon

Offline Shimy87

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Re: valve springs
« Reply #5 on: June 29 2016, 02:03:37 PM »
ordered some 981's and borrowed a tool from a local garage, hope to have them in and installed next week  :D Been reading a lot on here and looks like I'm way conservative on my tune, fast guys running O2's in the 760 area. I'm in 790 area, and a few times in the first 100 ft showed some knock but figured it was from tire spin and not real knock, as it went away. I don't trailer to track, I drive and hour and a half, so I don't want to break the ol girl :icon_eyes: or I'm just chicken.
87 GN, K&N cold air, gutted cat, TT 5.7 chip, AFPR, 340 Walbro w/ hotwire, 60 LBS injectors, 981 valve springs, 206/206 Cam, RJC Powerplate, LS1 MAF & translator, Vacuum brakes, Hellwig rear sway bar, Energy suspension poly bushings, Razors Alky, Pypes exhaust, 5931 turbo, CK9.5 converter

Offline 1KWIKSIX

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Re: valve springs
« Reply #6 on: June 29 2016, 05:01:59 PM »
Question for you?
What do Comp Cam state the 981's spring rates are at 1) closed- 1.727"  & 2) open- on the nose - 1.340"


You really should use a valve spring micrometer to check the installed heights .  Your spring pressures could be way over or under due to variances in the valve seat, valve tip , etc, etc. that will exist for each valve in your cylinder head.
I'm guessing your using a flat tapped cam?
Would hate to wipe a cam lobe.


Valve spring shims are available to help you fine tune each spring to achieve your desired numbers in your target (or at least get closer to it).


I used compressed air to keep the valves open when I recently did this change over with no problems (except you gotta watch out for those damn valve spring keepers as they will sometimes shoot out  and good luck finding them) I was lucky to have someone come to my rescue!   LOL - Thanks Brad

Offline Scoobum

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Re: valve springs
« Reply #7 on: June 29 2016, 09:24:13 PM »
980's or 981's won't bring him anywhere near the valve spring pressure I'm running...and the lifters in my engine are showing zero wear after 2 years of weekend beatings...wit h no ZDDP. Oh...and I'm currently running a Fram filter. I live life on the edge...


Shimy...if you had PL...you'd be able to verify if the KR is real...or not. :)
Hard work pays off, dreams come true. Bad times don't last, but BAD GUYS do!

RIP Scott Hall AKA Razor Ramon

Offline earlbrown

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Re: valve springs
« Reply #8 on: June 30 2016, 02:22:58 PM »
I thought Comp Cams springs went to shit when they moved production to Mexico?

I have to use the hive mind here as I switched to PAC and haven't personally bought any Comp springs since all the reported problems.
'87 GN - 4.2L SFI Turbocharged innercooled V6 - Chrome valve covers - supra pump - 14" K&N - 52mm throttlebody - rocker shaft supports -  1/2 intake spacer - TB coolant bypass - 3" ATR exhaust tip - Alum intake pipe - NOS timing cover - chip - relocated charcoal canister - CR42's - stock

Offline Shimy87

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Re: valve springs
« Reply #9 on: July 15 2016, 12:19:47 PM »
Tried to install the 981's yesterday, got all but the last 3 on passenger side. Had to order the tool from Cotton's, tool I had would not fit there. I did not reinstall the metal cups that went around the old springs....was that a bad idea?
87 GN, K&N cold air, gutted cat, TT 5.7 chip, AFPR, 340 Walbro w/ hotwire, 60 LBS injectors, 981 valve springs, 206/206 Cam, RJC Powerplate, LS1 MAF & translator, Vacuum brakes, Hellwig rear sway bar, Energy suspension poly bushings, Razors Alky, Pypes exhaust, 5931 turbo, CK9.5 converter

Offline larrym

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valve springs
« Reply #10 on: July 15 2016, 01:12:42 PM »
No you did the right thing did you measure installed hight? We usually cut a piece of wire to measure with.
86 white T type with t tops and blackout trim. 60lb injectors Gen 2 with Extender Chip TR6 ignition 212/206 roller cam Turbonetics BB CPT 61 CAS V4 Intercooler Cobbled together Alky Injection 4 inch MAF pipe with integral sensor
2800 stall lots of fun with a little 6 banger!
Best ET 11.36

Offline Shimy87

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Re: valve springs
« Reply #11 on: July 15 2016, 04:05:49 PM »
Just cut wire to top of retainer or top of spring then measure? What should it be?
87 GN, K&N cold air, gutted cat, TT 5.7 chip, AFPR, 340 Walbro w/ hotwire, 60 LBS injectors, 981 valve springs, 206/206 Cam, RJC Powerplate, LS1 MAF & translator, Vacuum brakes, Hellwig rear sway bar, Energy suspension poly bushings, Razors Alky, Pypes exhaust, 5931 turbo, CK9.5 converter

Offline Steve Wood

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Re: valve springs
« Reply #12 on: July 15 2016, 04:15:11 PM »
I would not worry about it at all if you have installed most of them already
Steve Wood

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A lot of broken parts does not make you a racer; it makes you a slow learner.

Offline Shimy87

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Re: valve springs
« Reply #13 on: July 20 2016, 03:56:52 PM »
Got time to finish these up yesterday, put in some CR43ts gapped at .035, hope to fire it up tonight!! Those back 2 on the passenger side are kinda a pain in the ass :068:
87 GN, K&N cold air, gutted cat, TT 5.7 chip, AFPR, 340 Walbro w/ hotwire, 60 LBS injectors, 981 valve springs, 206/206 Cam, RJC Powerplate, LS1 MAF & translator, Vacuum brakes, Hellwig rear sway bar, Energy suspension poly bushings, Razors Alky, Pypes exhaust, 5931 turbo, CK9.5 converter

Offline Steve Wood

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Re: valve springs
« Reply #14 on: July 20 2016, 04:58:56 PM »
yes, they are!
Steve Wood

http://www.vortexbuicks-etc.com

A lot of broken parts does not make you a racer; it makes you a slow learner.

 

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