time limit on valve spring replacement?

[OneLethal87GN]

My car has turned 154k and I've been wanting to do the valvespring replacement for a while. My mechanic is scared it'll wipe the cam. Is it too late? My car definitely doesn't give the performance I expect from my mods. Gotta new tranny, pretty good tune, just not what I expect from the mods I have on this thing.

 

[salvageV6]

If you do it with a stock spec. spring you shouldn't have any problems in MHO.

I bet your originals are about 65lb. force.

Never too late I did mine at 123K and 112K on the other car.

What rpms does it shift at?

 

[U1ARUNIT]

If you use stock type springs it will be fine. I agree that it's never too late.

 

[bschultz]

What about LT-1 springs?

My 86 GN has 119,000 miles on it and I'm sure it needs valve springs. I was planning on getting 100lbs springs. Is this too much for a high mileage engine? If so, what should I shoot for? TIA

 

[salvageV6]

78-82 lbs. force.

Comp Cams 980's were 85-86 lbs., brand new, when I tested the sample from two sets I used.

Didn't use the stock cups as they add about 9lbs. force to the spring.

 

[bschultz]

So LT-1's are not for me?

I guess I won't be using the LT-1 valve springs I just got then....

 

[qtr@atyme]

Used 100lbs on my 103,000 mile motor drove the car pretty regular never had any problems with it or anyone else car that I've changed the springs on. My car ran 7.25 @ 92 on the 1/8 with the stock motor with these springs 34 turbo and plenty of boost. I belive that once a cam has been run a wear pattern is established and unless problems are on the front anyways that you will be fine. AND I never HAD to replace the head gaskets!
I sold the motor after installing the stg 2 and its still running strong last I heard.

 

[cruzn57]

Valve springs

For what its worth, as long as your cam isn't worn now, installing new springs sure won't cause any abnormal wear problems.
By now ,the lifters have a wear pattern on the cam, and short of installing roller springs, you shouldn't have any problems.
With that many miles, you may want to concider a timing chain replacement, (increased valve spring pressure, causes more stress on the timing chain)
good luck
cruzn57


Hey! sometimes us experienced (read that not so young anymore) folks, have been down that road before!

 

[jsta6]

100lbs is to much IMHO.

I got the cc980's but I have not put them on yet.

 

[bschultz]

Already got 100lbs

Thanks for the response guys....since I already have the LT-1 (100lbs) springs, I guess I will use them along with a new timing set....thanks cruzn57!

 

[jsta6]

FWIW, I heard that there were some different kinds of "LT1" springs out there. Anywhere from 90 - 110lbs...

 

[OneLethal87GN]

Thanks for the imput. I just wanted an idea of how long anyone else has waited to replace theirs. I think I remember GM High-Tech's mule, Old Gray, had hers replaced with around 200k miles. I already replaced the timing chain, twice. I just had a feeling the springs were hurting my performance. I'll try to run some before and after drag strip times to see how much of a difference they made.

 

[bschultz]

Kirban part #6746

These are the valve springs that I got. Tested at 100lbs. I've heard the same about other "LT-1" springs having different ratings, so I went with what has been tested and proven to work. Thanks....

 

[Red Regal T]

Re: Kirban part #6746

Originally posted by bschultz
These are the valve springs that I got. Tested at 100lbs. I've heard the same about other "LT-1" springs having different ratings, so I went with what has been tested and proven to work. Thanks....

I'LL SECOND THAT !!