I have a '97 with 72k. I am changing out to stronger valve springs (they are Manley but forgot the specs, I think good to .55). Is there a real reason I should swap out the stock lifters? Should I go with LS7 just in case or for longevity?

Hal

 

As long as they are in good shape there is no reason as to why you couldn't reuse them. And with your low mileage I'd be confident in reusing them. I can only assume you are upgrading the cam as well, correct?

 

No. Just uping the rockers to 1.7 instead.

Hal

 

Stock is plenty then!

 

How about re-writing this. There are no 1.7 lifters. Tell us exactly what you're doing.

Jake

 

I caught it before I read your comment but most anyone could have guess my intentions.

 

Id pull them to inspect. If all the rollers look fine, Id reuse them. But if any of them have wear marks or are questionable, Id pull them. LS7, or CC lifters would work just fine.

 

If he does this, he'll need to remove the intake manifold. Since he mentioned later in his post that he is only replacing the rockers, I doubt it's an extra step he will need to do.

 

Okay, I understand what you're doing now; springs and rockers.

I suspect you've already crunched the numbers and have figured out that your new springs can handle the additional lift the 1.7s will give.

Not knowing what springs you have on the engine now and which ones you're going to install, if I was doing it, I'd check the installed height of the new springs to be sure the height will give you the seat pressure you want.

I have an inexpensive pressure tester that works with a bench vise. Using it and a spring, I clamp it to the installed height I want, then check to see what the pressure is. I then go from there as far as adding shims.

Another trick I learned from AFR more than 20 years ago was to clamp each new spring in a bench vise (with some sort of protection on the ends of the springs to prevent them getting nicked), and bring each one to coil bind.

This pre-stresses the springs and they will hold pressure much better once installed on the heads. Since learning that from AFR, I've seen it written about in a couple of mag Tech articles too.

So, now to get back to your original question, the only way to check the lifters is to pull the intake, but if you haven't noticed any unusual noise, I'd leave them as is.

However, if I heard any ticking noise, I'd bite the bullet, pull the intake and check each one. If one shows wear, a loose roller or any roughness when the roller is turned, I'd replace the entire set.

I didn't want to get off topic, but I thought the other info would be of interest.

Jake

West Point ROCKS!

 

Sorry I didn't mention this but I already pulled my intake due to a suspected oil leak. It's off at the powder coaters so I'll do all the suggestions of pulling the lifters to inspect, pre-stressing the springs in a vice, then doing the install height pressure test. I remember way back after adding 1.6 rockers that there was a tick I could never get rid of on one of cylinder valve train so maybe an inspection will turn up a cause.

I'm switching to the 1.7 rockers because I already had better springs which I never installed. It is getting a little costly with all the additional tools needed alone (pressure tester, install height mic, rod length tester, spring compressor) adding more than $100. But, like most I just want to do it once correctly. My 1.6 rr never had a problem with the valve covers but my luck the 1.7 will and require new covers too. I should probably just leave sleeping dogs lie but at least check the lifters.

Thanks for all the great suggestions!

 

Hal, of course there are specialized tools for setting up the installed height and seat pressure, but for me the cost wasn't worth it just for the fre times I'd use it. However, there is a work-around for setting up the springs if you don't have those specialized tools.

First, remove all the old springs, retainers and locks and set them aside. Now just replace one retainer and its locks, leaving any shims in place on the head.

Now, use your vice to stress-relieve all the springs, one at a time and set them aside.

Using the spring pressure tester and your vice, install one spring and tester in the vice and turn the handle of the vice, closing its jaws, while watching the pressure gauge on the tester.

When the pressure reads the seat pressure you want, measure the height of the spring at that pressure.

If you don't have a tool to make the measurement, just cut a length of coat hangar/welding rod, etc., (anything thin, rigid and easy to cut) to the same length of the spring at it's seat pressure height.

Now take that length of coat hangar over to the engine and insert it vertically between the retainer and the shims, making sure it's a straight as possible.

There may be a gap, so if there is, add another shim(s) until the piece of coat hangar fits snugly between the underside of the retainer (the area where the spring will ride) and the shim(s). Add or remove shims until you get a nice coat hangar fit.

Check to see how many and what thickness shims it took to get that height. Some, who are ****, repeat this process for each and every spring, but most recommend that you only have to do ONE, then duplicate that shim stack on the other 15.

Now, when you install the spring, you'll know that you have the spring seat pressure you want. That's because the spring height you measured (or the coat hangar length) you measured with the spring in the vice is the same as when you installed the spring on the head.

After installing the spring, retainer and locks, use a rubber mallet and give the valve stem tip a HEALTHY WHACK OR TWO which'll insure that locks are seated fully.

If you don't have a pressure tester, I'll mail you mine if you promise to return it when you're done. I'm not using it now. Send me a PM of email - jcameron266@sbcglobal.net - if you want to borrow it.

Hope this helps.

Jake

West Point ROCKS!

 

Ive had my 1.6 comp magnum rr's for a month trying to decide whether or not i need to change springs when i do the swap. did you use stockers when you went to 1.6s? i think i have found enough people who've done it with stock and think im gonna do so this weekend. the alt was to order some lt4s and reuse the locks and retainers... oh ya its on the 96 formula in sig w/ 150k but runs amazing (like 50k)

thanks in advance

Nick

 

Many people, including me, recommend it's best to change springs when going to higher ratio rocker arms, expecially when the existing springs have a lot of miles on them. However, many guys choose not to change them.

NOT changing springs can compromise the benefit of the new rockers at higher rpms by not being able to control the valve as well.

The critical issue is clearance between the coils of the springs. With the valve at full lift, there should be .060" clearance between the coils and because the new rockers will add about .030" more lift, the clearance will be reduced.

This question is sort of like "Should I degree in my new camshaft?"; while it's not absolutely required, it's best to do so.

Jake

West Point ROCKS!