Guys I know a few of you might be thinking that I'm beating this to death but I really want to get this right the first time.
I have figured out the rope thing and the valve seals are no problem.
My hesitation is with the springs. The assemblies that I am taking off are very different from what I have to put on. I just want to make sure that I am supposed to take off everything, or if I should re-use something, etc.
In this picture the close row of parts is an old exhaust set up, the next row is an old intake set up and the third is a new set up.
do I have this correct? I understand I need shims for the exaust side. Where exactly in this set up do the shims go? Under, over, between?
Thanks in advance.
Jeff
http://i12.photobucket.com/albums/a2...ngine06002.jpg
http://i12.photobucket.com/albums/a2...ngine06001.jpg

 

Assemble 1 of each valve, with the new spring,seat and retainer, and measure the installed height.

If you want you should be able omit the spring and measure the distance between the new seat and the new retainer, while holding the retainer up against the locks.

From there you can determine how much you have to shim each to get the desired installed height.

Also, with the spring out, be sure to check retainer to guide, or retainer to seal clearance if your using umbrella type seals. This may limit your allowable lift.

Note: The exhaust clearance on my 88 was too tight to run an umbrella shield, so I added some oil shields on the exhaust springs.

To measure. I used an old business card, cut into a strip to just fit between the guide and the retainer, and then measured the thickness of the strip with a steel rule. I think you want at least 0.060 more than your valve lift, since the valve may bounce.

I also took a digital photo of the strip and ruler measurement to be sure i didn't mis read it.

 

Thanks tequilaboy, I think you made me more confused than I was before. I'm not worried too much about the measuring or the shim thickness because I have heard from others who have measured with the same parts. I was told that I didn't need to shim the intake but needed .120 on the exhaust.

When I install the shims where do they go?
Thanks

 

Hate to be the one to say it, but I feel you're in over your head. If you do this wrong, you can easily end up with engine damage or at best an engine that won't rev to the rpm you'd want.

I suggest you do some research to find a step by step procedure or grab someone who really knows how to do it. I'd hate to see you really hurt something in the engine.

You're working on something that REALLY has to be done correctly.

Just trying to help.

Jake

 

I think your right but I will do it.
The car is in pieces and in the basement of my house. The only way to get it out is to drive it and that can't happen until the snow and ice is gone.
I'm not in a rush and am quite capeable of taking things apart and putting them back together. Just in this case I am changing something and putting it back together different. None of my manuals tell me how to do this and it seems I am tool challenged at times.
If the only way to do this is to take an accurate measurement and shim accordingly then that is what I will do.
If doing it the way someone else has done it won't work for every car and I would be taking a risk, then I wont do it that way.
Is this the case?
I think there are enough people who have done this job that can help me step by step even if it does take a month or two.
I'm always willing to help others when I can.

 

Jake, I hope I didn't come across too defensive. You have helped me before and I appreciate your knowledge. You say you are just trying to help and I believe you.
I think you could likely give me the information I need to do this job.
What do you say? I'm looking for someone with the skills and the patience.

 

Turf everything from the stock spring setup except the locks if you are reusing them. Shim under the LT4 spring seat. Here's a pic of mine installed. Good Luck and measure twice

 

Here is a copy of the answer I sent to your PM:

The only one that can say that you need no shims on the intakes, and .120" on the exhausts, is someone that has measured YOUR engine and determined that. Parts vary. Especially castings (the heads) you can't make precision adjustments based on popular opinion or a consensus. A two thirds majority don't rule, here. Are you following your FSM? Even with non-stock parts the procedures are the same. Listen carefully to, and take Jake's caveat to heart.

RACE ON!!!

 

Thank you Agent 86
Your picture and description answer all of my original questions.

CFI_EFI I hear you and Jake loud and clear. All I needed to know was that I was going down the wrong path. Now that I know that all engines and measurement are not created equal I'll buy the tool to take the propper measurement and set it up correctly.
You can't blame a guy for looking for a shortcut. That's half of why I post the questions. This lets people like Jake or yourself stop me before I eff something up.
I have the FSM, actually I have two. Sometimes it is just a bit too technical or I need to put things in my own words and have someone confirm that I understand.

Jeff Out.

 

Good to see you are making progress over there......

 

Thanks Rick, baby steps but it's all good.
I've got until April.

 

Yeah, Get her ready for Bowling Green in May.

 

Take your time and measure everything 2x or more. Setting up springs is simply math and patients. Once you learn it and do it once, it gets very easy the next time around. Remember too, that with stock, or non stock parts, always check pushrod length when changing valve train parts. This is a critical measurement that also varies from engine to engine. Never trust anyones word on it. Always check.

 

Thanks Pete.

 

It's all about measure, measure, measure.

Correctly installing valve springs calls for using some specialized tools and some precise measurements. Many guys just plop springs on and drive away, which ain't the way. In doing it that way, you'd be making too many assumptions and precision will be out the window.

Shops have a valve spring pressure tester to check spring pressures at various heights/compressions. They also have mikes to measure heights.

The springs have to be measured and set correctly, within a hundredth of an inch, to give the correct seat pressure and open pressure. But it's also possible that the recommended installed height WILL NOT give you the seat pressure called for, so you've got to check to be sure. If the seat pressure is off, so will the open pressure.

Springs compress at a certain rate per inch of travel. You'd have to do the math to determine how much each additional amount of compression effects pressure. In other words, if you compress the spring an additional .100, how much with the pressure increase.

The springs - assuming they are the correct ones for the camshaft - come with a recommended installed height and a recommended seat pressure. These have to be compatible with the cam you're running. It's the cam that determines which spring you run.

Too much seat pressure can give you too much open pressure, and vice versa. If the spring has to be shimmed excessively to give you the desired seat/open pressure, you can end up with coil bind and/or retainer to guide interference at max lift.

At max lift, there is a minimum amount of clearance between the coils that has to be maintained. Running less than the recommended coil clearance can over-work the spring, shorten it's life and risk coil bind, especially at high RPMs. That's why just shimming a set of springs to increase pressure can really cause valve train woes and engine damage.

After measuring, shims are installed to set that height. You can't just install X number of shims or X thickness of shims under the springs and button everything up; you've got to measure first.

Some valves may call for different thickness shims than others ON THE SAME HEAD. Depends on a few variables, such as how deeply the spring seat is cut in the head. For example, one valve may call for a .030 shim while another .040. If you don't shim them individually, you may end up with un-equal spring pressures.

Eliminating rotators is another can of worms altogether.

AFR and others recommend that each spring should be placed in a vise and fully compressed to coil bind BEFORE being measured and installed on the head. Doing this lessens the change in spring pressure after the engine has run for a while by relaxing the spring. Springs tend to loose a little pressure after being initially run.

You must remove the spring you're replacing, then re-install the retainer and locks. Pull up on the retainer and then measure from the underside of the retainer where the spring will seat against the retainer to the spring seat on the head. That'll give you the seat to seat distance you'll be dealing with. This can measurement can vary.

Then you must measure the spring at its recommended installed height. and make sure that the pressure at that height is what's called for. If it is, you then take the height of the spring, subtract that height figure from the measurement you took of retainer to spring seat on the head.

That'll tell you the thickness of shim(s) you'll need to place under the spring.

How much distance is there between the head and retainer. Then what is the height of the spring at the seat pressure called for. Shims make up the difference.

Fifteen more times and you're done. Hit each valve stem tip with a rubber mallet to set the locks.

This is complicated stuff for those who don't do it on a regular basis. That's why I leave it to the machine shop rather than puzzle my puzzler over it.

Jake

 

Absolutely!

I only take exceprion to one minor point.The retainer to guide relationship doesn't change.

Heed Jake.

RACE ON!!!

 

One other thing worth mentioning. Most cam manufacturers want you to run a spring that suits open and closed pressures based on valve lift. They also like to see you run the spring somewhat close to coil bind. Not dangerously close, but close. It was explained to me by the comp cams tech department. Something about harmonics. The first time I set up springs, I never thought it would be so detailed, but it is and needs to be.

 

Jake you are the man.
It's written in english that I understand. Thank you for taking the time to put that together. It obviously took more than just a couple of minutes.
I'm not affraid of math especially just adding and subtracting. I'm going to do this myself but I can see I need to spend a couple of dollars on the proper tools for the job.
I have months to get this done and have it all back together.
Thanks again.
Also thanks to Pete K.
CFI what's an exceprion?

Jeff

 

Valve spring Height Micrometer has been ordered.

 

They are handy tools. I usually use snap guages and a dial caliper. Height mike works very well.