Valve spring question for Duke, Joe L. Clem

[Robert M.]

Hi all.
I have the 1970 L46 motor. I just had the heads worked with a 3 angle valve cut. The heads are 186's. I was told there was some valve recession. I measured the valve height this evening, and it appears I will have a installed valve height of about 1.800" using a .060 shim and the umbrella. Obviously I can't use the stock 068 springs and retain any kind of pressure on the seat. I saw that the clevite 212-1183 seem to have similar characteristics, and I calculate they would be about 77 lbs @ 1.800". The open pressure would be a bit higher, as the stock spring is 267 lbs @ in against about 323 lbs @ in for the 212-1183.

Do you think it would be acceptable to use the 1183 spring at 1.800" to keep a good seat pressure and not be excessive when open?

[Duke W.]

Re: Valve spring question for Duke, Joe L. Clem

The nominal installed height for the 068 is 1.70". I don't like that higher rate! Too many shims on the bottom can raise the bottom of the spring above the valve spring pocket, which must be avoided, but I think you can put shims between the retainer and oil shield or oil shield and spring.

I think John McRae did this on his 327. Because we are looking for maximum lifter pump-up speed, I recommended that he shim the inlet side (which has a .2981" lobe) to a range of 1.657-1.675", which is doable with a proper selection of .030 and .015" shims, but the spring ended up out of the pocket, so he put at least one shim on the top. I think he is not running the shields on the inlet side, but did install them on the exhaust side - just to get the installed height to the recommended lower range with the "smaller" .273" lobe and fewer shims.

Maybe he can chime in here to verify.

The above spring height range should leave at least .080" coil bind margin based on a maximum rocker ratio of 1.44:1 at maximum lobe lift. Since your lobes are .3000/.3067, you might want to increase the above range by about .005" on the inlet side and .012" on the exhaust side.

I hope you used new valve springs, and you don't have to pay GM prices. Their 068 is just a Sealed Power VS677 in a GM box with a GM part number. You can buy the VS677s on the Web for about a buck a piece. The same spring from NAPA is 2121150.

You will probably end up spending more on shims!

Duke

[Robert M.]

Re: Valve spring question for Duke, Joe L. Clem

I have a good selection of shims in .015, .030, and .060, and the 2121150's are available at the local Napa. I hadn't thought of installing shims under the oil shield. The stack of shims i had to get the 1.70" height left me with very little spring cup, and i could just see the spring wandering about while I'm reaching for the higher RPM's.

Friday i will try and adjust for proper height by installing some shims under the oil shield, and then hopefully, go with the stock 2121150's

Duke, thanks again for helping.

[Joe L.]

Re: Valve spring question for Duke, Joe L. Clem

I have a good selection of shims in .015, .030, and .060, and the 2121150's are available at the local Napa. I hadn't thought of installing shims under the oil shield. The stack of shims i had to get the 1.70" height left me with very little spring cup, and i could just see the spring wandering about while I'm reaching for the higher RPM's.

Friday i will try and adjust for proper height by installing some shims under the oil shield, and then hopefully, go with the stock 2121150's

Duke, thanks again for helping.

Bob-----


I hate to tell you this, but if I had cylinder heads with so much valve seat recission that stock valve springs would not work without massive shimming or other efforts, I'd be more worried about using the heads than I would about finding valve springs that I could make work. I've used small block heads that had previously had 3 or more valve jobs and I never had so much recission that I could not make stock valve springs work without problems. I'm talking NEW valve springs, though.

[Clem Z.]

Re: Valve spring question for Duke, Joe L. Clem

i am with joe on this as that means the valves have been "sunk" a LOT. they should have used new valves with bigger head diameter so they did not have to "sink" the valves so much. this is going to cause a loss in top end preformance. i would go with "longer" springs so you don't need all those shims as long as the spring rate in pounds per inch does not go over 300#

[Robert M.]

Re: Valve spring question for Duke, Joe L. Clem

I think I've found a solution to the problem. I've spend the evening looking at my situation, and the spring retainers for answers. My retainers looked odd compared with another stock retainer I had laying around. I learned that Crane Cams has some valve spring retainers that are made to reduce installed height to -.090" (Part Number: 99916) and they also offer valve locks with a -.050" installed height. Using either one or the other with a correctly selected thin shim, i should be able to get a desired seat pressure, without over filling the spring seat with multiple shims, and use a stock 2121150 spring.

The valve recession may not be as bad as I thought, as it maybe because of the components I've selected to assemble the heads. A user error.

[Joe M.]

Re: Valve spring question for Duke, Joe L. Clem

If you had a valve that appears 'sunken' more than the others would installation of valve seats such as performed when installing hardened valve seats eliminate the problem? Say in small valve 461 or 896 heads.

Joe

[Clem Z.]

Re: Valve spring question for Duke, Joe L. Clem

If you had a valve that appears 'sunken' more than the others would installation of valve seats such as performed when installing hardened valve seats eliminate the problem? Say in small valve 461 or 896 heads.

Joe

it is better to just use a valve with a larger head diameter which will move the seats out farther than the original "sunken" seat.

[Robert M.]

Re: Valve spring question for Duke, Joe L. Clem

An update on my valve spring problem. To sum up the problem, after installing a .060 shim, the new Manley valve, and retainer, and measuring everything with a valve micrometer, I had an installed height of 1.80".

This morning I found an old valve spring retainer, and noticed it was much different than what I am attempting to use. I did an online search of the Napa line, and found the clevite 216-4118, which I bought 16. I found the new clevite retainer reduced my heights by .120" measured. I also dug out my old valves, and found that they are .040" less height installed & measured that the Manley's. The guy at the machine shop confirmed that the Manley's are longer than stock. So by installing the new clevite retainers with the Manley valves and a .060 shim, I get measured heights of approximately 1.68" on all my valves plus and minus a few thousandths. These heights are lower than spec, and close to Dukes preferred heights.
I also bought new 212-1150 springs for the install.

So the bottom line is the sunken valve seats I thought I had were not the problem, but rather it was the hot rod go-fast parts I tried to install, with out fully knowing the exact specs of the parts.

In the photo below, the clevite 216-4118 on the left, the +.120" unknown retainer on right

[Joe L.]

Re: Valve spring question for Duke, Joe L. Clem

An update on my valve spring problem. To sum up the problem, after installing a .060 shim, the new Manley valve, and retainer, and measuring everything with a valve micrometer, I had an installed height of 1.80".

This morning I found an old valve spring retainer, and noticed it was much different than what I am attempting to use. I did an online search of the Napa line, and found the clevite 216-4118, which I bought 16. I found the new clevite retainer reduced my heights by .120" measured. I also dug out my old valves, and found that they are .040" less height installed & measured that the Manley's. The guy at the machine shop confirmed that the Manley's are longer than stock. So by installing the new clevite retainers with the Manley valves and a .060 shim, I get measured heights of approximately 1.68" on all my valves plus and minus a few thousandths. These heights are lower than spec, and close to Dukes preferred heights.
I also bought new 212-1150 springs for the install.

So the bottom line is the sunken valve seats I thought I had were not the problem, but rather it was the hot rod go-fast parts I tried to install, with out fully knowing the exact specs of the parts.

In the photo below, the clevite 216-4118 on the left, the +.120" unknown retainer on right

Bob------


Neither of the retainers are configured like a GM retainer. However, the Clevite retainer is much closer to the GM configuration.

[Duke W.]

Re: Valve spring question for Duke, Joe L. Clem

An update on my valve spring problem. To sum up the problem, after installing a .060 shim, the new Manley valve, and retainer, and measuring everything with a valve micrometer, I had an installed height of 1.80".

This morning I found an old valve spring retainer, and noticed it was much different than what I am attempting to use. I did an online search of the Napa line, and found the clevite 216-4118, which I bought 16. I found the new clevite retainer reduced my heights by .120" measured. I also dug out my old valves, and found that they are .040" less height installed & measured that the Manley's. The guy at the machine shop confirmed that the Manley's are longer than stock. So by installing the new clevite retainers with the Manley valves and a .060 shim, I get measured heights of approximately 1.68" on all my valves plus and minus a few thousandths. These heights are lower than spec, and close to Dukes preferred heights.
I also bought new 212-1150 springs for the install.

So the bottom line is the sunken valve seats I thought I had were not the problem, but rather it was the hot rod go-fast parts I tried to install, with out fully knowing the exact specs of the parts.

In the photo below, the clevite 216-4118 on the left, the +.120" unknown retainer on right

Another reason why I always preach: "Use OE or OE equivalent parts" and "avoid hot rod parts".

Clevite (Dana Corp.) and Sealed Power (Federal Mogul) OE replacement parts can be be trusted to be OE spec and OE quality.

Duke