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Discussion Starter · #1 ·
Try as I might, I can not find a spec for installed height for stock valve springs on a 1965 327. I am using Melling VS-170 springs and they don't come with any spec papers in the box. The only thing I can find is [email protected]" in the Melling book, but is 1.696" necessarily the installed height or is that just the height they measure the seat pressure at?
 

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Try as I might, I can not find a spec for installed height for stock valve springs on a 1965 327. I am using Melling VS-170 springs and they don't come with any spec papers in the box. The only thing I can find is [email protected]" in the Melling book, but is (#1) 1.696" necessarily the installed height or (#2) is that just the height they measure the seat pressure at?
#1. Nope
#2. Yup
 

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Try as I might, I can not find a spec for installed height for stock valve springs on a 1965 327. I am using Melling VS-170 springs and they don't come with any spec papers in the box. The only thing I can find is [email protected]" in the Melling book, but is 1.696" necessarily the installed height or is that just the height they measure the seat pressure at?
the general excepted height is 1.7" or .004" more than you listed!
 

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Hi Carl,

As Veno said, the general installed height with a stock early spring is 1.7.


Believe it or not, I used to used that comparable spring, installed at around that pressure in NHRA stock eliminator cars, and they would see about 6500 +, for several passes.


In some 302s I have seen that spring go about 8800 (for about 6-10 passes).


You can use a lot better spring now and there is no rule on pressure (that I know of).
 

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Discussion Starter · #5 ·
Thanks very much guys.

This is a basically stock engine except for an L79 cam. It won't see any crazy rpm. I just wanted to make sure I had it close to proper specs.

Thanks again.
 

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Discussion Starter · #6 · (Edited)
If I could add to this question, I was thinking more about this. Are you guys saying as long as I am close to 1.70" that is good enough? Right now they range from 1.655" to 1.700". Am I being too precise?
 

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I would look more at the spring pressure at your installed height. If is a mild cammed street motor that may see 6000 rpm once in a while you need 80 pounds with the valve closed(spring seat pressure). Dont forget to check the distance from the bottom of the retainer to the top of the guide (without the spring) put the valve in the head retainer and keepers together and pull the valve closed. One more thing if you dont know this already I have seen a lot of guys make this mistake compress the spring with the retainer first then put the o ring on the valve in the lower groove so it sandwiches between the retainer and the keys.
 

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If I could add to this question, I was thinking more about this. Are you guys saying as long as I am close to 1.70" that is good enough? Right now they range from 1.655" to 1.700". Am I being too precise?
That'll be fine. :yes:
 

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Carl,


Personally I wouldnt want to go any tighter than 1.700".

The 1.655 kinda surprises me a bit. Most stock heads are 1.700" or larger from the factory.

By chance have larger valves been installed in the heads? If so that might explain the tighter height dimensions. If that is the case I would not only worry about the closer spring height and related issues (like coil bind) but valve to piston clearance may be of concern?


Good Luck

Jeff
 

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You will have to click twice.

SPEC FOR A 1965 327


iNSTALL HIGH IS 1.66

The melling spring you have does have a 1.70 spec. (IE: VS-170- Valve Spring 1.70)
 

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Hi Al,


Do yo think the installed height on a 1967 327 valve spring is actually 1.156"?


Or am I reading that wrong?




Jeff
I see it now, under 1967

I am not real sure about that one. :confused:

Who knows?:rolleyes::confused:

I bet they all have been updated to the vs170 spring and spec.

AL
 

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Discussion Starter · #15 ·
Digging up an old thread....

I had planned to assemble this engine in the spring but a number of issues (4 week flood, GM terminated the contract at our dealership, etc etc) arose and it didn't happen.

Now I hope to get back to it.

Re: these heads, no, the valves are still the stock sizes.

And yes, it is a basically stock 327 with an L79 cam, 69 Z28 intake and a Holley. It really will likely only ever see 6000 RPM max.
 

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You'll find the problem with setting the installed height is the size of shims. They .015", .030" and .060". If your valves are ground unevenly or in varying depths then it may be difficult to get them exactly to specs.
 

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Discussion Starter · #17 ·
I was reading all the measurements last night and calculating. I have exactly those shims and you are exactly right.

Am I better to go a bit tighter or a bit looser when I have to make that decision.

Any min/max figures I should be using?
 

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Define "a bit".
If you go looser the spring has less pressure and the engine won't seal as well. The springs will lose tension over time so I would go slightly tighter. Running 90-100 pounds of pressure won't hurt. The danger of going too tight is running into coil bind. Too bad you are so far away. This kind of valve fitting is right up my alley.
 

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Discussion Starter · #19 ·
I will try to post up the specs tonight and you can give me an opinion on which way to go on some of them if you don't mind then Paul.

I have all the measurements, just have to decide which shims.

Thanks.
 
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