Safe amount to cut spring seat depth on SCJ heads

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Safe amount to cut spring seat depth on SCJ heads

Post  frank13 on May 11th 2016, 5:40 am

As the title states, looking for what is safe to take off of SCJ heads.

Want to be at 1.95- and after rechecking the maching shop I am:

cylinder intake exhaust
1 1.870 1.916
2 1.900 1.918
3 1.88 1.921
4 1.85 1.920
5 1.876 1.911
6 1.87 1.910
7 1.90 1.916
8 1.897 1.914

Id like to take .080 off- doable?

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Re: Safe amount to cut spring seat depth on SCJ heads

Post  dfree383 on May 11th 2016, 7:15 am

Have you looked at +.050 locks and different retainers?

And a better more consistent valve job ?
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Re: Safe amount to cut spring seat depth on SCJ heads

Post  68galaxie on May 11th 2016, 9:32 am

I would not cut the spring seat depth.

First fix the valve job, and then change retainers or locks or both as needed.
+0.100" retainers and possibly + 0.050" locks if needed.

Cheers
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Re: Safe amount to cut spring seat depth on SCJ heads

Post  rmcomprandy on May 11th 2016, 10:15 am

I have gone .030" and also then used a .030" thick spring locater to get an extra .060" but, I have no idea how far is to far.

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Re: Safe amount to cut spring seat depth on SCJ heads

Post  frank13 on May 11th 2016, 9:57 pm

Well went to the machine shop. After some talk about options I went with

Comp valve job
New longer intake valves
Everything installed at 1.95
Was all cleaned chased and built.
Ready to bolt on
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Re: Safe amount to cut spring seat depth on SCJ heads

Post  frank13 on May 12th 2016, 10:37 pm

...


Last edited by frank13 on May 12th 2016, 10:41 pm; edited 1 time in total
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Re: Safe amount to cut spring seat depth on SCJ heads

Post  frank13 on May 12th 2016, 10:41 pm

shop had them done same day, and I picked them up in the am:


  So I went to the machine shop with a fix in mind and after some talk and some thinking I decided to bit the bullet for new intake valves, fresh competition valve job and make sure the heads were flat and straight.  

Well heads were off 11 thousandths which of course they fixed and the heads came out great.

So here are some pics of the heads fresh from the shop:


Checking the installed heights



Checking the installed height still


Fresh heads:








Nice and pretty!


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