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Old Dec 28, 2001 | 09:50 PM
  #1  
1Fstz28's Avatar
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Default Valve Questions

I am looking at putting bigger valves in my heads and getting them ported. Most of the vehicles I work with here lately are DSMs. Well the questions I have are what Length valves come out of a LS1 head? Are they the same as older gm heads? How big of a valve can I go without changing the valve seat? What brand of valves are you people running? Just a few questions I had thanks for the help and if you can give me any other tips or pointers on them let me know. I don't plan on having anyone build the heads except for at our shop.
Thanks
Bryan
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Old Dec 29, 2001 | 09:14 AM
  #2  
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Default Re: Valve Questions

The LS1 valves are unique, not like the other Small Block Chevy motors, including the LT1.

First of all, they are a metric stem, 11mm if I remember correctly. Can't recall the length (damn hangover! hah)

You can move up to a 2.02" on the intake, and a 1.55" on the exhaust valve and keep the stock seats. This is what most stage 1 heads have.

Brands? Ferrea is pretty popular.

Tony
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Old Dec 29, 2001 | 09:35 AM
  #3  
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Default Re: Valve Questions

[quote]Originally posted by Nine Ball:
<strong>...First of all, they are a metric stem, 11mm if I remember correctly. Can't recall the length (damn hangover! hah)

You can move up to a 2.02" on the intake, and a 1.55" on the exhaust valve and keep the stock seats...</strong><hr></blockquote>

I'm pretty sure the valve stems are 8 mm. The stock intake is 2.00", but isn't the exhaust already 1.55"?
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Old Dec 29, 2001 | 09:43 AM
  #4  
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Default Re: Valve Questions

I was tring to figuer out how you guys do that quote thing.... but you are right. The size is 8mm. steam and 7mm locks. Stock sizes are 2.0 intake 1.55 Exuast. you can go to 2.02 Intake and 1.56 exaust with stock seats.

[ December 29, 2001: Message edited by: One Monkey ]</p>
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Old Dec 29, 2001 | 09:44 AM
  #5  
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Default Re: Valve Questions

Oops! 8mm is correct Fran. 7.976 mm to be precise. I'll check on the stock valve sizes...

Tony
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Old Dec 29, 2001 | 01:54 PM
  #6  
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Default Re: Valve Questions

I'm pretty sure you can go up to 1.57 exhuast valve since the stock size is 1.55 inches.
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Old Dec 29, 2001 | 03:24 PM
  #7  
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Default Re: Valve Questions

[quote]Originally posted by TA2SLOW:
<strong>I'm pretty sure you can go up to 1.57 exhuast valve since the stock size is 1.55 inches.</strong><hr></blockquote>

Like they said above, they are 8mm valves. Stock valve size is 2.00/1.55 and you can fit a 2.02/1.57 in the stock seats.
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Old Dec 29, 2001 | 04:53 PM
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1Fstz28's Avatar
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Default Re: Valve Questions

Thanks guys for the usefull info I will probally be changing the seats on them so I can go bigger.
Bryan
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