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Discussion Starter · #1 ·
I've been getting some requests to setup people's cylinder heads and re-use the stock valves. I will not re-use stock valves and here is why. Have you ever wondered why your intake valves are tight every time you adjust them? The reason is, the stock intake valves are very soft material and the face of the valve gets eaten away by the harder valve seat, when this happens, the valve receeds up into the head, this is what makes the clearance tight. Now, the stock spring pressure is only 20Lbs, all of the aftermarket double valve springs measure out at 50 LBs, so if you have a problem at 20 Lbs of force, image what problems you will have at 50Lbs of force, not to mention that you'll be hitting higher RPM levels with your new porting/cam combo than you could reach before, which will add even more stress to the valve train.

So, for long-term reliability
1. Never re-use the stock valves, always replace them with stainless steel valves. (I like Ferrea but there is nothing wrong with KW or Black Diamond)
2. replace the timing chain when you go to the double valve springs (20 dollars worth of cheap insurance) Your old chain is probably tired, before, it only had to open 5 valves with 20Lbs of spring pressure each, now it has to open 5 valves with 50Lbs of spring pressure each, a 450% increase in spring pressure on the same old chain (has to open 3 intakes at a time)
3. Do replace your decompression button if it is worn
4. Do replace the rocker arm the decompression pin rides on if the decompression pin has worn a groove in it.

All these things will help you achieve a trouble free and long-term reliable setup.
 

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Nice and simple write-up Mike, I agree 100% :thumbsup:
 

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Well, as an experienced engine builder myself, i would have to you are spot on. But that's just my expert opinion. JK. Nice write-up, good info.
 

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Discussion Starter · #4 ·
I hope I don't come across wrong with this but I've seen it a thousand times where people try to save a few bucks on a build but end up with a broke motor and a huge repair bill because of a 20 dollar timing chain or someting small like that.

I know there are alot of DIY builders out there so this info is really for them, I don't have to worry about putting out junk because I'll just go without the work before I build junk but for the guy who might not have done many builds and have the expierence of seeing many of these little problems, hopefully this info will convince them to buy the one or two extra pieces that will add reliability to their motor refresh or hop up.
 

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he should...mine was probably the one he was talking about..It was bad in my opinion.
 

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CoalShedRacing said:
I hope I don't come across wrong with this but I've seen it a thousand times where people try to save a few bucks on a build but end up with a broke motor and a huge repair bill because of a 20 dollar timing chain or someting small like that.

I know there are alot of DIY builders out there so this info is really for them, I don't have to worry about putting out junk because I'll just go without the work before I build junk but for the guy who might not have done many builds and have the expierence of seeing many of these little problems, hopefully this info will convince them to buy the one or two extra pieces that will add reliability to their motor refresh or hop up.
No i didn't mean anything by it. Just playin around like i am an expert, which i'm not. just a joke. You know way more about all this than i ever will... Cheers
 

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CoalShedRacing said:
rt said:
he should...mine was probably the one he was talking about..It was bad in my opinion.
Yours was one but there have been several others as well.
Was being sarcastic! :lol:
 
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