INTERNAL ENGINE MODIFICATIONS Valvetrain |Heads | Strokers | Design | Assembly

Before Heads get installed

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Old Apr 14, 2017 | 10:21 AM
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Default Before Heads get installed

I just bought some 243 heads because my castech 706 heads cracked. The 243 heads are used and are said to have 65k miles on them. What do I need to do before I just stick them on my block and bolt everything back up? What is recommended? I don't have any money to port them out wish I did.
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Old Apr 14, 2017 | 11:10 AM
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What's your budget? Ask whatever machine shop you use what the pricing is to have them cleaned up. I think i was quoted close to $800 to have some stock heads rebuilt
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Old Apr 14, 2017 | 11:16 AM
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Originally Posted by wretched73
What's your budget? Ask whatever machine shop you use what the pricing is to have them cleaned up. I think i was quoted close to $800 to have some stock heads rebuilt
I would have to find a machine shop around me cause I have never been to one before. The heads are already pretty clean. And does everyone pretty much recommend rebuilding them before install of used heads? Some guy told me you need to have the valves reseated and something with lapping. Said he would do it for $200 I just don't want to be ripped off figured I would ask here.
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Old Apr 14, 2017 | 11:21 AM
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They do that to make sure the valve seals properly.

Everything really depends on budget. You can do it the right way or the cheap way. Many argue that you can do it correct and cheap but its easier and cheaper to just do it the right way the first time
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Old Apr 14, 2017 | 11:24 AM
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Originally Posted by wretched73
They do that to make sure the valve seals properly.

Everything really depends on budget. You can do it the right way or the cheap way. Many argue that you can do it correct and cheap but its easier and cheaper to just do it the right way the first time
Is re sealing the valves something that average Joe can do?
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Old Apr 14, 2017 | 11:39 AM
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Change seals and lap valves. Can do it in your garage. Easy peasy.
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Old Apr 14, 2017 | 11:42 AM
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Originally Posted by ezdaar
Change seals and lap valves. Can do it in your garage. Easy peasy.
Is that sarcasm? I can't tell honestly. I heard from someone else that reseating the valves also means machining the area where the valves sit so that combustion doesn't leak out. I don't think I can do that in my garage lol.
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Old Apr 14, 2017 | 12:05 PM
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Why dont you do some research, a 2 min you tube video will show you how to lap valves.


No it doesnt Require machine work. Its literaly matching the valve sealing surface to the valve seat with a polish.
Can be done by hand with a stick and suction cup or a hand cranked tool.

You are aware of a thing called google right? Youtube? You could have gpt all your answers in milliseconds by a simple search "how to lap valves".

Thats sarcasm.
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Old Apr 14, 2017 | 12:43 PM
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Originally Posted by ezdaar
Why dont you do some research, a 2 min you tube video will show you how to lap valves.


No it doesnt Require machine work. Its literaly matching the valve sealing surface to the valve seat with a polish.
Can be done by hand with a stick and suction cup or a hand cranked tool.

You are aware of a thing called google right? Youtube? You could have gpt all your answers in milliseconds by a simple search "how to lap valves".

Thats sarcasm.

Be glad you posted on this site and not yellowbullet.
My work blocks youtube but thanks
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Old Apr 14, 2017 | 05:19 PM
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Valve lapping compound, valve stem seals and either a small piece of rubber hose on the end of the valve and in a drill, or a valve lapping tool(two suction cups on a wood handle)... take springs off, remove valve seals, apply small amount of compound to head of the valve, turn valve a few times against the seat, does not take much, if you use the drill method, pull the valve against the seat lightly while the drill is turning it maybe twice for about a second each, check and make sure there is a consistent ring of compound on the seat and valve wipe it off and go to next valve... however keep in mind that a gm doesnt recommend lapping valves, and the lapping compound will eat a seat and the face of the valve quickly! If the heads truly have 65k on them and the valves dont look bad, honestly i would throw them on and run with them, if you want to make sure the valves are sealing, turn the head upside down and fill the combustion chamber with water, if you lose water you have a leaking valve, if it holds youre good!
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