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1973 Spider; the daily
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Discussion Starter #1
I got my head back from the machine shop recently. They took of 5 thousands. Would it be a good idea to check my valve piston clearances. If so how should I check that. I've heard of using the old headgasket and putty on the piston.
 

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1973 Spider; the daily
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137 Posts
Discussion Starter #3
If everything else is stock I don't think you'll have an issue. But it certainly wouldn't hurt to check. @Alfar7 's trick is to use a zip tie tail slid thru the sparkplug hole.
Is the zip tie trick just pull the spark plug and see if you can slide a zip tie in between the valve and the piston? I might check the local parts store and see if the have a horoscope I can borrow.
 

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Not sure reading your horoscope will be of much help (unless you're from Cali 😂😂😂).

Anyway, you slip the tie thru plug hole and far enough that it lays on the piston below the valve (intake or exhaust). Then rotate the crank until the piston is coming up while the valve is coming down (opening). If you do it right, the PV will imprint on the tie and then you can measure the thickness to determine the clearance. You need zip ties that are thicker than your clearance spec and the cams need to be set properly.

It takes a bit of patience but it beats the clay route.

I'll ask @Alfar7 to chime in if I'm off base...
 

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Discussion Starter #5
Lol my bad I meant boroscope.
 

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Richard Jemison
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The way to check P to V clearance is on a recent post on my "Technical questions" thread.

Cutting .005" off is NOTHING! If you cut .050" off you should check P to V, or when using high lift camshafts.
 

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I just did a head swap. If you are using stock cams and valves, don't bother. You are fine. You will spend plenty of time on shims
 

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1973 Spider; the daily
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Discussion Starter #9
The way to check P to V clearance is on a recent post on my "Technical questions" thread.

Cutting .005" off is NOTHING! If you cut .050" off you should check P to V, or when using high lift camshafts.
Are we talking cm or inches here? Because that makes a big diffrence here.
 
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