Calling all cylinder head experts
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Teching In
Joined: Jun 2010
Posts: 26
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Calling all cylinder head experts I just had an exhaust valve guide changed by a reputable shop but I am starting to question their work. It felt like the new valve and guide have more clearance than the 30,000 mile guides. So today at work I measured everything out and here is what I found.
New valve stem diameter - 0.3136"
took measurements at ~1/4" intervals down the guide:
Top of guide
.3182" ------> 0.0046" clearance
.3160" ------> 0.0024" clearance
.3159" ------> 0.0023" clearance
.3158" ------> 0.0022" clearance
.3158" ------> 0.0022" clearance
.3159" ------> 0.0023" clearance
.3175" ------> 0.0039" clearance
I measured the next exhaust valve over (30,000 miles)
0.3155" give or take .0002" pretty much the whole length of the bore.
I also found a bunch of grooves around the circumference of the inside of the new guide, while the old guides are perfectly smooth.
Looking for anyone who may be able to shed some light on if this is a problem or not.
New valve stem diameter - 0.3136"
took measurements at ~1/4" intervals down the guide:
Top of guide
.3182" ------> 0.0046" clearance
.3160" ------> 0.0024" clearance
.3159" ------> 0.0023" clearance
.3158" ------> 0.0022" clearance
.3158" ------> 0.0022" clearance
.3159" ------> 0.0023" clearance
.3175" ------> 0.0039" clearance
I measured the next exhaust valve over (30,000 miles)
0.3155" give or take .0002" pretty much the whole length of the bore.
I also found a bunch of grooves around the circumference of the inside of the new guide, while the old guides are perfectly smooth.
Looking for anyone who may be able to shed some light on if this is a problem or not.
Some replacement cast iron guides are knurled out of the box. Hard to say if those are from the photo however .002" and some tenths clearance shouldn't cause an oiling problem providing the valve seal is new and installed properly even with the knurling groove.
Richard
Richard
