RH4 head question

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NickZ

NickZ

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I picked up this RH4 head and I am wondering how concerned I should be with the porousness and/or pitting of the metal, especially in the left chamber. RH4 head question
RH4 head question
RH4 head questionRH4 head question
 
Yep... Dye pen is a wise man's move for certain. It does look a tad natty, but my understanding is they don't grow on trees.
 
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Time Warp said:
No guides ?
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This head came stripped but clean with a bunch of parts I acquired. Also in the bunch of parts was a bag of head parts (rockers, springs etc. but no guides) that may or may not be from this head.
 
baz said:
That's what I was thinking
The lack of guides in an rh4 head don't bode well
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Why is that significant? I thought guides are removed for replacement when necessary.
 
baz said:
The porosity does look bad
As does the spark plug threads but I doubt the combustion chamber will mind once it's racked up a few miles
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Some of the stuff in the spark plug threads is dirt and fell off when poked.
baz said:
What's the history of the head?
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I acquired this head as pictured with a bunch of parts, you could almost call it a basket case.
baz said:
Any cracks around the inlet guide holes?
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I didn't see any cracks on the inlet guide holes (or anywhere else). But I will give it a go with visible penetrant.
RH4 head questionRH4 head question
 
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CanukNortonNut said:
Nick,
These heads in perticular were prone to cracking at the Intake tunnels.
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I read a thread on that, and looked for cracking there. As I said, looked ok, but I assume that is an important place to use the visible penetrant dye.
 
On closer examination of the head, it appears that it was media blasted, then spray painted (including all gasket surfaces). Not sure what kind of paint was used. It didn't come up when I tested it with lacquer thinner or denatured alcohol. I sanded it off the center head steady bus and you can see it compared to the other bus and also compare the exhaust ports which appear to have been machined after the painting (pictured with initial post).
This is significant because I don't think my dye penetrant will be effective if applied over this paint. Any ideas on what kind of paint this might be?
RH4 head question
 
I am including photos of the inlet guide tubes, which I think appear ok.
I want to thank everyone for not busting me for including photos of the exhaust guide tubes earlier when I was referring to inlets..lol
RH4 head question
 
Surface must be clean of paint, grease, oil, etc. prior to dye pen check. Just doesn't work any other way.
 
I have a "GUY" who routinely welds aluminum racing cycle heads,. He has seen many Norton's cracked between intake spring seat and intake port. Some because of over porting. He won't touch them in this area because the porous casting and oil penetrating into it. Just had a engine case with a poor casting and when I applied air to the inside, oil came thru at least an inch away on the outside.
 
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