 Why do you set Chromoly Rods to 0 clearance?, Just wondering the mechanics behind it |
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| keske968 |
 Oct 29 2011, 09:25 AM
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Member  Group: Members Posts: 132 Joined: 5-September 06 From: Papillion, Ne Member No.: 6,778 Region Association: None  |
So I am rebuilding my engine and bought Chromoly pushrods from Raby. I have read that you set the valve clearance to 0.000 instead of the .006 that you would with an alumium rod. I am just wondering what are the physics behind that difference? It just seems that as things expand I would end up cooking valves. Hoping someone much smarter than me (not hard to do) can explain the reasoning behind this.
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| Dave_Darling |
Oct 29 2011, 09:43 AM
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914 Idiot Group: Members Posts: 15,161 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California 
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Aluminum expands a whole lot when heated. Chrome-moly steel only expands a little bit when heated. You set the valve clearances cold, and the clearances shrink as the pushrods expand. When you have aluminum pushrods, you are compensating for their expansion when you use the 0.006" clearance. When you have chromo pushrods, you don't have to compensate for that, so you use 0 clerance.
At least, that is my understanding of the reason. --DD |
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Posts in this topic
keske968 Why do you set Chromoly Rods to 0 clearance? Oct 29 2011, 09:25 AM
URY914 ^^^ Correct. Rate of expansion is much different. Oct 29 2011, 10:01 AM keske968 Thank you. Oct 29 2011, 03:50 PM Jake Raby To get those pushrods to expand .001" require... Oct 29 2011, 08:24 PM
ArtechnikA The wood pushrods in my 356 engine don't expan... Oct 30 2011, 05:12 AM |
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