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Yamabond case halfs?

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afmcg

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Discussion starter · #1 ·
Yamabond case halves?

Ok, so I can't spell. Too bad I can't change the post title on the main page...



Maybe I should say Hondabond. The Yamabond tube is already open though...



My question pertains to the NICE 110, but the same applies to any 50-based engine with a case gasket.



Has anyone tried assembling the cases with sealant only and no gasket? Does it work? It's that, or sealant on the old gasket.



Long story, Asian Concepts engine related. More when I finish.
 
#5 ·
Case gaskets are there for a reason!Without it you lose the engineered in end play for crank and trans,and since aluminum expands roughly twice what steel does, could bind when it gets warm.Also,case edges are too thin for sealer only.good luck! 'nutcase
 
Discussion starter · #6 ·
I may just eat my words and screw up my engine, but:



fatcaaat said:
...the case gaskets are easy to get...
Click to expand...
Apparently not where I live. No one could get an XR50 one for days, and the engine needed to go back together. I'm not even sure if they're identical.



zbnutcase said:
...since aluminum expands roughly twice what steel does, could bind when it gets warm...
Click to expand...
Regarding the CTE, the Al expands out, so it should get more loose. If it was Al parts in a steel case, then that would be a problem.



We'll see...
 
Discussion starter · #9 ·
zbnutcase said:
Wrong!! Aluminum expands in ALL directions! I wasn't always asleep in college

'nutcase
Click to expand...
I hate to get into these little Forum arguments, but here goes nothing...



I disagree. If you have a hole in a piece of Al, or any metal for that matter, and you heat it up, the hole gets bigger. The piece may expand out in every other direction, but never in to make the hole smaller.



It's a gross oversimplification to call the inside of a crankcase "a hole in a piece of Al," but the same applies. The case will grow out, not in. Consider a crankcase made out of a billet of Al. It starts out as a block, which expands out when heated. Then bore out a large amount of the block. It acts as stated above, the block expands on the outside, and the hole grows larger. Now cut off the excess material on the outside, put a few holes in it, and you've got a shiny engine case. Should it not still exhibit the same behavior, with the case (former block) growing out, and the cavity (former hole) growing larger?



Another simple example is the lid on a glass jar (another simplification of a case half). When it gets stuck, you heat it up under hot water. In this case it's steel (larger CTE) vs glass (smaller CTE). The steel lid expands out, and loosens up.
 
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afmcg
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