Thread: New block
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Old 05-22-2017, 07:28 PM   #218
Bored&Stroked
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Default Re: New block

Quote:
Originally Posted by Tod View Post
In order to keep a .200 wall thickness for 3.500 bore I would have to Siamese the front two and rear two cylinders in the water jacket. Increasing the bore means less sand between cylinders. The sand in those areas needs to be substantial enough to hold up under the heat and weight of iron during casting. Larger bores will end up with an effect on coolant flow. If I go to .180 wall at 3.5 bore I will have only .14 thickness of sand between cylinders. That is asking for scrap castings. I suppose I could Siamese between them at strategic places from the bottom of the cylinder. Since the deck will be .500 thick instead of .26, there will be added strength up top. But where there is sand between the cylinders I need to make it enough to hold up during casting. I can probably go to 3.9 cylinder wall OD and make it work.

Tod
Hey Tod - I like the way you're thinking it through. Having partial flow between the cylinders is probably a good idea - versus a "full siamese" top-to-bottom. I really like the idea of a 3.5" bore. With a 4 3/8" stroke crank, that would give us a 336 cubic inch flathead! With solid improvements in both intake and exhaust port designs - we'd have enough air flow to support the cubic inches . . . that would be really fun!

Keep up the good work and let me know if I can help you in any way!

Dale
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