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I've been told that when the factory brought out the 253 it had thicker cylinder walls than the 308, because they planned to bore it out later.Hence iot would be alot stronger for turbo or supercharging/stroking.
true or false....?
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Have a look at this topic regarding bore wall thicknesses and maximum bore sizes. Its best to get indivdual blocks tested before you decide how big to make the bores as core shift can be a problem with cast iron items. http://www.gmh-torana.com/forums/ |
You only have to be in front at the end of the race. |
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interesting article, they reckon 253 had bores 6mm to 8mm and could be bored to 98.42mm, where as a 308 only has 2mm to 4mmm...?
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A 308 bore is 4" (101.6 mm) and the 253 is 3.625". The difference in overbore capacity is because youre starting with a smaller bore with the same cylinder spacing in the 253. James
You only h Edited by user Friday, 15 February 2008 7:59:30 PM(UTC)
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You only have to be in front at the end of the race. |
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Is the 253 & 308 the same cast ? Just machined differently ??
John
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The core for the water jacket may be different because you cant take a 253 bore out to 4". The outside dimensions are the same and would have been a common pattern with the different engine size cast mark pattern insert being removable to suit the inner c |
You only have to be in front at the end of the race. |
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No I meant the cylinder casting itself not the bore was supposed to be thicker on 253 from the factory, a bit like a diesel.
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speedway has a catagory running only useing 253 red motors theirs hundreds in it so their going to need need 253s on an on going bases one would think plus i hate the thought ofv junking them cheers
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personaly I like the 253 over the 308, I dont know why becasue on paper it really is a piss poor option but it just has a querky feel to it, its really hard to explain,
does any one have any build information for the speedway or commodoor cup 253s
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personaly I like the 253 over the 308, I dont know why becasue on paper it really is a piss poor option but it just has a querky feel to it, it's really hard to explain,
does any one have any build information for the speedway or commodoor cup 253's
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