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Old 01-13-2003, 12:48 AM   #1
tkeduk8r
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250 cyl head????

welll i decided to pul my head off today after seein some moisture in my oil, and since my head gasket looked good i was gonna bring the head up to my machinist and have them go over it.... so my question is... if i leave the lower end as it is (its a 74 250), how much can i mill the head to get bout 9-9.5:1 compression, up from the stock 8.0???? figure as long as im there may as well do it... might help effeciancy and milage a little bit.... thanks in advance..
--mike
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Old 09-24-2024, 09:26 AM   #2
D'Monsta
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Re: 250 cyl head????

It's 2024 and I am in the same predicament.. Anybody out there know an answer?
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Old 09-24-2024, 09:40 AM   #3
leegreen
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Re: 250 cyl head????

https://www.inliners.org/ubbthreads/...t&Number=68506
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Old 09-24-2024, 09:55 AM   #4
Ziegelsteinfaust
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Re: 250 cyl head????

Becareful how much you mill.

You may end up needing new push rods to go with it.
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Old 09-24-2024, 10:24 AM   #5
67 twins
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Re: 250 cyl head????

You will never get to that compression ratio with the stock pistons.
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Old 09-24-2024, 02:07 PM   #6
theastronaut
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Re: 250 cyl head????

To figure out how much to mill to get a certain chamber volume, use a graduated cylinder to measure out that many cc of water (add a drop of dish soap), level the head, add that water to the chamber, then measure down to the water level.

Not sure, but there might be thinner head gaskets available that would also help bump the compression up. If you can find them, flat top 307 pistons work great to bring compression up.
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