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Location:
Brisbane
Registered:
July 2004
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3K-H Head???
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Mon, 06 September 2004 13:44
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I finally picked up a 3K head, but i notice the compliance plate says 3K-H its from a KE36, the wagon type, it has a compression of 9.5:1 and i was wanting to bolt this on to my 4K and start to work it up heaps, like a cam, carby, exhaust, is there a down side to running this head becuase an 9:1 3K-C has 10:2-1 comp on a 4K block what would mine become and should i port it or not? any help would be great
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Location:
Gumeracha
Registered:
August 2004
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Re: 3K-H Head???
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Tue, 07 September 2004 08:43
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Yea it will work fine ive got a mate who did the same and he hasnt had any trouble with it. he didnt do anything to it in the way of porting.
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Registered:
June 2004
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Re: 3K-H Head???
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Tue, 07 September 2004 08:47
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did a quick calculation, about 10.5:1,though it's probly not right coz that engine could have a different combustion chamber and/or different piston tops. the only way to get it exactly right is to give me all the measurements of the piston domes(or pots) and the capacity of the combustion chamber. that is, the pistons of the 4k and the head of the 3k by the way.
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Location:
Brisbane
Registered:
June 2004
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Re: 3K-H Head???
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Wed, 08 September 2004 01:31
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having said that my compression is roughly 10.5 to 1 what is the advantage of this am i most likely to blow head gaskets, will i reach higher revs quicker? what do i do about fitting the head, timing? what sparks? what gap on plugs, do i run PULP on the stock 3k-h head???? help please
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: 3K-H Head???
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Wed, 08 September 2004 01:45
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it's the combsution chambers that are different.
the pistons are all flat tops (until the 4K/5K dished ones)
with 10.5:1 it might be a good idea to remove any sharp edges fromt he combustion chamber and make sure it lines up with the bores. you will probably need 98 octane for best results.
higher compression will give you a little more torque, but can also create more heat int he motor (ie run hotter).
advance. whatever works... in my 4K with 10.2:1, i've run between 10deg and 35 deg. currently around 20-25 deg.
plug gap is determined by the health of your ignition system. with jaycar HEI, i still run 0.8mm and find that to be MY best compromise.
for the first questions. porting can help a great deal. the size of intake ports is determined by the RPM you want to run to. bigger ports = lower velocity down low. it is beneficial to unshroud the valves in the combustion chamber, and this may bring your compression closer to 10:1.
check out my combustion chamber pics at:
http://www.materials.unsw.edu.au/~sford/3khdpixnew .html
and
http://www.materials.unsw.edu.au/~sford/headpics.h tml
what you need to do is design the engine fromt he ground up, to do what you want it to do.. doing it bit by bit is not the best way.. design everything to wrok as a system, to produce power in the rpm range of your choice.
Cya, Stewart
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