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Location:
Sydney
Registered:
May 2003
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 Stroked
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Thu, 04 December 2003 05:51
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mates thinking of buying a 7k and is after any prior experiences of stroking them or if its possible and if so what can be used
any info appreciated ty 
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Stroked
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Thu, 04 December 2003 07:41
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you want to stroke a 7K?? thats keen 
the bores are getting pretty close (5K and 7K are same) and the 7K is basically a stroked 5K.
can't remember what the exact specs are but..
4K = 75x73
5K = 80.5x73
7K = 80.5x???
i don't know if the skirt of the block is wide enough to put a bigger crank in there, and afaik, there are no other K compatible cranks with longer throw... 7K is abotu it as far as a K block goes..
you could always do a dodgy and offset ground the crank, and get smaller diameter big ends...
whats your theory in stroking the 7K??
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On Probation
Location:
North East NSW
Registered:
December 2002
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Re: Stroked
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Thu, 04 December 2003 08:31
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7k stroke is 87.5
and yeah i think the only way to do it* would be to offset grind the crank. say you went 050 under thats about 2.5mm, which would move your displacement up from 1781cc to 1832cc. i dont know if you'd have piston-valve clearance issues then, but i expect so. it barely seems worth it for the weakening of the crank, i wouldn't be very keen on revving that sort of motor past 6000 at all
cheers
Jamie
*of course you could get custom crank and rods made, but i doubt anyone has done this with a 7k before, so you'd be looking at alot of money in development work. i love k motors more than anyone else i know, but even i think that could be money spent better elsewhere, like on a 2t with 3t stroker crank and 89mm pistons
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Location:
Sydney
Registered:
May 2003
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Re: Stroked
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Fri, 05 December 2003 02:11
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thanks guys
this is 4 a mate
another of his crazy ideas
so the 5k he currently has in the car can be turned into a 7k with a crank rods pistons and boring the block slightly?
is that correct ?
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Stroked
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Fri, 05 December 2003 02:43
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no, not correct.
bore is same for 5K and 7K.
7K crank will not fit in 5K block as the skirt of the 7K block is wider. the 7K deck height is also taller.
to make a 5K a 7K, you would need:
block
crank
rods
pistons
etc
you are much more likely to find a good condition 7K block than 5K block (due to age).
Cya, Stewart
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Location:
New Zealand
Registered:
May 2002
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 Re: Stroked
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Fri, 05 December 2003 03:07
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I wouldn't bet on being able to put 7k internals in a 5k block. Odds are they increased the deck height to cope with the extra stroke, as they did between the 3k and 4k. But then again, if you can get the internals, why not just get the whole engine? Strap a SC14 on the side and just don't expect it to rev like a 3k.
Callum
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Location:
Sydney
Registered:
May 2003
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Re: Stroked
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Fri, 05 December 2003 03:37
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thanska gain
he isnt too fussed about the condition fo the 7k as his brother wil rebuild it 4 him as i think already is planned
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Stroked
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Fri, 05 December 2003 04:22
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| 4DaDrift wrote on Fri, 05 December 2003 14:37 |
thanska gain
he isnt too fussed about the condition fo the 7k as his brother wil rebuild it 4 him as i think already is planned
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so, when it gets pulled down you are going to take lots of pictures of the head and pistons, and measure the combustion chamber volume and piston dish volume and port sizes etc and become a legend in car land??
you know you want to
so, is he sticking with the hyd lifters or going to solids? increasing cam lift?
be aware that in stock form, the cam duration was chosen to have peak torque at very low rpm...
Cya, Stewart
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On Probation
Location:
North East NSW
Registered:
December 2002
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Re: Stroked
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Fri, 05 December 2003 06:22
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you can use holden six 202 lifters to convert to solids if the motor is anything like the 4k. put a big phat 20-60 cam grind in it
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Location:
Sydney
Registered:
May 2003
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Re: Stroked
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Sun, 07 December 2003 04:38
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tell u guys the truth i dont know yet will advise him fo what u lot have shared and ask if tehy will take the fotos n do the measurements and c how it goes
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