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Location:
Brisbane
Registered:
July 2004
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Fast 4K
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Thu, 29 July 2004 13:38
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Hey just after some help for my engine, ive decieded to stay with the orignal 4K engine, im going to compresion test it to find out what its averaging whats a good compression for the 4K? im also looknig for a 3K head, is the proceedure basically straight swap or do i need a 3k head gasket or what?? are the water jackets and oil holes all similar? what work should be done to the heads? mild port and polish?? should i get stainless valves and hardend seats or is there no need?,
secondly, im after a set of extractors and exhuast i got quoted $430 for hurricane extractors and 1.75" straight thru fitted is this resonable and will i notice a gain in power?
thirdly im after a camshaft for the engine i live in brisbane and close to tighe cams so ill get a 25/65 grind done but is the engine OHC? if not is hte cam reliatevly easy to get out and ground?
and lastly what carby should i look at getting for this engine with these mods? i can get webers, and nikki's or what is best suited to an engine of what i want to do,
also what fuel would be best suited to run in my engine? avgas crossed my mind  but im thinking PULP??? any advice would be great, thanks heaps
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Fast 4K
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Thu, 29 July 2004 15:05
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have you thought about what rpm range you are designing the motor for?
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On Probation
Location:
North East NSW
Registered:
December 2002
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Re: Fast 4K
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Thu, 29 July 2004 23:03
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compression test should be 175-155 psi
3k head bolts straight on. use the 4k valve gear, this is all in my faq. the head already has hardened valve seats. get bigger valves if you're going to spend the money. don't have the inlet ports enlarged with stock valve size, exhaust ports as big as you can
get 2" exhaust, you could get it cheaper
tighe stage 3 is the best cam, lots of torque down low and solid pull to 8 grand. power peak 7500
look under the bonnet, it's not ohc. you'll need to drop the front of the sump and take the timing cover off to get to the cam. easy stuff just don't drop the timing chain bolts in the sump
it will run with the stock carb, anything up to a 32/36 is an improvement, after that they start getting too big for low rpm response
use bp ultimate
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Fast 4K
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Fri, 30 July 2004 01:13
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you only need alternative rocker gear AND valves if you get a 3K bigport which has o-rings on the valves (double grooved stems)
bigger valves are a waste of time for a street motor imho.
for porting it's not exactly bigger = better.. it's abotu the shape of the ports.
meh, the best cam is one that does what you want, ie. with the lift you want, and the rpm range you want. how the cam works will depend on the rest of your system.
meh, i think32/36 is bad for response. even the 24mm choke one i have is lacking in idle and off-idle. stock primary choke is 21mm.. maybe 22-23mm would be a good compromise?
Cya, Stewart
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Location:
adelaide
Registered:
April 2003
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Re: Fast 4K
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Fri, 30 July 2004 02:29
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your 4k will never be 'fast'
so put twin webers on, who cares how it drives - at least it will sound good 
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On Probation
Location:
North East NSW
Registered:
December 2002
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Re: Fast 4K
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Fri, 30 July 2004 02:37
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in any sort of 4k that you run on street compression, no cam makes more torque or more top end power than a 25/65, period. 7500 isn't too tall at all, and it's got bucketloads down low. this is the best cam for a street motor, the end
you can make a 4k fast. doug's ke15 eats v8s all the time, both at low and high speeds
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Location:
Adelaide, SA
Registered:
May 2002
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On Probation
Location:
North East NSW
Registered:
December 2002
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Re: Fast 4K
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Fri, 30 July 2004 06:27
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| lumpy wrote on Fri, 30 July 2004 13:17 |
Underground, Overground, Wombling free,
the Wombles of Wimbledon common are we,
making good use of the things that we find,
things that the everyday folk leave behind.
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WICKED signature you've got there dude
any pics or info on your clubman? it's not the one that was at speed on tweed last year is it?
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Location:
adelaide
Registered:
April 2003
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Re: Fast 4K
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Fri, 30 July 2004 06:39
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jamie, just to clarify 'v8s' are not necissarily fast, i dare say a stock 5k could take on a 253 powered HZ and come out best
even the old style 350 chev motors in stock form have nothing on the gen 3 ones...
4k motor
single non overhead cam + non crossflow head + 1300cc
= very very expensive to make genuinely 'fast'
you can make them 'nippy' but short of the patented angela turbo setup they will not be 'fast'. 2nd best is to make them sound fast, it becomes more fun to drive that way!
love from pro_ke (a realistic 4k owner!)
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Location:
Adelaide, SA
Registered:
May 2002
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Re: Fast 4K
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Fri, 30 July 2004 07:07
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| Super Jamie wrote on Fri, 30 July 2004 15:57 |
| lumpy wrote on Fri, 30 July 2004 13:17 |
Underground, Overground, Wombling free,
the Wombles of Wimbledon common are we,
making good use of the things that we find,
things that the everyday folk leave behind.
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WICKED signature you've got there dude
any pics or info on your clubman? it's not the one that was at speed on tweed last year is it?
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Thanks - I've had the bloody wombles song in my head ever since I put it there though!!
To clarify - I missed a word, it's not my clubman, it's my mates dad's (middle-age crisis toy car!). It is a historic racer, built in Sydney 1969 and is called a (sp?) Schazum. I've got some photo's at home and will try to scan them in. Apparently 2 or 3 were built by the same guy and this is the only one left. It runs a 3K motor, ford escort gearbox (not sure why??) and a morris diff!.
My mate is an ex-go cart racer so can lap Mallala in 1.18" in the clubman - pretty good for a 3k! I couldn't even fit in the bloody thing!
Essentially it has a heavily ported head, big cam (unsure of specs), forged motorbike pistons (I think triumph ones), extractors, and twin 40mm sidedraft webbers. The compression ratio is 11:1 and it runs on avgas. He bought it like this so is unsure of some specs. When at full throttle (hell, even idling) it sounds bloody awesome!
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On Probation
Location:
North East NSW
Registered:
December 2002
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Re: Fast 4K
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Fri, 30 July 2004 08:47
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doug's car beats AU XR8s and VY SSs off the lights, he's raced a done up WB ute and pulled away from it at 180km/h. that's fast in my book
but yeah, a 4k powered car is never going to beat a turbo car, or even a moderately quick large four. if you did all the shit you can do to a "quick" 4k, to say a pinto 2L or L20B then you'd have a missile
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Location:
Brisbane / Gold Coast
Registered:
May 2002
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Re: Fast 4K
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Fri, 30 July 2004 09:00
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| pro_ke wrote on Fri, 30 July 2004 12:29 |
your 4k will never be 'fast'
so put twin webers on, who cares how it drives - at least it will sound good
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Well they can be made to go quite well - 150hp and 9000rpm has been done many times - but it costs a lot to do it and they don't last long.
There's far cheaper and easier ways to make good power, but they involve using a more modern engine, etc.
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Fast 4K
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Fri, 30 July 2004 09:43
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| Super Jamie wrote on Fri, 30 July 2004 18:47 |
doug's car beats AU XR8s and VY SSs off the lights, he's raced a done up WB ute and pulled away from it at 180km/h. that's fast in my book
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sounds like dougs KE15 is much much faster than mine then (what do you think Jamie, you've been in both). new XR6 and 6 cyl commodores keep up roughly until end of second gear. the new V8's pull away slightly (when we both start at same time with same intentions  ). once in third tho, i lose all my advantage. my car was dynoed (toymods dynoday 5) with 47rwkw at wheels (compared to stock 86kw 4AG's with 55rwkw).
i seriously doubt a 4K'd 800kg (with driver) car, would beat these V8's once into 3rd gear... and old utes don't count
as Bill said, they can be fast, but compared to modern engine, will have buggerall bottom end, cost a lot, and not last long.
as i said before many times, pick your rev range, and optimise the motor for that.
Cya, Stewart
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On Probation
Location:
North East NSW
Registered:
December 2002
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Re: Fast 4K
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Sat, 31 July 2004 00:58
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after being in it again, i would say doug's is quicker. he's got better timing, air fuel setup, head, and a better cam  the thing's actually a bit of a freak, it lights up so easy
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: Fast 4K
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Sat, 31 July 2004 14:25
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LOL, fairy nuff..
i choose NOT to light mine up
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