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Location:
New Zealand
Registered:
November 2004
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4K engine mods what to go for ?
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Sat, 13 November 2004 20:34
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hey guys!
i know this questions been asked a heck of alot but half the time i dont understand the talk u guys use as im not the most Mechanically minded person alive anywho...
i have a 4K i recently bought has twin carbs ones that sit up right not the sidedraft ones umm...has extractors lumpy cam not sure what stage how would u find that out !? but yeah i wanna put a 3k head on it i heard it makes em better and it sounds like a cheap mod i guess you just get hold of one bolt the 3 k head on the 4k block with the 4k rocker gear and your away !? thats basically all i wanna know...oh and also how do i ID my engine where are the codes and what not !? i also have 2 other 4ks so i got lots of spares all engines in great nick anywho thanks for your time hopefully my info is enuff cheers for your time!
p.s. sounds stupid but whats a welsh plug !? 
from the land down DOWN under!
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On Probation
Registered:
January 2004
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Re: 4K engine mods what to go for ?
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Sat, 13 November 2004 22:00
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Hello.
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has twin carbs ones that sit up right not the sidedraft ones
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You mean the twin down draft carby's ? - Do you have an inlet manifold to suit that ? (came off a 3K-B)
Extractors are good. Are they Customs? 4:1's ? 4:2:1's ? - they are so much better than the stock POS exhaust manifold.
Lumpy cam... ehh unless the previous owner / builder has the card that came with the cam when it was done, i woudnt know what cam it is or how to find out.
Rule of thumb. 4k block / bottom end + 3k Head = 10.0 : 1 Compression (where as stock 4k motor is 8.5 :1 / 9.0 :1 - can never remember  ) - Its a quick upgrade. If you want even better results, track down a 3k Bigport head - its basically the same as a stock 3k head, but its got much larger ports, and a Welsh plug at the back of the head (welsh plug = keeps coolant in motor... in simple terms)
Are you wanting to stay NA or go turbo / supercharger ?
Cheers
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: 4K engine mods what to go for ?
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Sat, 13 November 2004 22:53
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[quote title=KiwiKe70wagon wrote on Sun, 14 November 2004 07:34]p.s. sounds stupid but whats a welsh plug !?
quote]
sounds like you know of the bigports then  the 3K bigports have 30mm intake ports, vs 27mm (or 25mm!!) for standard ones.
the exhaust ports are near identical between K to 4K heads tho.
regardles of ports, the stock manifolds all seem to go down to about 25mm in the runners, so they can definitely be a restriction.
a picture of the carbs would be good to identify them, same for extractors.
for cam, take off rocker cover, rotate motor until one of the valves is full open and an adjacent one is fully closed, then measure the height difference at the top of the valve spring retainer (just below where the rockers act on the valves).. also check when both valves have same height when fully closed..
this is the valve lift. stock is around 8.5-9mm. highly modded is 11mm and greater!!
as for duration, it's a bit harder.. you need a degree wheel (google for tania free degre wheel) and then attach to your carnk pulley and rotate motor and measure angles at which the valves open and close.
YES. 3K head, original rocker gear, and should be ok... if you get a bigport or early 3K head, then there are issues. they have no valve stem seal, and instead have an o-ring above the spring retainer.. so they have a taller retainer and a double groove on the valve stem.. restricting the amount of lift you can run.. BUT you can swap in the 4K valves too. if you have much higher than stock lift i recommend getting the rocker shaft towers machned down by the increase in lift (over standard.. ie 11mm lift = 2.5mm machining)
if it's a 4K, the engine code is on drivers side, at the bacjk, just below the head (ie top of block), but if it's a 4K.. it's a 4K
also look on the head for the numbers "24010". thats a 3K bigport head.
welsh/welch plug is a metal disc that seals a round hole in a head or block.. it's kinda like a cup i guess..
google for an image.
if your 4K head has had porting work, then it is likely better than a stock 3K head.. if it has been shaved, it may have 10:1 compression anyway. the larger intake ports of bigport are only an advantage in minimising porting time, and also allowing larger ports to be used... 30mm intakes i think are a little overkill for mid-range.. still need to compare to stock suzuki swift ports...
Cya, Stewart
ps, get some pics
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Location:
New Zealand
Registered:
November 2004
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Re: 4K engine mods what to go for ?
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Sun, 14 November 2004 06:29
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hey!
got a pic! its not the best but until i remove the engine outta my stuffed ke20 they gotta do anywho thanks so much for the info guys btw i found a number stamped on the left side (if looking into the engine) of the head near the front of the engine said n612 ? dunno what it is or means my other 4k standy one doesnt even have a number there maybe its nothing anyways heres the pic of the carbs cant really see the extractors will get a better one shortly cheers!
http://img.photobucket.com/albums/v507/kiwike70wag on/4K.jpg
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: 4K engine mods what to go for ?
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Sun, 14 November 2004 07:24
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means it's not a bigport head not that it is really an issue if you have work done to the 4K one.... it's not that much of a biggie..
the extractors look nice.. 4-1, reasonable length, and reasonably even in length..
Cya, Stewart
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Location:
Vic, AU
Registered:
September 2004
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Re: 4K engine mods what to go for ?
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Sun, 14 November 2004 11:46
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Those carbies just look like normal ones (ie. 2 x stock 4k carbies). Anyone else confirm my thoughts?
Interesting idea though, except I'm pretty sure the flow of the stock carbies is shithouse, would imagine 2 wouldn't be that much better... 
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: 4K engine mods what to go for ?
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Sun, 14 November 2004 11:52
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nope they are eithe K-B or 3K-B twin carbs. they are aisans but have smaller venturis, and different jetting. they also have linkages that work in a twin setup, and are actuated from between them.
well, stock single has 21 and 24mm venturis.
= 800 square mm
twin 19/21 carbs have 1260 square mm....
sounds like more flow to me
atomisation is something else....
Cya, Stewart
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