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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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I supported Toymods
Location:
Berowra-Sydney
Registered:
July 2002
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Re: pictures of porting and CC's on 3K bigport head
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Tue, 02 March 2004 22:19
 
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What tools did you use to do the work?
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I supported Toymods
Location:
melbourne.victoria.austra...
Registered:
June 2002
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Re: pictures of porting and CC's on 3K bigport head
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Tue, 02 March 2004 23:55
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some very nice work the stewart. those valves should seal up nicely too - suggesting with 11mm lift flycutting was required?
have you crunched the numbers on flow and expected hp it will flow with this work?
once again, nice indeed.
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: pictures of porting and CC's on 3K bigport head
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Wed, 03 March 2004 02:38
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for the ports, i mainly used a power drill with various die grinding burrs... i recommend to get a die-grinder tho as power drills are just not fast enough.
for the combustion chamber work, i initially started using dremel burrs, but they are too small and their rate of metal removal is poor.
i ended up using some discs made by 3M. i can't remember the numbers atm  . basically they look like scourer pads, but the brown one is very firm and gives high rate of removal, and the grey one is soft and polishes it up to the finish shown.
the ones i used were 1 inch diameter and hard has 3mm thickness, soft 6mm thickness. they mount in a dremel using the 'sanding drum mandrel'
i actually bought a whole bunch from Blackwoods a while back, and they were about $2.60 each... so if anyone wants a couple for testing
flycutting was not required as the valves are never at full lift when the piston is at TDC. should the timing chain fail and a valve stop at full lift, i think it would make a big mess =D
i didn't get it flowed at all, i just did what i thought would be nice, using some of my own theories. i do know that with my home made extractors, running the early series straight runner inlet manifold, a weber 34DMS carb, and a camtech 609 reground cam (231/235 @50 thou) it made peak torque@4600rpm, and power did not peak. dyno was stopped at 8000rpm and it made 47.3rwkw (toymods dynoday5) compared to 86kw 4AG getting 55kw.
i have an injection setup that will be going on in the next couple of months, so it should release more potential from the motor 
Cya, Stewart
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I supported Toymods
Location:
melbourne.victoria.austra...
Registered:
June 2002
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Re: pictures of porting and CC's on 3K bigport head
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Wed, 03 March 2004 03:07
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ok. all good.
get a good timing chain mate
are those figures with this head stewart? thats not too bad at all for NA - what was peak torque out of interest and how does it compare to a 4A(GE)
4KE or 7KE injection setup. pretty sure torque would be right up there with that sexy chrome 4KE setup.
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: pictures of porting and CC's on 3K bigport head
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Wed, 03 March 2004 03:22
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well, i have/had new timing chain and sprockets.. fingers crossed
yup, from this head. it gets a little confusing with diff ratios and all that, but a rough back calculation from the 86kw motors making 55kw gives me
peak torque of 103Nm at 4600rpm
max power of 100hp (and 86Nm) at 8000rpm
AFR goes from about 11:1 at 4600 to about 12.3 at 8000rpm and is reasonably linear. i have a fair way to go there, but should be easy with the injection (Megasquirt )
torque curve is pretty much linear between those points. i honestly think output is a bit lower than that but it's hard to tell without and engine dyno.
but even so, 103Nm from 1.3L is a bit lacking. i am hoping for peak torque around 120Nm with the injection
i have a 4KE setup atm, but have just organised to buy a 7KE setup as well not sure which will go on first
probably 4KE, but 7KE looks better for any boosted application.
i do want to try both to see what difference there are, especially in regard to throttle response and high rpm figures.
Cya, Stewart
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Registered:
August 2002
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Location:
Brisbane - Chapel Hill
Registered:
June 2002
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Re: pictures of porting and CC's on 3K bigport head
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Thu, 11 March 2004 01:13
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Hey Stewart, have you started the Megasquirt yet? Interested to see how you go with it, I'm looking to do the same in the next month on a 4AFC (just a test motor)
Hmm, I tihnk I have some of those 3M discs, they are ok for polishing, but as for shaping inside ports and stuff, I dont have any tools I can use for that.
I have a great little die grinder, but the grinding stones are really poor, Anyone know where I could get some good ones? how about Carbide Cutting tools? are they any more useful?
TIA
Esteban
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Location:
Hobart, Tasmania
Registered:
June 2003
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Re: pictures of porting and CC's on 3K bigport head
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Thu, 11 March 2004 10:31
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Im told there is 2 types of 3k heads, a small port and a big port? how do I tell the difference? I was told something about a plate on the back of the head? could someone explain it for me??
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Location:
Vic
Registered:
May 2002
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Re: pictures of porting and CC's on 3K bigport head
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Thu, 11 March 2004 10:44
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the big port type has bigger ports:)
The later small port heads have a plate that bolts to the rear of the head.
The big port head has an round alloy plug instead.
This is an easy way to identify them if the motor is still complete.
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Location:
Montrose, VIC
Registered:
May 2002
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Re: pictures of porting and CC's on 3K bigport head
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Thu, 11 March 2004 12:38
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Those little stones in the die grinder really are a poor excuse... Well worth the $50 to go buy a proper burr!
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: pictures of porting and CC's on 3K bigport head
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Thu, 11 March 2004 13:13
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Black Supra: lots!! infact maybe a CC or 2!! basically smoothed any sharp edges, removed all of the machining marks around the seats and blended it in at a better angle. before unshrouding, the valve heads had between 2 and 3mm of clearnace to the side of the combustion chamber. after they had minimum of 5mm at low to mid lift. so quite a lot of metal, but was shaved 40 thou to bring compression back up (so maybe 3cc of metal?)
Esteban, have made the MS and the MV, but won't install until end of PhD thesis.
the discs i used were:
polishing: 3M EXL-2S-FIN Blackwood cat:00909891
Grinding: 3M EXL-6A-MED Blackwood cat: 00909738
cost about $2.50 each
http://www.materials.unsw.edu.au/~sford/3mabrasive s.jpg
small port has either 27mm (common) or 25mm (uncommon) intake ports. exhaust ports are virtually the same. usualyl has a bolt on plate on back of head.
large port has 30mm diameter intake ports. has a welch plug at the back of the head.
you can port the small port to be a large port, but a large port can be done more... realistically, you would not want more than 30mm intakes for the street anyway.
yup, stones are virtually useless. for ports i will always use die-grinder bits, but for combustion chambers the 6A-MED discs are fantastic and have a high rate of metal removal.
Cya, Stewart
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Location:
Hobart, Tasmania
Registered:
June 2003
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Re: pictures of porting and CC's on 3K bigport head
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Fri, 12 March 2004 05:25
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Yeah thats exactly what I wanted to hear I have 2 big port heads one in use and the other spare  might wack one on a 5 or 4k with a twin carbie manifold to relpace my 3k in the KE20 
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: pictures of porting and CC's on 3K bigport head
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Fri, 12 March 2004 05:51
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goes straight on a 4K, but 5K has dished pistons, so you need to find flat tops and maybe open up the CC a bit.
Cya, Stewart
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