RC Car Actions "How to port a Nitro Engine"
10-24-2007, 09:43 AM
#301
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RE: RC Car Actions "How to port a Nitro Engine"
ORIGINAL: JB COMP
Ok need alittle help.
I have a STS 21B that I want to mod (somtime don't know when) but I don't know how to mod the 2 little ports (see pictures below, there the ones the aeros are pointing to)
Ok need alittle help.
I have a STS 21B that I want to mod (somtime don't know when) but I don't know how to mod the 2 little ports (see pictures below, there the ones the aeros are pointing to)
I am curios as to why STS did not integrate those lower cuts into th lateral ports above it. That way, they do not just transfer fuel-air for the next intake, they actually assist in vectoring the fuel-air charge into the cylinder in a loop (Schneurle) manner.
10-24-2007, 11:32 AM
#303
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RE: RC Car Actions "How to port a Nitro Engine"
ORIGINAL: SAVAGEJIM
At the bottom of those littls lower transfe ports, make fang cuts (flow channels) that extend down to the bottom of the sleeve skirt. This will help in flowing more fuel-air into those ports.
I am curios as to why STS did not integrate those lower cuts into th lateral ports above it. That way, they do not just transfer fuel-air for the next intake, they actually assist in vectoring the fuel-air charge into the cylinder in a loop (Schneurle) manner.
ORIGINAL: JB COMP
Ok need alittle help.
I have a STS 21B that I want to mod (somtime don't know when) but I don't know how to mod the 2 little ports (see pictures below, there the ones the aeros are pointing to)
Ok need alittle help.
I have a STS 21B that I want to mod (somtime don't know when) but I don't know how to mod the 2 little ports (see pictures below, there the ones the aeros are pointing to)
I am curios as to why STS did not integrate those lower cuts into th lateral ports above it. That way, they do not just transfer fuel-air for the next intake, they actually assist in vectoring the fuel-air charge into the cylinder in a loop (Schneurle) manner.
Sorry SAVAGEJIM but that's not the way the air/fuel flows in those ports. Look at the piston, there should be a hole in it that lines up with the port.
If anything should be done it should be done on the top outside of it, not the bottom. The fuel flow from inside the piston and up through those ports.
Look at it and it's obvious.
10-24-2007, 01:32 PM
#305
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RE: RC Car Actions "How to port a Nitro Engine"
ORIGINAL: JB COMP
Sman, theres no holes in the piston.
Sman, theres no holes in the piston.
That's weird. In that case there is no way these ports are intended to flow fuel but only aid in lubricating the piston. The TTR PRO .21 is done the same way, so I made holes myself
10-24-2007, 02:15 PM
#306
RE: RC Car Actions "How to port a Nitro Engine"
Those holes in the piston and the sub piston ports in the sleeve are actually "boost" ports that allow trapped mixture to get out from under the piston...but it's hard to believe they (STS ) didn't follow through with the holes in the piston to take advantage of the ports in the sleeve?
It's a much trickier proposition (you need to be very precise ) than just "porting" the outside of a sleeve.
Put the piston in the sleeve so that the wrist pin holes line up (are centered ) fore and aft w/ the E. port and I. port.
Bring the piston up until the top of the piston is even with the lower edge of the E. port.
Locate the position of the boost ports by scribing the outline of the ports onto the piston.
Take the rod/wrist pin off so they don't get damaged.
"Create" your new boost ports in the piston...the "flame" shaped Carbide (Dremel ) cutter works good for this sort of thing.
De-burr the holes...
It's a much trickier proposition (you need to be very precise ) than just "porting" the outside of a sleeve.
Put the piston in the sleeve so that the wrist pin holes line up (are centered ) fore and aft w/ the E. port and I. port.
Bring the piston up until the top of the piston is even with the lower edge of the E. port.
Locate the position of the boost ports by scribing the outline of the ports onto the piston.
Take the rod/wrist pin off so they don't get damaged.
"Create" your new boost ports in the piston...the "flame" shaped Carbide (Dremel ) cutter works good for this sort of thing.
De-burr the holes...
10-25-2007, 06:57 PM
#308
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RE: RC Car Actions "How to port a Nitro Engine"
ORIGINAL: proptop
Those holes in the piston and the sub piston ports in the sleeve are actually "boost" ports that allow trapped mixture to get out from under the piston...but it's hard to believe they (STS ) didn't follow through with the holes in the piston to take advantage of the ports in the sleeve?
It's a much trickier proposition (you need to be very precise ) than just "porting" the outside of a sleeve.
Put the piston in the sleeve so that the wrist pin holes line up (are centered ) fore and aft w/ the E. port and F. port.
Bring the piston up until the top of the piston is even with the lower edge of the E. port.
Locate the position of the boost ports by scribing the outline of the ports onto the piston.
Take the rod/wrist pin off so they don't get damaged.
"Create" your new boost ports in the piston...the "flame" shaped Carbide (Dremel ) cutter works good for this sort of thing.
De-burr the holes...
Those holes in the piston and the sub piston ports in the sleeve are actually "boost" ports that allow trapped mixture to get out from under the piston...but it's hard to believe they (STS ) didn't follow through with the holes in the piston to take advantage of the ports in the sleeve?
It's a much trickier proposition (you need to be very precise ) than just "porting" the outside of a sleeve.
Put the piston in the sleeve so that the wrist pin holes line up (are centered ) fore and aft w/ the E. port and F. port.
Bring the piston up until the top of the piston is even with the lower edge of the E. port.
Locate the position of the boost ports by scribing the outline of the ports onto the piston.
Take the rod/wrist pin off so they don't get damaged.
"Create" your new boost ports in the piston...the "flame" shaped Carbide (Dremel ) cutter works good for this sort of thing.
De-burr the holes...
...E. and F. ports...
How do you determine port lettering?
And when you say line up wrist pin holes fore and aft, are you referring to the position the piston is in when the motor is together?
10-26-2007, 02:16 PM
#314
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RE: RC Car Actions "How to port a Nitro Engine"
ORIGINAL: duckedup
I'm pretty sure there were only 20 posts / page before, there are now 25 per...
I'm pretty sure there were only 20 posts / page before, there are now 25 per...
10-28-2007, 02:54 PM
#317
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RE: RC Car Actions "How to port a Nitro Engine"
ORIGINAL: SManMTB
Pretty bad.
Pretty bad.
hehe, [&:] what was wrong?
i cant test the sleeve. so do you think this wold have helped?
10-28-2007, 02:57 PM
#318
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RE: RC Car Actions "How to port a Nitro Engine"
your fangs are pointing toward the E port (exhaust) and you can go longer and deeper, and open the ports more.
10-28-2007, 03:05 PM
#319
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RE: RC Car Actions "How to port a Nitro Engine"
ORIGINAL: JB COMP
your fangs are pointing toward the E port (exhaust) and you can go longer and deeper, and open the ports more.
your fangs are pointing toward the E port (exhaust) and you can go longer and deeper, and open the ports more.
bummer, they are pointing the wrong way[:'(] but this is only practice... so basicly i should go deeper and longer and make the cuts the right way. maybe some cuts in the boost port to?
10-28-2007, 04:19 PM
#320
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RE: RC Car Actions "How to port a Nitro Engine"
if you want, you can pick up a STS 12 piston and sleeve for like $25 at www.projectzen.net cheap way to get some sleeves.
10-30-2007, 05:34 AM
#322
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RE: RC Car Actions "How to port a Nitro Engine"
Hey,
Thinking of porting an OS 12 TZ..
Now questions
1. What determines the way in which the flow channels/"fangs" are cut into the sleeve.
2. What are the most common bits used on a dremel to work these channels/fangs.
3. What is everybody using to polish the sleeve/crank.
Thanks
Thinking of porting an OS 12 TZ..
Now questions
1. What determines the way in which the flow channels/"fangs" are cut into the sleeve.
2. What are the most common bits used on a dremel to work these channels/fangs.
3. What is everybody using to polish the sleeve/crank.
Thanks
10-30-2007, 08:32 AM
#323
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RE: RC Car Actions "How to port a Nitro Engine"
this is what I use.
[link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXYA53&P=0]Dremel Rubber Polishing Cylinder [/link] (these two work good on the crank and sleeve, with rubbing and polishing compand)
[link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXYA54&P=0]Dremel Rubber Polishing Cone Point [/link]
[link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXC574&P=0]Dremel 194 High-Speed Steel Cutter [/link] (this is what I use on the sleeve)
[link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXYA51&P=0]Dremel Chain Saw Sharpening Stone 3/16"[/link] (this is what I use on the crank)
EDIT: sorry forgot your other question.
you cut your fangs to point the fuel/air away from the exhaust port.
[link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXYA53&P=0]Dremel Rubber Polishing Cylinder [/link] (these two work good on the crank and sleeve, with rubbing and polishing compand)
[link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXYA54&P=0]Dremel Rubber Polishing Cone Point [/link]
[link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXC574&P=0]Dremel 194 High-Speed Steel Cutter [/link] (this is what I use on the sleeve)
[link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXYA51&P=0]Dremel Chain Saw Sharpening Stone 3/16"[/link] (this is what I use on the crank)
EDIT: sorry forgot your other question.
you cut your fangs to point the fuel/air away from the exhaust port.
10-30-2007, 07:19 PM
#324
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RE: RC Car Actions "How to port a Nitro Engine"
JB COMP, did you mod the 21B? i believe its a 5 port, how did you do it? i have one coming soon and will "improve" it as soon as its broke-in. thanks.
10-30-2007, 07:40 PM
#325
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RE: RC Car Actions "How to port a Nitro Engine"
j_blaze, I haven't yet, I have other projects I'm working on at the moment, and I also need to pick up a new steel cutter. the one I have now is dull and taking a long time to cut.
when I do mod it, I'll post pictures of it here.
when I do mod it, I'll post pictures of it here.