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caution - the lint primarliy deals with 4 stroke engine porting. Two stroke porting is a completely different animal and should not be undertaken by amatures without a lot of research beforhand and maybe some practice. With two strokes the ports are the valves and small changes have huge impacts unlike 4 strokes where it is more forgiving.
 

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caution - the lint primarliy deals with 4 stroke engine porting. Two stroke porting is a completely different animal and should not be undertaken by amatures without a lot of research beforhand and maybe some practice. With two strokes the ports are the valves and small changes have huge impacts unlike 4 strokes where it is more forgiving.
 

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Even on a four stroke I would only recommend the most basic of porting to the average individual. Any heavy porting and a person is more likely to screw up the flow rather than improve it. And don't even cosider sending it to a shop without a flowbench.
Stick to matching the intake port, cleaning off casting flash, smoothing off the ceiling a bit, cleaning up around the valve guide...any reshaping of the port should be left to a professional.

And on almost all vintage four stroke japanese bikes....forget doing any porting unless you increase valve size...that's almost always the limiting factor on these engines. Sure you don't want your intake flange and head flange 1/4" off...or a big piece of casting slag hanging in the port....but for the most part, unless you get bigger valves it's a waste of time.
JohnnyB
 

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Even on a four stroke I would only recommend the most basic of porting to the average individual. Any heavy porting and a person is more likely to screw up the flow rather than improve it. And don't even cosider sending it to a shop without a flowbench.
Stick to matching the intake port, cleaning off casting flash, smoothing off the ceiling a bit, cleaning up around the valve guide...any reshaping of the port should be left to a professional.

And on almost all vintage four stroke japanese bikes....forget doing any porting unless you increase valve size...that's almost always the limiting factor on these engines. Sure you don't want your intake flange and head flange 1/4" off...or a big piece of casting slag hanging in the port....but for the most part, unless you get bigger valves it's a waste of time.
JohnnyB
 

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Discussion Starter #6
of course, of course. Sometimes I forget this is a public forum and just drop info directly for y'all.

It is a tidy little kit.



Why post this? I am re-doing the top-end of my 450. Most of the Honda ports I've seen are pretty rough (what do you call it Johnny? casting flash?) from the factory, figured it would be a good idea to tidy up while I'm in there.

BORN TO LURK, FORCED TO WORK.
www.NYCvinMoto.com
www.VinMoto.org
 

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Discussion Starter #7
of course, of course. Sometimes I forget this is a public forum and just drop info directly for y'all.

It is a tidy little kit.



Why post this? I am re-doing the top-end of my 450. Most of the Honda ports I've seen are pretty rough (what do you call it Johnny? casting flash?) from the factory, figured it would be a good idea to tidy up while I'm in there.

BORN TO LURK, FORCED TO WORK.
www.NYCvinMoto.com
www.VinMoto.org
 

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Rosko...don't mean to diss your post of course, always cool to see what tools are out there.
But...for porting I would recommend just a couple of quality carbide bits and die grinder. A good carbide burr will last literally as long as a couple of hundred of those sanders. The sanders are good for the finish work, but even burrs are good for that if you get good with them. Also, current thinking on porting is a too smooth finish on the ports leads to laminar flow and fuel dropping out of suspension in the air flow...where as a slight rough finish creates a turbulent flow that keeps the fuel in suspension and will often actually flow a bit more....just like dimples on a golf ball.
JohnnyB
 

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Rosko...don't mean to diss your post of course, always cool to see what tools are out there.
But...for porting I would recommend just a couple of quality carbide bits and die grinder. A good carbide burr will last literally as long as a couple of hundred of those sanders. The sanders are good for the finish work, but even burrs are good for that if you get good with them. Also, current thinking on porting is a too smooth finish on the ports leads to laminar flow and fuel dropping out of suspension in the air flow...where as a slight rough finish creates a turbulent flow that keeps the fuel in suspension and will often actually flow a bit more....just like dimples on a golf ball.
JohnnyB
 

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rosko, e-town is next month and there are always guys there with the black carbide bits for car head porting for cheap in a thousand designs. Branson is right sanders are for finish work and you still have to be careful you don't take out too much rough texture in your intake - engines need turbulent yet fast moving air in their intake tracts.
 

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rosko, e-town is next month and there are always guys there with the black carbide bits for car head porting for cheap in a thousand designs. Branson is right sanders are for finish work and you still have to be careful you don't take out too much rough texture in your intake - engines need turbulent yet fast moving air in their intake tracts.
 

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Discussion Starter #12
Thanks for the info guys. For individual peices I'd probably go McMaster, the kit just looked good for an 'all-in-one' solution.

I will be smoothing out the rough patches, no polishing or anything like that. I'll post some pics when I get to it.

BORN TO LURK, FORCED TO WORK.
www.NYCvinMoto.com
www.VinMoto.org
 

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Discussion Starter #13
Thanks for the info guys. For individual peices I'd probably go McMaster, the kit just looked good for an 'all-in-one' solution.

I will be smoothing out the rough patches, no polishing or anything like that. I'll post some pics when I get to it.

BORN TO LURK, FORCED TO WORK.
www.NYCvinMoto.com
www.VinMoto.org
 

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My cylinder head guy likes the ports about like maybe 80-120 grit sandpaper might look. When I got my cylinder head back and mentioned it finish on the ports he specifically told me not to polish it out...which went against most things I'd learned, so he explained it to me. Interesting.
And...like Geeto said...modern thought is for high velocity ports. I remember reading a great article a while back on how a late model R6 actually had smaller intake ports than the previous year but made more hp due to increase port velocity. Don't want that intake charge sitting around stagnant...you want it to keep moving. That's why flow benches and computer software are the norm in good engine shops these days.
JohnnyB
 

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My cylinder head guy likes the ports about like maybe 80-120 grit sandpaper might look. When I got my cylinder head back and mentioned it finish on the ports he specifically told me not to polish it out...which went against most things I'd learned, so he explained it to me. Interesting.
And...like Geeto said...modern thought is for high velocity ports. I remember reading a great article a while back on how a late model R6 actually had smaller intake ports than the previous year but made more hp due to increase port velocity. Don't want that intake charge sitting around stagnant...you want it to keep moving. That's why flow benches and computer software are the norm in good engine shops these days.
JohnnyB
 

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a follow up to Dr. bransons thread on too smooth...fish and birds have had multiple generations of trial (get laid) and error (get eaten) (maybe o.k. if you're a lesbian fish but a bummer otherwise) so here's something to think about. look at feathers and scales and you'll see a similar concept at work. the media (water or air respectivlely) will "organize" its flow nicely when random turbulence is eliminated. a series of small "tornados" roll off the trailing edges of scales and feathers which actually smooth out the general flow. even some swimsuit companies (like speedo) are experimenting with certain textures to improve the overall slippery-ness of swimmers. just a few thoughts. don't know how i can impart this kind of texture into my intake and transfer ports in my bultaco though.
parks
 

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a follow up to Dr. bransons thread on too smooth...fish and birds have had multiple generations of trial (get laid) and error (get eaten) (maybe o.k. if you're a lesbian fish but a bummer otherwise) so here's something to think about. look at feathers and scales and you'll see a similar concept at work. the media (water or air respectivlely) will "organize" its flow nicely when random turbulence is eliminated. a series of small "tornados" roll off the trailing edges of scales and feathers which actually smooth out the general flow. even some swimsuit companies (like speedo) are experimenting with certain textures to improve the overall slippery-ness of swimmers. just a few thoughts. don't know how i can impart this kind of texture into my intake and transfer ports in my bultaco though.
parks
 

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Yea, porting is cool and it does help quite a bit in hp. Height in the intake chamber and a vortex type path makes the pulses. Just listen to my Ducati. Sounds like no other on the track.

Champ
 

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Yea, porting is cool and it does help quite a bit in hp. Height in the intake chamber and a vortex type path makes the pulses. Just listen to my Ducati. Sounds like no other on the track.

Champ
 
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