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Hi everyone,
As you all know, Coffee (Dean) passed away a couple of years ago. I am Dean's ex-wife's husband and happen to have spent my career in tech. Over the years, I occasionally helped Dean with various tech issues.
When he passed, I worked with his kids to gather the necessary credentials to keep this site running. Since then (and for however long they worked with Coffee), Woodschick and Dirtdame have been maintaining the site and covering the costs. Without their hard work and financial support, CafeHusky would have been lost.
Over the past couple of weeks, I’ve been working to migrate the site to a free cloud compute instance so that Woodschick and Dirtdame no longer have to fund it. At the same time, I’ve updated the site to a current version of XenForo (the discussion software it runs on). The previous version was outdated and no longer supported.
Unfortunately, the new software version doesn’t support importing the old site’s styles, so for now, you’ll see the XenForo default style. This may change over time.
Coffee didn’t document the work he did on the site, so I’ve been digging through the old setup to understand how everything was running. There may still be things I’ve missed. One known issue is that email functionality is not yet working on the new site, but I hope to resolve this over time.
Thanks for your patience and support!
Hot cams for the 610?
- Thread starter Goosedog
- Start date
Contact Uptite. George has made really outstanding cams for the single cam Huskies in the past and has been talking about making another production run. I think that he just needs to be sure that he still has a market for them. You can tell him that I'll take one to if he makes some more.
http://www.ferracci.com/store/cart.php?m=product_detail&p=169
Not sure if the piston will fit a late model 610?
Not sure if the piston will fit a late model 610?
Goosedog
Husqvarna
B Class
Thanks for all the input, still not sure what all I'm gonna do besides some head work. New piston's for sure too but waiting to see if it'll be OEM or AM. Here's a link to the tear-down over at SMJ.
http://www.supermotojunkie.com/showthread.php?t=93147
http://www.supermotojunkie.com/showthread.php?t=93147
Muddy Waters
Husqvarna
AA Class
Goosedog;66531 said:
Goose you’ve got to put it on a dyno after it’s all said and “done” (<--relatively speaking…
)
Goosedog
Husqvarna
B Class
After some good advise and doing a bit of research I've decided porting and polishing would not be a good thing for a single cylinder thumper like the 610. Yes it would add horses, but at the expense of low end torque which is exactly the desired feature of any 4stroke single. Case in point, the Wikipedia article ASO posted above. Here's the section that discusses this point:
The "Porting and Polishing" myth
It is popularly held that enlarging the ports to the maximum possible size and applying a mirror finish is what porting is. However that is not so. Some ports may be enlarged to their maximum possible size (in keeping with the highest level of aerodynamic efficiency) but those engines are highly developed very high speed units where the actual size of the ports has become a restriction. Larger ports flow more fuel/air at higher RPM's but sacrifice torque at lower RPM's due to lower fuel/air velocity. A mirror finish of the port does not provide the increase that intuition would suggest. In fact, within intake systems, the surface is usually deliberately textured to a degree of uniform roughness to encourage fuel deposited on the port walls to evaporate quickly. A rough surface on selected areas of the port may also alter flow by energizing the boundary layer, which can alter the flow path noticeably, possibly increasing flow. This is similar to what the dimples on a golf ball do. Flow bench testing shows that the difference between a mirror finished intake port and a rough textured port is typically less than 1%. The difference between a smooth to the touch port and an optically mirrored surface is not measurable by ordinary means. Exhaust ports may be smooth finished because of the dry gas flow and in the interest of minimizing exhaust by-product build-up. A 300 - 400 Grit finish followed by a light buff is generally accepted to be representative of a near optimal finish for exhaust gas ports.
The reason that polished ports are not advantageous from a flow standpoint is that at the interface between the metal wall and the air, the air speed is ZERO (see boundary layer and laminar flow). This is due to the wetting action of the air and indeed all fluids. The first layer of molecules adheres to the wall and does not move significantly. The rest of the flow field must shear past which develops a velocity profile (or gradient) across the duct. In order for surface roughness to impact flow appreciably, the high spots must be high enough to protrude into the faster moving air toward the center. Only a very rough surface does this.
I will however still be installing new valves and custom cut seats with a 5 bevel grind. A new piston will be going in too, however I've not decided on OEM or a high-comp aftermarket one.
The "Porting and Polishing" myth
It is popularly held that enlarging the ports to the maximum possible size and applying a mirror finish is what porting is. However that is not so. Some ports may be enlarged to their maximum possible size (in keeping with the highest level of aerodynamic efficiency) but those engines are highly developed very high speed units where the actual size of the ports has become a restriction. Larger ports flow more fuel/air at higher RPM's but sacrifice torque at lower RPM's due to lower fuel/air velocity. A mirror finish of the port does not provide the increase that intuition would suggest. In fact, within intake systems, the surface is usually deliberately textured to a degree of uniform roughness to encourage fuel deposited on the port walls to evaporate quickly. A rough surface on selected areas of the port may also alter flow by energizing the boundary layer, which can alter the flow path noticeably, possibly increasing flow. This is similar to what the dimples on a golf ball do. Flow bench testing shows that the difference between a mirror finished intake port and a rough textured port is typically less than 1%. The difference between a smooth to the touch port and an optically mirrored surface is not measurable by ordinary means. Exhaust ports may be smooth finished because of the dry gas flow and in the interest of minimizing exhaust by-product build-up. A 300 - 400 Grit finish followed by a light buff is generally accepted to be representative of a near optimal finish for exhaust gas ports.
The reason that polished ports are not advantageous from a flow standpoint is that at the interface between the metal wall and the air, the air speed is ZERO (see boundary layer and laminar flow). This is due to the wetting action of the air and indeed all fluids. The first layer of molecules adheres to the wall and does not move significantly. The rest of the flow field must shear past which develops a velocity profile (or gradient) across the duct. In order for surface roughness to impact flow appreciably, the high spots must be high enough to protrude into the faster moving air toward the center. Only a very rough surface does this.
I will however still be installing new valves and custom cut seats with a 5 bevel grind. A new piston will be going in too, however I've not decided on OEM or a high-comp aftermarket one.
Goosedog
Husqvarna
B Class
Okay, so completely aside from the debate over porting/polishing a single cylinder dirtbike head and whether it's a good idea or not, I came up with a plan for my 610 after talking to George at Uptite Racing in SoCal. I believe that he probably knows this motor better than anyone on the planet and so I'm gonna trust his opinion. Thanks for the suggestion, Rajobigguy.
First of all let me say you couldn't find a nicer guy to talk with about bikes, he's polite, friendly and will talk to you about your Husky as long as you want. I explained to him that I had gone into the motor for the cam chain swap and wanted to come out picking up any extra ponies I could without compromising the 610's integrity. He says leave the head alone. No altering nessesary what-so-ever because it's one of the best designed he's ever seen on any Husky or even dirtbike for that matter. The intake ports are straight, smooth and simple...don't try and fix what's not broken. As far as going for higher compession by cutting the head down or going with an aftermarket piston, don't do that either. He said he's seen quite a bit of wrist pin failure on the Ferracci piston (and not wanting to diss a product I've never seen), I think I'll still take his advice and leave that stock too.
Next we talked about the valves and what can be done there. My plan was to have KWS regrind and seat them while they were doing the head work and he says go ahead with that, it can hurt and will definitely improve engine efficiency. Side note: my valve guide seals were leaking bad so I knew I was going to be changing them out, so why not do a valve job too. What I thought was oil coming from the valve adjust covers drooling down from the top of the head was in fact leaky valve seals dripping into the exhaust ports and past the header pipes.
The only thing he say's really wakes that bike up is an aftermarket hot cam. And just by chance he makes one. ...or at least he use to. He quit making it when the 610 went to electric start because the starting motor doesn't spin the crank fast to enough to fire the bikes with taller, fatter lobes on his custom cam. But.....just by chance (again), he's developing another one for the modern 610, it will be tested sometime in January 2010, and possibly available by mid Feburary.
So that's my plan. Valve work, new OEM piston (although George said I could stick the original right back in with just new rings), new cam chain (staying with the OEM auto adjuster as per his recomendation too), and a new Uptite hot cam should round out the motorwork I'm planning.
First of all let me say you couldn't find a nicer guy to talk with about bikes, he's polite, friendly and will talk to you about your Husky as long as you want. I explained to him that I had gone into the motor for the cam chain swap and wanted to come out picking up any extra ponies I could without compromising the 610's integrity. He says leave the head alone. No altering nessesary what-so-ever because it's one of the best designed he's ever seen on any Husky or even dirtbike for that matter. The intake ports are straight, smooth and simple...don't try and fix what's not broken. As far as going for higher compession by cutting the head down or going with an aftermarket piston, don't do that either. He said he's seen quite a bit of wrist pin failure on the Ferracci piston (and not wanting to diss a product I've never seen), I think I'll still take his advice and leave that stock too.
Next we talked about the valves and what can be done there. My plan was to have KWS regrind and seat them while they were doing the head work and he says go ahead with that, it can hurt and will definitely improve engine efficiency. Side note: my valve guide seals were leaking bad so I knew I was going to be changing them out, so why not do a valve job too. What I thought was oil coming from the valve adjust covers drooling down from the top of the head was in fact leaky valve seals dripping into the exhaust ports and past the header pipes.
The only thing he say's really wakes that bike up is an aftermarket hot cam. And just by chance he makes one. ...or at least he use to. He quit making it when the 610 went to electric start because the starting motor doesn't spin the crank fast to enough to fire the bikes with taller, fatter lobes on his custom cam. But.....just by chance (again), he's developing another one for the modern 610, it will be tested sometime in January 2010, and possibly available by mid Feburary.
So that's my plan. Valve work, new OEM piston (although George said I could stick the original right back in with just new rings), new cam chain (staying with the OEM auto adjuster as per his recomendation too), and a new Uptite hot cam should round out the motorwork I'm planning.
Sounds like the right plan of attack to me. Uptites older single cam bikes were about the hottest things around, the cams that George developed really woke them up without making them a overcammed, overcabureted beast.