stinkbait
Addicted to ArboristSite
The popups are actually the piston crown turned down in a lathe, and the domed piston like this is actually added material to the crown of the piston.
Building a Dome piston
- Thread starter Husq445
- Start date
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The popups are actually the piston crown turned down in a lathe, and the domed piston like this is actually added material to the crown of the piston.
little possum
Crash and Burn
Darn you guys, and your crazy ideas. I want to mod something, real bad. Have access to everything that I would need like the lathe, millin machine, TIG welder, dremel.
Just dont have the guts to start. Hopefully I will score on a cheap find, and be able to part with it.
Just dont have the guts to start. Hopefully I will score on a cheap find, and be able to part with it.
little possum
Crash and Burn
Darn you guys, and your crazy ideas. I want to mod something, real bad. Have access to everything that I would need like the lathe, millin machine, TIG welder, dremel.
Just dont have the guts to start. Hopefully I will score on a cheap find, and be able to part with it.
Nice work on the piston.
Just dont have the guts to start. Hopefully I will score on a cheap find, and be able to part with it.
Nice work on the piston.
nategyoder
ArboristSite Operative
I understand that the milled down popups would be easier since there is no welding. I have also seen popups on here that were built up like the domed one and then milled down. I would think the domed would provide the most compression but are the hardest to make? Husq445 are you going to run 100ll or some other really high octane fuel when you add the new rings to avoid predetonation?
Again really awesome work!
Again really awesome work!
TW, just wanted to say that I like how you contribute substance and never discourage people from trying things when modding a saw. This site is lucky to have you.:yourock:
Mr. HE
parrisw
Tree Freak
TW, just wanted to say that I like how you contribute substance and never discourage people from trying things when modding a saw. This site is lucky to have you.:yourock:
Mr. HE
Ya, I totally agree. Unlike some people that have been around. TW is awesome, he has helped me allot!!!!
Same here.
breymeyerfam
Addicted to ArboristSite
yup me too.
TW, just wanted to say that I like how you contribute substance and never discourage people from trying things when modding a saw. This site is lucky to have you.:yourock:
Mr. HE
Brian (Timberwolf) is the original Mad Scientist when it comes to all things mechanical. His knowledge and talents extend far beyond chainsaws.
Husq445- Your work looks good. I'd be interested in having you do a couple Mac pistons for me for fixed-head 103cc Mac engines if you're interested and have the time.
parrisw
Tree Freak
What kind of saw? Looks like a clamshell design motor?
Husky 445.
PetrolHead
ArboristSite Operative
LOL, I can't tell if your working hard or grinning from ear to ear? Strange how something mechanical can give so much pleasure.
parrisw
Tree Freak
Cool, thanks. How'd ya know that.
Timberwolf, you are right on the money! 5.27 grams added weght! PSI gain 55, not sure what stock compression was until after some modding ( because of all you guys, had to buy a comp guage, Mac Tools too) just kidding this is very addictive! I do very much appreciate all your info Timberwolf and rep you for it! People that are willing to go out on a limb and try something new should not be made fun of. I'm sure thats how saw modding started, somebody had to try it. Brad has also been ther for advice on the few threads that I have started, and I thak you too.
Actually got this saw a little warm when it was stock (think thats when I ruined the ring) and tore the motor down (over and over) to see what I could do with this, have ported and raced snowmobiles before so familiar with two strokes and always wanting more power.
Anyway, I know that this is a very small saw compared to most, but, all the better reason to mod it, right?
First started out with a muffler mod.
that was not enough so I ported the exhaust
nope still not enough, tore down again, now intake and tranfers
after more hours on here of reading, tore down carb and ported it
NOW running like a raped ape, cant stop, have cut a LOT of wood through all of these upgrades.
Cannot stop now, I know ultimately I am going to blow this saw up. It's also a cheap saw and I will know my limits for next time. But it has paid for itself for all the wood it has cut and all I am learning. ( Also will be an excuse when it does go down for upgrade!
So here we we are to the piston dome project, have cut down two ash trees now with it running unbeliveable but I think Timberwolf is right, New ring=shaved dome, by the way I did have to relieve one side a little for plug clearance after these pics were taken.
As far as doing a Dome on someone elses piston. I would not have a problem with that as someone asked earlier, but this was my first one. I am a specialty welder by trade ( Aluminum, Stainless, Cast steel, Cast Iron, Brass, Copper, Titanium, Mig, Tig, Arc)
Apreciate everyone input, yes this is out of a Husqvarna 445, just curious what any ones thoughts on the porting? dont have any pics on the transfer internals or the carb, maybe later, probably too square but any input would be great?
Thanks to all.
Rick
I was thinking a little too square when I saw the pics. I didn't say anything because pic angle plays a factor and also because my first port job was a little bit square and it runs fine. I did chamfer the edges really good and I'm sure that is why it has worked so far. The chamfer did essentially raise the exhaust port, but I'm still making 185 in that saw with .017 squish running gasketless.
Mr. HE
Mr. HE
Has anyone ever approched Wiesco? I used to work in a machine shop, engine/speed shop. Alot of the engines we did we would get custom pistons from Wiesco. Yeah, it was 8 pistons but they were pretty open on any custom orders. They do alot of bike/atv pistons. If they have a forging "blank" that is close to a saw piston already in production it is nothing for them to machine it to your specs. Just a thought. I am not up to the whole piston modification thing, yet. Are most saw pistons cast? If so, I would be nervous about welding a on them. I used to TIG alot of Aluminum castings to repair cracks and it does not always turn out the way I feel it shoud strength wise. I feel there may be a chance of the build up seperating from the piston??? Not and expert here but have my worries.
. Are most saw pistons cast? If so, I would be nervous about welding a on them. I used to TIG alot of Aluminum castings to repair cracks and it does not always turn out the way I feel it shoud strength wise. I feel there may be a chance of the build up seperating from the piston??? Not and expert here but have my worries.
Wiseco is the way to go on sleds, never heard of them doing custom work. that would be nice too.
As far as these cast pistons, they are very dense, not porus, spongelike. Plus I did some research on the composition of the piston, and fill rod first. 4043 and 4047 are close to the piston composition the 4043 has a higher melting point. I know what you are talking about as far as weld separation on cast alum. Preheat and right fill rod are the key. Pretty much the same on cast anything.
Thought I had gotten carried away and went too square on the ports after looking at a lot of pics of other ports, maybe not, time will tell.
As far as these cast pistons, they are very dense, not porus, spongelike. Plus I did some research on the composition of the piston, and fill rod first. 4043 and 4047 are close to the piston composition the 4043 has a higher melting point. I know what you are talking about as far as weld separation on cast alum. Preheat and right fill rod are the key. Pretty much the same on cast anything.
Thought I had gotten carried away and went too square on the ports after looking at a lot of pics of other ports, maybe not, time will tell.
parrisw
Tree Freak
With all this talk, we need to see a video of that little beast.
wigglesworth
Booned
:agree2:
