Chainsaw Repair
Husqvarna - Stihl - Poulan - Jonsered - Dolmar chainsaws and more => Husqvarna => Topic started by: Cut4fun on January 06, 2016, 12:30:51 pm
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@EHP @aclarke and others please share your info.
I remember back when folks were trying the 357xp without the stuffers on the cranks. Can you share the outcome? I swear folks were saying better PORTED without them.
I remember the 359 that dont come with stuffers being used with 357 and 359 tops and the 357 lower ends being used with 359 tops in testing back in the day.
Anyone remember the outcomes?
My 357 had the stuffers and 357 top. What are the gains if any to building the 357 top without the stuffers?
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Along the lines of this.
Should I add crank stuffers to my ported 2159?
http://www.arboristsite.com/community/index.php?threads/Should-I-add-crank-stuffers-to-my-ported-2159%3F.286483/
I need to measure up my stuff to better understand the numbers. Then I need to learn what they mean.
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The smaller case volume of the 357 will have a delivery ratio that's more efficient at a slightly higher rpm vs the bigger case of the 359. In theory, the stuffed case would be better suited for a saw that has been ported for higher rpm.
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I want to understand it better but in simple terms, if I want a strong broad power curve for a work saw the stuffers should be left out when ported, right? I really need to get my degree wheel set up so I can start to read it like a book. Thanks for the input.
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Leave the stuffers in.
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I believe the 357 is rated at about a half hp more than the 359xp and rated for higher rpm. 13500, vs 14,000?
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Sorry I'm the other way , I take the stuffers off cause crankcase is to tight and cannot move enough air volume threw the crankcase . The motor can only move the amount of air threw the smallest restriction point with stuffers that's the problems , doesnot matter how big of carb you bolt to the motor , your limited by that point . Biggest problem is this , with stuffers off and motor ported to work with the crankcase your going to need a lot more fuel so depending on your carb you may have to drill your carb . . I do agree that using stuffers your can make a motor turn more rpms but you will not have the torque that you can make with a larger volume crankcase . Most will not agree with me on this but this is what I found . Yes you can read all you want on motors but these are chainsaw motors not dirt bikes or snowmobile engines , they are a lot different in design and porting and the major thing is cooling
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359 bottomend with 357 topend worked better ported
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Is the only way to know if a walbro 199 is enough is to try it?
Ed did you ever measure the ratio with and without stuffers? If not do you have tips on measuring.
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Does anyone have any links or advice for measuring engine volume and finding crankcase to combustion ratio. I swear I read some stuff but can't find it. Something like blocking in and ex then filling the complete engine with oil. But I don't understand how to separate the top from bottom volume and where in the stroke is the division line. Seems to me it has to be where trapped compression starts.
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Plug in "port mapping" at the top of the forum in the search feature. Joe has that in his thread
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Found another similar thread, figured I'd connect them.
http://chainsawrepair.createaforum.com/husqvarna/359357xp/30/
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Found another similar thread, figured I'd connect them.
http://chainsawrepair.createaforum.com/husqvarna/359357xp/30/
Can merge threads if needed?
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199 191 175 etc all work great on the ported 357 359 saws IMO
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I have a 359 with 357 top end (no stuffers). Not ported yet, but squish set at ,020", 200 psi. Good runner, but not very impressive. It'll get ported at some point.
I also have a 357 (w/stuffers) that I ported (basically just widened the ports, opened up the exhaust & matched the lowers to the case, no degree wheel), 190 psi... It's an animal! Much stronger/faster than the other one.
Both these running walbro 199 carbs.
I had planned to add stuffers to the 359, but I guess I need to port if first and see?
EHP, is there a big difference in how one ports one of these if stuffers aren't used?
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That's what I've been wondering too Don. I'm so green I can't see it clearly. It makes sense that stuffers could be a restriction but then I says how large do the transfers need to be to deliver the volume increase. I read through this http://chainsawrepair.createaforum.com/ported-saws/crankcase-vol-(no-drilling-involved)/ but I have questions about the putty. Really I need to take some of my carcasses and start measuring stuff just to get a hands on, maybe something will click.
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the 359 is probably the biggest gainer in power with porting of pretty much any saw . Yes there is a lot of different ways to port or machine the cylinder and everyone has their own way , My way is different than most , its a dam worksaw not a racesaw so build the saw to last under hard use so no high compression as that doesnot help really , At low rpms big compression builds torque but hurts the motor as it tries to turn a higher rpm and live , big compression builds big heat that's some thing a worksaw cannot live with, ya sure if you go out and make a couple cuts and then shut it off and talk about it but that's not a worksaw . . The first 359 I ever ported or seen came fro Baileys and was for a guy to go to a GTG we were having , it was to be a 357 but they sent a 359 and it got to my place 3 days before GTG and I was working a full time job . There was no way of getting a 357 in time so I ported it in one night as that's all the time I had . That saw won its class by a mile . Where you really learn about crankcase volume is once your running alcohol/nitro , take a saw that has a full circle crank in it and run it on that fuel, in a lot of cases you donot even have to mad the carb to pass more fuel as the crankcase cannot move fuel , now put a normal crank in that same saw so the only thing you did was the crank , saw willnot even run in most cases cause not enough fuel compared to the amount of air the motor can now move . So now you need to do a lot of mod work to the carb but it will pull hard once you get enough fuel to it . Because your not running huge compression you need to do a lot more port work to help and your motor will have a higher rpm torque band
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I've got a 357 here to play with. Another guy was talking about sending a 359 as well.
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Jump to 4min 10 seconds for 2 cuts in dry sycamore cant with Big Dave Neiger woods port 357xp with crank stuffers. Was 180psi with pop up piston, intake was a little low.
https://youtu.be/cC5P0FXJ10c
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Good running saw.
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Good running saw.
Took 1st again and sold at that gtg afterwards to a friend that was there.
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If I can get my butt in gear I'll be sending a 359 with 357 top over to the tree'd monkey, if he'll still have me.
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You talking about Scott Kunz? His contact info is in his sig here too using his real name for username.
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He's the one. I wish Lake Michigan was not in between. Would be nice to deliver it in person.