# Capacity and bore of a chain saw

 Forum topic by DocSavage45 posted 09-04-2018 11:15 PM 609 views 0 times favorited 14 replies
 DocSavage458830 posts in 3265 days 09-04-2018 11:15 PM Topic tags/keywords: chainsaw milling question Hey LJ’s, Looking for some advice beyond my knowledge base and I didn’t find an answer through a search engine, as I was looking for a simple direct answer. SO…. if a chainsaw is claiming 105 ccs and 4.8 KW of power ( about 4 hp) What is the cc size of the bore of the engine. Seeing different numbers and sometimes, omissions. Looking to make an informed choice but I don’t have the knowledge at this point. Thanks -- Cau Haus Designs, Thomas J. Tieffenbacher

## 14 replies so far

 woodshaver Tony C 6691 posts in 3776 days #1 posted 09-04-2018 11:22 PM HI Tom, Found this info on line… “The bore also represents the size, in terms of diameter, of the cylinder in which a piston travels. The value of a cylinder’s bore, and stroke, is used to establish the displacement of an engine. The term “bore” can also be applied to the bore of a locomotive cylinder or steam engine pistons.” I also found this calculator. Does this help? https://www.revetec.com/Calculators/Engine_Displacement_Calculator-2.htm -- St Augustine FL, Experience is the sum of our mistakes! DocSavage458830 posts in 3265 days #2 posted 09-04-2018 11:42 PM Not sure Tony. LOL! I’ve seen different numbers relating to the wattage output. 58 cc appears to be half of 106 cc of displacement. Bore and stroke are numbers that relate as well as rpms. It’s still a bit of a mystery for me. Thanks. Hoping to get a simple answer from someone who works with and knows the dynamics of chainsaws. so I can get a simple but specific answer. Thanks! -- Cau Haus Designs, Thomas J. Tieffenbacher woodshaver Tony C 6691 posts in 3776 days #3 posted 09-04-2018 11:47 PM I see you mentioned “wattage”. I’ve only seen that term used with electric motors. Hope you find an answer Tom. -- St Augustine FL, Experience is the sum of our mistakes! DocSavage458830 posts in 3265 days #4 posted 09-05-2018 12:00 AM hp and wattage are parallel measures. me too. LOL1 Thanks. -- Cau Haus Designs, Thomas J. Tieffenbacher Jared_S206 posts in 382 days #5 posted 09-05-2018 01:38 AM Your question is a bit confusing. You are stating the displacement (in cubic centimeters) and asking about the bore (again in cubic centimeters). I assume you mean if the saw is said to displace 105cc, what is the bore in mm? The problem is you would need to know the stroke to figure that out… each brand varies the bore and stroke for their saws to get a specific displacement. Dolmar is an exception in their 64/72/79cc saws where the stroke stays the same and the bore just gets larger on the different models. now if you mean the cryptic ebay listing of 105cc and no real information I’d pass on principal. My advice buy a reputable brand I prefer dolmar myself mostly because I have a bunch of them Lazyman3574 posts in 1810 days #6 posted 09-05-2018 01:55 AM As Jared said, I too am a little confused about what specs you are trying to compare. I would think that HP and torque would be the simplest ratings to compare. If 2 saws have the same HP but one has a higher torque, I would think that would be the better saw? Perhaps if you post the saws you are comparing and what you want to use it for, you’ll get some feedback (and if you are lucky a consensus) from owners. Regardless of the specs, there are just some saws that should be avoided. -- Nathan, TX -- Hire the lazy man. He may not do as much work but that's because he will find a better way. msinc567 posts in 926 days #7 posted 09-05-2018 02:34 AM Everything is relative when you are talking about an internal combustion engine. Bore is the piston size, stroke is the amount of travel the piston goes up and down in the bore. As posted, together this sets the displacement. In general, a longer stroke can equate to more torque, shorter stroke will allow for higher rpm’s. The higher the rpm’s the more horsepower and this will continue to climb with rpm’s. But, there is another thing that they do to change horsepower ratings…a bigger carb or throttle body if fuel injected. A lot of engines, especially marine outboards and such have identical displacements and interchangeable engine parts but have that bigger carb. Yamaha 50,60, and 70 hp outboards were at one time all the same engine save the carb. One other important fact regarding IC engines…two stroke engines fire and make power every time the piston comes to the top…four stroke engines make power every other time. Two strokes have way less parts as well and are lighter in weight. So, for a given displacement, two strokes are always more powerful and rev higher than four strokes. There is no free lunch though, four strokes are quieter, consume less fuel and last longer. As engines go, neither two nor four stroke reciprocating {piston going up and down} engines are very efficient. As to chain saws…I cut down and mill as many logs per year as just about anyone and have owned them all…you will not regret a Stihl. Reminds me of the joke about the priest and the kid that sold him a mower. Father is trying to get it started and calls the kid over. The kid says, “you got to put a good cussing on it” and father says, “I’m a priest, I haven’t cussed in so long I cant even remember how!!” and the kid says, “you just juke on that thing long enough and it’ll come back to ya!!!!!” Juke on some Chinese junk long enough and you’ll go get that Stihl!!! DocSavage458830 posts in 3265 days #8 posted 09-05-2018 03:34 AM msinc, Lazyman, and Jarads, Thanks! don’t have all the information and I was attempting to figure it out. Did get dimensions of one saw as it was posted ie. 58 mm, 4.5 KW at max rpms. The saws I am looking at are …I’m going to say it…Chinese. Lets hear a big ewwww! They are modeled after/copied from Sthil who has a plant in China. Yep! Why am I doing this? Not going to saw more than a large diameter walnut trunk/log sitting in my parking area. Three 6 ft @ 32 inch diameter big logs. Tried to find a local portable saw mill and there appears to be only one and he blew me off! Have a 460 Rancher and I’ve been sawing/milling small logs for woodworking. Don’t want to spend more money than I have to and I saw these knock offs. Specs on the less expensive saw don’t inclued the piston diameter but both saws are 105 cc displacement and have a 36 inch bar. Will have Oregon replacement bar and ripping chain if I buy the saw. Not going to be a lumberjack just wanting to slab what I have? This is the saw I’m considering buying direct from China if the price I was quoted is right. https://www.amazon.com/OJENAS-Gasoline-Chain-105cc-4-8KW/dp/B07D14VVSH/ref=pd_rhf_se_p_img_2?_encoding=UTF8&psc=1&refRID=S59JRKA2Q84NW2290TKR Following is the detail. Power type Single Cylinder, Two-stroke, Air-cooling Cylinder diameter 58mm40mmEngine Displacement 105ccRated output power 4.8kw (6.4 hp)Relevant speed 8000rpmStandard Bar Lengths 36” (91.4cm)Chain pitch (inch) 0.404” Chain Gauge 0.063” Fuel mixture ratio 25:1(Gasoline 25 : Two-cycle Oil 1)Ignition system DigitalMeas 558370370mmBox weight 15.5kg (34.2 lbs.) Update! Just received a quote, and the price of shipping the damn thing is more expensive than the saw! * Have to pass on this one_. Thanks for the education Lj’s -- Cau Haus Designs, Thomas J. Tieffenbacher MrUnix7409 posts in 2622 days #9 posted 09-05-2018 05:03 AM Update! Just received a quote, and the price of shipping the damn thing is more expensive than the saw!- DocSavage45 Thats weird… I didn’t go through the checkout, but this is what it was showing me as for shipping: Cheers,Brad -- Brad in FL - In Dog I trust... everything else is questionable DocSavage458830 posts in 3265 days #10 posted 09-05-2018 05:29 AM Brad, I was in communication with Alibaba. And directly with the company that sells the saw. since I already have a 460 rancher and a 62 cc Timberpro I was looking for a stronger saw to cut the walnut tree logs. The price was quoted at 112 dollars and the presentation was leading me to believe it was 184 dollars with shipping. But that was a misinterpretation. The shipping by Fedex was 184 dollars. The price on amazon is total cost from same company, but I’m not spending any more money. I’ll have to figure a way to make do. Any case it was exciting while it lasted. -- Cau Haus Designs, Thomas J. Tieffenbacher Fresch434 posts in 2343 days #11 posted 09-05-2018 11:59 AM Get the \$30 chicom “beam maker” and cut multiple shallow cuts. mahdee4291 posts in 2190 days #12 posted 09-05-2018 12:10 PM Do you have a rental place?You might be able to rent a saw instead of buying one. -- earthartandfoods.com DocSavage458830 posts in 3265 days #13 posted 09-06-2018 01:17 AM mahdee, Good idea, rental place is 44 miles away and they have a Sthil with 18 inch blade. And 66 dollars a day. Nothing of the magnitude of my 460 rancher in my local area. A Sthil saw and 30 inch blade is selling for 1900 dollars. LOL! -- Cau Haus Designs, Thomas J. Tieffenbacher DocSavage458830 posts in 3265 days #14 posted 09-06-2018 01:21 AM Fresch, Thinking about the Grandberg version of a beam cutter. Probably going with that and my rancher and then my Panther saw mill for slabbing, but I have to make an extension with some square tubing. -- Cau Haus Designs, Thomas J. Tieffenbacher

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