picking brains
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Lawn Masters
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The general rule is that older saws are low revving, high low end torque beasts, while new saws are high revving machines.
How old is the saw in question? and what make/model is it?
How old is the saw in question? and what make/model is it?
Mange
Addicted to ArboristSite
That is a big saw.
Stumper
One Man Band
Several saws were rated that high-whether they really achieved that is debatable because there are a couple of standard ways to determine horsepower plus some rather inventive and optimistic ways. The Stihl 090 is generally accepted as achieving over 8hp. The Dolmar KMS4 was rated up there high in hp but probably didn'tcome close . Some big Macs probably got there. The biggest Solos (642) may have achieved it. Maybe the Dolmar Ct did as well (that one was advertised as 12hp US.-8DIN)
Dolmar_Tech_Mgr
ArboristSite Operative
I would bet that the Dolmar KMS4 did get there. It was a Wankel rotary engine and it was a kick a&& powerful saw. Just the muffler got to hot from the design.
Stumper
One Man Band
TechMan-I'd love to experience a KMS4. -It was such a cool concept. I based my doubt on what I have read and the displacement-3.5 cid.-No criticism of Dolmar was intended-I'm a Dolmar fan-but their hp figures were always pretty high for the displacement even with conventional 2 cycles.
Al Smith
Addicted to ArboristSite
Good question
The subject of H.P.,has came up on many occasions,but with little resolve.The genaraly accepted standard,for years,was based on cu.inchs,and that being slightly over 1 h.p. per cu.in.Just my opinion,but I would also assume the h.p. rating would be based on a certain r.p.m.A case in point could be Stihl 046[and 048] at 4.67 cu in,and 6.03 h.p.,most likely taken at 12,000 rpm.This,as opposed to McCulloch super 44A[oldie] at 5.3 cu in,and 6.5 hp,at 6,500[governer equipted]I am also under the opinion that some of the ratings were "enhanced",from the manufacturers.Case in point,Sachs-Dolmar 166,with a rating of 12 Hp,at 123cc.At the same ccs,are Stihl 084,088,McCulloch cp-125 and sp 125 and Husqvarna 3120[118 cc]Homelite 2100s[114cc] ,yet all these have ratings around 8 to 8.5 hp,if I'm not mistaken.
The subject of H.P.,has came up on many occasions,but with little resolve.The genaraly accepted standard,for years,was based on cu.inchs,and that being slightly over 1 h.p. per cu.in.Just my opinion,but I would also assume the h.p. rating would be based on a certain r.p.m.A case in point could be Stihl 046[and 048] at 4.67 cu in,and 6.03 h.p.,most likely taken at 12,000 rpm.This,as opposed to McCulloch super 44A[oldie] at 5.3 cu in,and 6.5 hp,at 6,500[governer equipted]I am also under the opinion that some of the ratings were "enhanced",from the manufacturers.Case in point,Sachs-Dolmar 166,with a rating of 12 Hp,at 123cc.At the same ccs,are Stihl 084,088,McCulloch cp-125 and sp 125 and Husqvarna 3120[118 cc]Homelite 2100s[114cc] ,yet all these have ratings around 8 to 8.5 hp,if I'm not mistaken.
Dolmar_Tech_Mgr
ArboristSite Operative
Look at the current Stihl saws and the Horsepower is listed a bHp or brake Horse power a term used today by all companies not longer is HP used. bHP is a better rating and much more accurate. I know that when other companies were using HP the ratings were much higher than today.
The KMS4 was in fact a 3.5 ci engine and it delivered. When running it sounded like a small block V8 running. I never had much experience with the saw only ran 1 a couple of times. I did talk to a guy using one in a go kart and he told me NOTHING in a 3.5 cu in class could get near it.
The KMS4 was in fact a 3.5 ci engine and it delivered. When running it sounded like a small block V8 running. I never had much experience with the saw only ran 1 a couple of times. I did talk to a guy using one in a go kart and he told me NOTHING in a 3.5 cu in class could get near it.
Mange
Addicted to ArboristSite
The Wankel engine is a good thought, but hard to pull off.
i talked to a collector a few days ago that has his Delmer Wankel as a Firewood saw!!!!!!!!!!!
To the point is that he burns about one cubic meter wood/year.
I will post a pic off his saw
Another collector says the biggest problem is the sparks, the muffler gets glowing hot very fast and the engine too, but not glowing.
he told me that if run it at night, there are 30cm flames and a lot of sparks.
I have never seen it run, but worked on the Mazda's Wankel xxxxxx years ago. We pulled the afterburner and the beast got about 25hp more. But then again it consumed twice the fuel too. There were a meter of flames behind it.
Very fun, but dangerous. We mounted the afterburner and put it back.
I think if the saw had this afterburner like the cars, many of the problems would go away.
i talked to a collector a few days ago that has his Delmer Wankel as a Firewood saw!!!!!!!!!!!
To the point is that he burns about one cubic meter wood/year.
I will post a pic off his saw
Another collector says the biggest problem is the sparks, the muffler gets glowing hot very fast and the engine too, but not glowing.
he told me that if run it at night, there are 30cm flames and a lot of sparks.
I have never seen it run, but worked on the Mazda's Wankel xxxxxx years ago. We pulled the afterburner and the beast got about 25hp more. But then again it consumed twice the fuel too. There were a meter of flames behind it.
Very fun, but dangerous. We mounted the afterburner and put it back.
I think if the saw had this afterburner like the cars, many of the problems would go away.
Dolmar_Tech_Mgr
ArboristSite Operative
The KMS4 was the reason Fitchel and Sachs bought Dolmar and formed Sachs-Dolmar back in 1975. The saw had the muffler issue and was forced out of the woods for obivious reasons as you stated about the muffler. But Sachs who I believe owned the rights to the Wankel engine then and maybe even still do was interested in the saw business and bought the Dolmar factory. I think that saw needed one more spark plug for the single rotor in the engine. Maybe an additional spark plug would have reduced the raw fuel from entering the muffler and have stopped the excessive heat at the muffler.
Lawn Masters
Addicted to ArboristSite
I guess maybe a little more R&D and the KMS 4 would have been a continued model, still in production until about 1995. nothing is impossible, as long as theres funding to do the research, engineering, testing, development, and marketing.
I'd love a KMS4 in my collection, but they're hard to come by when you're not making much money.
I'd love a KMS4 in my collection, but they're hard to come by when you're not making much money.
Mange
Addicted to ArboristSite
I think they are hard even with mony, at least here.
Al Smith
Addicted to ArboristSite
I spent a little time on the "dummy" end of one of those old Malls.The model 7 was a little over 12 cu in,and I think about 6 hp.Keep in mind they only ran at about 4 or 5 thousand rpm,and then only in a heavy cut [governer].Perhaps some of the Macs could have produced 8 hp.One that comes to mind is the model 99,at 9.9 cu in.,also heavy,powerhead weight is 56 lbs.[ the old timbermen earned their money]
Dolmar_Tech_Mgr
ArboristSite Operative
When I was working for Sachs-Dolmar in Shreveport we had a brand new still in the box never been run KMS4. The then president of Sachs-Dolmar gave the saw to one of our top distributors - Huskypower in Shreveport the guys name that ran the business was Ed Barras. Not sure what happen to that saw as they later went out of business after the man that owned the company (Jim Thompson) from Charlotte passed away and is sons took over but was not their main interest. Would love to have that saw back to take around to shows. One thing about the KMS4 it had no anti-vibration mounts as the saw ran so smooth they were not really needed to bad.
Al Smith
Addicted to ArboristSite
The Wankel design engine,is a subject,all of its own.If one thinks about it,the design is relatively simple.It being merely a rotary compressor,modified to run on combustion.The problems arose,much due to high temperatures,with the combustion process,such as rotor seals,lube break down,etc.Being of a basic"turbine"design,for want of a better word,they were never very efficient in terms of fuel usage,etc.The usage,was attempted on many application,such as snowmobiles,autos,motorcycles[experimental],but never gained acceptance.Perhaps,as technology evolves,they may make a come back.
