할리 엔진의 윤활장치의 특징( 드라이 섬프 방식 )

[Nostalgia]

안녕하세요. 회원님들 가장추운 겨울인데도 날씨가 영하로 않떨어지고 가끔 해나면 잠깐 할리 탈수 있을것 같습니다.

전에 왜? 겨울에 할리타면 엔진에 않좋나? 모든바이크가 다그런데, 할리는 특히 더않좋죠? 왜? 그런지 궁금하셨던 분들 아래의 각 바이크 윤활 장치설명 보시면 좀 이해하실수 있을겁니다. 할리엔진은 기본구조가 클래식엔진이고 20세기초 영국, 독일의 항공기엔진에서 많은 영향을 받았기에 그들의 엔진구조와 비슷합니다. 공냉식에 오일탱크가 따로 달린 드라이 섬프( Dry sump)방식입니다. 반대로 대부분의 오늘날 바이크,자동차들은 엔진내부에 오일팬이 있는 웨트 섬프( wet sump) 방식입니다. 그럼, 영어지만 그림만보아도 각 윤활장치의 차이점을 좀 아실겁니다. 할리는 태생이 어메리칸 바이크다 보니 영어 좀 공부하셔야 앞으로 타시는데 좀 편하실겁니다 ㅎㅎ 우리들이 타는 할리의 윤활,냉각장치에 관심있으신 분들  영어공부 하실겸 천천히 읽어주십시오.

FOUR STROKE ENGINE LUBRICATION

There are four styles of lubrication used on Four Stroke Motorcycles.

1. Wet Sump
2. Dry Sump
3. Splash
4. Total Loss

Wet Sump engines use an oil pan (sump) to store the oil at the bottom of the engine and use an oil pump to pump the oil to where it is needed in the engine. Some engines of this type will have a removable oil pan and some won't. Most Wet Sump engines have a plate under the crankshaft and over the oil. This is to prevent friction losses from the oil splashing on the spinning crankshaft. this seems to be the most popular oiling system. Most Japanese machines are Wet Sump, but not all !

Dry Sump engines carry their oil in an oil tank that is separate from the engine. This can be an actual tank or inside of the tubes of the frame. This engine lubrication type uses two oil pumps. One to pump oil to the engine, where it lubes everything and then drops to the bottom of the engine. From there, the second or scavenge pump pumps the oil back to the oil tank. Sometimes the scavenge pump also pumps oil to the transmission, valves and other places in the engine. The scavenge pump is twice as big as the main oil pump. If you look at the oil return pipe, when the engine is running, it will be spurting oil. This is normal. Dry Sump engines tend to back flow oil into the lower part of the engine when they sit for long periods of time. Because of this, you will need to run the engine for about five minutes before checking the oil. If you are not sure whether the engine has any oil or not, add a pint and then start the engine. If the oil level rises you can siphon some out. If not, add some more oil. At worst the oil will overflow, which is better then no oil ! The first Honda 750/4s used dry sump as did Triumph, BSA, Norton, Harley Davidson, Suzuki DR350s and others.

Splash Lubrication is pretty primitive. A hook, cast or bolted onto the crankshaft, dips into the oil in the sump and splashes it around the inside of the engine. This system was used on some of the first motorcycles in the early 1900s. It was also used in small Briggs and Stratton engines up until a few years ago. These engines where used on Heald motorcycle and three wheeler kits. For low speed (3600-4000 RPM), side valve engines, this was a very workable system. I've seen these little engines run, quite happily, for 1000 hours and more if you keep the oil level up. These are pretty much fazed out now, but you will still run into one now and then.

Lastly we have Total Loss lubrication. This was used on motorcycles back in the early 1900s. Early motorcycle engines had plain babbet bearings or roller and needle bearings or a combination of both. Oil, oilpumps, babbet and everything else were all kind of new back then and not as good of quality as we have today. Because of this, high output engines used roller and needle bearings. The engines had hand pumps on their oil tanks. When you started the engine you gave 'er a shot of oil. Every so many miles you would give the engine another stroke of the pump. The engine used up the oil and got more clean, fresh oil to the bearings with each stroke of the pump. The engines had sumps and these where filled with oil to start with and splash lubrication took care of the rest of the engine. This gave lots of clean, fresh oil always going through the engine. Sometimes the engines had a Drip feed Lubricator, in addition to the hand pump. One pump of oil every eight to ten miles at 20 MPH was deemed sufficient. At 30 MPH you needed one pump every five or six miles. The Drip Feed should be set at 8 drops per minute, just in case you wanted to know. I don't think you will run into too many of these machines !

There are four types of oil pumps. At least that's all I've found so far ! Now Harley did have a "Vane" type oilpump, but it gave way to the gear type back in the 1950s or so. A bit before my time !

1. Gear Oil Pumps Closely meshed gears, in a housing pump the oil. Used on early Hondas, BSAs, Harley Davidsons, and others.
   
   
   
2. Piston Oil Pumps A piston in a small cylinder with one way valves pumps the oil. used on Honda 160/350 twins, Triumphs, and others.
   
   
   
3. Trochoidal Oil Pumps A star shaped gear with rounded points, rotating in a special housing pumps the oil. Used on most all modern motorcycles. Harley Davidson calls these "Gerotor" oil pumps.
   
   
   
4. Centrifugal Oil Pumps Grooves cut in the camshaft bearing surface force oil up to the valves. Used on 50/70cc pushrod Hondas.

Gear, Piston, and Centrifugal have been fazed out for the most part. Most all current oil pumps are of the Trochoidal type. It seems to be the most efficient and most popular. Trochoidal pumps can be measured for wear with a feeler gauge.

"A" The clearance between the inner rotor (1) and the outer rotor (2). Should be around .002" to .006"

"B" The clearance between the outer rotor (2) and Oil Pump Housing (3). Should be around.003" to 006"

"C" The clearance between the face of the inner (1) and outer rotors (2) and the Oil Pump Cover (3). Should be around .001" to .009"

These are VERY general specs. The specs for each make of Trochoidal oilpump vary quite a bit so check your shop manual.

Honda Gold Wings are wet sump but use two oil pumps. The main engine pump and an extra pump to lubricate the clutch.

Most of these oil pumps can be removed with the engine in the frame, but you may have to remove the clutch basket to get at them. Some, like the DR350 Suzuki single have one pump on the outside of the crankcase and the other inside. It just depends on how dumb the designers where.

Oil pumps are normally very reliable, but if the engine has blown up, it's a good idea to check their screens and pump clearances in case debris has gotten into them. If the engine is a dry sump, check and clean the oil tank too.

Often, there will be restrictors in the oil passages. This is to control the oil pressure, in the engine, before or after the restrictor. Make sure you check these restrictors for gook, bits of metal, or anything that would plug them up. Also check and see where the Oil Pump Screen is. Lots of times, these screens can only be checked and cleaned with the crankcases split or the clutch cover off. Don't find out the screen is plugged after you put everything together !

Sometimes there will be an external oil line to the head, and they will brag about how easy it is to clean. Then they put the oil route up one of the cylinder studs and brag that it can't be damaged by a rock or some such thing. Seems to me it's six of one, half dozen of another. Just make sure the passages are clear !

Below are some exploded Oil Pump views for you to study and HERE are a goodly number of Oil Flow Charts, from different engines, for you to study too.

Honda 250/305 gear oil Pump	BSA Gear Oil Pump
Triumph Piston Oil Pump	Triumph Piston Oil Pump
Harley Davidson Gear Oil Pump	Honda 160 Twin Piston Oil Pump
Trochoidal Oil Pump	Centrifugal Oil Pump

위 자료는 미국의 Dan's motorcycle 이라는  바이크 리스토어숍 사이트에서 퍼온글입니다.  각 바이크마다 기본적인 엔진구조는 비슷하나  할리의 엔진구조는 좀독특하죠,  지금이야 현대화 되었지만 에보모델만 하더라도 기본구조는 1936년에 나온 너클헤드의 엔진구조와 거의 비슷합니다. 특히 윤활장치는 거의 같습니다. 지금까지도 할리사가 복잡하고 거추장 스럽고 비용이 많이드는

드라이섬프를 고집하는 이유는 클래식한면도 있지만, 항공기처럼 오랜시간 작동시켜도 확실한 냉각,윤활효과 때문에 이방식을 쓰지 않나생각됩니다. v-rod는 다른바이크처럼 웨트 섬프지만, 그래서 별개의 할리로 쳐주는지.. 그럼 좋은 참조 바랍니다.

각 그림을 클릭하면 화면이 확대되고 빨간단어를 클릭하면 사진이 크게 나옵니다. 한번씩 클릭해보시시 바랍니다.

좀 기계용어가 있다보니 잘 이해않가시는점  계시면 댓글로 달아주세요, 적당히 의역해서 알려 드리겠습니다.

참고로, 에보까지의 빅트인 할리는 위사진의 Gear Oil Pump 를 사용했지만  트윈캠 부터는 일제하고 같은 Trochoidal OilPump(geroter)를 사용하고 있습니다. 트윈캠서 첨으로 사용해서 그런지 초기 트윈캠 모델의 Oil pump 가 좀 문제가 있었다고 합니다.

[와이드맨]

좋은 정보 감사합니다.

[Nostalgia]

뭘요, 와이드님 잘계시죠? 할리의 핵심은 엔진인데 현대의 엔진하고 좀 틀린 구형엔진이다보니, 할리엔진에 궁금하신분들 위해서 올렸습니다. 앞으로 가끔 올리겟습니다.

[풍선]

정말 감사합니다. 기막힌 우연이네요... 궁금했던 내용이라 요즘 여기 저기 검색하고 있더 중이었거든요... 한가지 여쭙겠습니다. 다이나, 투어링은 소프테일이나 스포스터 처럼 별도의 오일탱크가 없습니다. 크랭크케이스쪽에 오일을 넣기에 Wet Sump로 생각했었는데... V-Rod이외의 할리가 모두 Dry sump 방식이라면, 다이나, 투어링 계열도 크랭크 케이스 근처에 독립된 오일 탱크가 있는 것인가요 ?

[풍선]

그랬었군요... 별도의 탱크가 있었군요... 조만간에 Maintenance Manual 하나 구해서 미션과 엔진 얼개 공부 좀 해야겠습니다 ㅠㅠ... 감사합니다 !!!

[Nostalgia]

예, 풍선님 오늘날 드라이 섬프방식의 피스턴 엔진은 거의 찿아보기 힘들죠, 바이크에선 아마 할리가 이젠 마지막 일겁니다. 서비스메뉴얼 있으면 웬만한 정비는 스스로 할수있습니다. 할리공부 많이 되는데 값이 비쌉니다. 아시는 숍에 가셔서 카피 하시면 돈 많이 절약되실겁니다.

[풍선]

열심히 공부하겠습니다.^^

[퍼그(이두희)]

엔진 리스토어할때 ,생전처음보는 오일펌푸의 부품들이 왜그리 작은지....미국미케닉들 손도 클텐데라는 걱정아닌 걱정을 했던 기억이 생각나네요.노스텔지어님 좋은정보 감사합니다.

[Nostalgia]

ㅎ ㅎ 오일펌프는 아주 초정밀가공품이라 다른건 대만서 만들어도 이것은 아직 미국서 만들더군요 값도비싸고, 그래도 할리부품들은 크더라구요, 국산 125 오일펌프 보면 정말 작게 만들었습니다.