Heavy duty oil pump?
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Road Warrior
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Heavy duty oil pump?
Im an old ironhead and shovelhead man and I know the pumps on those old scoots moved a lot of volume with not a lot of pressure. Are the stock oil pumps on twin cams the same? I am finding out I like running straight 50 wt oil and until I put about 20 miles on the bike, it tends to rattle a tad. Not bad but you do hear it. Once the oil is hot the skoot is quiet and better than any thing else I have ever tried. Im wondering if a heavier pump will flow more when the oil is cold. Just wondering. I didn't change it when I did cams and tensioners and am looking for something to do over the up coming winter months.
randy
randy
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From: Honah Lee
You need to under stand the relationship of your two terms. At a set 1000 rpm of idle at and with 20W-50 , a TC oil pump will put out a volume of oil with the pressure relief valve of 35 lb so the 18 set relief setting of the oil injectors do not open. Oil pressure will be apx 8-12lbs. This keeps from cooking oil at idle. On up thru rpm, as volume builds, the relief opens at 35 dumping excess.excess so you do not push oil past seals.
Resistance make pressure and cuts volume. Your older design would make pressure if you put resistance in it.
Roller bearings do not need a lot of pressure to get oil around say like car motors that need enough pressure to get to last lubrication point.
The old sporties are like your design. Over a period of years they had a relief flow valve in five different areas. All it served was to hold enough pressure so oil light did not come on at idle. Think you have this. That valve gets worn and oilpressure light comes on at idle causing all kinds of aggravation when oiling is fine
Resistance make pressure and cuts volume. Your older design would make pressure if you put resistance in it.
Roller bearings do not need a lot of pressure to get oil around say like car motors that need enough pressure to get to last lubrication point.
The old sporties are like your design. Over a period of years they had a relief flow valve in five different areas. All it served was to hold enough pressure so oil light did not come on at idle. Think you have this. That valve gets worn and oilpressure light comes on at idle causing all kinds of aggravation when oiling is fine
Last edited by Jackie Paper; Aug 19, 2018 at 04:08 PM.
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From: Cape Cod
Ok then, guess you're not on the Gulf Coast.........50W in Canada in my opinion is WAY too high(too thick). YMMV.........
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Road Warrior
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Well to answer a couple questions, my oil light doesn't come on even at idle and I have had a pressure gauge put on it and it is per spec. As far as being in Canada, I have always run 20w50 and as per the owners manual I decided to try 50 straight. Its just an observation I am seeing with this twin cam. With the iron and shovelheads, those bikes were quiet until the oil heated up then then sounded like a typewriter. The twincam is the exact opposite. A little valve train noise until the oil is hot and then it quiets down. I was trying to understand why and thought perhaps a heavier pump, since when many do their tensioners its a suggestion. Bike runs fine and doesn't burn any oil. 2003 RKC, 42,000 Km.
randy
randy
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From: Honah Lee
TC is a very close tolerance motor for air cooled Piston to cylinder has only a few thousands of and inch tolerance with Teflon patch pistons.
The noise you do hear when warmed up is the clearance of steel to steel roller bearing. They are noisy as compared to sleeve bearing engines.
You do not need to fix that with more or thicker oil.
The noise you do hear when warmed up is the clearance of steel to steel roller bearing. They are noisy as compared to sleeve bearing engines.
You do not need to fix that with more or thicker oil.
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From: along the shore of Mishigami
Many on this forum are swearing the use of dino 20W50 oil over Syn. oils due to an alleged thinning of syn. oil at operating temps. Something else of noted interest, HD has an improved oil pump flow and pressure with their hybrid cam plate and standard in newer bikes. Maybe the mother ship saw something coming down the road, who knows.
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Joe Kucinski
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From: British Columbia
cajun1957a ; 50 weight is just fine for your bike in the summer months in your geographic location and climate; 20W50 simply acts thinner at the lower end temperature. I too note that my twin can runs quieter with straight 50 weight in July and August months. Same scenario as yours. As a lot of folks who have never spent time riding in Canad, we get temperatures in the 100 to 110 F range. Litton B,C, and southern Ontario experiences high 80 to 90 F frequently during the summer months. Do what you're doing. You'll be fine.
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Im an old ironhead and shovelhead man and I know the pumps on those old scoots moved a lot of volume with not a lot of pressure. Are the stock oil pumps on twin cams the same? I am finding out I like running straight 50 wt oil and until I put about 20 miles on the bike, it tends to rattle a tad. Not bad but you do hear it. Once the oil is hot the skoot is quiet and better than any thing else I have ever tried. Im wondering if a heavier pump will flow more when the oil is cold. Just wondering. I didn't change it when I did cams and tensioners and am looking for something to do over the up coming winter months.
randy
randy
Fug I don't know if straight 50 works in a Twinky but now you do.
Cheers man..