Oil pressure

[Mi Infidel]

All right gurus I have a question. I've searched but I really haven't found an answer.
I had to pull my top end off because I smoked a piston 😞 and I checked my piston oilers and they are both free flowing. I am planning on replacing them with the S&S piston oilers.
I have the Fueling oil pump on the stock cam plate with a Fueling pressure relief spring using Fueling .543 cams.
At idle when warm the bike has 25ish pounds of oil pressure so wouldn't this cause the piston oilers to be open all the time anyway? Should I go back to the stock oil pressure relief spring? Maybe I'm not understanding how the oil system works...
Thank you for your help!

Pic for fun and your viewing pleasure.

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[Ohio HD]

Yes, the oilers would be open all of the time. At idle that may be more than the oil pump can pull back from the crank, but I don't know that for sure. I guess it depends on how long you idle.

I recently tested some S&S oiler jets for Twin Cam. What I saw was they started dripping oil just after 10psi, and were completely open at 18psi. The test I made was using 20w-50.


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[RoadKingKohn]

All right gurus I have a question. I've searched but I really haven't found an answer.
I had to pull my top end off because I smoked a piston 😞 and I checked my piston oilers and they are both free flowing. I am planning on replacing them with the S&S piston oilers.
I have the Fueling oil pump on the stock cam plate with a Fueling pressure relief spring using Fueling .543 cams.
At idle when warm the bike has 25ish pounds of oil pressure so wouldn't this cause the piston oilers to be open all the time anyway? Should I go back to the stock oil pressure relief spring? Maybe I'm not understanding how the oil system works...
Thank you for your help!

Pic for fun and your viewing pleasure.

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I have three suggestions.

Replace your valve seals.

Replace the umbrella valve/flapper in the heads.

Install an intake breather.

[Mi Infidel]

All three were done. Those pistons have less than 1500 miles on them. I also enlarged the oil drain return holes in the rocker boxes and upgraded the oil pump.
My question is if the piston oilers are going to be opened all the time because the oil pressure at idle is above 20# is there a point in even replacing them? Should I just put the stock pressure relief spring in? I would assume that this is pretty common for anyone that has installed a Baisley (or aftermarket) pressure relief spring. It seems like there must be a lot of bikes out there that are pushing oil through the piston oilers at idle because upgrading the spring was pretty popular whenever someone opened up the cam chest.

[rigidthumper]

Are you thinking the seized piston was caused by the oil pressure?
Looks like it got hot, or fit too tight.

[kd]

Are you thinking the seized piston was caused by the oil pressure?
Looks like it got hot, or fit too tight.

 

When I look at the piston skirts (mostly the good one on the left) I don't see any amber staining below the rings,  That tells me the rings have seated well.  If you are concerned that the piston oilers are causing the carbon buildup (which to me looks excessive for 1500 miles), It isn't likely to be related to the oilers.

I run the Baisley spring in my 120.  It idles above 40# and runs 60# on the road until it gets hot several miles later.  It never dips to that 10# range.  I have endoscope pictures where I can read the piston numbers after thousands of miles.  I do use a catch can system. 

[Mi Infidel]

I probably shouldn't have posted the pic for this question. I was mainly curious about the piston oilers and oil pressure. It sounds like for bikes with higher oil pressure the oilers are going to be squirting all the time. If that's the case then I'm wondering
A is there a reason to replace them if they are open all the time and
B should we be trying to lower the oil pressure by putting a stock spring back in the pressure bypass
I had a massive sumping issue right after I put the 98" kit on it last year. I forgot to align the oil pump. I believe that is what the carbon build up is from on the top of the pistons. I could be wrong and I'm always willing to learn. The heads were 2006+ and practically new take offs when I put them on at the same time I did the 98" kit.

[JSD]

I run the fueling race pump and R&R camplate no issues sumping 01 fxst 107" 

[60Gunner]

I know you know this but that is a God awful lot of carbon build up for 1500 miles. Even for breathers going into the intake which is a bad idea. I know you know this too.
Harleys breather(umbrella) valves leave a lot to be desired as well.
Drilling the drain holes helps the oil drain away from them but doesn't fix the crap.umbrella valves.
I don't care what anyone says those umbrella valves are junk on a good day. I went to using external reed valves. There's a reason other manufacturers use them. No.one uses those stupid umbrella valves but Harley because they are cheap.
As for your question, when I had a guy from S&S put my S&S crank in he checked my oilers because they are known to be an issue at times. Mine were good and he said no need to replace the stock ones.
Take that fwiw.
Also, I wouldn't increase oil pressure without increasing scavenging. A 3 stage pump is worth the peace of mind of never having a sumping issue. There are only two 3 stage pumps. Dan Thayer's and S&S. Oil pressure is adjustable on these too.
I'm not sure why anyone going with an aftermarket pump wouldn't go to a 3 stage with 2 scavenge ports but that's just me I guess.

[Geezer_Glider]

Would second the professional advice, don't worry about the oilers running at idle. Ran a modified 103 for 75K miles that never went below 15psi at idle, never a problem, stock pump and plate with extra pressure on the relief spring.
R Meyer

[Mi Infidel]

Thanks guys. 
I finally got the breather situation straightened out and vented externally. I also have a Fueling pump and all seems good on that now. I will double check my valve stem seals just to be sure.
I have one oil jet that functions like it supposed to and one that is wide open. Unless I'm missing something I don't really see a reason to change them. Am I missing something?

[Ohio HD]

I'll take a wild guess and say the one that does shut off with over 25 psi is the same cylinder the piston cooked?

[Mi Infidel]

I'll take a wild guess and say the one that does shut off with over 25 psi is the same cylinder the piston cooked?

Yes. When I first took it off and blew air through it it was blocked. After spraying some brake cleaner and more air through it now it flows freely from 1 psi up.

[Ohio HD]

Sounds like a good enough reason to buy new oilers. It may very well stick again, and cause the same damage.

[FXDBI]

Thanks guys.
I finally got the breather situation straightened out and vented externally. I also have a Fueling pump and all seems good on that now. I will double check my valve stem seals just to be sure.
I have one oil jet that functions like it supposed to and one that is wide open. Unless I'm missing something I don't really see a reason to change them. Am I missing something?

If it was okay to be stuck wide open why dont they come that way from the factory. You will continue to have engine problems if thats your standard of craftsmanship. You have to be surgically clean doing engine work.  Bob

[Mi Infidel]

Thanks guys.
I finally got the breather situation straightened out and vented externally. I also have a Fueling pump and all seems good on that now. I will double check my valve stem seals just to be sure.
I have one oil jet that functions like it supposed to and one that is wide open. Unless I'm missing something I don't really see a reason to change them. Am I missing something?

If it was okay to be stuck wide open why dont they come that way from the factory. You will continue to have engine problems if thats your standard of craftsmanship. You have to be surgically clean doing engine work.  Bob

The failure rate on the factory oilers is fairly high from everything I've seen. I believe it was Kevin from Baxters Garage on YouTube that tested 8 sets of oilers and four of them were open. I don't know if the spring wears out or what but he said it's common for him to test them and they flow freely or with very little pressure.
My question is if the oilers open at 12-18 pounds and my bike (and a lot of bikes with aftermarket oil pumps and or cam plates) has 20-25 pounds of oil pressure at idle then the oilers are always open and is there a reason to replace them? Sure it's a failure of the check valve (which again seems common) but even a new oiler will be open all the time because of the higher idle oil pressure. Hopefully that makes sense.

[Ohio HD]

I run no more than 6 to 7 psi at idle with a warmed up motor and oil. As soon as you twist the throttle to move the bike you go over 10 psi and the oilers start releasing oil to the cylinders. At a cruising speed I have about 35 to 37 psi adjusted with the S&S cam plate. At higher RPM I see around 45 to 50 psi.

Starting out with a known failed part is just asking for more trouble. But you can do that, just don't expect anyone here to agree that it's a good practice.

[FSG]

Starting out with a known failed part is just asking for more trouble. But you can do that, just don't expect anyone here to agree that it's a good practice.

ain't that the truth   

[Mi Infidel]

I already have the S&S oilers ordered. I don't think I'm explaining myself very well. It seems to me we could gut the factory oilers of the spring and ball and end up with the same results IF our oil pressure is above the relief spring threshold. 
My original thought was that if oil pressure is above 20# at idle and the oilers are always oiling should I be worried about it. Sumping at idle or not enough oil reaching the top end. 
Maybe I'm just thinking too much 🤔

[Hilly13]

I already have the S&S oilers ordered. I don't think I'm explaining myself very well. It seems to me we could gut the factory oilers of the spring and ball and end up with the same results IF our oil pressure is above the relief spring threshold.
My original thought was that if oil pressure is above 20# at idle and the oilers are always oiling should I be worried about it. Sumping at idle or not enough oil reaching the top end.
Maybe I'm just thinking too much 🤔

I'll have a crack at it, If for some reason your 20psi at idle dropped to below the opening threshold of the oilers the available oil would then be sent to more vital parts that don't take kindly to running dry, think of it as a safety net, like your body shutting down extremities to save the core.

[kd]

I already have the S&S oilers ordered. I don't think I'm explaining myself very well. It seems to me we could gut the factory oilers of the spring and ball and end up with the same results IF our oil pressure is above the relief spring threshold.
My original thought was that if oil pressure is above 20# at idle and the oilers are always oiling should I be worried about it. Sumping at idle or not enough oil reaching the top end.
Maybe I'm just thinking too much 🤔

I almost don't want to respond to this but I will. 

The problem with the early M8 faulty (loose) oiler mounting caused more than the metered amount of oil to escape around the oiler mounting base when running at higher rpm and pressure.  It poured in so fast that the oil pump couldn't evacuate the sump and you know the rest.  Under normal conditions only squirting the metered amount it was designed to, there were no issues.  The pump would catch up and get the oil out if you idled the engine before shutting it off. As long as your piston coolers are securely attached, don't contribute extra oil and your oil pump is functioning properly you should be OK.

[Mi Infidel]

I already have the S&S oilers ordered. I don't think I'm explaining myself very well. It seems to me we could gut the factory oilers of the spring and ball and end up with the same results IF our oil pressure is above the relief spring threshold.
My original thought was that if oil pressure is above 20# at idle and the oilers are always oiling should I be worried about it. Sumping at idle or not enough oil reaching the top end.
Maybe I'm just thinking too much 🤔

I'll have a crack at it, If for some reason your 20psi at idle dropped to below the opening threshold of the oilers the available oil would then be sent to more vital parts that don't take kindly to running dry, think of it as a safety net, like your body shutting down extremities to save the core.

This coupled with what KD said makes sense to me. As long as the oil pump is scavenging like it should and the oil pressure is above XX oil is getting to the vital areas and it doesn't matter if the oilers are always oiling because the pressure is above XX.

Thank you everyone for taking the time to help me understand this.

[nibroc]

 



this has been a good thread

[ziggy24]

All three were done. Those pistons have less than 1500 miles on them. I also enlarged the oil drain return holes in the rocker boxes and upgraded the oil pump.
My question is if the piston oilers are going to be opened all the time because the oil pressure at idle is above 20# is there a point in even replacing them? Should I just put the stock pressure relief spring in? I would assume that this is pretty common for anyone that has installed a Baisley (or aftermarket) pressure relief spring. It seems like there must be a lot of bikes out there that are pushing oil through the piston oilers at idle because upgrading the spring was pretty popular whenever someone opened up the cam chest.

All three were done. Those pistons have less than 1500 miles on them. I also enlarged the oil drain return holes in the rocker boxes and upgraded the oil pump.
My question is if the piston oilers are going to be opened all the time because the oil pressure at idle is above 20# is there a point in even replacing them? Should I just put the stock pressure relief spring in? I would assume that this is pretty common for anyone that has installed a Baisley (or aftermarket) pressure relief spring. It seems like there must be a lot of bikes out there that are pushing oil through the piston oilers at idle because upgrading the spring was pretty popular whenever someone opened up the cam chest.

 Not for nothing, but adding a higher pressure spring does nothing at idle. If the pump cant make pressure the spring will never open. The spring only works to allow higher pressures when the pump is capable of doing so.

[OldBogie]

If those pistons are photoed in front to rear order the back which runs hotter than the front is out of skirt to wall clearance, if it's the front cylinder's piston this could be a cold seizure. This mostly a cold weather thing where running hot, hard  and fast then snapping the throttle closed like on a fairly long coast the front cylinder chills faster than the hot piston inside and things run out of skirt clearance. Either way a hot or chilled seizure is begging for more skirt to wall clearance.

The crowns of those pistons are really carboned! This could be over fueling or it's pulling oil from somewhere. With a high pressure pump this could be the rings can't keep up with wiping the cylinder walls so oil is getting into the combustion space. Or it could be passing the valve guides which can be the seals are shot and or the guide to stem clearance is too loose. Generally too much oil getting past the guides is more an intake valve problem because the intake port always sees vacuum. However, there can be more damage done on the exhaust side as this side sees hot gas pressure that tends to blow the lube, what little there is, out of the stem clearance drying this out thus increasing the wear rate to the point that oil gets down the guide in opposition to hot gasses up flow.

Bogie