Hi guys. I'm working on Triumph TR5T right now and am interested in Return Oil modification which is listed on www.b50.org. I have a question about the mods. Most of people do the same way as the return oil mods on www.b50.org but just wondering why nobody connects the oil return hose with the oil drain plug under the seat? Any info would be appreciated!
I had seen that page some years ago. Maybe I read it wrong but connecting the rear drain outlet (which I bet rarely gets used) to the oil outlet unfiltered might be a problem unless great lengths have been made to remove all the gunge that collects at the rear portion. On my first TR5T it took a bare frame and a good amount of time (weeks) to clean the internals but it might have had one oil change since new!
The drain plug (bolt) is around 5/16" ? so any fitting is going to have a very small bore I would think.
Re: BSA B50 return oil modification
[Re: Les P]
#592960 04/01/159:15 am04/01/159:15 am
I've already removed all the gunge at the rear portion and cleaned the inside of the frame. It took about a week to clean the internals as you said:cry Have you done the mods on your TR5T?
If the gunge would be the problem, I think the return oil mods would be the problem too because I think the oil with a lot of gunge might go to oil feed hose from the rear drain anyway? The common oil filter can't be used at feed side,right?
The rear drain plug is 3/8". The oil return pipe brazed behind the oil inlet is 5/16" and the ID of the pipe is around 1/4". The 3/8 brake fitting has around 1/8" bore but I think the bore can be bigger to 7/32". Too small to return the oil? But the oil pump hole is around 3/16" which I think is quite small too.
I did two mods as per: a) I made a fitting to screw into the drain plug. I then connected this via a small fuel filter to a tee with the two other connections from the tee coming from the front down tube and going into the crankcase. b) I fitted a B25 type filter into the return line. HTH
"Did you feel any improvements after two mods?" No--none at all--except for an increase in peace of mind ---in that I believe that the modified system is better than the original and might be what BSA would have done if they did not have cost constraints. HTH
Connecting the return hose to the rear drain plug will soon turn your oil to foam. You need to vent the air from the oil, trying to do that in the oil makes a mess.
Connecting the front and rear of the frame does work nice. Shame BSA didn't see fit to do this modification.
Excellent point Rich. I had never considered foaming but it would be like blowing bubbles with a straw in the bottom of a soda, I have done the same mod as you, teeing the rear drain and the downtube drain just before the infeed. Also put a spin on filter on the return with a tee to feed the rockerbox.
I'm not sure but a lot of oil might go to the rocker boxes when the return hose is connected to the rear drain. Because the bore of the fitting for the rear drain is too small so the small bore could restrict return oil flow too much. What do you guys think?
What do I think? DO NOT connect the return line to the rear drain. Why not?---bore too small, you will be blowing bubbles into the oil reservoir and designers of oil tanks went to some lengths to allow the air to separate from the oil--you don't want to be putting more air into the oil. My views: a) Connect the drain at the rear via a small (e.g. gas filter) to a tee with the feed from the front down tube and then feed into the engine. b) Put a filter into the return line (just like the B25s) and plumb in the rocker feed line after the filter (between the filter and the oil tank). This gives the same pressure balance and so the same oil flow to the rockers as standard. Just my 2 centsworth. HTH
I have never used the rear drain for an oil return. But, that question comes up from time to time on this board. It is a bad idea.....
The stock return does have a restriction built into it at the filler me k to provide back pressure to lube the rockers. I have run rocker feed from before and after a return line filter and have never had a problem either way. I prefer to feed the rockers after the filter, I like clean oil going to my engine parts.
Someday, maybe, I am going to do the conversion to feed the rockers off the pressure side. Or not.......
For my own stuff, I don't put any filter between the rear tank drain and engine oil feed. Start with a clean frame and use a return line filter and you should be good to go. but that is just me.
"Start with a clean frame " is the operative phrase. Other posters have mentioned the difficulty of getting the frame clean at the back near the drain. OK to use different methods if you have a bare frame but if the bike is fully assembled and you are just doing the mods mentioned then it is common sense I believe to put a small filter between the drain pipe (now feed) and the engine. A small fuel filter is fine--it doesn't matter how little oil goes down this route--whatever does is that much more than the standard set up. Just my 2 centsworth.
By unfiltered I was meaning as stock, a (low restriction) gauze filter to remove the 'big bits. That comes back to the problem of it being hard to fit a element filter into the pressure side of the oil pump.
To some degree it comes back to the lay out, OIF or separate oil tank and a dry sump. At some point any particles and or combustion contamination needs to settle somewhere based on non detergent oil use. The only way to avoid that might be a detergent oil but there is no filter to collect the debris now in suspension so if not done already the first thing to be addressed is a element filter in the return line before trying to tap into a possibly contaminated access point. Just my thoughts on the matter.
Yes 3/8" for some reason I thought it was smaller.
I have done the same mod as you, teeing the rear drain and the downtube drain just before the infeed. Also put a spin on filter on the return with a tee to feed the rockerbox.
Did you use the oil filter between rear drain and the tee before the infeed? It is not needed because of the spin on filter on return?
Machico, Below is a description of the filter and piping changes. It is not a good idea to place a filter on the infeed side. Gear pumps do not generate a lot of suction and you might unknowing starve the engine for oil. Most people I have talked with install a filter on the return side similar to below where the pressure of the scavenge gears forces the oil thru the filter. You can tee off to the rockers before or after the filter. I chose after and there is no shortage of oil going to the top end.
B50 Oil Filter and piping changes
I mounted a canister type oil filter (HD style)to my B50 The perfect place is to weld a small 1" x 3/16ths flat plate, approximately 2Ē long to the back of the two brackets that provide the rear engine mounts. The new mounting plate, which now connects the two engine mounting brackets, is located about 1Ē above the lower mounting bolt holes. I took the brackets off and made some spacers out of plastic pipe so the bracket would be the correct width when they are joined by welding as described above. I drilled the two holes to mount the HD type filter housing to the now joined mounting brackets. I mounted the filter housing with Allen caps screws as regular hex head are hard to get a socket on them. Now you have an oil filter that has it's inlet and outlet right next to the lines coming from the sump. It is vertical so you can spin off the filter and not cover your driveway with oil and it its out of the way of the swing arm. When piping up the filter, you need to be careful so you don't flood (or starve) the top end. You need to plug that rocker outlet on the bottom of the engine and install a Tee after the filter so that the top end is not overfed. Iím afraid that if you donít put in the Tee, the head will get more and more flow of unfiltered oil as the filter backpressure increases. The above arrangement is very clean and neat. When changing oil ALWAYS remember to fill up the filter before screwing it on. I also remove my plugs and kick over motor by foot until I see oil returning to the tank and I also use a piece of clear hose going to the rockers so I can see the oil going up there. This prevents a dry startup.
On the Tee, I used a brass female tee with 1/8th-inch pipe threads in all three connections. On the inlet side from the filter output I screwed in a 3/8ths brass barbed fitting that matches up with the 3/8ths outlet from the HD filter. On the tee to the top end I screwed in a 1/8th barbed fitting to match the top end feed. The straight through outlet to the tank is 5/16ths and you use a 5/16ths-barbed fitting. All these parts I found in the plumbing section of a Lowes Home Improvement Center.
Next I removed the drain plug from the rear part of the upper frame member. Using a brake line fitting available at any automotive parts supply house, I screwed the brake line fitting into the drain plug hole after cutting off the steel brake line at about one inch. Using 5/16ths hose I routed the hose down to the sump manifold and using a brass tee with 5/16ths barbed fitting on all three ends, I connected the feed hose from the front frame down member to the new line I then installed and connected the tee with a 2 inch piece of hose to the sump. Now the oil feeds the pump from both the original feed and from the rear of the frame. This will eliminate that large pocket of uncirculated oil that stays stagnant in the rear of the frame.
Filters are from an early eighties HD filter and are also manufactured my EMGO and are available from JC Whitney mail order or automotive parts suppliers. The mounting manifold with filter can be bought from ED Valiket. You donít need the mounting bracket that comes with it.
I was thinking of using the oil filter between the drain plug and the Tee as tridentman said. As Les P said, I was thinking that the low restriction filter which is same as the filter at down tube might be good idea because it's a suction side so I thought the same filter as the down tube filter affects anything.
But if the inside of the frame is totally clean and the spin on filter is fitted on return side, I'm thinking the oil filter would not be needed on feed side.
Thank you so much for the details. Appreciate it.　It's very helpful to know.I decided I won't connect the return hose to the drain plug.
The inside of the frame is perfectly clean now. I checked the inside endoscopically. I'll use the oil filter on return side and connect the rear drain plug to the feed side with tee. I'll be careful not to flood the top end.
Machico, I think you will find that the oiling system works very well. When you reassemble your top end (assuming it is apart) take care to ensure that the mating surfaces of the rocker boxes are flat and smooth. The B50 rocker box is prone to leak. Ed V sells a very nice gasket that is well worth the money. Also, you may consider replacing the rocker studs with helicoils and bolts so that the rocker box can be removed without removing the engine. I removed my rocker box many times trying to cure leaks. Good luck with your bike. A well tuned B50 with a sprocket change for roadwork will eat up the roads with the best of period bikes.
Sorry Nachico, My one track mind kept thinking B50. While your Triumph shared a lot of the BSA parts when they went OIF it was a different engine, but the frame was pretty much BSA. Don't see too many of those bikes around here.