Oil feed, pressure gauge and threads

[Berticus]

I am rebuilding my 850 engine after an episode with a broken con rod. The rocker oil feed lines are looking a bit tatty and I thought about replacing them but then had an idea about making up my own. I could also connect up a pressure gauge to check the oil pressure. I still don't know why the con rod snapped - I don't think it was a lack of oil but I'd like the reassurance when it is running. Anyway, the point is if I use a double banjo bolt I could temporarily connect a pressure gauge. I don't really want to permanently fit it. Anyway, I'm not very good at identifying threads so could anyone tell me what are the standard banjo bolt thread sizes and is there a supplier of suitable bolts, hoses and connectors that I can make up myself? I could make up a new hose for the front brake to match at the same time if anyone knows the connections I need for that as well. Thanks.

[Jeandr]

The threads for the banjo bolts are 5/16" at 22tpi. You could run a single oil line to the right side of the head, drill the intake rocker shafts and put the pressure gauge on the left side of the head either temporarrily and block the hole with a suitable plug or permanently. I wonder if a small oil pressure gauge could be screwed in that hole There are some kits to mount the gauge on the handlebars, they would fit right in.

Jean

[gtsun]

I think any good hose place should have what you need. You can buy all the fittings, bolts, banjos ferrals and hose to make your own from oldbritts.com Or have what you want made. They also have a nice oil pressure Gage set up if you want.

[DogT]

You can also use the old banjos with the nylon hose, if that is what you have now. Get some Nylon 11 in the correct size, hold the pipe with a flaring tool and beat the banjo fitting back into the pipe with a rubber or hide mallet, WITHOUT HEAT. Believe me, I have done it upon the recommendation of DynoDave. The line is also known as diesel air brake line. The only place I have found it is at MSC, but am told some NAPA stores carry it. It is quite inexpensive and you don't need any hose clamps. However if you want stainless lines, it only comes in black and clear.

Dave
69S

[ludwig]

Agree with DogT . A line made like this will last forever .
If you don't have a flaring tool : take a small block of wood , drill a 6mm hole and cut in half .
Make shure the banjo goes in straight : that it doesn't cut in the wall of the line .
Berticus : we are only 20 km apart .
If you want , I'll be happy to make one for you .

[Diamondjet]

I have two questions for DogT. What is nylon 11 and what does MSC stand for? I would like to try this idea but don't understand what those two references are too. Thanks.

[DogT]

Nylon 11 is a nylon type tubing. MSC is an industrial supply house. Google will get you there as well as:

http://www1.mscdirect.com part# 74203753

Dave
69S

[RennieK]

Here is a simple method of running an oil pressure gage. The only additional plumbing required was a T fitting, another foot of tubing and the gage fitting that probably came with the gage. The yellow line was an air hose that was very hard and difficult to slip over the fittings and thicker than stock. You can see the T fitting above the ground strap on the head steady. It went straight to the gage from the pump and the other outlet went to the right side double banjo on the head. The other end of the double banjo came back across to the left side rocker feed just as is stock. This allowed routing the feed between the carbs and more centrally which I also preferred. I kept a close eye on the line for the 1st while and eventually forgot about it. It has lasted 30 years although the last 25 have been storage but it was still full of oil. This line had ID markings printed on the outside when new but there is no trace of them now.

[Per G]

The threads for the banjo bolts are 5/16" at 22tpi. You could run a single oil line to the right side of the head, drill the intake rocker shafts and put the pressure gauge on the left side of the head either temporarrily and block the hole with a suitable plug or permanently. I wonder if a small oil pressure gauge could be screwed in that hole There are some kits to mount the gauge on the handlebars, they would fit right in.

Jean

Jean,
I did that on my bike last winter. Only one oil line up to the right hand side of the head. Fitted an oil pressure switch (from a car) on the left side . Removed the small switch in the headlight and fitted a warning light there. Connected the light to the switch. Works and looks fine

/Per

[Berticus]

Thanks, I think I will try making up some new nylon pipes. I'm still not decided about permanently fitting a pressure gauge yet. If I can find a double length banjo bolt I will make up a seperate line that I can disconnect. Fitting a gauge is a good idea but I'd rather lash something up temporarily to reassure me that I can get it back on the road and then think about longer term improvements later.

Ludwig, do you know anywhere local I could get some tubing? I haven't had a lot of joy searching the Internet.

[ludwig]

Berticus ,
deze zit in Anderlecht :
http://www.lefort.be/lefort.pdf
scroll down .

[Hortons Norton]

Per G, What kind of oil pressure switch did you use? I wanted to do the same but was worried it would be lit to often as the pressure gets low at idle. Thanks, Chuck.

[Berticus]

According the technical description on the website for the "RECTULASTIC" nylon 12 hoses the working pressure drops off very steeply after 20 degees C and is down to 2 bar at 70 degrees. Is this good enough? I thought the oil temperature was somewhere up around 100 degrees C.

[R Model Tony]

Use the proper diameter, truck, air brake, nylon tubing. I'm not at home to check the markings at the moment but it IS the ticket. Tony

[Diamondjet]

Parker NB-4-062 is an N series nylon tubing with a id of .125" and an of of approximately .25" (which is the od of my stock lines on a 1973 850). The burst pressures are 2000 psi @ 73F and working pressure of 500 psi @ 73F. Will this fit the barbettes on the rocker oil feed banjos? I've read here in the past that some say they will fit if heated first....another posted that they must be fitted cold in order to assure they don't loosen? I sure don't want to spend $100+ on this oil line when there are other parts I need.