The BSA A7-A10 Forum

Technical => A7 & A10 Engine => Topic started by: alanp on 22.10. 2009 16:50

Title: Oil pressure connection
Post by: alanp on 22.10. 2009 16:50
Anyone know enough about the area around the pressure relief valve on the timing side engine casing to enable me to tap into the supply system for connecting either an oil line or a sender unit (electric) to run an oil pressure gauge? I'm sure numerous owners have done this, I just hope they're forum contributors!
Title: Re: Oil pressure connection
Post by: A10Boy on 22.10. 2009 19:56
Ive not done this but seen it done.

If you remove the Pressure Relief Valve you can see what you are dealing with in the cases. It should be a simple operation to drill and tap a thread into the oilway behind the valve.
Title: Re: Oil pressure connection
Post by: RichardL on 22.10. 2009 20:57
I believe Nigel has done this, as mentioned in the following post. Please wait for others to confirm if this works and is a good idea, because I don't really know.

Richard L.

http://www.a7a10.net/forum/index.php/topic,1712.msg11392.html#msg11392
Title: Re: Oil pressure connection
Post by: muskrat on 23.10. 2009 13:50
G'day Alanp,
                I have done it. Drilled in from side about 3/8" from inner cover and tapped 1/8" BSP and used a oil pressure gauge kit from local auto store. Runs about 50psi cold and 20psi hot at idle. Will post a pic tomorrow.
Cheers
Title: Re: Oil pressure connection
Post by: BSA500 on 26.10. 2009 10:29
Please do post a pic and how to I have been wanting to do this to my A7 for years *smiley4*
Title: Re: Oil pressure connection
Post by: nigeldtr on 26.10. 2009 11:17
Hi,

Here are a couple of pictures of the connection. I actually drilled two holes, the first, larger hole,  was tapped for the union and the second, smaller (I think 2 mm) was drilled at an angle from the bottom of hole 1 to break through the casing below the  bottom of the release valve.

Regards

Nigel
Title: Re: Oil pressure connection
Post by: muskrat on 27.10. 2009 11:29
G'day alanp, same as Nigel but from the side, as close to the cover as possible. Be careful there isn"t much meat there. Use a good thread sealant cement as it will only be in a few threads, don"t be too heavy with the spanner.
Cheers
Title: Re: Oil pressure connection
Post by: alanp on 27.10. 2009 12:40
I think my rev counter drive is adjacent so I'll have to come in underneath.
Title: Re: Oil pressure connection
Post by: A10Boy on 27.10. 2009 19:34
Nigel

That's a very good update, I wish i had done that during my rebuild.  *smiley4*
Title: Re: Oil pressure connection
Post by: nigeldtr on 27.10. 2009 20:09
Hi Andy,

I actually did this with a hand drill while the engine was in the frames, Just took off the exhaust. I made sure I used a corse thread and as mentioned, thread sealant and only lightly nipped up the union.

I put ?pig tails? in at both ends of the copper pipe to allow it to ?move?.


Regards

Nigel
Title: Re: Oil pressure connection
Post by: alanp on 27.10. 2009 20:50
Nigel, now I'm really curious, could you clarify how you used copper pipe up to the gauge please? How did you cope with the steering lock movement by putting pigtails in the run? I was going to use flexible plastic tube because I didn't think the copper would survive the frequent steering movement and copper loops would not have looked very neat. The next point is that, based on various sources of gauges and fittings, it looked like the thread to tap into the casing needed to be 1/8" NPTF-27tpi., so I have the tap ready. Am I missing something here? Thanks. Alan.
Title: Re: Oil pressure connection
Post by: BSA500 on 29.10. 2009 08:54
A couple of questions...
1.What is the adaptor called that screws into the crankcases so I can source one(difficult to do if you are unsure of the correct term).
2.Who sells the above
3.What sizes/thread forms are aviable as I have whitworth/bsf and ba taps.
Demon Tweeks sell made up pipes out of plastic flexi pipe with the fittings you specify for around £7.

Andy
Title: Re: Oil pressure connection
Post by: alanp on 29.10. 2009 11:51
Andy, take a look at www.holden.co.uk, they have a section with diagrams to show the parts you need. Actually, you need to start with the type of gauge you are going to use e.g. pipes connecting to Smiths gauges have a flat collar end and a gasket ring to seal with the gauge, others have cones etc. So, having decided on the pipe end fitting you need you can select the pipe and the adaptor to fit into your crank case. I'm going to use 1/8" nptf-27tpi in the case and got the tap and tapping drill (letter Q) from ebay. Personally, I think Smiths gauges with chrome outer ring, black faces and white lettering look best on classic bikes to match the Smiths speedo/rev counter, but watch out as far as I can see at the moment, new gauges described as Smiths don't always have Smiths marked on the face, so I bought an old one on ebay (cheaper by a long way as well).  I'm a way off working on the engine yet, still sorting out the RGS cycle parts, but in preparation I'm looking for info. on where to tap into the oil supply on this post subject. I've almost sorted it out with help from this forum.
Title: Re: Oil pressure connection
Post by: muskrat on 29.10. 2009 12:51
G'day alanp, if you take the OPR valve out you will see it has two threaded sections seperated by a groove with holes. this is where the oil goes when the valve lifts. You need to break into the gallery before the OPR valve. Measure from the washer to the gauze of the OPRV and add a mm. thats where your hole should end up. Measure on the outside from the face that distance (side or under) & drill 2mm hole into the gallery. Measure the depth of hole and subtract 2mm. Drill tapping size to that depth. Tap thread. Most kits are 1/8" nptf nipple and use an olive fitting for the tube.
I am about to re-modify mine with a 1/8" bsp m/fm elbow to bring the tube facing forward. Male nptf will screw into a bsp loosely so use lots of sealer/cement.
hope this helps
Cheers
Title: Re: Oil pressure connection
Post by: alanp on 29.10. 2009 16:06
Muskrat, yours will be ok with the elbow because you don't have the rev counter drive to stop you going in on the horizontal whereas I have to go in underneath and couldn't 'swing' an elbow around to clear the side of the casing...I think..
I saw one where the owner had somehow screwed an adaptor underneath into the casing and then used a banjo fitting which gave him the freedom to position the banjo outlet to get the pipe horizontal and facing forwards without having to worry about swinging the 90deg elbow around. I can't for the life of me find the bits to do this i.e. a banjo that can take the usual type of gauge pipe ends (yet). Thanks for your interest and keep us posted on any further thoughts. Cheers mate, Alan.
Title: Re: Oil pressure connection
Post by: chaterlea25 on 29.10. 2009 21:16
Hi All,
Regarding flexible pipe and banjo connections for the oil pressure tapping
I would look at stainless braided piping and fittings,
 These brakepipe fittings come in all shapes and sizes
I dont know how the flexible brake pipe would work with the higher temperature
involved with the engine side of the setup
If you have an SRM type conversion a tapping can be made where the pipe is pressed in
and welded over,
Just my ?0.02 thoughts
Regards
John O R
Title: Re: Oil pressure connection
Post by: nigeldtr on 29.10. 2009 22:25
Hi Alanp,

I play a lot with model steam locomotives so I have a lot of copper pipe and fittings kicking around. Probably the stiff hydraulic plastic pipe is better but just need to take care with the exhaust. I mounted the pressure gauge on a bracket which was fixed to the petrol tank front mounting and is actually just below the top yoke so there is no "twisting" I can see the gauge by leaning forward a little, please see the pictures.

Regards

Nigel
Title: Re: Oil pressure connection
Post by: nigeldtr on 29.10. 2009 22:27
Sorry one of the above pictures was incorrectly added - please see below.

Nigel
Title: Re: Oil pressure connection
Post by: alanp on 30.10. 2009 14:12
Thanks for the help on this one gentlemen.
I've just taken the timing side covers off and I think that the engine has had an SRM conversion. It appears to have a needle main bearing and the oil supply to the crank appears to come from the pump through a tube in the inner timing side casing (with small o rings either side of the casing) to the outer and then up to an oil seal which sits in the outer and feeds oil into a tube in the end of the crank shaft. If this isn't an SRM conversion, perhaps someone can tell me, I've never seen one? If it has been done on this engine it would have been about 9 years ago (2 owners back from me) and I don't know if the SRM have altered the design of their conversion since then.

However, JOHN, I can't see where ..'the pipe is pressed in and welded over'. Can you give me more idea of where this is please? Is this the small tube which I mentioned above which goes through the inner casing?

It does seem that, for those of us with a rev counter drive taken from the oil pump which blocks off access to the nice convenient flat face at the side of the pressure relief valve area (as used by lucky Muskrat), we could either come in at 6 o'clock under the PRV, (like Nigel) or into the casing flange just below the PRV breaking into the oil hole feeding up to the PRV from the pump. I'll check on casing thickesses to decide on the optimum approach.
Alan.
Title: Re: Oil pressure connection
Post by: A10Boy on 30.10. 2009 14:50
Alan

From What you describe, that is indeed a Divimead / SRM conversion - lucky you!  *smile*  You can find many happy hours of reading in the forum on that subject. [use the search facility].

If I discovered I had a Needle Roller conversion, I would re-consider fitting an oil pressure gauge. Obviously its all about confidence in the engine, and the SRM conversion would give me that confidence assuming the engine is in good condition, but thats a personal choice.
Title: Re: Oil pressure connection
Post by: chaterlea25 on 30.10. 2009 17:48
HI Alan,
Yes that sounds like an SRM conversion, there should be a job number engraved on the inside of the casings,
If you follow the line of the pressed in pipe towards the front of the crankcase it should be possible to find the spot where it was drilled, not easy as their guy is a seriously good welder!!!!
You can also drill into the outer cover and through the welded in block to the oilway going to the crank, even though now knowing you have an SRM bottom end I wouldn't
bother

Cheers
John O R
Title: Re: Oil pressure connection
Post by: alanp on 30.10. 2009 20:18
I've found a good supplier for oil pressure pipes and fittings it's www.speedograph-richfield.com. They're in the UK and if you get onto their site and select Instrument Fittings all will be revealed. Don't be put off by the very long lengths of made up piping they list since if you call them you'll find that they will make up whatever pipe length you want. As a result my plan is - 1/8"npt-27 thread in the casing flange, adaptor in the casing with a Smiths type male outer end, copper pipe with Smiths type connections on both ends from this casing adaptor up to an adaptor in the frame area at the front/behind the tank, from this adaptor to a flexible pipe which will feed around the steering head to the gauge mounted between the speedo and rev counter, all with Smiths type connections.
Well, those are the parts I've ordered, so I hope the plan works out.
Again, thanks to all those who contributed to my enlightenment!