The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => A7 & A10 Engine => Topic started by: stu.andrews on 23.03. 2012 16:43
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I am about to become the owner of a rebuilt A7, 1962. The bottom end of the engine is all new. In the garage I have a large quantity of semi synthetic 20/50 oil. After the engine has been run in, would this oil be suitable, taking into account the type of bearings used?
I know oil is always subject to opinions & debate, but any suggestions would be appreciated.
Thank you.
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Don't see why not.
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Stu,
Welcome to the forum and glad you could join us. We look forward to some pictures of your bike. Usually a little initial introduction is appreciated in your first post, as noted under Forum Info as:
For the 1st post, please start with an introduction post in Bikes, Pictures & Members, appreciated by all.
As for synthetic oil, I'll leave that to those more knowledgeable in that area.
Richard L.
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Thanks, Guys, any more info about the use of semi synthetic would be appreciated.
Have now introduced myself. Sorry, blotted my copybook already!
Stu
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Semi synthetic should be a good oil. 20W/50 is a suitable grade.
If I can use synthetic in a Triumph, why can't you use semi in a BSA?
If it wet sumps faster or some such, stop using it.
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Just as long as you remember that it will have to be changed just as often as regular oil.
In reality the actual oil you use is no where as important as the length of time it is in there.
So if you have a lot semi-synthetic then go ahead & use it.
All my cars, vans & bikes get 20w50 and none have blown up yet.
Keeps things simple and I use enough to buy it in 44's so it is really cheap.
As it is really cheap I can justify doing the vans every month and the beesas just about every time I take them out.
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It will be looked after with regular oil changes etc, have no fear. Oil's cheaper than engines!
Stu
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It's odds on that it will wet sump more since when sitting in your garage the oil viscosity is going to be lower. It does on mine.
The next thing to remember is that the semi synthetic oil ideally needs to run through a proper filter just like in your car on the way back to the oil tank e.g. in the tool box like I and many others have done, since it's a detergent oil and will clean and collect more 'stuff' from inside the engine, more so than the usual classic type oils, which you don't want recirculated. Alternatively change the oil more frequently, but clean out the oil tank thoroughly each time you do.
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since it's a detergent oil and will clean and collect more 'stuff' from inside the engine
So hopefully this newly rebuilt engine will have had its sludge trap cleaned out? :!
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Yes, the sludge trap has been cleaned. I am familiar with the fact that S/S oil has detergent properties so, without a filter, will need to be changed often. I was a little more concerned about having S/S oil as I have heard, perhaps wrongly, that it can cause roller & ball "skid" in bearings, namely the drive side. No problem with the timing side as this is, as you know, a plain bearing. Might stick to straight old fashioned 20/50 & change often.
Thanks for your help.
Stu
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Just to add an alternative view.
The advice from my reconditioner was to use single viscosity non deterent oil. The logic is that deterent oil is used to carry particles in suspension to a paper filter for it to be taken out. As there is no paper filter in the system the oil carries the particles around accelerating engine wear. He also advised not to fit a paper filter as the standard oil pump is not designed for it.
He advised using single viscosity non deterent oil with a magnetic drain plug and change the oil more often.
Stu
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Just to add an alternative view.
The advice from my reconditioner was to use single viscosity non deterent oil. The logic is that deterent oil is used to carry particles in suspension to a paper filter for it to be taken out. As there is no paper filter in the system the oil carries the particles around accelerating engine wear. He also advised not to fit a paper filter as the standard oil pump is not designed for it.
He advised using single viscosity non deterent oil with a magnetic drain plug and change the oil more often.
Stu
Many would say your reconditioner is badly wrong in his advice. What terrible thing does he think a filter does to the pump that is "not designed for it?"
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What terrible thing does he think a filter does to the pump that is "not designed for it?"
Yes I agree with Triton Thrasher, seems like people sometimes forget what the original design holds, I have not measured the return pressure in any way but have a sneaking suspicion the hole in the top of the return pipe in the oil tank might restrict oil flow (as BSA intended) as much as a filter does.
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The only time I have seen an oil filter in the return line give a oil pump a problem was on a B40, cure was a recondition of the oil pump as it was badly worn and as soon as it seen the new larger back pressure it gave up and wet sumped. Its ran fine ever since with the oil filter.