Author Topic: Multigrade oil in a A10 ?  (Read 1577 times)

Offline Viking

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Multigrade oil in a A10 ?
« on: 18.09. 2015 18:54 »
Do any of you run the A10 engine with multigrade oil ?
(With a propper oil filter)

Do not start the 3rd WW on the oil topic !
(I use SAE 50&40 , But is multi better ?)

Online bsa-bill

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Re: Multigrade oil in a A10 ?
« Reply #1 on: 18.09. 2015 19:35 »
yep, partly because I'm not sure which straight oils have a detergent in them- an oil filter needs some detergent in the oil to suspend and carry the bits you want the filter to catch, you lot are probably going to tell me most of them have  ;)

By multigrade I'm not talking about real fancy expensive 5w/55 gold supreme or whatever, just a bog standard 20/50 like Duchams produced all those years ago and now sold as "for older engines" at Halfords or others.
Many here do good mileages but I don't unfortunately and I change the oil start of the year so really  I doubt  it's in there long enough to do any harm even if it was capable of doing so
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Offline Beezageezauk

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Re: Multigrade oil in a A10 ?
« Reply #2 on: 18.09. 2015 20:32 »
Hi Viking, 

I travelled over 18,000 miles (30,000km) over a 5 year period on my last A10 and the engine was still sweet when I sold it.  It wasn't fitted with an oil filter and I ran it on 20/50 multigrade.  The only problem I had was trying to find 20/50 when I was riding on the continent.  I topped up a few times with 10/40.

My latest bike is an A10SR which has an in-line oil filter and has had an SRM engine upgrade by the previous owner.  I'm running this one on straight 40grade as recommended by SRM.  So far no problems and I've recently covered over 1800miles by attending the BSAOC International Rally in Denmark.

Beezageezauk.

Offline stu.andrews

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Re: Multigrade oil in a A10 ?
« Reply #3 on: 18.09. 2015 22:50 »
Do you know the history of the engine? If the oilways & sludge trap are clean then a multigrade is fine, particularly with a filter. The engine may "wet sump" more than before though. If you are unsure of the internal state of the oilways, I would not use a multigrade, even if it was only a low detergent one, as any sludge could be dislodged & carried through to vital bearings etc.
I, too, have no intention of starting another "Oil thread!"
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Offline Viking

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Re: Multigrade oil in a A10 ?
« Reply #4 on: 19.09. 2015 08:58 »
I know the history of the bike since 1993.
I striped the engine, cleaned it and shiped it to SRM for the full monty..

New timing gear, new bearings, new crank, new cam, cam followers, engine half rebored to correct 50ies tollerance. SRM oil way and bering conv.
Rebored and new hep. pist. Dyn.ball.  etc..
New SRM oil pump in 2008

Head to the cylinder head shop. Comp. Monty on that...

Done approx 10Kmiles, with sae 40 spring / autom and sae 50 sommer.
Max 1000 miles on a oil charge...

Oil tank washed each winter with diesel.

The engine is top shape...


Online Greybeard

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Re: Multigrade oil in a A10 ?
« Reply #5 on: 19.09. 2015 10:07 »
I decided on a belt and braces approach, so have cleaned the sludge trap, fitted a filter and run on straight SAE40 with oil and filter changes at 1k miles. I also check and clean the sump filter at the same time. My engine internals are standard design.

Offline a101960

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Re: Multigrade oil in a A10 ?
« Reply #6 on: 19.09. 2015 11:15 »
The Achilles heel of the A10 lubrication system (or for that matter many other bikes)seems to be the sludge trap. With the advent or modern detergent oils and the fitment of external oil filters could the sludge trap be omitted? In by gone days before efficient filtration was readily available the sludge trap was a crude but practical way of removing damaging debris from the oil, but of course it has one major flaw. Eventually it blocks up and, at best the bearings fail and, at worst catastrophic engine failure occurs. For instance I run my engine on 20/50 fully synthetic oil. You can read about the oil that I use here: http://www.fuchslubricants.com/comp-4-20w-50  Personally am very pleased with it. This oil is relatively expensive, but I work on the premise that oil is far cheaper than engine rebuilds. There are of course many people that continue to use the original spec mono grade oils for all kinds of reasons. A frequent criticism of 20/50 oil is that it causes engines to leak. That is not my experience however. This article makes for interesting reading http://www.realclassic.co.uk/techfiles/oil030319.html written by a guy that spent his entire working life in the oil industry. The general consensus seems to be that a filter should only be fitted to the  return line on our engines. The most frequently stated reason is because if the filter becomes blocked then the engine will be starved of oil. Fair enough, but isn’t that exactly what happens with the sludge trap? If the oil is changed at regular intervals I would have thought that the probability of a full flow filter becoming blocked is very unlikely. BMC A series engines used to have an in line oil filter on the delivery side that incorporated a by pass that allowed the oil to flow unfiltered if for any reason the filter became blocked. Should this happen a warning light came on indicating that the oil filter was blocked and needed attention. Quite possibly the Mini filter head could be adapted for use on a bike? Having said that I am not aware of any problem with filters blocking on car engines on a regular basis. Maybe there is a problem with a difference in oil pressure between a car and a bike. Having said that the filters used for bike applications are often sourced from  filters originally designed for use in cars, so I cannot see why there should be a problem. Maybe someone with a more technical automotive back ground could expand on this? It does seem to me that given the importance of keeping the sludge trap clear to maintain a healthy supply of oil to the engine that it is, at the very least highly inconvenient because to do this it requires a full engine strip. Of course another problem is that it impossible to monitor the state of the sludge trap to see if it requires cleaning out!
It is interesting to note that the BSA / Triumph triples were not fitted with sludge traps, ( the crankshaft design rendered this an impossibility) and that the oil filter was fitted to the delivery side. Neither was there any by pass facility provided to protect against filter blockage. Not only that, the recommended oil was 20/50. Remember that like our A10’s the engine was air cooled, and was basically a Triumph twin with an extra cylinder added on! I thought that I should just add that I change my oil at 1000 mile intervals too.

Online edboy

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Re: Multigrade oil in a A10 ?
« Reply #7 on: 19.09. 2015 22:43 »
something the triumph twin and triples have which the cheap old bsa never had was a tell tale pressure switch and red dash light which would have saved a lot of holed d/s crankcases on the new motorways. i always thought that mono oils took longer to wet sump and the engine always ran cooler. the main problem is finding where to buy it.

Online trevinoz

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Re: Multigrade oil in a A10 ?
« Reply #8 on: 20.09. 2015 01:13 »
The sludge trap can't be omitted. Even if the tube on the post 1957 models is left out, it is still a sludge trap.

Offline coater87

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Re: Multigrade oil in a A10 ?
« Reply #9 on: 20.09. 2015 02:57 »
something the triumph twin and triples have which the cheap old bsa never had was a tell tale pressure switch and red dash light which would have saved a lot of holed d/s crankcases on the new motorways. i always thought that mono oils took longer to wet sump and the engine always ran cooler. the main problem is finding where to buy it.

 Have a search around for this oil-  Maxum4 for big twins. This is formulated for older bikes, comes in straight grade and even multi-grade. I am not sure if it would be available locally to you, but there is always Amazon. *smile*
Central Wisconsin in the U.S.

Online cyclobutch

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Re: Multigrade oil in a A10 ?
« Reply #10 on: 20.09. 2015 06:25 »
I've been using this:

http://www.opieoils.co.uk/p-780-silkolene-chatsworth-sae-40-classic-vintage-monograde-mineral-engine-oil.aspx

I'm running a filter and change the oil every 1k miles - which isn't very often.
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Offline Rocket Racer

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Re: Multigrade oil in a A10 ?
« Reply #11 on: 05.10. 2015 00:14 »
https://mobiloil.com/en/motor-oils/mobil-1/mobil-1-v-twin-motorcycle-oil
While I typically run Morris monogrades, my FIL runs mobil 1 in his '74 Benelli S2 and it has the advantage of containing zinc and being suitable for clutches and gearboxes in a common oil wetsump situation.  But it is a full synthetic and I havent tried it.

I have no issue with motorcycle multigrades designed for flat tappet engines, but that would not extend to most common car multigrades built to different specifications.
I would also suspect that too light a weight oils will be more likely to wet sump.

Likewise for any engine where the state of the sludge trap is unclear would be recommending a low detergent monograde like Morris so the sludge is not dislodged and washed through the mains.
A good rider periodically checks all nuts and bolts with a spanner to see that they are tight - Instruction Manual for BSA B series, p46, para 2.
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Offline East_Coast_BSA

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Re: Multigrade oil in a A10 ?
« Reply #12 on: 05.10. 2015 03:52 »
I was advised by the guy who rebuilt my motor to use Valvoline VR1 Racing oil in 50w.  It has a high Zinc content and anti-foam properties.  I dump the oil every 1000 miles and I don't have a filter.  It seems to work good so far with minimal wet sumping and no engine leaks.  Once the weather around here starts getting cool, the bikes get parked for the winter, so a straight viscosity works fine for me.

Offline Viking

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Re: Multigrade oil in a A10 ?
« Reply #13 on: 05.10. 2015 07:34 »
I use Gulf oil, with high Zinc contend, 2400 PPM:

http://www.veterandele.dk/shop/gulf-classic-967c1.html

Change every 1000 miles of less...

Spring and autumn: SAE 40
Summer: SAE 50