SRM oil pump

[metalflake11]

I'm going back into the sea Bill!

[a101960]

Isn't an end feed conversion the brainchild of the B.S.A. race department? If so, they did design A10 engines that way. The name Les Mason rings a bell here.

The crankshaft end feed conversion was indeed a product of the BSA race department. The conversion was pioneered by Les Mason and Chris Vincent whom, no doubt, many of you will remember had great success racing a BSA in sidecar events. Les Mason was the proprietor of Devimead. Les traded from shop in Stafford after BSA closed down in 1972. When Devimead decided to discontinue doing the conversions and retire, SRM took over the "intellectual property" to the timing side bush/bearing job from Devimead some time in the 1980s. In fact if I remember correctly SRM traded for a while as Devimead (Devimead (BSA) Ltd). So, the end feed oil feed conversion can be traced back directly to BSA. BSA of course as we all know did not officially go racing, but they did have a competition department and that was where the development was done. If Bert Hopwood can be believed many developments were vetoed by the BSA managment not on technical merit, but on the grounds of cost. No doubt that explains why the modification was never adopted for over the counter production models.
John

[nimrod650]

oil is cheaper than metal 

[Rocket Racer]

On this side of the planet there is no SRM warranty, they didnt fit the product and cannot see how we fitted it or treated it.
Having blown our dough on a high volume high priced item, we have no doubt also flushed the sludge traps so can run the best oil available or whatever we fancy as long as we keep it clean.
Both my A10's run return filters, my B33 doesnt as it doesnt have fragile plain bearings.
Both my A10's also run end fed bearing conversions.

If I'd got my bike rebuilt by SRM I would follow their warranty conditions for the duration of that warranty, but thats never going to apply to me, so I make my own decisions with the best advice I can find from the forum and mates.

I'm probably the only person running both my A10's on Castor but hey thats just so I can readily swap out the motors if I want to.

[muskrat]

RR, so your running Castor so you can drop some methanol in the roady? 
Cheers

[Rocket Racer]

I love the smell of castor and methanol in the morning

[Butch (cb)]

I love the smell of castor and methanol in the morning

Now that surely is the smell of victory.

[bikerboy]

To be honest most of the old brit bikes I see dont need a filter the oil does not stay in them long enough to get dirty :)

[ellis]

Speak for yourself bikerboy. My A10 is leak free so that's why I run a cartridge filter and change the oil annually. Penrite classic light oil 20w-60 with high zinc levels.   

[Rocket Racer]

I think Bikerboy was actually saying A7/A10 owners are more likely to change their oils religiously (twice a year) rather than casting aspersions about prolific leaking as distinct from territorial marking.
If a bike has regular changes so clean fluids and a clean sludge trap then filters are not necessary even though many of us prefer and recommend them.



 

[Sandy]

Once upon a time in the dim and distant past I was gainfully employed in the buying dept of a local engineering firm, part of my job being to see visiting reps. At the time I was running a vintage bike (not BSA) as well as my Shooting Star, and multi grade oils had not long appeared on the market. (Told you it was a long time ago!) A pal had just changed from Castrol Grand Prix sae 50 to a certain brand of green 20-50, leading to the almost immediate and spectacular demise of his Star Twin's bottom half. This led to shall we say some thought, and when a suitable Oil Company rep appeared, I proceeded to pick his brains. His advice was thus; "Multi-grade oil, say 20-50, is essentially a 20 grade oil with things called VI improvers added. These stop the oil thinning out as much as it would otherwise. Unfortunately, due to the temperatures and pressures in these old engines, the VI improvers rapidly break down, leaving you with basically an SAE20 oil, which the clearances in these old engines are unable to tolerate."  His advice was to use a monograde oil, for preferance one formulated for diesel engines, as these operate at much higher loadings than a petrol engine. This I proceeded to do with my A7SS, on which I subsequently covered 90,000 miles in 6 years. The vintage bike got fed something a bit cheaper, being a total loss system. As a matter of interest, I found out some years later that Volkswagen and Porsche made the same recommendation for their air cooled engines. Might answer queries as to SRM's oil spec.

[worntorn]

This is from the 1960 BSA A series Instruction Manual, back when oils where just starting to become a bit multi in grade. What do we see there but a recommendation to use very early Multi-grade oil from Esso?
Glen

[Rocket Racer]

A while back i rebuilt a mini engine for my sins and as part of that the oil pump is considered a consumable and replaced (cheap as chips) as a matter of course, because they suck up unfiltered oil from the sump so wear, the oil is then pressure filtered before it hits the main bearings.
Now if we don't want dirty oil (particularly with multigrades) taking these particles into our mains, the easiest options we have are to firstly keep the oil tank clean as, then to fit a filter on the return line. This does mean crud goes through the return circuit of the pump but is kept away from the mains.

If SRM have a recommendation for monogrades and oil changes, then yes the filter is largely unnecessary.

Trying to avoid the "oil thread" direction, personally I would not run multigrades on any crank I hadn't personally cleaned first, as a switch from a straight 50 to say a 20/50 opens the risk (however remote) of washing through any sludge and trashing the bottom end.

But I do like return line filters as they are better than relying on a bit of gauze.
I guess what we really need is a window in the timing cover so we can still look at that rather expensive blue device pumping the engines lifeblood    rather than it being hidden away...

[Rocket Racer]

the following taken from Roland Pike http://beezagent.blogspot.co.nz/2009_02_01_archive.html
"Oil Pumps.The BSA gear type pump is very simple and reliable, at one time we did some tests by simply running a pump on a drill press in a can of oil and measuring the temperature of the oil, we were surprised at how quickly the temperature rose especially as there was not resistance to the flow. On examination of the pump we decided that some oil was being compressed between the two gears, accordingly a small bypass was cut in the cover plate allowing oil to feed back to the inlet side of the pump. Further testing showed practically no heat build up in the oil. Some tests were carried out on A7 (using various viscosity oils, starting with 50 wt and coming down to 40 wt to 30 wt, 20 wt SAE 10 and finally 5 wt. We discovered that normal oil pressure was maintained on the SAE 10 50 wt, 40 wt and 30 wt. At SAE 20 viscosity pressure tended to drop particularly when hot. The engine was stripped at this point to see if the low pressure caused any bearing problems, everything looked pretty good. At SAE 10 wt pressure seemed very low in fact when hot was nil a further examination of the bearings and pistons showed no sign of trouble but the cam followers did not look too happy, starting to score."

[shuswapkev]

 I installed a spin on on a 51 motor.. I reckon it works well...I tapped into the elbow on the infeed to the filter and ran that line to the rockerbox....
my filter is the one that fits a Toyota v8 diesel 2015...and likely a thousand others.
did a bit of investigating,  as I was wondering about pressures and whatevers...turns out the filter is supposed to bypass most of the oil on startup...cold oil....and high pressure  (and high rpm) ....and really only designed to filter about 20% of the volume....
the reason for the weak bypass is likely the design of a car engine...the oil is directed to  (or around ) the filter before it gets to the crank and other shiny bits...where my BSA has it on the return line...
i.m pretty happy with it...this old lump has lasted likely 3 times longer than it was ever designed for.... and likely to be oiling the roads for another 50 years