nortonspeed said:
This argument will confuse the anti-wet-sump-valve hater :twisted:
I don't think it should, unless they just want to hate.
I'm not suggesting that a valve is or isn't the answer, just that oil delivery is important, especially avoiding delays in delivery time at start-up.
I've not made any suggestions in my post above, but don't mind wading into the fray with my very limited knowledge - certainly hasn't stopped many, many others in the past. :lol:
My original '73 Commando never had a problem with wet-sumping so fortunately, I never had to deal with it back in 73-76. So, why do we have this issue now? I don't know, but the opinion that a worn oil pump is the cause would seem to make some sense and, if that is the case, it would be pretty short-sighted to install a valve rather than fix the problem. After-all, one would think a worn oil pump would have a reduced ability to circulate it's designed volume. I don't know how much of a reduction would occur, nor do I know how much of a safety margin was built into the design for a properly working pump, but those are concerns that I would have.
Whenever one treats the symptom rather than the cause (outside of a triage situation) they run the risk of finding that they have stuck their head in the sand and when they pull it out - there are often bigger problems than when they put it in.
To me a valve might be a reasonable answer, but only if I felt comfortable that the worn pump (if that were the culprit) was circulating sufficient oil.
However, there are a few things that would be absolute musts for me, as it doesn't make sense to make things less reliable and go backwards.
1) Whatever is used, it's "fail mode" must not result in - no delivery of oil - it's fail mode should be wet-sumping (far less dangerous than no oil delivery at all)
2) The system must be simple to use (or it might not always be used)
3) It has to be automatic or virtually automatic and have
real safe-guards built-in (everyone gets distracted)
hobot said:
Duh * its mainly the cam/lifters that scuff at start up and low speeds so my reasoning is a cerntain amount of wet sump to instantly splash lobes before the ZADP nano layer gets wiped off is desirable. I don't know but think if all the oil ends up in cases there's still enough oil in crank to sling out for the big ends protection til a few seconds later oil from tank being fed full force as rest of wet sump empties. If a factory Combat or a comnoz style low down sump vents the first piston disent will send a slug of oil back to the tank rather faster than can be pumped out or of tank or pumped back out of cases. Yoose guys with pressure guages, How long does it take for the needle to move after kick off? On this subject how long before its best to hit cam surfing rpm? Before or after wet sump cleared? This can take a couple dozen seconds or more below 2grand. Its the function of ZADP to protect on start ups and shut downs and idle times below cam surfing and of course low oil pressure from turns that uncover the tank drain, not much a Commando issue. Most thoughtful solution I've seen was a tap in TS cover that set wet sump level by over flow into catch can then drain closed and can added back, if significant. Not likely to forget to close the obvious leak at hand but can imagine forgetingaboutit til trying to lean a fast corner.
I agree hobot,
ZDDP gives great protection and the very low revs help significantly, however:
- First, one has to be using a ZDDP high oil to really benefit and
- Second, and most important, I am at all not sure that it is anywhere near an
"instantly splash lobes" situation.
My feeling/concern is that there is
way too long a gap in delivery time to be healthy.
Remember that the system is designed to deliver oil to the valve-train first specifically because
it is important and vulnerable. A "wet-sumped" dry-sump system virtually reverses this and delivers oil to the valve-train last. Not only that, I also have a concern that the cavitation that occurs from the wet-sumping only exacerbates the situation as that means, not only is the valve-train the last to get oiled but it is then receiving the greatest concentration of cavitated oil. Not good at all. Remember, there would be virtually no oil btween the return area up to the tank and down to the pump. That means that entire volume of air will be pumped until there is oil. I don't think there is anywhere prior to the valve-train for the air to escape from the oil system. So for me, the delay in delivery time of any oil compounded by the additional delay until non-cavitated oil is delivered is of concern.
+1, +1 Tim - the fact that it was a Norton design doesn't make it right or beneficial, just makes it OE.
lwmcd1 said:
Would resurfacing the oil pump help? Isn't a worn pump the main cause of sumping?
That is my question/concern. It would certainly appear to be the culprit and therefore I would only avoid rectifying that situation if I felt comfortable that the compromised pump was a) originally over-designed sufficiently to still deliver enough oil to be safe, and b) had a way of verifying and monitoring.
Isn't it less expensive and simpler to rebuild an oil pump than install the valve and oil-flow rate monitoring and then have to constantly monitor it? Installing the valve
does not increase a reduced oil flow from the pump, it only eliminates the lag-time caused by a worn pump. That could, perhaps, be equally or even more dangerous.
Identify and fix the cause, not the symptom.
