Triumphrat

lovecuba

No, I intend leaving the return where it sits presently. Part of the experiment will be oil seepage back past the rocker spindles, how much, over what period of time (hot & cold).
As previously noted, oil will be added in stages, firstly 1 litre additional then maybe another and so on. When problems arise, i.e. oil escaping through the breather under braking then the experiment may end.

Morris the Cat

Have just recently read somewhere that the original intent for the OIF, was just that- most of the frame tube to carry oil.

Early tests showed 'frothing' and so the modified location as we now have it.

More oil volume would equal more cooling- part of the reason for the design change?

Early Yamahaha's had a counterbalencer crank that also had frothing oil problems as I recall.
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Morris of Main Street

Mr.Pete

Here's some rough estimate figures.If I'm out by a power of ten,the effect is much the same but it takes 10 times longer.

With a 6" head of oil above the spindles,say you get one drop of cold oil off each spindle every 4 seconds.Total leakage is approx 3ml/minute or 4.32 litres per day.Of course,it will be slower when you only have 3" head of oil remaining (a little over 2ml/minute total).

There will be plenty of extra oil in the crankcase when you go to start the engine.Even 500 ml extra is a lot (much exhaust smoke).

It will take about 2 minutes at 3000 rpm to lower the crankcase oil level by 500 ml.If the oil level is then correct,things will run fine until you stop and the leakage/drainage begins again.

jonkster

Just out of curiousity, does anyone know how the original plan for having the higher oil level in the frame get around leakage back through to the rockers?

Were they originally going to place the oil return line near the steering head as well as the filler?

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JohnA

Here's my thoughts for what they're worth: Extra oil capacity seems to me a definitely good thing. One of the main mods John Young carried out to his Iron Butt Rally T150 was to almost double the volume of the oil tank. His near-10,000 miles in 11 days journey was through all kinds of weather, not only desert heat but cold rainstorms. The results, in his case, seem to indicate that there was certainly no harm in increasing oil capacity and very probably quite a lot of good in it.

Whether the T140 frame has a better cooling effect on the oil or not, to have reduced the oil volume compared to pre-OIF models seems a backward step. I didn't previously realise that Triumph had intended to have the filler neck behind the steering head as per B50/TR5T etc., though it always seemed illogical not to have done so. Why they chaged this design to what we ended up with seems a bit of a mystery. The principle that increasing the oil capacity to at least what the pre OIF T120s had seems unquestionable to me.

I don't like the idea of leaving the return pipe outlet where it is, and submerging it in oil. The B50 OIFrames had the return pipe up by the filler, and a breather a little higher up (not far above the maximum oil level). I rode a B50 for over 20,000 miles and never had any problems with oil escaping from the breather, and never noticed any oil frothing. That was up to 1983, so 'modern' oils weren't available then, it was plain old Duckhams Q.

I had a T140 frame modified to have the filler by the stering head (Nick Parravani did the modification work - this included re-routing the return pipe, blanking-off the original filler neck, and adding a new filler neck and breather pipe copied directly from my B50). Unfortunately I had that frame grit blasted and stove enamelled and when I found loads of grit inside, I couldn't bring myself to risk using it and sold it. It must be out there somewhere, reg: PEX 751R if anyone knows where it is! I have a spare frame and I might well do the same thing again - I'll wait to hear what your findings are first though LoveCuba!

lovecuba

All which of course could be mitigated (during the experimental stage) by placing a small inline on/off valve or having a look around for a low pressure one way flow fitting that would also fit in the line.

RII

I was just going to suggest a one-way check valve, otherwise you will end up flooding the bottom end due to drain back.

Wouldn't suggest an "on/off" valve as we're all human and a mistake could be very painfull where oil flow is concerned.

By the way, riding here in Texas, max oil temp I have seen has been in the 170's(F), even when head temps have been over 350(F). Such a small quantity of oil at any point in time in the engine, not sure that the extra capacity will make a difference that way. Certainly will help it stay cleaner longer, but otherwise...

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redhawk4

RII, that's a pretty low oil temperature my Honda XR650L, which is oil in frame, will regularly hit 250 degrees F on 100 degree days.

RII

Thats what I thought as well, but have measured it on multiple occasions (non contact thermometer). Have an intake design I created and had 3D printed and had to know the temps before I could proceed. Only other option was for having them CNC'd, but wanted to try the printing first as proof of concept. Intake maifold temps alone exceeded 250F regularly. Head/Cyl junction has always been the hottest at 350 plus when ambient has been 100 plus.

I started monitoring oil temps as well for the same reasons mentioned in this thread: i.e. do I need to add an oil cooler or find a way to fill the neck further, etc...

Traffic here is terrible due to construction, and most of my commute has been sitting at idle in traffic (not fun all the way around). Start out sitting for around 15 minutes, get to run down the road 55-60 for about 15 (with both me and the bike a lot happier), then sit idling to 25-30mph for another 15-25 minutes depending on the day. Often the engine has been hot enough that it's not happy by the time I roll into the garage at home. Ambient temp has often been well over 100-107F, and I still only see 170's as oil temps even under these conditions. Normally I'd like to see temps over 180 just to keep the oil clean, but doesn't seem to happen.

In part, I suspect that the combination of the rapid movement of oil through the engine, the relatively short time spent there, and the 2-1 ratio of feed to return that results in air (frothing) allows the oil to shed it's thermal load rather rapidly. Add too that the large surface area of the frame tubes and the thermal mass it provides and you end up with oil temps that are surprisingly low.

Would be interested in data collected by others as well, to get a more through picture, but seems no one else has gone quite so far. Many have done the "finger test", but not much in the way of posted temps. Would be curious as to the temps of earlier (pre-OIF) tanks as well, just for comparison purposes.

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A GOOD friend will bail you out of jail, a TRUE friend is sitting on the bench next to you saying "Damn, that was fun!".

redhawk4

I'd be interested if anyone else has figures. On my XR650L I've not seen the temp go up much when idling for long periods, or in traffic, when it really spikes is when you really get on the throttle using the revs. A blast up a long incline will see it jump up. Long periods of high speed see it gradually increase mile on mile, I think what happens here is the frame heats up because of the continuous supply of hot oil so after 20 or 30 miles the heat no longer dissipates in to the frame. as before because that is now hot too, so the oil gets hotter and hotter a bit at a time. It amazes me how quickly it cools down when you stop for a few minutes. What surprised me is how little the ambient temperature affects the oil temp whether 75 degrees or 100, it doesn't make very much difference, given the same usage.