Triumphrat

lovecuba

Quite wrong really! The cappilliary hose is a lot smaller diameter than the breather pipe, hence the name, cappilliary!!!!!!! It actually fits inside the breather pipe with plenty of room to spare to allow displaced air to escape.

Another ridiculous theory disposed off! And as for the raincoat, well the mind boggles!!!!!!!!!!

johnquinnell

Lovecuba, I certainly will never claim to be an expert on Meriden twins but I will admit to being a thinker & question asker to better understand things in my own head.
From what I can understand, you are looking to maximize the oil storage capacity of an OIF frame by filling the frame with oil right to the top near the steering head?
Are you concerned that the oil pump may not have sufficient capacity to push against the additional head of oil?
I don't know if you've had the pleasure of removing the oil filler cap with the engine idling and watched the oil pump returning the oil scavenged from the sump back to the top oil level near the filler cap? The flow and pressure on idle isn't what you'd call brilliant?
I suppose you never know until you try something little out of the ordinary?

meriden4ever

Adding an oil cooler , like the period Lockhart fitted to my TR65 (to Ministry of Defence spec) and TR7T (to my own spec), helps in crease oil capacity as well as cool the oil itself ! I found that with the trail/low geared TR7T, oil would burn up quicker than on the taller geared TSS-AV and TSX so I did what the MoD had for their TR65 and found and fitted a NOS Lockhart- really worth it !.

Snakeoil

I missed that you are running a smaller tube up inside the breather. I agree that no pressurization will take place in with that method.

Instead of a cooler, which previous posts would indicate would not be required for these engines, why not just plumb in an extra tank and connect as if it were an oil cooler? This would negate any additional head pressure since it would be below the level of the return line. Although I think the amount of added head will be nil for the angled backbone. I would think if anything, the added head, as slight as it might be, would help the pump on the suction side, since it's been reported that these pumps don't suck as well as they pump.

Don't like my raincoat, huh? It's something you wish you had when a hydraulic line lets go. Trust me on that one.

Better make sure the original fill cap seals well. And you might put a piece of tape over it with DO NOT OPEN on it. Because if you don't, you know one of your mates is gonna open up that cap to smell your oil or something one day when your back is turned. You might still want to keep that tarp on the floor.

regards,
Rob

lovecuba

Hi John, I do not believe that the extra head caused by the addition of 1-2 litres of oil will impact on the scavenge pipe outlet. The oil pump is of the piston variety and thus provides a 'positive' and solid flow. I would have more concern in respect to strain on the pump if the scavenge side had to feed both an after market oil filter and force oil through a front mounted radiator. Although, many on this forum have no problem whatsoever with that arrangement. The reason why the flow from the scavenge pipe is intermittant and slow is that the scavenge side of the pump has a lot more capacity than the pressure side. This is evidenced by the relative diameters of the pump pistons where it can be seen that the scavenge piston has a 12.3mm and the pressure side 10.3mm.
Just to further prove the point, try to hold your finger against the outlet of the pipe with engine idleing and cold, this will give you an indication of the force inherent in the pump.

Yes Rob, will ensure there is no accidental opening of the sealed filler cap.

Speaking of the filler cap, it has been suggested by a Mate that I drill and tap into the filler cap a pressure oil filler. A bit like a grease nipple and designed to feed oil into tanks where there is no access at the head. A standard grease gun, with an adapter for the oil nipple fitted, can then be used to feed in the additional oil. Hmmmmmmmmmm !

redhawk4

Did this ever happen? was there ever a final answer?

Marc Beaudry

but...WHY ? to what advantage ? is an extra litre or two of oil an improvement ? it's not necessary. it never ceases to amaze me what lenghs people will go to to achieve - nothing. the oif , like the earlier units - holds sufficient oil . if you're really all that concerned about it - keep a litre of oil in your sadlle bag -

redhawk4

I think the fact that the new frame ended up with 1 1/2 pints less capacity than the previous oil tank model and this was obviously not how it was originally designed to be, holds a certain fascination and intrigue for many. Norman Hyde who was a design engineer working on the T140's original development team is quoted in an article in Classic Bike from 1999 as saying the oil filler was moved at the last minute because of fears of it being confused with the petrol filler. He seemed to see the reduced oil capacity as a negative in terms of the quantity and the oil temperature implications. There's nothing like telling someone they can't have something to make them want it. It does seem in general that motors with large oil capacities seem to last longer. If the top part of the frame was filled with oil it would no doubt keep oil temperatures down in hot conditions which could certainly be beneficial, although it may well not be necessary. It would also give more head of oil for the oil pump which could be beneficial if using a Charlies type filter. A benefit that's often quoted of using an oil cooler and a return filter is increasing oil capacity, so there are many who have a concern about the reduced capacity, whether that is real or imagined.

From my perspective, I'm just curious to see how the setup would have worked as originally designed. I've read of people moving the filler back to the neck of the frame on Flat Tracker builds etc. but never heard how it actually worked for anyone.

mike1976

on my 76 bonneville i to was drawn in to oil capacity issue. and am still not resolved to answer. but i did install both a trident type oil filter and a old style lockhart vertical oil cooler on the right side frame down tube. in my case what ever capacity i have gained is a plus as bike uses a bit of oil. bike runs strong so new rings as well as a valve job will be later then sooner. during cold weather i run a homemade leather cover on the cooler.

lovecuba

This re-build is taking quite some time (engine still to be assembled) but yes, in due course will report back on the adding of two extra litres of oil into the frame tank as I still intend having a go at it.