• Welcome to the forum website of the Vincent H.R.D. Owners Club.

    Should you have any questions relating to the Vincent H.R.D. Owners Club, or Vincent H.R.D. motorcycles in general, please contact Graham Smith, Online Forum Webmaster by calling 07977 001 025 or please CLICK HERE.

    You are unrecognised, and therefore, only have VERY restricted access to the many features of this forum website.

    If you have previously registered to use this forum website, you should log in now. CLICK HERE.

    If you have never registered to use this forum website before, please CLICK HERE.

Twin Oil Consumption - What's Yours?

Robert Watson

Well Known and Active Forum Website User
VOC Member
Two up with luggage all over Europe last fall, 5700 miles, added one litre, changed it when I got home, probably could have used another 1/2 litre if it didn't need changing.
 

Tom Gaynor

Well Known and Active Forum Website User
VOC Member
If I don't use a catch bottle, about 300 mpp. If I do, upwards - I don't know exactly - of 800 mpp (because I empty the bottle back into the oil tank). I have a two-start pump (not advised) and over 70 mph oil is dumped from the breather. Pistons are new as are valves and (sealed) guides. Or if not new, not very old.

Robert: I can't remember what kind of breather the Mammoth has....
 

Robert Watson

Well Known and Active Forum Website User
VOC Member
Robert: I can't remember what kind of breather the Mammoth has....[/QUOTE said:
It is basically a stock timed breather, except the exit pipe goes over the banjo instead of inside it, so is more like 7/16 instead of 5/16 tubing. The secret is stopping the source - Round Bores, Honda Chrome rings (as expensive as the pistons), no blowby, no crankcase pressure to speak of, mostly standard breather works fine, leaves a little puddle of "milk" if left idling after a good run. I think I'm up to about 40-50K miles on that set of pistons and crank, and by the way that's @ 9.4:1 compression.
 

clevtrev

Well Known and Active Forum Website User
VOC Member
It is basically a stock timed breather, except the exit pipe goes over the banjo instead of inside it, so is more like 7/16 instead of 5/16 tubing. The secret is stopping the source - Round Bores, Honda Chrome rings (as expensive as the pistons), no blowby, no crankcase pressure to speak of, mostly standard breather works fine, leaves a little puddle of "milk" if left idling after a good run. I think I'm up to about 40-50K miles on that set of pistons and crank, and by the way that's @ 9.4:1 compression.
Your rollers on the crank pin, will now be 1 1/2 thou small. So do a check now. Save you a lot if the pin and eye is good, no reason for it not to be, re-roller, and do another 40,000.
 

Tom Gaynor

Well Known and Active Forum Website User
VOC Member
My system is more or less the same.
Single-start pump? If yes, I think that's the difference. The standard breather (or series D variations thereon) has enough oil / gas separation capacity to deal with a single start, but not with a twin start. The advantage of a neffalump's trunk (seems to me) is not its breathability, but its much greater capacity to get the oil out of the air. Pity that it 1) looks hideous and that 2) I don't have an enclosed D...
I remain silent on "Ray of Comfort" Southwell's comment...
All that said, I have a great deal of sympathy with Roy's remarks. 500 mpp is OK by me, but a catch bottle is useful so I know how much I burn, and how much I dump. And if I keep recycling the stuff by tipping the contents of the bottle back to whence it came, sooner or later I'll get a Nobel Prize for saving the planet.

It is basically a stock timed breather, except the exit pipe goes over the banjo instead of inside it, so is more like 7/16 instead of 5/16 tubing. The secret is stopping the source - Round Bores, Honda Chrome rings (as expensive as the pistons), no blowby, no crankcase pressure to speak of, mostly standard breather works fine, leaves a little puddle of "milk" if left idling after a good run. I think I'm up to about 40-50K miles on that set of pistons and crank, and by the way that's @ 9.4:1 compression.
 

Tony Cording

Well Known and Active Forum Website User
VOC Member
Not sure what the negative is about a two start pump. I run a two start on the prettiest twin in the West, same basic engine refinements as Robert has mentioned, except 8 - 1, and like Robert only have a milky puddle exiting the breather at the end of a run. 600 miles with a minimal top up.

Tony
 

Howard

Well Known and Active Forum Website User
VOC Member
I have no idea how many miles per pint-provided there's some left when I check it before the next outing!

Thanks Roy. I haven't a clue either, I was beginning to think I was ill treating my engine.
I check oil regularly, and top up if required. I don't do as many miles as I'd like, or as far as I'd like, so mpp is probably less important to me than it used to be.

H
 
Warning! This thread is more than 11yrs ago old.
It's likely that no further discussion is required, in which case we recommend starting a new thread. If however you feel your response is required you can still do so.
Top