(the more people that tell you this, the greater the chance that you'll just get in it and go!
)
I have an oil pressure problem on my hayabusa engine.
Here what happens:
-At start up, oil pressure seems normal. From about 20psi at idle up to around 60psi at 6,000rpm and 95psi at 10,000rpm.
-Oil pressure stays like that for about 10-15 minutes.
-Then oil pressure drops to 8-11psi at idle up to 45psi at 6,000rpm but doesn't go over 50-55psi at 10,000rpm.
-Oil pressure will stay like that for as long as I drive.
-If the car is turned off for a couple minutes (approx. 10min) then oil pressure will jump back up to 95psi at 10,000rpm. But will drop again after a
few minutes.
Do you have any idea of what can be the problem??
[Edited on 12/9/05 by darth G-F]
Sounds pretty normal to me, the oil gets thinner with temp and will cause the drop in pressure you note. As long as pressure stays above approx 40psi
when you are giving it some welly all should be well.
I'm not over familair with the busa, but what does the service manual say the min oil pressure should be?
Cheers
Paul
Sounds normal to me too, the busa does have quite low oil pressure at hot idle, something that the stock oil pump contributes to as the casing expands
so widening the seal gap on the pump impellor wheel.
Dont forget that the oil pressure shouldnt rise linearly with revs, it should reach around 50-60psi or so at around 4-6k rpm and be capped at that by
the pressure relief valve. The reason you get higher at cold oil temps is because the oil is too thick to pass through the pressure relief valve
quickly enough.
According to Bazzer's post
here
quote:
The manual says oil pressure should be between 43psi and 71psi at 3000 revs with the oil at 60degC
Most engines I have seen have been at the lower end of this scale
Generally speaking the oil will aerate more at high revs which also contributes to a lowering of pressure. Would a swirl pot & higher capacity (better positioned?) oil cooler help?
quote:
Originally posted by Kissy
Generally speaking the oil will aerate more at high revs which also contributes to a lowering of pressure. Would a swirl pot & higher capacity (better positioned?) oil cooler help?
Thicker oil won't do the trick - it won't run where you want it to when cold and will be virtually as runny as the modern multigrade. I think most people (me included) run a semi-synthetic like Rock Oil. Apparently some of the synthetics give major clutch slip (when used with a wet clutch!). My engine runs up to 100psi+ when hot/cold, but is at 20 on idle (1000rpm) when hot.
Like Kissy said, using a higher viscosity oil is not really going to help. I assume you're not dry sumped? If you're really concerned about
it then speak to someone like Mistral who might be able to advise how to raise it (one possibility is a replacement oil pump casting that doesnt
expand). Having said that, nothing you have said hints at anything out of the ordinary for a Busa or bike engines in general, foe example my R1 idles
hot at around 8-9psi and peaks at around 55psi at revs when hot. Im sure you havent run a bearing etc because you'd likely get absolutely no oil
pressure and it would be making a horrible noise.
Everyone has their own opinions on the oil debate, but in my experience (and that of several other trackday mates over the last few years) synthetics
designed for the job (ie SG rated for wet clutches such as Redline, Castrol R4 and Mobil1 4T - not normal Mobil1) are absolutely fine with bike
engines.
[Edited on 13/9/05 by ChrisGamlin]
Thanks for the info. Maybe I am a bit paranoid.
I'm using Motorcycle Motul 300V synthetic oil in the engine. It is quite possibly the best oil for that engine. It is 10W40 grade (like suggested
by Suzuki) but there is a 20W50 grade also available in the 300V line up.
The engine runs fine and makes no particular sound that might indicate a bearing failure. So like I said, I might a bit of a parano.
I'm not using a dry sump but the Koenig swivel and pan. Should be allright with as many are already using on track cars without problems.
Yep I only asked about the dry sump because with some (the 3 stage ones that dont use the bikes own pump), you can vary the pressure .
300V is marvellous stuff, and 10w40 will be absolutely fine. Mr Motul knows exactly what he's doing! You're being paranoid.....
(the more people that tell you this, the greater the chance that you'll just get in it and go! )
quote:
Originally posted by Coose
300V is marvellous stuff, and 10w40 will be absolutely fine. Mr Motul knows exactly what he's doing! You're being paranoid.....
(the more people that tell you this, the greater the chance that you'll just get in it and go!
Are 'busa on shell bearings or rollers as per the old GSX1100 (air cooled)? If they're on rollers they can run on almost zero oil pressure!
50psi should be fine for shells.....