darth G-F
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| posted on 12/9/05 at 07:33 PM |
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Oil pressure problem with Hayabusa engine!!!
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]
Hayabusa powered caterham
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progers
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| posted on 12/9/05 at 07:42 PM |
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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
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ChrisGamlin
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| posted on 12/9/05 at 08:28 PM |
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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.
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ChrisGamlin
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| posted on 12/9/05 at 08:33 PM |
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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
[Edited on 12/9/05 by ChrisGamlin]
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Kissy
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| posted on 12/9/05 at 09:09 PM |
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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?
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darth G-F
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| posted on 12/9/05 at 10:29 PM |
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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?
My oil cooler is partly blocked by a coolant hose. So I might try to re-route that hose.
I also read somewhere that there is a high pressure gear that rises oil pressure a bit. So this could be a solution.
What about using thicker oil? I will give this one a try.
I am still afraid I might have a busted bearing or something. But then, wouldn't the oil pressure be low even when oil is cold?
Hayabusa powered caterham
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Kissy
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| posted on 13/9/05 at 05:49 AM |
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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.
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ChrisGamlin
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| posted on 13/9/05 at 04:59 PM |
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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]
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darth G-F
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| posted on 13/9/05 at 08:51 PM |
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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.
Hayabusa powered caterham
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ChrisGamlin
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| posted on 13/9/05 at 09:06 PM |
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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 .
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Coose
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| posted on 14/9/05 at 07:51 AM |
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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!  )
Spin 'er off Well...
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darth G-F
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| posted on 14/9/05 at 02:01 PM |
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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! )
Sure am. But if I blow the engine up, can we split the bill? Just kidding.
In fact, if I blow it, I'll finally know what was the problem. If there is one.
Hayabusa powered caterham
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Coose
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| posted on 14/9/05 at 03:17 PM |
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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.....
Spin 'er off Well...
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