loafersmate
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posted on 27/10/03 at 08:33 AM |
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Warning
I thought I'd go out for a blat round my local 20 mile 'circuit' on friday evening. Imagine my suprise when I got home to find a
trail of oil behind be and a pool forming under the engine!! After about 30 mins inspection I found that the T piece I had put into the oil pressure
switch tapping had sheared most of the way through and was held on by about 1/3 of a thread.........not good. I was using a T so that I had an oil
pressure switch and a pressure sender, but the pressure sender was faulty and the hole was blanked off at the time. I can only summise that the offset
load of the oil pressure sender (telemetrix type) on the T was too much for the 1/8 BSP thread and it let go (even though the sender wasn't
fitted at the time!) So anyone who has a similar setup beware. I still haven't dared starting it although the low oil pressure light
didn't come on and there is a tiny bit of oil on the dipstick when it is screwed in.
Ben
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Jasper
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posted on 27/10/03 at 10:07 AM |
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I hope it's all ok.
I was advised by Digidash to fit the oil pressure sender (due to it's size and weight) onto the chassis and use a piece of high pressure braided
hose to connect it to the block. So no vibration/breakage problems.
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loafersmate
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posted on 27/10/03 at 01:03 PM |
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I think oil pressure senders off to the bin and I'll live with just the switch as on the bike!
Ben
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ChrisGamlin
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posted on 27/10/03 at 10:57 PM |
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I would just use a pressure gauge if I were you, preferably one with a tell-tale warning light that you can set to a reasonable pressure. The standard
pressure light is pretty much useless as it often comes in at such a low pressure (about 5psi) that by the time it comes on, the engine is quite often
screwed anyway. My 'blade pressure light never came on until the whole contents of the sump had been dropped (drain plug fell out) and by that
time the engine was on its way out as it had run a big-end, so now Ive got an SPA gauge with a warning light that comes on at about 3bar when Im on
track.
Chris
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loafersmate
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posted on 28/10/03 at 08:06 AM |
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I've got a 1 bar switch in at the moment anyway, with a 3 bar light it must be on all the time below about 4000rpm??!!
Ben
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ChrisGamlin
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posted on 28/10/03 at 01:14 PM |
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Yeh it is, but then Im not worried about oil pressure below that sort of revs when on track. At 3 bar its only ever on when i am sitting in the pit
lane (and I can see from the gauge it still has pressure), once out on track it never drops below about 4 bar, so if the light comes on I know I have
a problem straight away.
On the road I knock it down to about 2 bar, then it'll only ever come on when idling, again at this time its easy to check with the gauge that
all is OK.
The ideal scenario is similar to that used on the Digidash etc, whereby you program in limits above certain revs, for example only flash a warning if
the pressure is below 3 bar when revs are above 4k.
Chris
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Jasper
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posted on 28/10/03 at 02:18 PM |
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Still comes in when larging it around a corner and you get oil surge though! (that's even with a baffle plate)
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Alan B
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posted on 28/10/03 at 02:43 PM |
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Yep, sounds like classic fatigue.....vibration causing cyclic loading.....screw threads causing a natural stress raiser....
Glad you caught it in time....timely warning for all of us....
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ChrisGamlin
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posted on 28/10/03 at 03:59 PM |
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Mine sits rock solid at about 5.5 bar even in long sweepers, are you getting a bit of surge then Jasper?
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Jasper
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posted on 28/10/03 at 04:21 PM |
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The pressure sender has a gauge and switch, and it's the switch side that comes on sometimes when cornering heavily - though I can't
remember what it alarms at.
Spoke to the chaps at ETB and they said not to worry, as long as the oil pressure gauge reads ok after the corner, which it does, then it will be
fine. So far it's only done this at Donny.
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ChrisGamlin
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posted on 28/10/03 at 05:15 PM |
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Jasper, you can set your pressure warnings up as I described above, to only allow it to warn you below a certain pressure and above a certain rpm. Do
you know what parameters yours is set up to at the moment, it could be that they arent set properly for your engine?
Really you shouldnt get any deviation in pressure right throughout the corner assuming static revs, and ETB simply saying "well as long as it
goes back to normal afterwards" is a bit naive.
Chris
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Peteff
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posted on 28/10/03 at 09:32 PM |
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A lot of bikes are fitted with oil level warning lights and not pressure warning lights or are you fitting your own aftermarket kit?.
yours, Pete.
yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
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Stu16v
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posted on 28/10/03 at 11:41 PM |
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quote:
Really you shouldnt get any deviation in pressure right throughout the corner assuming static revs, and ETB simply saying "well as long as it
goes back to normal afterwards" is a bit naive.
I agree. A slight 'wibble' in pressure mid corner is effectively a slug of air in the oil gallerys, which means no oil to crucial bits,
even though it is only for a split second....
Dont just build it.....make it!
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ChrisGamlin
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posted on 29/10/03 at 09:55 AM |
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quote: Originally posted by Peteff
A lot of bikes are fitted with oil level warning lights and not pressure warning lights or are you fitting your own aftermarket kit?.
yours, Pete.
Pete, they geneally arent oil level warning lights, they are oil pressure warning lights, although the R1 engine does have an oil level sender which
you could link up to something like a Digidash to report the amount of oil in the engine.
Chris
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loafersmate
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posted on 30/10/03 at 08:24 AM |
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I guess the gods were looking down on me the other day, I only needed just over 1 litre to fill the sump to top of
dipstick.................phew
Chris, where did you get your SPA guage from??
Cheers
Ben
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ChrisGamlin
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posted on 30/10/03 at 10:06 AM |
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Sounds like you were lucky, you obviously didnt loose all the oil so hopefully you should have escaped!
I go the SPA gauge from Rally Design I think, but most of the usual suppliers (Tweaks etc) stock them. Mine is a dual oil pressure/ oil temperature
gauge, with and oil pressure sender connected into the engine where the oil pressure switch used to be (albeit via a 10" long piece of Aeroquip
hose to protect the gauge from vibraton), and the temperature gauge mounted directly in the sump pan.
Chris
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