peterrosey Posted December 8, 2002 Share Posted December 8, 2002 Recently checked the dry sump belt on my Megabusa (Westfield's dry sump kit) and found the belt to be slacker than usual. On closer inspection the sheet metal bracket supporting the dry sump pump had fatigued around the weld at the oil filter end and around the front end. The only thing holding the pump in place were a couple of M8 bolts and the oil pipes themselves. And if the belt had come off... bye bye engine. Check yours now guys and keep an eye on them. I'm going to get a new bracket off Westfield and them reinforce it with extra steel. Quote Link to comment Share on other sites More sharing options...
luke.duke Posted December 10, 2002 Share Posted December 10, 2002 same problem in my Megabusa after 1500 km. Regards. Luca. Quote Link to comment Share on other sites More sharing options...
Nick Algar - Competition Secretary Posted December 11, 2002 Share Posted December 11, 2002 Thanks Peter, Will check my'n this weekend. Nick Quote Link to comment Share on other sites More sharing options...
samcooke Posted December 11, 2002 Share Posted December 11, 2002 Recently checked the dry sump belt on my Megabusa It's terrible that a part should fail so early in it's life. Saved. Quote Link to comment Share on other sites More sharing options...
peterrosey Posted December 13, 2002 Author Share Posted December 13, 2002 Ahem... warranty, warranty... But anyway the pump bracket had gone before that, I just didn't look that closely until later. Quote Link to comment Share on other sites More sharing options...
legin Posted December 23, 2002 Share Posted December 23, 2002 Whilst we are on the subject of failed dry sump, I too have experienced the failed bracket problem. Fixed it (for now) by welding two new brackets back to back. The next problem however is fatigue failure of the M10 bolt holding the drive cog to the crank - this is an unusual thread size. I have bought a box full and change out every 1000 track miles. Mine failed and I lost the oil, fortunately I spotted the oil light I fitted the day before ! A big job if it fails, 10m mins if it hasnt. I have now wired a relay into the oil circuit with a start override. No oil pressure then engine stops. Quote Link to comment Share on other sites More sharing options...
Nick M Posted December 23, 2002 Share Posted December 23, 2002 legin, While the oil pressure over-ride is, in principle, a good idea, some things to be careful of : 1. Make sure it isn't set too low - you don't want the engine cutting out when idling with hot oil 2. Is it better to lunch an engine or to have the engine cut out half-way round a corner, possibly resulting in an accident ? I have seen a description of a system (on Peter Carmichael's car) somewhere on Blatchat where there was a micro switch which sensed the presence of the dry sump belt. No belt = big warning light comes on. The difference with the c******m dry sump system is that the loss of the belt only affects the scavenge side of things as the original pressure pump will keep pulling oil into the engine so it's not quite as catastrophic as with a Pace system where the pump handles everything. Also, if there is a fatigue problem with the bolts holding the drive cog to the crank, I'd suggest someone has specced the wrong bolt, either size or material. Quote Link to comment Share on other sites More sharing options...
legin Posted December 24, 2002 Share Posted December 24, 2002 Nick, Thanks for the reply. Understand your sentiments and indeed the belt device (like porsche 911 fan) looks a good idea. For trackday use the crash in a bend doesnt really materialise. Firstly engine braking on a Busa isnt enough to substantially upset the balance (too crash). Secondly when it happens the effect is like fuel surge and most Busa drivers are used to it as it is not uncommon. On balance I would much rather risk a bit of opposite lock, unless I was racing or on the road then I would risk engine damage. The problem with the bolt is due to overstress and cyclic load from poor alignment of the pulley to the belt (quality or lack of it), it breaks the brkt as stated but also the bolt which is very long. The bolt is a 12.9 so about as good as it gets, you are correct though in that early kits were supplied with bolts too short which were overstressed at the thread as a result - this is what happened with mine. My advice is change it for the cost, £1 and 10 mins. Anyone had the clutch brkt (3 times)fatigue and snap or the gear selector fail ? I have and its fatigue again. The bain of a Busa. Quote Link to comment Share on other sites More sharing options...
Nick M Posted December 24, 2002 Share Posted December 24, 2002 Hmmm, sounds like someone needs to go back to engineering school if all these brackets and bolts keep breaking !! Is the pulley on the front of the crank dowel pinned or held in place with a Woodruff key as well or is it just clamped in place with the bolt ? While changing the bolt is obviously a precautionary measure, I'd be inclined to push Westfield to find a long term solution to cure the problem rather than just treating the symptoms. Do any of the other dry sump systems, e.g. TTS ??, suffer from this as well ? As for the oil pressure cut out switch, I was admittedly looking at it from a road going perspective where there is generally less margin and room for error than on track. Even so, I'd still not like my engine to cut out mid corner on a circuit but then, if it went *BANG* in a big way I might not have an option anyway !! Quote Link to comment Share on other sites More sharing options...
peterrosey Posted December 24, 2002 Author Share Posted December 24, 2002 Inspected the old broken dry sump pump bracket when the new one arrived and the reason for the failure is obvious - poor weld penetration (oo er!. The new bracket had much beefier welding, so I'll see how long it lasts... I'm wondering if all these failures are due to the vibration that the Busa engine puts out - maybe a cushdrive in the drivetrain might help? My propshafts are as inline as I can possibly get them, so I don't think they're the culprit. Quote Link to comment Share on other sites More sharing options...
legin Posted December 24, 2002 Share Posted December 24, 2002 Yep, I am certain that the Busa is a bit of a vibrator if you get my drift. I had a blade before this and in fact still have it and it has only suffered one vibration induced failure - similar track miles at 3000. The equally infamous VDO oil pressure sensor unit failure. By way of a v rough measure, Blade lasted 500 track miles and Busa 50 ish. Two sensors later I gave up and mounted via impulse line onto the bulkhead with rubber mounts - 2k still works. I took the feed off the main gallery next to the bulkhead, much easier than the impossible location westfield use -need to machine a special fitting to do it though. On the blade I fitted a capillary gauge and although it doesnt match the clocks is by far the best and easiest route. Agree that the weld penetration is not good but my brkt also failed at the rear end which is not welded, probably failed here first. Stress raiser in the corner after bending. Basically to improve vibration you need either increased stiffness or mass. In my case I used stiffness the mass being secondary. Also I have the belt much slacker to reduce load on the crank pulley. Nick the drive is by two roll pins (dia ~ 3 mm) but the bolt is M10 x 1 but I think 75 long. I have looked at redesign but it is really a start again so I just change the bolt. Dont know where to stop here but another tip remove the screwed 5 mm orifice from behind the oil filter sandwich plate as this breaks down the oil molecules prematurely and could limit oil flow rate - westfield dry sump cars only ! Quote Link to comment Share on other sites More sharing options...
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