What's this plate? - Unidentified plate below crankshaft

[ROZZER]

Hi Zed world, another horror found in my Z1B motor, took sump plate off and found pieces of aluminium plate in bottom. Removed oil pump and in the attached photo you can see where the bits of plate came from. What is this plate? It's not shown in my manual and is not in the Z power parts book. Can it be removed and not replaced again?
Whatever it is, the crankcases will need to be split, not something I relish doing but thats life.

[Iain marshall]

Came across similar type of plates in performance car engine in the past,they seem to be fitted to stop the crankshaft picking up oil from the sump and slowing it down,thats my theory anyway

[Big John]

They call them windage trays, as Iain says they prevent the crank creating a vortex of oil around it at high revs.Looks like theres a clearance issue or something has parted company to cause that damage.

[paul doran]

but what caused the hole in it

[Iain marshall]

by the looks of it as John says a clearance problem,or is there a bit of movement in that bigend?John i knew there was a name for the plate but couldn't think of it

[Jeff Saunders]

maybe a broken can chain guide caused it? Any pieces of it in the oil sump?

I have one of these windage trays in my turbo bike - the prevous owner put it in there when he assembled the motor.

[Padders]

I had a similar one fitted to my Harris to stop oil surge creating oil starvation and as the others have said to stop frothing of the oil from movement. I had a concern over the angle of the engine in the Harris frame with having shorter forks fitted. Not sure if it actually worked but whilst the engine was apart I thought I may as well fit it just in case.

Really sorry though to see you having another problem with the engine. Hope nothing else turns up from within.

Padders.

[ROZZER]

:( Thanks for all the comments, I suspected it wasn't standard but who know's with improvements on each successive model. I definately think the problem is due to lack of clearance on No 2 conrod. The rod has worn thro' the plate rather than anything letting go like say camchain guide, no other bits found in sump, no damage to conrod/crank weight cos the windage plate is so soft and I think has been distorted when the numpty fitted it. No noises from crank area when the motor was running and I cannot detect any play in the big end when pushing/pulling on the conrod.
Looks like a full strip is on the cards to check the crank and locate any smaller metallic pieces if there are any left (never done this before so I'm a little daunted by the prospect).
One things for sure a replacement plate won't be going back in!!!
Looking on the bright side, its gonna cost, but while the whole motors stripped, I think I will send the whole set of cases to Mr Smethurst to work his shiney magic on, so it will look the 'Dogs Danglies' when it's all back together in say 2012!!
Now wheres she hidden my VISA card? ??? ??? ???

[Garn 1]

John, I've seen these "windage trays" before. It is retained by the four centre crankshaft "bearing block" bolts.

You may not have to split the crank-cases to remove it. Although, mine was not as wide the one shown, I believe, after removing these bolts you could possibly jiggle it out or carefully cut it away, without sustaining any damage.
RegardZ

[ROZZER]

Thanks Garn, have thought about that but cannot get a socket or ring spanner on one of the crank cap bolts cos its too close to a web on the casing. Need to look for more debris/wash out bearings at the very least so I've resigned myself to the split- not much else to do on cold Cumbrian evenings so in 'fer a penny, in fer a potential sizeable wedge' (the way my lucks going I don't think this will be the last of the story, expecting crank issues when it's removed so stay tuned).
Appreciate the comment mate.

John

[Garn 1]

Sorry John, I put my brain into gear and realised that you will ideed have trouble getting two of those bolts out, without splitting the crank-cases. RegardZ.

[Jeff Saunders]

It's not that bad of a job.

You do have to remove the engine from the frame, but you can split the cases and leave the complete top-end on the engine. Just remove all the engine side covers (clutch, kick starter, inner points, alternator, sprocket and transmission cover), the oil filter, sump, and then all the case bolts (top and bottom).

I would recommend pulling the cams out to get a good look at the cam chain guide and idler sprockets, center idler assembly, etc.

By pulling the cam cover and cams out, having the oil pan off, it's fairly easy to remove the engine from the frame - two sets of hands certainly help...

[debben1]

Hello John, This is a windage tray, ?15.70 from
Windage tray, Never seen damage like that though, strange that if the crank had been rubbing through the windage tray you would expect to see signs of heat, either the plate has been distorted and caused to rub on the con rod or something has become trapped between the too, check for play in the big end bearing. There is normaly a fair amount of clearance between the windage tray and crank, the reason for fitting these is to reduce crankcase pressure by redirecting crankcase pressure from the piston coming down the bore to underneath the piston that is going up the bore, also reduces the amount of oil the crankshaft flicks about. Regards, Steve

[ROZZER]

Top end of motor was already off and in process of refurbishment (New valves, guides, seals, cam chain, rollers, guides etc -see earlier threads), Have now split cases to check the whole of the bottom end, it all checks out fine, all bearings AOK.
Windage tray is very thin alloy and has obviously been distorted when fitted, it will have worn thro' in no time as it is so soft, the cracks are stress cracks caused by pumping action of crank as it spins past (Boffin metalurgist friend has confirmed).
Steve, you reckon they run with plenty of clearance but in reality it can only be a few mm, the plate touches the cases hence cannot be fitted to give any more clearance, hence any distortion on installation will lead to the situation I had. Problem is, it appears a/some real monkeys have worked on this motor in the past.
Glad I've stripped it all, as now I've got peace of mind that it is all good, also taken the opportunity to get whole motor cleaned/burnished by Steve Smethurst so as they say 'every dark cloud has a silver lining' it just costs!
When checking crankcases, found bolt sheared at output shaft bearing point, it was stuck in with silicon sealant! Another thread stripped at the crank bearing behind points - this time PTFE tape had been wrapped around the bolt!! as I said earlier, some real monkeys have been at it in the past, now thankfully I have put thread inserts in and it will all be 'top banana' when put back together.
Let the good times roll!

(thanks everyone for all the help, this board Brill' for advice and has been a god send to me)

[debben1]

Glad to hear its going back together and with some care and attention, "only a few mm" is plenty of clearance isnt it? but as you say, for it to have been fouling the path of the crankshaft it must of been fitted by a very hamfisted prevous owner, It is amazing how badly some of these engines have been built yet still they continue to run and run.