998/1098 crank thrust washer clearance

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AndyB72
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998/1098 crank thrust washer clearance

Post by AndyB72 »

I'm starting to build the mild/fast road overbored 1098 engine for the surf blue Mini and as I haven't put an engine together for several years expect some daft question from me other the next few weeks.

I'm getting 6 thou crank end float on a set of new standard thrusts, it that too much or should I be ok? As oversized thrusts are NLA correcting the clearance could be very tricky.
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Re: 998/1098 crank thrust washer clearance

Post by goff »

Andy , Clearance should be around 2-3 thou , the Machine shop at Bawtry i was telling you about ( Stanwood Engineering ) got me over size ones and machined them to fit, if you have to much end float , you will have problems getting the clutch to disengage ,
Hope this helps and stay safe .

Goff
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Re: 998/1098 crank thrust washer clearance

Post by whistler »

Oversize thrusts are available from Somerfords. I bought some recently to get back to 4 thou clearance. I bought the plus 5 thou ones but only fitted 1 pair.
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Re: 998/1098 crank thrust washer clearance

Post by AndyB72 »

whistler wrote: Mon May 04, 2020 5:06 pm Oversize thrusts are available from Somerfords. I bought some recently to get back to 4 thou clearance. I bought the plus 5 thou ones but only fitted 1 pair.
Were they small bore thrusts, MiniSpares sell +5 1275 ones, I'll have a nosey on their site.
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Re: 998/1098 crank thrust washer clearance

Post by Spider »

I know the book says 2 - 3 thou clearance on these, but IMO, that's a little tight.

On these smaller engines, I aim for 3 - 4, but, if it's going to be a screamer, the 4 - 5.
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Re: 998/1098 crank thrust washer clearance

Post by Dearg1275 »

goff wrote: Mon May 04, 2020 3:48 pm Andy , Clearance should be around 2-3 thou , the Machine shop at Bawtry i was telling you about ( Stanwood Engineering ) got me over size ones and machined them to fit, if you have to much end float , you will have problems getting the clutch to disengage ,
Hope this helps and stay safe .

Goff
To me that just means you have 4 thou unusable clutch plate as it wears out. I’ve seen clutch plates run right back to the rivets so clutch adjustment can take care of this degree of tolerance. The difficulty with clutch throw comes from all the worn parts of the linkage before you get to the clutch plate itself.

I’m running 6thou clearance on my 50bhp 850 with no clutch problems whatsoever.

D
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Re: 998/1098 crank thrust washer clearance

Post by timmy201 »

ACL make them in
STD
+003
+005
+015
+030

https://classicmotoring.net.au/thrust-washers/
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Re: 998/1098 crank thrust washer clearance

Post by AndyB72 »

Thanks I've sent them an email to see if they can ship to the UK.
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Re: 998/1098 crank thrust washer clearance

Post by timmy201 »

If not, I can post them over for you. Just let me know
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Re: 998/1098 crank thrust washer clearance

Post by AndyB72 »

Thanks very much I might take you up on that offer, at the moment it looks like MED stock them, will see how I get on.

Another question, which side of the main cap should the thicker thrust washers go?
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Re: 998/1098 crank thrust washer clearance

Post by AndyB72 »

Makes sense.
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Re: 998/1098 crank thrust washer clearance

Post by AndyB72 »

The thrusts have arrived from MED. Which side of the cap should I fit the thicker thrusts?
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Re: 998/1098 crank thrust washer clearance

Post by Spider »

It's pretty much academic but I tend to fit the thicker pair on the back of flywheel side.
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Re: 998/1098 crank thrust washer clearance

Post by Vegard »

Spider wrote: Mon May 18, 2020 11:00 am It's pretty much academic but I tend to fit the thicker pair on the back of flywheel side.
So do I, but it does not matter onw blind bit :)
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