28 replies to this topic

[andyt]

I fitted the crank to the block tonight at the start of my engine rebuild, all went well until I checked the end float which I measured at 10 thou. What thrust washers do I need to buy to reduce the figure and what is an exceptable endfloat.

 

Andy. 

[Swift_General]

10 thou is a bit on the big side. Aim for around 3 thou, certainly no less than 2 thou. You don't say what washers you have at the moment. Oversize are +3 or +30 thou (the +30 needs to be machined down). If they are new STD washers then a set of +3s either side would bring you endfloat down to about 4 thou which would work fine, but obviously service life would be a bit less than with a lower figure. If you are using used STD washers then you may already have some wear so even just fitting new STD washers would bring the endfloat down.

[Spider]

yeah, 0.010" is a bit on the high side for a roadie.

 

I run with 0.004 to 0.006".    0.003" is to tight I've found (and yes, I know what the book says).

 

Fitting the +0.003's will get you to 0.007", which I feel is still too high, though you'd get away with it.

 

Your best option here is to get a set of +0.030" thrusts and have them ground.

[andyt]

They are standard size at the moment, from the 70,000 mile engine before rebuild.

[Cooperman]

If you fit +0.003" on both sides you will reduce the float by 0.006" and that, at 0.004" float, will be ideal.

[Spider]

10 thou is a bit on the big side. Aim for around 3 thou, certainly no less than 2 thou. You don't say what washers you have at the moment. Oversize are +3 or +30 thou (the +30 needs to be machined down). If they are new STD washers then a set of +3s either side would bring you endfloat down to about 4 thou which would work fine, but obviously service life would be a bit less than with a lower figure. If you are using used STD washers then you may already have some wear so even just fitting new STD washers would bring the endfloat down.

 

 

If you fit +0.003" on both sides you will reduce the float by 0.006" and that, at 0.004" float, will be ideal.

 

What Thrust Washers can you guys get? Seems they are 0.003" per side (0.006") in total.

 

The ACL ones I use are 0.003" in total.  Would be handy to get some like you guys get a hold of.

[gazza82]

They are standard size at the moment, from the 70,000 mile engine before rebuild.

 

So they are already worn?

 

What Thrust Washers can you guys get? Seems they are 0.003" per side (0.006") in total.

 

 

Minispares sell standard, .003 and .030.

[andyt]

Thanks for the replies, minispares has 003 though ones listed but they only mention 1275 and not 998 is there a difference.
Andy.

[carbon]

1275 and 998/1098 use same crank thrust washers.

 

850s use smaller crank thrust washers

[myredmini]

Did you measure it on worn thrusts?

[andyt]

Yes I did,10 thou on originals from 70,000 mile engine.

[Spider]

Yes I did,10 thou on originals from 70,000 mile engine.

 

Ah, OK, you should find some new STD Thrusts and measure again.

[andyt]

Oh should i just buy new standard thrusts or the +003 thou ones?

 

Andy.

[Cooperman]

They are so cheap you could get a set of standard and a set of +0.003", then you can 'mix & match' until you get the float within limits. Or measure the thickness of the ones you took out and someone on here will tell you the thickness of standard ones. remember, the pair nearest the clutch end will have most of the wear and the ones on the timing chain side will be virtually unworn.

[Spider]

It can be a bit of a pain. Normally you'd buy STD Thrusts, fit them and measure again. Then if the end float is outside of spec. and going to the next size will bring it within spec, then buy another set, next size up. Why it's a bit of a pain is that you'll possibly end up with a set of STD washers as the supplier is under no obligation to take them back. They are not expensive though.

 

If you know a friendly engine builder, they may lend you a set of each, or buy your unused STD washers from you, if you find you are stuck with them.

 

<Edit: Cooperman's suggestion is a better one, he was quicker on the keys than me!>

Edited by Moke Spider, 13 October 2015 - 08:00 PM.