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fox889

Sump's off and..............

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It's cold, windy & raining outside so you might as well read this blurb & have a giggle:

 

So, sump came off today. Checked end float on the crankshaft pulley to find it was 0.40mm........horrendous!!!!??? Nearly twice the max it should be?

(You'll have to forgive me with measurements etc, maths & metric are not my speciality!)......anyway......I had visions of finding the thrust washers laying in the sump & the crank mangled as has happened here on the forum.

First thing to greet me was a spotlessly clean oil pump gauze although the sump has 1/8th worth of crud-grey sludge but no TW's nor 'bits' so that pleased me.

Took the rear main bearing cap off & the crank looks shiny & unscathed. Took the big-end cap off & the same, the shells are below (providing they upload ok) & don't seem too bad. I have seen much worse on here so again, that pleases me.

ok, onto the shells & bearings. I thought, because I had no other reason to think different, that she was an unmolested engine (75k) in my care 3 years, previous owner 14 years (who didn't really look after her). It appears, if I read everything correctly, that she has been reground. I'll give you the info that's stamped on the shells etc.

 

Big-end shells:

G (with a box round it) S2022 SA D(with a box round it)

020U/ST/BDX

149549

 

Main bearings:

D (with a box round it) MX T/B

G (with a box round it) S2020 SA

010 U/S

149550

 

I haven't a clue what the above means but am I correct in thinking the big-ends are +20 and the mains are +10 meaning she's be reground at some time?

 

Lastly, for those who are still awake, this is the part that really muddles me.......maths.

ok, say the end float was 0.40mm (checked it a dozen times)

the rear T/W measured 2.65mm

the front T/W measured 2.82mm

what size thrusts do I need to order to get the recommended endfloat please?

 

If I've sent you to sleep I'm sorry, but those who are still awake I would really appreciate your thoughts.

 

ps Kevo, you replied to my other thread re-endfloat, I was slightly dubious about dropping the sump but in the end it was quite easy, hope your 'sump-off' this weekend goes ok, let us all know please.

 

I'm now going to hit the 'post' button & hopefully the photo's will remain on here, thanks again in anticipation!

 

Nick.

 

 

 

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Why won't my photo's show on the above thread?

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This blinking website. I use photobucket and post a link. Can't be bothered with resizing pictures and all that.

Looks like your mains are 10 thou undersized and big ends are 20 thou undersized as you suspect, so a regrind has been done.

Edited by peejay4A

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Hi Nick,

don't panic about the pics. You are not technically inept in the pic posting department - there is a web problem.

Being looked at while we sit here eating hobnobs (with chocolate)

 

Roger

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Ah! Thanks Roger, I even re-sized the photo's and still wouldn't upload, "server error" apparently!

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When I ordered my Bronze alloy ones from Scott Helms of sportycars@britishcarweek.org (in the USA) wanted the thickness in good old fashioned imperial thousands of an inch!

 

My last set made by Glacier were stamped .015" which were original white metal, which are too soft really!

Edited by Denis

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Denis, I've read a lot about Scott Helms which is an avenue I may have to take.

Looking at my measurements above, I need a 'wide' T/W? which now worries me!

 

Nick.

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Thrust washers are fairly easy to sort out. The movement of the the crank is a specific distance. The best way to measure is to find the maximum movement divide by 2 and work out the right size washers to put in allowing for the float. These can be bought from moss or rimmers etc

 

Cheers andy

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Thanks Andy, I'm having problems working out the maths on the measurements above, one part of me thinks I need massive wide T/W's!

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Basically you need distance of movement of the Crank this Is done by a dial test indicator., positioned on the end of the crack. Move the crank back and forth with a screwdriver to get the amount of movement. Note it, and remove the trust washers and measure the thickness of both. The formula for new washers is Thickness of old washers + movement of crank - tolerance = thickness of new thrust washers Divided by 2 gives equal thrust washer thickness.

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Only the rear thrust washer wears to any degree. Obviously. Therefore base any calculations on this fact.

Washer failure is down to the driver, not the engine. Always fire up in neutral, no clutch, & don't ride the clutch at a standstill.

"Uprated" clutch covers can be a big problem. Again, obvious.

Good observation on the aluminium-coated washers- always use the copperclad if possible.

Oversize washer pairs tend to be named in Imperial thou" steps; the quoted dimension refers to EACH washer, not the pair.

Flak, please?

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Hi Nick.

Good luck with working out your TW sizes, thanks for your good wishes and I will let you know how I get on at the weekend (hopefully there wont be any nasty surprises’). I was looking at the Solid and slightly wider ones that S & M Triumph in Lincoln sell but their web site is down at the moment. http://sandmtriumphrestoration.com/

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Nick, I take it that your TWs were still in place?...that's good news, so no need to panic!

 

As far as I recall both washers start out the same size (? Anyone) therefore the wear on your rear one started out the same thickness as your front one which wear very little...Check out the two oil grooves across the white metal surface, which start out very shallow to begin with, that's not very technical, but a good visual reference to start from.

My last Glacier ones had the size stamped on the steel backs. If yours don't have that, take your thicker one to an engineering shop and get them to measure it for you.

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Nick, I take it that your TWs were still in place?...that's good news, so no need to panic!

 

As far as I recall both washers start out the same size (? Anyone) therefore the wear on your rear one started out the same thickness as your front one which wear very little...Check out the two oil grooves across the white metal surface, which start out very shallow to begin with, that's not very technical, but a good visual reference to start from.

My last Glacier ones had the size stamped on the steel backs. If yours don't have that, take your thicker one to an engineering shop and get them to measure it for you.

The standard thrust washer is 0.092” (2.34mm) thick.

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Scot Helms quotes the Standard TW as .092" +.010" = .102" (whatever that's in metric?)

 

Mine last time around were .015" oversize = .107"

 

By the way Nick, the standard size Bronze ones are only 20 dollars each www.customthrustwashers.com

 

He also wanted to know the Outside Diameter too ...so I measured mine from the outter most ends of the tips.

Edited by Denis

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One thou is 0.025mm.

 

Or type 'convert 1 thou to mm ' into Google

( or any number of thou for that matter!)

 

Peter

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Seems I was getting myself into a bit of a tizzy trying to calculate the thrust washers I need.

Turned out that after my calculating in metric I hadn't realised that the thrust washers were in imperial.

Hopefully if my calculator is correct, I need +20's on each side or a mixture to get to 40 thou.

 

Thanks to everyone who gave their advice, as usual, much appreciated.

 

Nick.

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The spec for crankshaft NOT camshaft endfloat is .006 to .008 inch or .152 to .023 mm

Usually a standard size TW is used on the front. If an oversize is needed to reestablish specs, then the oversize TW is installed in the rear.

If you can measure the thickness of your old TW's and tell us what the endfloat was WITH those TW's in place, we can check your math for determining the size of the new TW's.

Here's a sample calculation:

Existing end float = .0011

Desired end float = .006

 

 

Thickness of existing front TW =.091

Thickness of existing rear TW =.089

 

 

A standard size new front @ .092 would decrease the endfloat to .0010 with the existing .089 rear

 

A standard size new front plus a new standard size rear would decrease the endfloat to .007

 

Therefore if you wanted to decrease the endfloat another .001 you would need a rear TW .093 thick.

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Thanks Poolboy, well here goes with my maths input:

 

end float measured with a dti gauge (with t/w below) 0.157 thou (0.40mm)

rear T/W 0.104 thou (2.65mm)

front T/W 0.111 thou (2.82mm)

 

going by what I have read before, thickness of old washers (0.215) + crank tolerance (0.007) = 0.222 thou.

2 standard thrust washers = 0.184 which means I have to find +38 thou from somewhere?

 

If I wanted to use 'off the shelf' thrust washers could I do the following:

 

Rear thrust could be +30 & front thrust could be +10

Rear thrust could be +25 & front thrust could be +15

 

Am I far out or do I get 5/10 'could do better, see me after school'?

 

Thanks in advance

 

Nick.

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Guest ntc

For what they cost get all sizes and fit as required.SPMPW is spot on and get ready for striping the thread in the seal carriers.

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I'm going to regret this Neil................what's SPMPW.............. :unsure:

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Got it............took a while, but I got it! :rolleyes:

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