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MG Midget and Sprite Technical - 1500 crank thrust washer !!!

I been stripping my old 1500 engine. there was a lot of end float in the crank, not unusual for the Triumph engine. On removing the crank I noted the big ends are 20thou u/s in good nick, the mains 10thou u/s also in good nick. the thrust washers at first glance looked hardly worn, until I looked at the back of the rear thrust washer. Completely ground away and so is the crank. The MUPPET who built the engine fitted the rear washer the wrong way round.

P J Vass

And here is the reverse side

P J Vass

I doubt it makes a big difference. The grooves are supposed to allow oil into the wear face. But I would have thought even with the thrust washer the wrong way around oil will still get in there. The washer just sits there in place free to float around.

I think it more down to driving style. If you sit at the traffic light with the clutch depressed it’s going to wear those thrust washers which ever way they are installed,

Just my hunch.
C MADGE

Yes they will wear really quickly if the clutch is held down for anything other than a quick gear change. The evidence is with the disproportionate wear on the C-shims on the rearwards side of the centre main.
GuyW

As JT says there's only two times you foot should ever be on the clutch -

". . . the clutch is only pressed twice, when you're taking off and when you're changing gears, that's all.

. . . Your foot is never on the clutch - except when taking off and changing gears."
Nigel Atkins

There is more to it than the grooves. The contact face has a layer of bearing material on it, so if reversed it will be steel to steel.
I found this wrong way round problem with a 1500 B series in my Oxford van years ago - unlike the Triumph,
not one that usually wears the thrusts. The results were the same. On top of that, someone had welded on the crank pulley!
Paul Walbran

Paul,

A mate of mine bought a Renault Alpine A110 supposedly built by an Alpine expert, it had 3 significant flaws which were all tracked down. the least obvious was only found on stripping the engine after the car caught fire at a local test day, I was in the passenger seat at the time but we were close to a marshalls post so they got there quickly but with the engine running still it ingested dry powder and caused bore rusting. The damage including paint damage was covered by insurance. During the engine strip it turned out the expert had tack welded the crank sprocket to the crankshaft with MIG rather than use an appropriate clamp and bolt into the crank end. Due to the low MIG heat input and the higher carbon content of the crank and sprocket the MIG tacks were only just adhered and my mate tapped them lightly with a hammer and cold chisel and all 3 popped off cleanly. The sprocket was a very good fit on the crank and key which is likely why the tacks hadn't broken. The other problems were over long dampers from a Renault Traffic which explained why it would go into sudden oversteer when cornering and you hit a bump, the damper went solid. The other issue was cantilevered engine mounts which kept coming loose at the ally block, I made a U frame to go below the engine and upto the engine mounts either side with vertical angle upwards to the block mounts to sort it, when my mate sold it he mentioned it to the buyer who said that was how it was done originally.

Experts, you have to love them although I doubt Nigel would agree.
David Billington

PJ
Bag luck man--
There are some gooses (muppets)about, at least he had the wide washer on the rear where it's supposed to be but as Paul says they are sided as you know, steel on one side and bearing material with oil grooves on t'other
You will have to sit them back in correct way round(that rear one will sit on the unworn outer section enough to get a measurement) and measure crank. end float
There are oversizes available but it will just depend on how much wear you have on the crank---the crank will have to be ground on that face where it is damaged in a crank grinder
Just asking--they were under the rear main cap---?
I pulled one apart once that someone had poked them in under the centre cap, it must have had monster end float, but luckily they hadn't fallen out--------as they can

willy
William Revit

Willy,
Yes the thrusts were in the right place, just the wrong way round. The crank is quite damaged, I don't know if there is enough meat on to to regrind.
PJ
P J Vass

I feel your pain.

When building a 'hot' and expensive (to me at the time anyway) engine for my Metro when I was eighteen I turned to my mate who was a car mechanic apprentice to give me a hand. He said it was easy and threw the bottom end together. After a few hundred miles of running in it started losing the clutch and needing adjusting. Not being very experienced I just kept driving. The oil looked a mess but was normal for a new engine I was told. Anyway it finally died when it got to the point when you pressed the clutch the engine nearly stopped!

A very embarrassing trip to Minisport revealed the thrusts had been fitted the wrong way round just like yours. New block, crank, rods, pistons, oil pump etc.

From then on I've always done my own engine work!!

Hope you get it sorted
John Payne

PJ
That's a shame that the crank is so badly worn
We have a local bearing manufacturer here by the name of ACL
They were quite well known in the performance industry supplying the US Nasca market
Unfortunately they went down the gurgler and started selling off their machinery
Luckily the US distributors got together and bought the whole place so that they could still source the Race Series bearings made here, -They got in before too much got sold, the only thing they don't do now is domestic gudgeon pin bushes but they get them somewhere so basically back in full production now
Long story, short, I just had a look in their catalogue and for the 1500 they do a thrust set to fit to the No2 (centre) main bearing
Don't know if there's machining to be done or if it's a straight conversion-?
Might be a way around a worn rear thrust surface--?
Here's what's in the cat.

ENGINEVIN CYLBore x StrokeTORQUE SETTINGS1296cc (1.3)L473.6mm x 76mm1493cc (1.5)L473.6mm x 87.6mm1493cc (1.5) (FP)L473.6mm x 87.6mm1493cc (1.5) (W)L473.6mm x 87.6mmConnecting Rod 45 ft. lbsMain Bearing 65 ft.lbs
Thrust - Non-Stock Items. Order ex-factory only.21T2407Std.F82022407TIH65.583/2.582065.837/2.592077.470/3.050077.724/3.06002.36/0.093Note : Set includes two pieces, use on No. 2 position. Required with 3M2407 main set.
William Revit

This thread was discussed between 28/05/2019 and 29/05/2019

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