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Re: 803 rebuild progress
Posted: Sat Oct 20, 2012 7:58 pm
by bmcecosse
They didn't mean THERE - they meant on the top half - half moon section where it fits to the block.......
Re: 803 rebuild progress
Posted: Sun Oct 21, 2012 6:04 pm
by JOWETTJAVELIN
Now for the ring-job. Starting in order (from No.2 cyl. in this case because No.1 is damaged and needs to be replaced with one out of the other engine), the old rings were carefully removed over the TOP of the piston. It states quite clearly that rings should never be removed or fitted over the skirt - always come over the top.
These cylinders had all been given a petrol bath but note the build-up of crud around these oil holes. You can clearly see the reduction in size which prevents the proper lubrication of the bores. Using a sewing needle these were reamed out and the debris blown away. Be careful not to scratch the piston.[frame]

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In the photograph below the damaged piston crown may be observed (Right hand piston). Note the pitting and combustion-chamber shaped outlines, where I suspect the piston hit the head due to the extra travel provided by the melted big-end bearing.[frame]

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Before fitting new rings the clearance must be checked - that is, the size of the gap when the ring is squarely in the bore. An un-ringed piston was placed in its correct bore and a ring gently put in on top, then the piston was brought up to ensure accuracy. Full details in the Workshop manual.
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Although full instructions are provided in both the Shop manual and the ring outfit, it is wise to leave the rings on one cylinder and have it to hand for comparison when fitting the new ones.[frame]

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Re: 803 rebuild progress
Posted: Sun Oct 21, 2012 9:48 pm
by bmcecosse
It may just be the shading/picture - but the ring grooves look as though they have a bit of wear on them........? In all your ring gap measuring - did you have to 'adjust' any of them??
Re: 803 rebuild progress
Posted: Mon Oct 22, 2012 10:20 pm
by JOWETTJAVELIN
Upon fitting the new rings all were a VERY snug fit in the grooves - and nice and tight in the bores.
Re: 803 rebuild progress
Posted: Tue Oct 23, 2012 6:03 pm
by bmcecosse
So - you didn't adjust any of the ring gaps after 'trying' them in the bores??
Re: 803 rebuild progress
Posted: Tue Oct 23, 2012 8:40 pm
by JOWETTJAVELIN
No - I tried them, checked them and they were all within the limits specified in the workshop manual.
They were an engineered set, after all.
Re: 803 rebuild progress
Posted: Tue Oct 23, 2012 9:21 pm
by bmcecosse
Yes - I've never found a problem with rings either.......
Re: 803 rebuild progress
Posted: Wed Oct 24, 2012 9:35 pm
by les
Re: 803 rebuild progress
Posted: Wed Oct 24, 2012 10:03 pm
by bmcecosse
It absolutely IS an 803 !
Re: 803 rebuild progress
Posted: Thu Oct 25, 2012 4:56 pm
by JOWETTJAVELIN
Thanks for that Les - much appreciated. But my rebuilt one should be up and running early next week. Also it's anyone's guess as to how these ebay engines are like inside. I've been caught out before by a total liar.

Re: 803 rebuild progress
Posted: Thu Oct 25, 2012 5:07 pm
by les
Ok, just wondered if there would have been any useful bits from it, went for £40 ish in the end.
Re: 803 rebuild progress
Posted: Thu Oct 25, 2012 5:21 pm
by bmcecosse
Well worth it just for the water pump!
Re: 803 rebuild progress
Posted: Thu Oct 25, 2012 5:39 pm
by JOWETTJAVELIN
Indeed!

Parts for these engines are drying up fast.
Re: 803 rebuild progress
Posted: Thu Oct 25, 2012 5:59 pm
by bmcecosse
And - how much did you pay for a new con-rod??
Re: 803 rebuild progress
Posted: Sun Nov 11, 2012 9:04 pm
by JOWETTJAVELIN
bmcecosse wrote:And - how much did you pay for a new con-rod??
I think it was around £35. I am nearing completion now and the old lump has been removed and one of the pistons has been borrowed from it. I note it is a '2' in a diamond rather than the original '1' in diamond. Will this make any difference?
Re: 803 rebuild progress
Posted: Sun Nov 11, 2012 9:11 pm
by bmcecosse
£35 for a con-rod../geeeezzzzzzzzzzzzzz. And no -the piston will be fine.
Re: 803 rebuild progress
Posted: Tue Nov 13, 2012 1:38 pm
by JOWETTJAVELIN
Today, whilst cleaning some more parts in petrol, I scrubbed out the gearbox bellhousing which was full of clutch dust and muck.
Note the jack - the 'box MUST be supported at all times.[frame]

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I could also examine the carbon thrust which in the words of Mr. bmc 'wears like mad'

Now I'm no expert but there seems to be plenty of 'meat' left on this one:[frame]

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Re: 803 rebuild progress
Posted: Tue Nov 13, 2012 2:55 pm
by Trickydicky
For the cost and hassle factor I would still replace it along the clutch plate.
Re: 803 rebuild progress
Posted: Tue Nov 13, 2012 3:09 pm
by liammonty
At around £100 for a new clutch kit of decent quality, I wouldn't!! It looks fine to me- hopefully the clutch plate is in similarly good condition!
Re: 803 rebuild progress
Posted: Tue Nov 13, 2012 3:34 pm
by bmcecosse
Yes - that one has years of life ahead......... Leave well alone.