803 rebuild progress

[JOWETTJAVELIN]

Today I had some good news in the form of the block, new crank and sump being returned to me after some work had been done on them. The sump and block had been submerged in a tank to degrease and clean them, and the bores had been honed and deglazed. Thanks to a club member, a secondhand crank was obtained which needed attention to the journals as they were a touch rusty, but this has polished up nicely and came back with the measurements:

Mains: 040
Big ends: 040
Thrust: STD

The cost for the polishing, honing and cleaning? £20.

I'll upload some photos soon but now the rebuild can progress in earnest and eventually I can start enjoying the car instead of it being laid up.

P.S. A few of you said the con-rod which was knocking may have been distorted. Will a used one from another engine do, or buy a new one or leave alone? My man in the trade has said it will most likely be fine.

[les]

First find out if the rod IS distorted. If it is ---you know what to do!

[bmcecosse]

I doubt you can buy a new rod for an 803!! Check the knocking rod carefully before reusing. I would scrap it and use another one if available. CERTAINLY use new bolts in the rods!

[mike.perry]

Plenty of conrods available for the side valve engine
I notice in a catalogue that it lists for A Series engines, rod connecting 1 & 3 cylinders and rod connecting 2 & 4 cylinders. The Workshop Manual lists two conrods as well. I was not aware that there was a difference

[les]

I think you'll find it's because of the cylinder spacing.

[Declan_Burns]

There is an interesting article written by Rolf Corbat on the Swiss Moggy website about crankshaft and main bearing failure on the 803 cc engine. It's in German but the photos and pressue tables are easily interpreted.
http://www.morrisminor.ch/pdf/oelfilterbeitrag.pdf
Basically what Rolf is saying is that the original filters had a hole for the oil passage of 1.5mm whereas the modern filters vary from 2.5 to 3.5 mm depending on the supplier. This causes a pressure drop which leads to premature failure. The table shows the measured pressures with the original compared with two modern filters and it is clear that the main problem occurs below 2900rpm. He recommends inserting a small orifice with the 1.5mm hole to fix the problem as shown in the photos.
These orifices are made and sold by Rolf Corbat. I have no idea of the price. His contact details are shown below and Rolf has an brilliant reputation here.
There is also an excellent article on engine rebuilding with brilliant photos on that website
http://www.morrisminor.ch/pdf/Motorrevision.pdf

If anybody wants to contact Rolf:
Rolf & Erika Corbat
Tel/Fax: +41(0)56 241 22 54
E-Mail: rolf.corbat@swissonline.ch

Regards
Declan

[bmcecosse]

The 803 filter is a by-pass filter - it doesn't filter ALL the oil. Just a miserable dribble that then returns to sump. so yes - in that sense there is a constant bleed of oil away from the bearings. The main problem mis the pathetic oil pump with 'vanes' instead of the later 'gear' formation. And of course the tiny big ends of the 803 crank! Conrods for a 948 will NOT fit.

[JOWETTJAVELIN]

As per your advice I am fitting a 1098 pump (making sure it is primed this time! ). Even on another worn out 803 this 1098 pump gave excellent pressure readings. My engine which has been the cause of so much trouble was fitted with the Burman rotary-vane pump, which, as you note, made little or no pressure at idle, even when the bearings were in good condition. Some 803s have a Hobourn-Eaton oil pump of an improved design, but as I have not driven a car thus equipped I am unable to report on its performance.

[JOWETTJAVELIN]

In any case Declan I thought oil was full pressure to all bearings? It is a by-pass filter and not full-flow (where does the rest of the oil go?) after all. Thanks for the link - certainly food for thought. Of course the increased pressure made by the later pump will force more oil through at a faster rate, going quite some way to ameliorate the problem (I hope).

[David53]

Great pictures on that site of the engine rebuild. But a bright orange A Series?? Sure looks strange

[stevey]

interesting point about the filter hole size. Going to start rebuilding my 803 soon, so a 1098 pump it is, any ideas about adapting the new filters?

[JOWETTJAVELIN]

I doubt it is worth the bother fitting a later filter. Keep it standard, fit a magnet to the sump plug and change the oil regularly.

[bmcecosse]

I don't know how you COULD fit a later filter to an 803 block..........

[JOWETTJAVELIN]

Thinking about it now, me neither... the filter hole is machined into the block and then there is the issue of the by-pass.

[stevey]

No, i wouldnt dream of fitting a later 1098 filter, i meant the new 803 filters you get now as per the article on the other website, about keeping the oil pressure up.

[bmcecosse]

Note - in picture #15 of the orange engine build - the oil thrower is on wrong way round........ And a crankshaft damper on an 803.......well......does no harm of course - but hardly an engine that's going to get revved enough to justify it!

[JOWETTJAVELIN]

Oh, I don't know - that step up from 3rd to top is quite a gap!

[irmscher]

[bmcecosse]

I you are wise - you will use a 948 box, reto-fitted with the 803 gearlever of course......

[JOWETTJAVELIN]

ESM surprisingly had a NOS 803 con rod in stock. I am just waiting for rings now - crank is in place and mains are done - though I do wonder about those loose thrust washers.