What goes in this hole then?

[chaterlea25]

Hi Simon,
"See I told ya"
I feel you should now remove the oilpump and use some aerosol cans of engine cleaner and an airline to clean out ALL the oilways, pipes and oiltank,
The oilway from the sump pipe goes up to the oil pump.
I dont understand how you could have poked a wire up this as there should be a captured ball bearing at the sump end
this acts as a one way valve to keep the return side of the oilpump primed????
Remove the pressure relief valve at the front of the crankcase and this will give you access to the oilways from the pump, and to the main bearing and cam gallery.
Remember there is a ball and spring in the delivery oilway behind the pump, the ball can be lifted using the nozzle extension on the aerosol  cleaner
HTH
Cheers
John O R

[Mosin]

Cheers John,

The ball bearing in the scavenger pipe is still in situ. I think the problem was that the gasket goo which was forming the obstruction was so soft that my piece of wire was simply going straight through it on my first couple of attempts.

I take on board your suggestions about removing the oil pump and clearing out the oil ways, but I think that before I remove any more bits from my engine I will build up the top end again with new gaskets and piston rings. Starting a whole new job on the oil pump will probably seem much less of an ordeal once the rest of the engine is back together.

Simon

[A10Boy]

Just my opinion, but since you found a lump of Hermatite like that in an oilway you should remove the timing cover and oil pump as suggested, [its a simple job], and make certain thats its all out BEFORE rebuilding anything otherwise you could be doing work over again.

 

[RichardL]

...plus a lot of other work, like: crank grinding; rod-journal replacment; timing-side bearing replacement; etc.  Of course, none of this may happen, but you will be kicking yourself if it does. It would be very easy, here, to say, "take the whole thing apart, check everything, rebuild everything," but, for now, all that is being suggested is look around under the timing cover for other signs of blockage and clean out what is easy.  If, then, you discover more Hermatite (gasket goo) or other issues, you can make a new assessment of the situation.

In my case, I rebuilt my engine with, I think, decent (not expert) engine experience but no experience with an A10 engine. I went merrily along following the Haynes manual but did not know about the importance of a clean sludge trap. I forget right now if you have a sludge trap, but that is not my total point here. The rebuilt engine, after 27 years of not running, started on about the second kick. This was great, until after about 100 miles when I blew a rod bearing, evidently due to crud in the sludge trap. Lesson learned. Re-rebuild now completed with about 1000 miles done.

One more thing I'd like to ask, did you ever determine what your pre-sieze piston clearance was? It's great that you discovered a possible source of blockage but, sometimes, the real problem is hidden by other simultaneous problems.


Richard L.

 

[Mosin]

Fair enough, you have me convinced. The timing cover & oil pump are coming off tonight when I get home from work! I've got this far, I might as well see the job through.

Richard, I never managed to determine my pre-sieze piston clearance. Is it to late to try and work it out now? I have spent quite a bit of time working on the piston with very fine wet & dry paper and have succeeded in getting most of the sieze marks off it, but I imagine that this will have altered the clearance (although this will only be by a tiny amount). What would be an acceptable tolerance here?

Simon

[RichardL]

Simon,

I assume you have been following the topic at http://www.a7a10.net/forum/index.php?topic=1194.0 .  There are some similarities between your problems and Nigel's.

As for clearance after the cleanup, I would guess you did not remove much diameter with the wet-dry paper. You could check the difference between pistons with the caliper to judge how much.  If you are now at 0.004"-0.006" clearance, you probabaly started with, at least. 0.003", which would be good, but would also seem to indicate oil shortage rather than simple siezing due to clearances being too tight.

By the way, it's a pleasure trying to help by offering my advice, but I hope others will chime in to confirm and/or offer different or additional advice.

Richard L

[chaterlea25]

Hi Simon,
All sound advice,
When the top end is apart you can check the oilway from the camshaft gallery back down to the pressure relief valve (very important)
Cheers
John

[Mosin]

Good evening Gents,

My wife has gone out for the evening, so I am taking advantage of the situation.

I have removed my timing cover and oil pump as suggested. I was amazed to find a massive amount of grease begind the timing cover which didn't really appear to be doing anything very much (see photo) and also quite a bit of sludge in the bottom of the casing, although this was pretty liquid and didn't seem to be forming any sort of an obstruction. I am now at a bit of a loss as to which of the holes behind the pump I should be cleaning out, looking for ball bearings in, which connects to my scavenger pipe etc. I am attaching a photo of what I am looking at at the minute, so any guidance would be most welcome.

Thanks as always,

Simon

[rocket man]

hi simon the grease is for the dinamo chain


dave

[a101960]

As Rocket Man says, the grease is to lubricate the dynamo drive chain. I am a little concerned to see evidence of red hermatite. If I was you I would clean that all off and just grease the gasket before fitting it. Grease will hold the gasket in place and you will get a leak free seal. I have refitted  my timing cover  three times now with the same gasket using grease and it is oil tight.

[RichardL]

That's a very good concern, since a chunk of it was found in the oil pickup tube.

[nigeldtr]

Simon,

Just a couple of things, I found a supplier of a sort of "liquid" grease for the dynamo chain which basically runs down when the engine is stopped and partially solidifies around the chain and lower sprocket when the engine cools. Don't need much of it as it always flows back down. Not sure if you can get something like this in the UK? Second is hows the main bearing? Nice and easy to check with the pump out of the way! Fully agree with not using sealant but grease on the gaskets and faces - saves gaskets and makes getting things apart nice and easy.

Nigel

[A10Boy]

Well at least the pump gasket area isnt covered in hermatite.

I would check to see where that red shite has been used, remove and clean whatever has been fitted using it, replace whatever without it using new gaskets, clean all oilways and pipes and remove and clean out the oil tank, remove the sump plate and clean that too.

While you have the covers off check for excessive end float on the crank and wear in the timing side bush, if it has wear you might need to consider stripping the bottom end and rebuilding it properly.

When you refit the timing cover, put a good dollop of Low Melting point grease in the dynamo chaincase area and it will melt and lube the chain. That grease in your pic is obviously high melting point as it still in a lump as when it was put in there.

[A10Boy]

Sorry Nigel, Didnt mean to crash your post.

[Mosin]

All good advice guys. I am following each suggestion as it comes. The red shite is virtually all gone now and things are beginning to look much cleaner.

As an interesting aside.... I have just removed, checked and replaced the oil feed and return hoses (they were fine) but as I was doing so, the chap in these pictures dropped out of somewhere and fell onto the floor. I have never seen 'im before and I've no idea where he came from. As you can see, he is a little over an inch long and threaded at one end. The threaded end has what looks like a phillips recess in the end of it and the non-threaded end is slightly chamfered.

I know this isn't a great description, but I am not an engineer. I hope that the photos will make up for my poor description. But I am not a photographer either....

Still, at least the sun is shining.


Simon