Timing chain / cam removal

[DavidLaver]

The timing cover was invisible last week.  With a clean, soak in wd, a try with the wrong screwdriver, another soak, loosen a turn (hooray!!) and a cautionary soak in wd today the cover was removed.

The tensioner works very well, lots of black grease, and the bolt in the end moves easily.

Got the two "side rocker shafts" off and able to loosen the bolts for the cam carrier but then got cold feet.  I also thought better to get the big sockets than try the adjustable on the end of the cam.

One tip is to tie the chain up so its not lost in the sump.  Another tip is to not loose the vernier pin, but what's the procedure to remove a cam?   At the moment the cam doesn't want to turn, but its chained to a crank that doesn't want to turn which may complicate things.  Do I wedge the tensioner in the "loose" position?  Seems to be I want the chain wheel off the cam at the very least...

Help!!

David

[ColinMarr]

From 40 years vivid memory: Yes, undo the big nut (22mm?) that holds the cam-wheel on the end of the camshaft. The cam-wheel will then be sitting on the end of the camshaft complete with the vernier pin protruding from one of the holes. Screw something into the threaded inner of the pin with some string attached in case you drop it. Twist some wire through one of the holes in the cam-wheel and wrap it round the chain so you don’t loose that too. Then pull the cam-wheel off the end of the camshaft, probably complete with the vernier pin and lay it to one side. I don't think you need alter the tensioner to do this - it's not that strong! Then undo the long bolts (6?) that hold the cam-carrier box to the head and the whole assembly will come away from the head with the cam still located in its bearings in the box. Then look for the head studs and nuts – and leave it for another day.

Enjoy,

Colin 

[DavidLaver]

Thankyou for the tips.  I was looking at the picture and wondering if the rocker assembly needed to come off the top of the cam box first or not.  Next visit, with the bigger sockets in the box, I should at least have the cam box off if not the head.  Head bolts all in oil and even the mucky stuff elsewhere has come loose as it should so no reason why not.

Tensioner wasn't very strong - I was a bit nervous undoing the nut as there was a big spring behind but with the luxury of another engine or two in bits can see the tensioner assembly sits on a fixed splined shaft.

With the head off is it diet coke down the bores?   Will start with WD, then diesel, then petrol.

Am taking photos each visit but yet to empty the camera.  The valve gear on an Aprilia is a marvel - it reminds me of Cathedral architecture and I could stare at it all day.  Am also cleaning up a spare Aurelia crank at the moment, again a work of art in its own right.

Thinking about my Fulvia S1 vs S3 thread I wonder if that's the key - I can look at S1 front suspension as art, and if the brakes needed servicing twice a year it would be a treat getting a wheel off not a chore.  Bolts under a hub cap and a dab of grease twice a year they'll not put up a fight like a modern car with the security key gone missing, torqued up by a teenager with an air hammer, and the steel bolt corroded to the alloy wheel.

David

[DavidLaver]

Head is off - three shiny bores and some light rust on the last but looks like will clean up ok. 

I put the vernier pin back in the cam.

Lots of dry powerder and flakes in the top of the block, will get a vacuum on it when it comes home.  Having a prod about all feels sound and the centre stud is set into good metal which I understand isn't always the case.   Chambers crusty with coke but valves look round and sound.  All the valve springs look nice.

Head nuts all came free - with the BIG bar on the socket - and spun off with finger pressure.  Noticed one of the "side rocker" bolts had sheared but that's the only casualty to date.

Bores all soaking in WD.  Am now keeping my fingers crossed that the bottom end is as nice.  What are the tips for that end?   Best to take it apart first or try and turn it?

David

[fay66]

Hi David,
Any photos please

Brian
8227

[DavidLaver]

Engine photos still in the camera - will post some when I get round to unloading.

Meanwhile here's the fact and the fiction pictures for the car as a whole, or should that be hole?

David

[DavidLaver]

The tech tip here is that the red looks soooo much better coloured with felt tip instead of crayon.  When I get a chance (find them!!) will do a blue over black with red interior as a v.tempting combination.   

Also need to do a sketch with a more honest back seat as its a bit lost under torneau and hood and the artistic licence.   Thinking about it a tracing of a photo from behind would be the next one, then use that information to make the view from the front more accurate.

These are based on a tracing of a photo of a saloon so there's no cheat on wheel size or wheel base or shifting the steering or seats.  The tarty touches are higher running boards which slims the side, a touch longer scuttle, and a much narrower tail.

David

[ColinMarr]

David,

Sounds and looks good. Presumably you are taking the engine to pieces with a view to rebuilding it! If so, I think you should dismantle the bottom end rather than try to force it to turn. The mains and big ends should undo easily and the crank should just lift out.

The point about looking for corrosion pits under all the crud at the bottom of the block is that this was a common failing – the first sign of which was water in the oil, which caused a misfire because the plugs run immersed in oil. Many a block was bodged back into use with Devcon filler, but I doubt it lasted very long.

Another familiar problem used to be severe wear of the cam-followers with a big dip where you might expect a smooth radius. Building up with Stellite and grinding back to a proper profile. And then there was corrosion of the alloy casting that formed the bottom radiator hose connector, but I guess now you could make one out of brass.

Is this a real project to produce an Augusta/ Aprilia special?  Or are you just having fun?

Colin

[DavidLaver]

Will soak and dismantle the bottom end.  The hope with THIS engine is that taking it to bits, cleaning everything, and putting back togeather will produce something that runs and passes the MOT "visible smoke" test.  If its really sound it might get the worked on head and lighter flywheel.

The other engine is rebored to suit some specially made wedge top pistons.  I lost track of the mods to the crank as it went through some itterations of plan and as with many things at BWE was "in progress" for the best part of a decade so how far it got who knows...  It still needs rods making, but I held off ordering (biiiig expense) until confident of the crank and mains which I never was.  In time will do the jigsaw and measure up and ponder - and then like everyone else take it to Reg at Serdi to do properly. 

You ask "Is this a real project to produce an Augusta/ Aprilia special?  Or are you just having fun?"   Do I have to choose?   The "excuse" for progressing it now is that I have to give back that lockup.  "Easier to move and store an engine in bits" I say to Mrs L. 

Am hopeful I can carve out a little corner at home for a mechanics bench, and find some half hours here and there for little jobs almost at random on the rest of the car.  The dash is really easy for me, the seats are a clean "indoors while the kids watch tv" job.  Stripping the bonnet would be good for moral, and at that point why not coach paint the bonnet and cowl and hang the grill and mock up the lights?  Derusting is a classic "little and often" job that is easier to do here "while the kids kick a ball about" than at the lockup "just popping out for an afternoon".

We'll see.

David

[DavidLaver]

There's a bit more on the Augusta thread.

David

[DavidLaver]

It was 27mm for the cam wheel and 24mm on the crank.  Left the crank pully in place for the moment but the bolt came loose - with the 2ft bar out of the "farmer size" socket set.

David

[DavidLaver]

...and a couple more...   

I think this looks good - not exactly what an F1 team might like but to me it all looks like it will clean up well enough. 

How did they used to look "back in the day" trying to find the "pick of the litter" in a scrap yard?

David

[ncundy]

David, it looks a very interesting project !
I don't know much about these engines but is it a wet liner engine ? If so be careful not to move the liners when withdrawing the pistons as it is very easy to disturb the seals internal to the liner/block interface and as they will have settled over time they very rarely seat properly again.
Great thread 

[DavidLaver]

Those liners haven't been wet in a while - but that's as the designer intended. 

A good tip - and as the plan now at the bottom end is to take it to bits rather than trying to turn it I can and should push each piston downwards to free it.  I'd expect the bore to be cleaner in that direction also.  What do you think about taking the pistons all the way down and out the bottom?  Out the top is conventional, having sorted the rubbish and maybe hone the ridge out first.  Out the bottom, instinctively, the bore is tighter but who knows how its worn.

With the other engine the liners were well stuck and left alone.   Anyone know if they were dropped into a very hot block to seal or if there's a ring at the bottom like an Aurelia?

David 

[ColinMarr]

David,

Looks good – and much as I might expect from a well used engine. You will have to explore right down into the wells in the block to see the corrosion pits - go gently or you might see daylight where you shouldn't.

I think Aprilia bores must have been in-situ when the block was cast - I am sure there is no lower seating ring. They are as you say ‘very dry’ and nobody ever attempted to pull them out. Re-bores were done rarely, because it was usually easier to go and see Harry and he would sort out a better block from the many that lay around in his yard, and he would probably let you have it for free!

I agree with you, soak the pistons in the bores and try to push them out from below, once the crank is out of the way.

More please,

Colin