Aprilia Cabrio - here we go again

[simonandjuliet]

Yes - some welding to do ! - It does look a bit like a dysfunctional noughts and crosses and David, I am not sure there would be many in the LMC who would find trailing arms as "sexy" as we do here ......

Good news on the parts-searching-front, I have found a Zenith carb and all the bits to fit it correctly, plus a correct starting handle.

NB there is a VERY dodgy chap in Italy who advertised a starting handle, with photo , but when it arrived it was completely different to the photo (not Aprilia) and did not fit either of my cars, plus he would not accept it back - I would say that was fraud

I rarely share bad experiences like these because they can get lost in translation , but not here, I have the proof !

His name is Giovanni Mungo from VintageItalianCar - avoid like the plague

[the.cern]

Thank you for flagging that one up for us!!!

I'm glad you managed to source the correct handle anyway!!!

[Lapsed Cesare Ferrari]

I am sorry to hear that Simon has had a bad experience with Giovanni Mungo. I have had a few useful things from him, and he sells excellent remade Aprilia hubcaps.
Caveat emptor though of course.
Cesare

[simonandjuliet]

More positive news this time - my chrome is back ...... and it is beautiful ! Most of it is still wrapped up but here is a sneak preview of the steering wheel. At the Avignon Motor festival earlier this year I met some guys who are based near Beziers but who work with a company in Barcelona . There is little or no chroming done in France now , only spray chrome where it is done .  I am very happy with the quality and the price seems reasonable (although still expensive !)

I tried out the new carb/linkage parts to see if everything is there - seems OK, I just need a small modification on the end of the butterfly spindle to locate the horizontal bar

Plus, the great clean up continues, the sump has probably taken 2 days to clean up if you include stripping the oil pump, taking the filter apart etc. The sump plug had to be drilled and cut before it would move.

Last job was to remove the gearknob so the lever can be re-chromed - another job for the heat induction thing because there was no way I could unscrew it by hand. A bit of gentle heat and it unthreaded easily without any damage to the bakelite

[davidwheeler]

I see you have solved the problem of engine suspension springs but, please tell us, how do you get the engine to levitate in the engine compartment?

[lancianut666]

That throttle linkage looks like it could of been part of the Titanic...
Clarkey

[stanley sweet]

That steering wheel is just gorgeous. How was it chromed? Do the spokes and boss detach from the bakelite?

[simonandjuliet]

David - it is a bit Harry Potter - "crankcasaium leviosa" and the Titanic had nothing on an Aprilia, they last a lot longer !

Stan, the wheel had a corded grip that I had to remove (will find an old photo later) then hub and rim were rechromed , the boss and centre were done separately. I will unwrap everything later in the week and take photos. At some point , I will find a way of re-doing the wheel with string/cord. Last time it was green , I will reflect on that one !

Next batch of chrome has gone off to be re-done

Having cleaned up lots of bits, it is time to start putting them back together. I started on the bottom end of the engine today. The machining has been done by Serdi UK - new pistons & liners, NOS conrods fitted with shells, ground crank, white-metaled mains , new studs etc etc - I have bought houses for less than this all cost  ...... but it is beautiful !

However, you still have to check it all. The oil pressure relief valve was completely gummed up, blocked and needed cleaning , also the big-ends have split pins and once you have the oilway fitted the split pins fouled it, so they needed to be trimmed. You also have to be careful how the baffle plates are refitted because they will go back both ways but need to be forced one way which risks breaking the vertical plate mountings - I think that this is the correct way !

This engine is made up from a number of donors (not surprising after nearly 80 yrs) so it is back to square one for the timing. So a new TDC has been identified, distributor drive synchronised and new timing chain and wheels fitted.

To get the distributor drive right I set 1&3 at TDC , left out out the peg (can't remember the correct word !!) on the crank so that the front pulley and drive can move, rotated the dizzy driveshaft so when it was pointing to #1 , the +ve supply and capacitor are 180° from the block and don't foul - allowing future timing adjustment. Once done , the peg was refitted

Aprilias don't have modern oil seals , but spiral throwers - a thread on the front and back of the crank that uses surface tension to return the oil back to the crankcase, so it is important to ensure that the surfaces are clean and even. I am sure that someone can explain this much more clearly ....... it is all very carefully machined and no sump gasket is used, so again all surfaces must be clean and have no damage.

So , bottom end finished , next is the top end . I have found everything , now I need to see what needs to be replaced/machined ..... and while I am waiting for that I can start on the ancillaries - for example, I need to get a working petrol pump and filter from this lot !

[davidwheeler]

Yes, Serdi are excellent but, beware!  You have an engine assembled from many others, i.e. a bitza.   NOS con rods (qu'est que c'est?)?    When they did mine they made some new con rods in steel as they reckoned that the original alloys would break.  As the originals weigh 600g and the new ones 800 g (from memory) the engine was wildly out of balance, unbeknown to me.    Vibration Free, to whom I took it before putting it in the car justincase told me it nearly jumped off the rig.   Narrow V4s are very fussy indeed about any change in the mass of the components.  At the very least I would advise running it on the bench (with radiator attached of course - you can use crankcasia leviosa again to simplify matters).   It should be smooth as silk and any vibration should earn it a trip to Vibration Free (assembled short engine minus piston rings but with a set included for them to apply appropriate weights to the piston tops).   In fact, if it were mine, I'd send it anyway.   If it is sweet it costs little as they charge by time (the Aprilia took so long that they only charged me 1/2 time as a favoured customer I suppose - or they were a bit embarrassed on my behalf). 
p.s. I am surprised cankcasium leviosa worked, I am sure the Latin Grammar is wrong but I do not have my wand with me at the moment to try them out.

[simonandjuliet]

David, thank you for your comments. I deliberated long and hard during the rebuild process about steel rods and decided against for 2 reasons - 1/ I didn't want to increase the reciprocating weight and then have to re-balance everything, as per your experience & 2/ I have a number of original, new and unused conrods that haven't been through the same mechanical "challenges" as most 70 yr old rods.

I also decided not to increase the engine capacity or increase the compression ratio and to stay roughly with the original setup. As with everything, time will tell !

In between wine-sales planning (we are shipping a small quantity of wine to a bonded warehouse in the UK for interested parties - please let me know if you would like to buy a case ....) I have been busy with the top end today

Head has been de-coked, fitted with new valves & springs. One of the inner springs was broken on this head, so I decided to change the lot - I have several sets of new springs if anyone is interested. Head has been painted and is now ready to fit. The old-school spring compressor was good for 7 of 8 valves .... the last one was done with a push type compressor which leaves a bruise on the solar-plexus

The rest of the afternoon was spent dismantling, cleaning and rebuilding the rocker gear.

Aprilia rocker gear can suffer from poor lubrication due to insufficient oil changes and a poor filtration system - compare the 2 cam followers - so I have gone through my spares and chosen the best followers I have and also fitted all new tappets. Some of the followers just need a light stoning but others were way beyond.

I had to remove the end plugs (just like core plugs) of the central shaft to clean it properly, all the lubrication holes were blocked and the rod was filled with a sludge that would have been more at home on the Brent oil fields

The cams suffer equally badly, and this is the best one I have . It has an unusual peg on the back , so presumably was for a rev counter or something ??

A few gratuitous photos to satisfy the detail-loving amongst us !

ps I made a new bracket and fitted the coil in the correct position .......
 

[simonandjuliet]

Next phase started today ..... the shell has gone off to Dog's new workshop for final welding and painting - it does mean that I will have to choose a colour scheme !

The shell is remarkably light once all the bits are removed, 2 of us managed to push it up onto the trailer very easily.

My garage now seems very empty so first job is to clean up and put everything away

[Parisien]

Simon, as ever fascinating stuff and great to hear how well things come together and the immense satisfaction everyone gets who read and reply to your threads.

Took this photo in Paris (Rue Charonne) its appears theres a classic/vintage bikers meetup there on a Sunday, thought it was amusing!

P

[stanley sweet]

You can't have an empty workshop! What are we going to read? Wheel the Fulvia in!

[JohnMillham]

You could add that at stage 3 take feeler gauge measurements 'till the two clearances are the same.
 Regards, John

[davidwheeler]

"Aprilias have a slightly odd cylinder numbering system, starting with #1 nearest the rad and then going around the head clockwise, not staggered with distance from the rad (ie on an Aprilia #3 would be #4 on a traditional numbering system)

However, firing order is in the opposite direction ie anti-clockwise - 1,4,3,2"

Same for Lambdas and, presumably, Gussies and Artenas also.  Cannot remember if it applies to the Fulvia (and I am not going to go and look)!