Alloy con rods

[welleyes]

Over the decades, I have read and listened to discussion on alloy rods in old engines. The consensus seemed usually to be that, after seventy plus years inside an engine, they are a bad thing. You could usually tell who had alloy rods because they would stay at the bar looking worried. Our Aprilia had what seemed to be a perfectly good engine though not one we had worked on or seen inside. As of yesterday, we know the inside of the engine all too well; a rod broke about two thirds of the way down from the little end. On its way out, it wrote off the block and the sump. Head is not off yet so we do not know if the liberated half of the rod complete with piston has done other damage. The engine will be rebuilt with steel rods. Does anyone have any comments? We are not soliciting sympathy, just curious to know if we were very unlucky or if seventy five year old connecting rods were a disaster threatening to happen imminently.

Stuart

[JohnMillham]

Sorry to hear that. I did hear a long time ago that a boffin at RAE Farnborough had worked out that ALL Aprilia rods would fail within a few years, due to their age. He was plainly wrong, but I don't think I'd trust them for ever. I have had (steel) rods made for both the Augusta and Lambda by Phoenix Crankshafts at Slough and been very happy with the results.
 Regards, John

[the.cern]

Sorry to hear that Stuart, an unscheduled engine rebuild is not a good thing, although you should be able to look just a tad smug at the bar after it has been done!!!

Now to display my ignorance, John, do Augusta  engines have alloy con rods? if not why did you need to have some made? Please, is someone able to advise on this issue with regard to Aurelia and Appia engines? I would like to know, although often, 'ignorance is bliss'!!

Hope the freed piston has not caused any additional problems and the rebuild is straightforward.

                                         Andy

[simonandjuliet]

Very sorry to hear about your problems and I hope that you manage to source all the necessary bits. Not sure which series your car is,but If I can help with any bits, please let me know as I have some 1st series spares (mine is 2nd)

Re conrods, be interested to hear about new steel ones, weight vs. ally rods, approx costings etc

[DavidLaver]

A VSCC friend got alloy rods made in the states - I think for a Hyper Leaf.  From the number google throws up I bet somewhere like Arrow would make alloy ones in the UK now. (or Doug Kiddie, Farndon, Phoenix, who else?)

Seem most likely for a small batch of an odd size:

  http://www.rrconnectingrods.com/aluminum-rods/aluminum-rods.html

As used by Barry Waterhouse for strange pistons - including Fulvia wedge tops.

   http://www.venolia.com/forged-rods.html

http://www.bmeltd.com/rods.htm
http://www.grpconrods.com/
http://www.mgpconnectingrods.com/innovations.html
http://www.manleyperformance.com/master_catalog.shtml
http://www.lightningconnectingrods.com/
http://www.ohiocrank.com/rodpage1.html

David

[DavidLaver]

The other thought is if we all promised to behave and not exceed 6000rpm or something one of the UK suppliers might do us some fragile looking rods of the right sort of weight.  Lighter pistons might help the cause as well.

As for a written off castings its amazing what gets welded up these days...

David

[welleyes]

I think we shall be going for steel rods. Early days; the engine only let go two days ago. We had three spare rods... please note, three... so someone had a rod break before. We do realise that new aluminium rods might last at least another seventy five years which we will not, but I think we would feel happier with steel rods. At least this gives us time to sort out one or two other problems.  The door trouble we have had is a consequence of severely worn hinge pins so that is fixable. Our Morgan tricycles seem much more sensible in that respect as they do without doors altogether. Not a good idea for a saloon car, of course.

Stuart

[ben]

Hi Stuart
          Please add my commiserations to the pile.
          I had something similar happen to my original engine back in the late sixties.
          I have always assumed the primary cause was seizure of the big-end so I will be very interested to hear if there is evidence of this in your case. Also what type of  big end it is, ie original direct on the rod or thick-walled shell or white metal direct into the rod or a more modern thin-walled shell.I have come across all these in various engines.
          What sort of revs were you doing when it happened?
          I have just rebuilt a series 2 engine using S1 ally rods machined to take thin-wall shells but I have not run it yet. Maybe I should leave it on the bench and retire to the bar!
          David Wheeler went down the steel rod route and will tell you that the extra weight makes it important to have the assembly balanced. I was put off this route by the cost. Also the original ally rods are a thing of great beauty.
          Finally if you need a lead as to where a spare block may be had, P.M. me.

[JohnMillham]

Now to display my ignorance, John, do Augusta  engines have alloy con rods? if not why did you need to have some made? Please, is someone able to advise on this issue with regard to Aurelia and Appia engines? I would like to know, although often, 'ignorance is bliss'!!



                                         Andy

  As far as I know, the Aprilia was the only Lancia to have alloy rods. I chose to have new rods on the Augusta (and on the Lambda, come to think of it) because I was in for some expense anyway, converting them to take shell bearings. It wasn't a great deal more expensive having new rods made and the new rods are much stronger than the originals, which were "delicate" to say the least. I also took a lot of trouble with the balancing of everything.
Regards, John

[the.cern]

Thank you John, at least that is one less thing to have to consider with the Gussie and the B20.

                                             Andy

[welleyes]

I have the big end of the broken rod in my hand. Bearings are bronze backed thinwall. The rod is stamped 'Lancia 1947' and on the other side is stamped a five pointed star. Bearings and journals seem fine with little wear.  This is the first time we have seen inside the engine other than the top end. It appears to have been well rebuilt but there are also signs of some very careless workmanship with a large foreign body in the sump. This was not implicated in the rod failure. When the rod broke, the car was pulling out of a junction in a thirty limit so excessive revs were not a factor. The car has been pretty kindly treated in our hands with no motorway travel. I suspect that the previous owner had a more liberal attitude.

I wrote at the start of this thread that I had listened to discussion on alloy rods down the years without being personally involved. The general feeling always seemed to be that nobody expected the cars to be on the road for more than a few years and that it was amazing how well alloy rods were lasting. The problem is that one never knows the entire history of an engine. Over a period of three quarters of a century and numerous owners, the red mist will have come down a few times, I am sure.

Our thanks to everyone for help so far. I think that we may have useable block and sump subject to passing a closer inspection. Fingers crossed! I think there will have to be a rake out of non-Lancia bits to raise money thus justifying keeping spares for cars we no longer have.

Stuart

Stuart

[BlueSky]

Along with everyone else sorry to hear about your engine disaster! Joe Wilson down here in Australia also used Phoenix Crankshafts to make some steel rods, and a new crank, for his 1st series Aprilia. He had a local engine man balance them and it has run well ever since. You've now got me thinking about what's inside my engine...
Noel

[brian]

As an Aprilia tyro I am beginning to worry about my S1. It has had a very tough life (ask chugga boom!) but now is bodily restored. All the talk about short-lived con rods reminds me that in 1988/9 on way to LMC AGM, my Augusta broke a con rod and cracked crankcase and skirt of liner in block. I think was due to vibration down to a monstrous mis-profiling of a camshaft by a national company allegedly specialising in such matters.
Should I think about preventative medicine and sort steel rods? It would be shame to have done the body and eventually trim to be laid low by a (?foreseeable) disaster!
PS
Let me add that am a total convert to the Fora - Flavia, Augusta and Aprilia especially. Semper floruent - or similar if I remember my 1964 Latin O level

[the.cern]

Semper floreant I think, but I only got a B !!!!!!!!!!

[davidwheeler]

A few years ago I had my engine rebuilt by Serdi and they got me some new steel rods made with conversion to Renault thinwall shells.   However, aluminium rods weigh 600g and steel ones 800g. This puts the engine wildly out of balance.  Vibration Free told me that it nearly leaped off the rig when they started to spin it up.  In order to balance it they had to put a lot of weight on the crank pulley and drill some big holes in the flywheel.  The engine is now as smooth as silk but don't think you can just fit steel rods without re-balancing.  It took them about ten hours to get it right, of which they only charged me half.  I would imagine they could do it a lot quicker now having done mine.
I routinely hammer down the motorway at 70mph.  She shows no signs of distress!