My Alfa Romeo 33 rebuild - FIRST TIMER

[Brit01]

Managed to get a 20 sec video shot when I arrived at work today. I took it from beneath the car this time with the ticking/clicking.

(Just my luck today a bulldozer was digging up some of the grass next to our nice parking lot in the business park here!!) Have to check out the video first to see if you can hear anything over it.

Guy: Would it be ok to post a youtube video to listen to?

An Alfa friend in the UK has some original small ends he can supply to me if needed.
How likely is it that the rod gets worn too? Or is it most likely the small end shell as it's a softer material?

Also to add I remember all of the piston gundgeon rods have a tight fit into the piston ends, there was no play. The small end bearings were noticeable looser and more free flowing especially piston 3 which is ALWAYS the problematic piston and bore in this Alfa boxer due to less lubrication (design flaw).




Thanks

[TomLouwrier]

hi Chris,

Floating pins in a small end bush and in the piston have what is called a 'sliding fit'. In absolute terms it is something between 0,005 and 0.02 mm. That's pretty tight tolerances. It means if you oil up a bit it and wipe clean, it should slide in without noticeable play.

(The following is meant in the most helpful way!)
Now considering your background and experience in this field, I would say that any play you have noticed, and especially differences between small ends, means at least one of them is shot. Most likely all of them. Sorry for possible bad news, but you should not have wobbly small ends at all.

The good news: they can be replaced. Press the old one out and a new one in. Then have it reamed or honed to size: mind those tolerances and the parallelness to the big end bore. There may be oil holes that must line up or drilled through. Read your manual carefully.
Over here it's a bit of a dying art, but you may find more old skool skills in workshops near you.

The rod will not have worn, unless the play was enough to knock the small end out of round. That should be checked before the new bushes go in.
Be aware that if this is the way you go, you will most likely need new pins too. Check for any noticeable signs of wear, especially where the pin sits in the small end. If you notice marks, ridges, or anything you can feel with your fingernail, junk the pin.

Show us some good pics and we'll be able to help you.

regards
Tom

[Brit01]

Many thanks Tom.

Sorry for possible bad news, but you should not have wobbly small ends at all.

Not bad news at all, if we've found the issue then it's the best news even if I have to take the engine apart again. wink!


I will plan on replacing pins and shells probably in December.
I can get new Alfa original ones from Argentina luckily.

Do they still need reaming or honed of both pin and shell are new original Alfa matching parts?
I thought they would be set to a perfect fit from the factory if they were new.

The right bank always has more wear than the left bank due to the pistons being higher.
This is where I noticed play.

Only have a shot of piston 1 at work here. I'll post more at the weekend.

[TomLouwrier]

They always need reaming or honing after pressing. Always. You compress the bush as it goes in and it's not realistic to set them up so they are within operating tolerances afterwards.
In the picture I already see one of the oil holes I mentioned, top side right under the piston.

That pin shows some brownish marks, can't tell you how serious. You should clean it carefully with something like wd40 and scotchbrite, then see if it still is completely smooth and unmarked. Like you would do with valve stems.

regards
Tom

[Brit01]

Yes each one actually has 3 oil holes drilled into the top.

I'm planning to replace the right bank pins and small ends this December. Left bank sounds smooth for now and really won't have enough time I think (and running out of funds!).

It was the right bank that had the looseness (and clicking) but I will look into the photos when I get home.

Right bank always has less lubrication on the boxer as mentioned.

Thanks very much for all your replies and assistance.

Maybe next weekend I'll have a pair of new pins and shells.

I have a friend who knows a workshop who prepare cylinders/rods/honing etc and can prepare these.
Looks like I'll have to take some days out of my holidays to travel to the workshop to get this done.
Try to get it arranged so he can do it the same day.
I didn't know the small ends needed honing after fitting.
wink

[Brit01]

Any kind of additive I can add to the oil in the meantime to reduce the damage while driving until I can get it off the road? Maybe a bit of molykote paste (assembly grease)?

I will drive much easier to put less strain on the small end until it's out.

(my stepfather just said I learnt my lesson and should have changed both small and big shells at the same time speaking from experience in his case).

[Brit01]

Getting familiar with the engine sounds now. Not a tappet sound now, was before as you saw with the damaged tappets and lobes (maybe hiding the sound of the rattling small end).

Listening today carefully sounds like the a small end 90% sure.

Anyway my alfasuds-parts friend is sending me some originals from UK for a very reasonable price. smile.

New mixture screws with the o-ring fitted worked nicely today, also the old bosch fan worked better on the new aluminium radiator than the cheap chinese thin multi-blade fan.

Will be looking for a new water sender unit tomorrow in the range of 82/87 instead of 80/90 which seems a little extreme to me especialy for hotter climates.

Regards

Chris

[Guy Croft]

Some good posts there and I'd like to thank Tom especially for sound engineering advice he has so willingly put forward on the rods.

G

[TomLouwrier]

My pleasure.

Chris,
There is an old old saying in Quality Management: "We never have time to do things right the first time, but there's always time to come back and repair it twice..."
I realize you're getting shortish on both time and cash, but if you're going to tear down the engine again to repair the rods, what's the real savings in doing just two? You'll be back here in no time saying "Oh, why me, the ticking's back again (cry)".

So before you'll learn another lesson: do them all, properly, while you're at it.

Give my regards to your stepfather ;-)
Tom

[WhizzMan]

You already arranged for "original" small ends, but there really wasn't a need for that. Any engine workshop worth their pay will have access to perfect bearings. There's nothing special about these, just the diameter and the material chosen.

There is no substitute for the material missing. Moly additive will maybe help a little in general wear, but I wouldn't put that in an engine that still is running in. Apart from that, it's not just friction that is causing damage here, but the play in the bearing will effectively make the pin "forge" the small end out of shape every time the piston changes direction.

You could take your chances and run it on low revs and low load, until you have time to replace the small end. This will also mess with your running in regime, so if at all possible, I would not drive it. It may break, it may influence the quality of the engine later on, even if it doesn't break.

[Brit01]

You'll be back here in no time saying "Oh, why me, the ticking's back again (cry)".

So before you'll learn another lesson: do them all, properly, while you're at it.

Thanks Tom/whizzman,

yes you are right, lesson learnt already. I will change all four.

Still will buy them from UK, original parts.
The workshops here unfortunately can and often use inferior materials (especially on shells) and it's a lottery.
Learnt my lesson on this one in Uruguay.

I know Peter who sells the Alfa parts and he's always been a good supplier of NOS parts from the UK.

Thanks chaps

You could take your chances and run it on low revs and low load, until you have time to replace the small end. This will also mess with your running in regime, so if at all possible, I would not drive it. It may break, it may influence the quality of the engine later on, even if it doesn't break

I wish not driving it was an option now but this is unavoidable the weeks coming up to summer and holidays especially as we have an 18 month old with trips to a beach house down the coast (where I'll be working on the car 'smile').
Have to drive it carfully and softly until it can be parked in December.
Luckily we don't use it everyday but will have some highway trips to the beach house in the next few weeks.

[Brit01]

At the beginning of this project we know the tappets were very badly damaged and were ticking like a sewing machine. I believe this was masking the small end bearing clicking.

The past week listening carefully it is a slightly different sound now and knowing that the tappets and cams are new I guess we can assume it's the small ends even before I remove them to inspect.


p.s getting new circlips also as Guy recommended. wink.

Well after listening again with headphones you can get something out of this badly recorded video with wind and a bulldozer working about 100 meters away! (Thanks Guy for his permission).
Engine hot and idling albeit a bit fast.
http://www.youtube.com/watch?v=vo2fe_0r_C8

I was listening to piston slap videos and very different - some sounded like a large diesel tractor really horrific.

Regards

Chris

[Brit01]

Ordering some plastigauge this weekend to double check the crank journals while I'll be in the crankcase again.

They should be 0.026mm - 0.063mm.

So Engine building. Bearings 0.001"-.007" is the one I need I believe.

Pack contents include 10 lengths of 0.001"-0.007" 0.025 mm - 0.175mm

Maybe after rebuilding and a slight run in with semi Valvoline 20w/50 I may go back to Motul 300V 15W/50 full.

What do you think? Good oil choice for a clean engine?

[Brit01]

Or even Castrol TWS 10w/60. Good thickness when hot. Not sure yet but many sprint owner in the UK have been happy with 10w/60 in their boxers.

maybe I'll use the plastigauge on the main crank bearings also as this wasn't done before, just a rough check on the underside shell with the crank in place.

QQ

If the bores on the pistons of the gudgeon pins are worn can these be repaired or does the whole piston need replacing?

I don't recall any play in these at all, when I slid them out they were tight but I've learnt a big lesson so far and don't want to mess it up again. (imagine a 3rd rebuild).
I have used up 8 lives with my wife so far - just 1 left! lol

[WhizzMan]

Worn out pistons need replacing. This hardly ever happens on these engines.

Don't assume anything on your radiator coolant temperatures. Measure with a calibrated thermometer. Blindly changing thermo-switches without proper proof your engine is running too hot will most likely just cost you money, not improve the car. Measure first, before spending money or concluding anything. The aging and inherent inaccuracy of thermo-switches will make the stamping on the outside totally irrelevant within a year after placement.