Lubrication problem on Alfa 33 flat-four engine

[16valvole]

Hi all,

I have an Alfa 33 16V for racing and I'm experiencing problems with lubrication.
The main bearings seem to last but the rod bearing no. 2 always shows excessive wear. I am running good oil (10W60) i.c.w. a modyne oil cooler and temperature never comes above 100‚°C

Nnow I have modified the oilpan but the problem persists.
There must be a design error in these engines. I did notice that the bearings 2 and 3 are lubricated through 1 line from the main oil passage, where the bearing 1 and 4 have a separate line. Could this be the problem?

Any help is appreciated.

Photo's of the modified oilpan

[Guy Croft]

Hannes hi

Firstly - I am not aware of a design problem with the motor. It is common to say 'oh, those engines always run bearings, bad engine design' whereas in fact the problem always tends to be something else. I have never actually found a 'bad engine' as such, although some suffer more than others from lubrication related problems, and prep of the lubrication system is something I spend a lot of time advising.

I think you either have a build-prep problem or - simply oil starvation. I cannot remember the design of that particular crankshaft so when you have it out of the engine publish a good photo showing the crank main and big-end journal oilways and any oil drillings in the crank webs, please.

Please state what preparation you did to the block, crank and rods, include details of how you measured everything prior to build. Tell me the last time you had this crank checked for straightness. Is the crank flywheel assembly balanced?

I would suggest perhaps that you should be considering an oil pressure accumulator to supplement the baffled sump, this device will sustain the oil pressure. If you search here by 'Moroso' you will see what I ma talking about.

GC

[16valvole]

Hannes hi

Firstly - I am not aware of a design problem with the motor. It is common to say 'oh, those engines always run bearings, bad engine design' whereas in fact the problem always tends to be something else. I have never actually found a 'bad engine' as such, although some suffer more than others from lubrication related problems, and prep of the lubrication system is something I spend a lot of time advising.

I think you either have a build-prep problem or - simply oil starvation. I cannot remember the design of that particular crankshaft so when you have it out of the engine publish a good photo showing the crank main and big-end journal oilways and any oil drillings in the crank webs, please.

Please state what preparation you did to the block, crank and rods, include details of how you measured everything prior to build. Tell me the last time you had this crank checked for straightness. Is the crank flywheel assembly balanced?

I would suggest perhaps that you should be considering an oil pressure accumulator to supplement the baffled sump, this device will sustain the oil pressure. If you search here by 'Moroso' you will see what I ma talking about.

GC

Hello GC,

thanks for your reply.

The engine was rebuilt from 0, we took everything apart and took upmost care when assembling.
The crank was absolutely straight and in perfect condition!
Crank, flywheel and pulleys are balanced together.
rods/pistons are also balanced, bores were flexhoned.
A new oil pump was installed.

It's not only with this engine, they other engine suffered from lubrification problems too.

This oil accumulator seems intersting. Can you give a price indication, maybe for a 2 quarter model with the electric valve. Is this oil accumulator usefull on a fast road/ occasional track day car like a Lancia delta?

[Guy Croft]

Hannes, hi

Yes - but I want to be sure that you don't have a crank oilway problem, please read about crossdrilled cranks at:

http://guy-croft.com/viewtopic.php?t=103

It is vital that cross-drilled cranks are unplugged for cleaning. Please let me have some background on yours. I am also interested in the condition of the holes in the crank - oil galleries, there must be a good radius (well polished with no sharp edges). I'd like to see a picture. It is vital to deal with these after a crank grind for example.

Some detail please - not just 'we did everything carefully', OK?

GC

[simon-spanner]

I built and looked after a Lancia Flavia sport Zagato for several years.
This is also a flat four engine. It suffered from horrendous oil surge, I tried everything-baffling the crankcase, accusump/accumulator, etc nothing worked..

The oil would flow up from the crankcase and into the heads in corners and couldn't drain back quick enough to stop the oil pump pick up from being uncovered.

We were replacing big end shells as a matter of course after every race meeting. Eventually I converted the engine to dry sump, problem solved...
Not cheap, not strictly legal for the class of racing, but it worked. The engine eventually exploded at 8000 rpm at the top of Eau Rouge at Spa Francorchamp when a rod bolt snapped

[TR-Spider]

I think Simon raised an interessting point with the oil flowing into the heads (of course horizontal-placed on a boxer engine).
On the other hand on the photo of the Alfa sump there seem to be trapdoors already on the drain inlets (can't see exactly on the picture)?

An Accusump should improve matters, at least it did so on my Fiat 124 with Argenta sump. I can even observe the Accusump kicking in by the oil temperature dropping. Certainly my best investment into engine safety. But if the corner is longer than the Accusumps volume, there's pressure loss again (so don't do roundabouts all day...)

Thomas

[16valvole]

Hannes, hi

Yes - but I want to be sure that you don't have a crank oilway problem, please read about crossdrilled cranks at:

http://guy-croft.com/viewtopic.php?t=103

It is vital that cross-drilled cranks are unplugged for cleaning. Please let me have some background on yours. I am also interested in the condition of the holes in the crank - oil galleries, there must be a good radius (well polished with no sharp edges). I'd like to see a picture. It is vital to deal with these after a crank grind for example.

Some detail please - not just 'we did everything carefully', OK?

GC

Sorry but i don't have a picture of the crank itself, i've lost some when my pc crashed. I did not prepare the crank myself but yes the oilways were cleaned and the holes were chamfered corretly and nicely polished.
I will need to ask him how exactly he cleaned the oilways because there are no drillings in the crank web.
The crank was in good condition and not regrinded.

Attached is a picture of the oil ways of the boxer engine. As you can see, the second main journal must deliver oil to 2 conrods and i think there is the real problem.

I will need to try this accusump i think, maybe a 2 quarter model to give me some extra cooling too.

On the other hand on the photo of the Alfa sump there seem to be trapdoors already on the drain inlets (can't see exactly on the picture)?

Thomas

Yes, you are right, there are trapdoors on the oil return lines, preventing the oil from going in during cornering.

[Guy Croft]

OK, well done.

Let us assume that there is not a problem with the crank prep. I am tempted to suggest that this is simply an oil starvation problem. I cannot see from the sump photo whether your sump has trapdoors. I do not know if the sump has boxes on bothe left and right sides, but certainly if you have added boxes with no trapdoors (search this site for info by me on 'big wing sump') it makes the oil starvation problem worse because the oil can travel even further from the oil pickup than before.

If you have trapdoors - then yes the answer is an accumulator. You can find info on those if you search this site by 'Moroso'.

GC

[16valvole]

OK, well done.

Let us assume that there is not a problem with the crank prep. I am tempted to suggest that this is simply an oil starvation problem. I cannot see from the sump photo whether your sump has trapdoors. I do not know if the sump has boxes on bothe left and right sides, but certainly if you have added boxes with no trapdoors (search this site for info by me on 'big wing sump') it makes the oil starvation problem worse because the oil can travel even further from the oil pickup than before.

If you have trapdoors - then yes the answer is an accumulator. You can find info on those if you search this site by 'Moroso'.

GC

Thank you for your advise.
The sump has trapdoors on the oil return lines (see photo). On the second design we've added a labyrinth of baffels inspired from the Alfa 75 sump. This was to keep the oil close to the pump pickup.
The splash plate also has the return in the middle, making the oil go in the sump as close as possible to the oil pump pickup. We did some tests with an old fuel pump and gasoline and saw that there was a huge improvement to the original sump and the labyrinth was also helping. If somebody has more ideas on how to make this sump better, i would be happy to hear it.

I've been reading a lot about the oil accumulator and i have on question.

There are a lot of 2 quart oil accumulators for sale on the net, but is this not overkill on this engine. I mean, if i put a 2 quarter model, i would have 7,5 litres of oil in total.

Hannes

[TR-Spider]

I think Guy is right, without trapdoors the boxes are of no help.

The basic idea behind the "wings" i.e. boxes on the side of the pan is to create a storage. This storage must be "sealed" by a wall with a hole towards the pump pickup and a trapdoor (and some holes/gaps for filling).
In a corner, the inside box evacuates through the (opened) trap-door hole directly onto the pump pickup while the outside trapdoor is closed. The volume of the box defines the additional time your pickup is covered. Without wall and trapdoor, the oil will just swap to the other side over the whole width of the pan...centrifugal forces do act on the oil.

Thomas

[Guy Croft]

Sorry but I cannot identify the necessary detail in that photo, it's blurred, too close and way too big, please replace it with something superior in detail and quality, you've taken it so close that I cannot ID where the trapdoor is actually located.

As far as trapdoor baffled sumps my article here may help.

http://guy-croft.com/viewtopic.php?t=48 ... =wing+sump

You could use a 1.5 qt or 2 qt accumulator, the capacity is really determined by engine size and how effective your wet sump is and the duration of the turns. In a very long turn with high oil temperature (I recommend 85deg C) even the biggest (Canton 3 qt) device will empty eventually. You have to pick a size that you think is right and hope the red light doesn't come on.

GC

[16valvole]

Sorry but I cannot identify the necessary detail in that photo, it's blurred, too close and way too big, please replace it with something superior in detail and quality, you've taken it so close that I cannot ID where the trapdoor is actually located.

As far as trapdoor baffled sumps my article here may help.

http://guy-croft.com/viewtopic.php?t=48 ... =wing+sump

GC

I read the topic carefully and my sump is pretty same to the one presented.

I think i understand your question GC

Sorry for the large foto i will take a better one when i take the sump of. The trapdoor on the 'big' foto is the one from the cylinder head return line. There are two other trapdoors that are placed on the acces from oil pickup place to the wings of the sump. The wings of the sump are not 'open' but closed by trapdoors. This was probably what you wanted to know.

I will have a closer look at this moroso. Can you send me a price indication for a 1,5qt moroso with electric valve?

You you sell modified sumps for Lancia delta turbo engines?

[Guy Croft]

Hi

I don't have time for fabrication these days, I am sorry. Price on Moroso 1.5 qt with solenoid pre-oiling valve is in GC V/W pricelist. In fairness to all I try to keep the site relatively non-commercial so forgive me for not publishing price right here.

If you e mail me I can send you my hose layout draaing for an accumulator system too.

GC