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Discussion Starter #941
The bearings were new manufacture, and now I’m thinking they came from CA.

This is a no-oil problem. But that’s about all I’m sure about.

When first started, pressure would go to about 60%. Typical Alfa. After oil temp came up, pressure at 3000-5000 about 35%-40%. Not acceptable. I checked and cleaned the pressure release valve, and added a washer under the spring. Pressure at start (cold) went to about 75%, showing that the unshimmed spring had been correctly controlling high pressure. Pressure when warm, still about 35%-40% at 3000-5000.

So, I’m not expecting release valve is the problem. I just wish it was.

I’ll post a pic of the bearing shells later, but the mods may yank the post for being gratuitously horrific.

After I get a new compressor (tank died), I’ll do more flow checks on galleys. It is pure conjecture, but it’s as though there would be a little flow at startup, but then something loose would block at a critical point, shutting down flow.

I’m expecting new head gasket(s) Monday. Replacement engine complete Tuesday. Maybe installed also.
 

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I don't want to distract you right now from getting the 2nd engine running. Feel free to ignore my questions -- either completely or until you have more time to analyze and/or comment on the failure -- I'm sure the post-mortem will become a very interesting (but unfortunately, for you, also frustrating part) of this thread.

Could you also tell us what oil you were using? I the past, I got the impression that synthetic 20W50 oil resulted in less pressure at operating temperature than 20W50 mineral oil -- i.e. that the viscosity was not the same despite what the label said.

Did you intend to use a different oil for the break-in period than for regular use? I heard from engine builders that they use a thinner oil for the first 20-50 hours of operation to let the rings get seated.
 

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I twisted off a bolt holding the pressure plate on. Here's a pic... It appears to have been a casting flaw that allowed corrosion to work along a fault line within the head. The shiny hole in the top of the remaining bolt was a drill-hole for the easy-out.
That is an interesting bolt failure. I've seen quite a few bolt failures, mainly during manufacturing, 'in the line of duty' -it's an occupational hazard. I've also caused a few fastener failures of my own. Bolts like these are cold headed from wire rod, or wire, if they have tight tolerances on size or tensile strength. Usually the entire head pops off the shaft because the radius is too sharp. Seams generally show up along the length of the part and when the blank is headed, the 'head' cracks open.:surprise:

It might be worth the extra expense to replace the other five pressure plate bolts and why you are in there the flywheel and guibo bolts...

Mark
 

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Discussion Starter #944
Mark.... alas

There is not an infinite supply of new, LOBO bolts.

The three special shoulder-bolts are new, sourced from AFRA. It was one of the three standard bolts that failed across the head. I have plenty of these standard M8-1.25 bolts, so replaced it with a good unit. As you can see, it was not over-tightening that caused the failure, rather an entrained corrosion. In 50+ years of playing with tools, this is the only one like this I’ve seen.

This engine was given its first start on Valvoline VR1 20W-50. After the 25 or so initial KM, I drained this oil and replaced it with Valvoline VR1 50W. I had noticed the low oil pressure during the last two drives, which had been long enough to warm the oil, so thought I’d see what the heavier oil produced.

It was on the next drive that things went pear shaped.

It seems unlikely that straight 50 did any harm. More likely the low pressure was indicating the impending failure.

Hit 10,000 miles in 00072 today. Bloody hot out, but he thunders on.

Picture of intact plug noted by Franco. This plug didn’t get removed for rodding during the overhaul, but early testing shows good flow through the rear main shell.
 

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This engine was given its first start on Valvoline VR1 20W-50. After the 25 or so initial KM, I drained this oil and replaced it with Valvoline VR1 50W. I had noticed the low oil pressure during the last two drives, which had been long enough to warm the oil, so thought I’d see what the heavier oil produced.
I had a similar 20-50 low oil pressure with a Maserati 3500 Sebring i once owned. The factory shop manual actually mentioned straight 50 being preferred for sustained high speed running or in hot climates. Switching to the straight 50 (all 16 quarts of it) did the trick and I had good oil pressure.
 

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Discussion Starter #946
I like the Valvoline VR1 50W Racing oil, as it contains plenty of zinc, preferred for our flat tappet engines. I don’t mind giving it time to warm up before pressing the loud button closer to the floor. I’ve also been using their VR1 20W-50 with no reduction in pressure. Like all Alfas I’ve had, the idle pressure can appear quite low, but it comes up as soon as the revs come up.
 

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Discussion Starter #947
Engine B installed

I received the urgent order from CA. Aren't they wonderful? I noted when ordering a new head gasket that they were offering an Elring-made unit! WOW! Not cheap, but boy is the quality nice.

Anyway, it arrived yesterday, and today I bolted together the B engine bottom end with the A engine top. Then, my son showed up, and we put the rest of it together and installed it into the car. Normal fiddling about the drive shaft and giubos, but as I write this the power unit is in place, with only a short list to complete tomorrow before a first-start. I expect to drive it before mid-afternoon, unless........

I've spent no time researching the failure, as I want to get the car rolling again. Plus, I need either a new compressor or a new tank, as mine ate its bottom out. Yes, probably due to neglect.

This is going to be a monumental week....
 

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Question -- the oil filter arrangement?

Don, your photos show more damage than the situation I had at 500 miles when I had a plugged crank that failed to feed #4 rod journal. You also mention that you did not rely on the old tapered plugs and actually used allen screws. And the damage is throughout, not just a single rod bearing.

I agree the damage seems to be from complete lack of oil pressure all over, and the only other time I saw that was my own fault. My self designed spin on oil filter cartridge adopter at first lacked a crucial peg to prevent the horizonal plate from moving in relationship to the center stem and the cross drilled oil holes closed to block all oil flow. Original Alfa Fespa oil filter system introduces oil on the inside and draws from the outside edges (junk is caught on inside and the filter gets washed out when changing oil). Spin on cartridge is opposite -- oil is introduced on the outside edges and is pushed up into the motor from the inside. You must realize the oil hits that filter at about 100 lbs per square inch. If I didn't always fill the spin on filter before I screwed it on the force of the oil would crush it all to a ball on the inside and almost stop the flow. Maybe the newer adopter which solved my "crush" problem ended up with that new system's initial pressure relief valve getting blocked. Remember that on two liter system the oil pressure spring determining oil pressure is AFTER the oil passes through the filter. Please determine if that newer spin on adopter has a problem with the initial pressure relief system using parts from Chevrolet, I believe. Maybe they don't work well with 20/50 oil. Just a suggestion, but troublesome to me so please report your observations of the unit at least to me. I have been recommending the newer adaptor. I use my own because I am careful enough to feel safe with it, but I always fear when someone else might not remember to fill the spin on filter before screwing it on, or fail to screw it on tight enough (like my son failed to do once and the filter rubber gasket blew out and spilled all the oil onto the floor when I was working on the tuning -- managed to shut off immediately when sound of engine changed, but I worry some damage might have been done). Get back to me.
 

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Discussion Starter #949
The failed engine was using the original cartridge filter, including all of the necessary parts. The tap for the oil pressure gauge is after the filter. I always had excellent pressure on startup, and until the oil got warm. It was after it fully warmed that I first got the hint something was wrong.

My replacement engine has one of Myron’s spin-on adapters. It uses the pressure release valve from the original cartridge unit. I have filled the spin-on to the brim, and made a device to pre-fill the pressure galley. I plan to spin the engine without spark plugs to pick up some prime for the pump.

The oil on the failed engine seemed to get very dark, very quickly.
 

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My primary suspect in this episode is the oil pump relief valve sticks open intermittently. From what i read the oil pressure gage shows expected oil pressure on start up ... then as things (metal) warm up the clearances close and as it warms a moving part ( the relief valve) will decide to bind up intermittently..eventually sticking and unsticking until expansion at peak temperature locks it in the place at the time the components and the temperature reach the threshold of locking in place. The location of the valve piston is random in this condition depending on where in the cycle of the relief valve piston is when it reaches the temp threshold to freeze it in place... It could lock in the open position, partially open/closed or it could happen in the closed position. In all the test runs of the engine it worked ok, it might happen it just found an unacceptable spot on the fateful 5 mile run , it decided to freeze in the open position. This to me is the only explanation for why the engine performed on earlier tests without warning of what was impending. It was a Russian roulette situation and this time spinning the ammo chamber landed on a live round.... poor analogy but I'll stick to it. It's the heart of the matter ..the pump relief valve. It's the only explanation for the mixed signals the machine is spewing out.
 

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Discussion Starter #951 (Edited)
My primary suspect in this episode is the oil pump relief valve sticks open intermittently. From what i read the oil pressure gage shows expected oil pressure on start up ... then as things (metal) warm up the clearances close and as it warms a moving part ( the relief valve) will decide to bind up intermittently..eventually sticking and unsticking until expansion at peak temperature locks it in the place at the time the components and the temperature reach the threshold of locking in place. The location of the valve piston is random in this condition depending on where in the cycle of the relief valve piston is when it reaches the temp threshold to freeze it in place... It could lock in the open position, partially open/closed or it could happen in the closed position. In all the test runs of the engine it worked ok, it might happen it just found an unacceptable spot on the fateful 5 mile run , it decided to freeze in the open position. This to me is the only explanation for why the engine performed on earlier tests without warning of what was impending. It was a Russian roulette situation and this time spinning the ammo chamber landed on a live round.... poor analogy but I'll stick to it. It's the heart of the matter ..the pump relief valve. It's the only explanation for the mixed signals the machine is spewing out.
I’ve not yet opened or inspected the filter element itself. I did inspect the relief valve, which is mounted in the upper body of the filter canister assembly. I found no indication of flawed operation.

To be clear, there was no intermittency in the pressure indications. After start it would immediately go to about 60-65% of gauge span, at which point the relief valve would prevent a higher pressure. As the engine slowly warmed, it would slowly drop to about 35-40% of span. I am used to Alfa engines, as they warm, dropping to mid-span, around 50%, and staying there so long as the revs are above about 2,000 RPM. Once I discovered the lower than good pressure after warming, I tested the relief valve by putting a couple of washers behind the spring. Upon cold start after this, the initial pressure went higher than it had with no washers, perhaps 70-75%. This shows the relief valve had been working correctly in maintaining the targeted max pressure. During the subsequent drive, the pressure dropped as the oil temp rose, reaching the same low pressure as before. It was during this drive that the #4 rod bearing spun and the rattling started.

The 2000 relief valve is similar to others I’ve seen in antique engines. There is always an unobstructed flow path from the filter canister to the oil feed galley. The relief valve opens only when the targeted pressure is reached, at which point it dumps enough oil back to the sump to maintain the targeted max pressure. The design warm-oil pressure itself is not much regulated, it is a function of the pump capacity, oil viscosity, and various bearing clearances. The relief valve is there primarily for when a targeted max is exceeded. You have probably observed your own pressure gauge, after thorough warming, varying with revs from near zero (actually perhaps 7-10 psi) up to around mid span. That behavior is indicative of an unregulated pressure system.

But.... once I get everything on the car ready for Concorso, I’ll get back inside the failed engine. I’m not going to be satisfied by “oh well....”.
 

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The pressure relief valve i speak of has nothing to do with the filter .. It is in the pump and modulates pressure by opening and closing in a rapid flurry of cycles and effectively killing the pump and leaving the bearings effectively unpressurized if the valve is stuck open .. it is the equivalent of a blowout in a pipe line. No matter what you pump into the pipe the pressure will be lost to the blowout. If yo are telling me there is no pressure relief valve in the pump then I stand corrected. I am only going by my knowledge of how every other pump on 4 Alfa 4 cylinder pumps work.

Sorry for the amendments (edits).. I'm just trying to help find the source of your engine's problem.
 

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Discussion Starter #953 (Edited)
Divot,

The cast iron 2-liter is, indeed, unlike the aluminum engines that came after. The cast iron engines owe much more of their design concepts to prewar engines than the later aluminum engines.

There is no relief valve in the pump. The only relief valve is in the upper filter-canister body, and works as I described. The pump is an external two-gear unit driven by a worm gear off of the crankshaft. It is just a pump, nothing else. It sends the unregulated oil to the filter (which works as Jay described above), thence to the relief valve, then onward to the pressure galley that runs down the side of the block. All five main bearings are directly fed by the pressure galley. Three of the main bearings feed oil to adjacent rod bearings.

Everyone of my rod and main bearings shows distress from lack of oil. Even the indicated 40% pressure should have been sufficient to avoid ruining the engine. So, we must assume a lack of flow somewhere. However, that the oil heated up over a typical time span suggests that it WAS circulating through the engine and rotating stuff. Oil that just sits in the pan won't get all that warm.

Back to finishing the new engine install....
 

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One last question?

Don,
You say you used the "complete original filter system". I am enclosing a photo of the parts book which shows all those parts (but also a drawing by one of my sons of the adaptor I use for spin on filters myself.

I agree with you that if the oil pressure did at least one time show on the gauge the oil got into the motor at least during that time.

But note that the original filter is NOT a cardboard cannister (such as perhaps used in Giulietta motors) as some people have erroneously thought could be used. Those are nothing other than "oil soaks" thrown into the cannister because the oil doesn't even pass through them. And, frankly, if the oil were to go through them I do not believe they would stand up under the pressure. Pieces from the filter could (and probably would) plug movement of the piston compressing the spring (i.e. the mechanism of the oil pressure regulator). The oil pressure is not measured there, but by the line fitted on the side of the block under the carbs.

So, question? Did you really have ALL the pieces of the original oil system?
 

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Discussion Starter #955
Hello Jay,

The proof will be when I get back to the forensics, and open up the canister. I built these two engines 5 or 6 years ago, but I recall closely studying the drawings during assembly. In fact, one of the reasons I bought one of Myron’s adapters was because I didn’t have enough bits to put together two, complete canister assemblies. I remember having only one surrounding cage, among other things.

I’ll report back. I’m trying to get to first-start of engine B today.
 

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Just wondering, if the damage was caused because the engine was built such a long time ago and sat still for so long. Maybe the bearings ended up with a "dent" in them?, or, while I am sure you assembled them wet, unless you externally pressured the oil system, the bearings may have been scraped while spinning (on the starter) with the plugs out causing premature wear, before the first powered run, that resulted in the loss of oil pressure once the oil was warm.

The reason I say this is you have one perfectly running engine in "your" car and this engine was built and started in the usual time frame and is still purring like a kitten. The same crankshaft resources were used, etc. and it is unusual for a skilled builder such as yourself to have such an early failure. The only difference I can see is the failed engine sat for ages ... and then engine you are about to install ALSO has sat for ages. I'd chuck her back on your engine stand and remove the sump and bottom end and lube her up big time :)
Pete
 

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There are pressure pots available to prime the oil system through a port in the block.

Like where the oil sender screws in.

I do this with the Alfa engines and most of the vintage marine engines were you can not spin the oil pump without spinning the engine over.
 

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Discussion Starter #958
Pete,

The engine will be started either today or tomorrow. Too late to yank it out for a rebuild.

But, you raise an interesting point...

Decades ago I worked with a machine shop that specialized in poured-babbit bearings. This was for the French aircraft engines I used to work on. He showed me the results of building an engine using a white lubricant the name of which escapes my memory, but which was/is often used for this purpose. “Molylube?” Anyway, if an engine was started and put into service soon after rebuilding, ok, but if it was stored for a period the lube would etch the surface of the bearings, leaving them rough, and dramatically shorten its life. He introduced me to something called “camlube” which can be stored for decades without harming the bearings.

I doubt your “denting” theory, as the static weight is far less than the power-loads put onto the bearing surfaces. The failed engine was stored indoors in our family room, in a glassed-in case, with full-time heat or AC, as needed, in a state known for a typical humidity of 15%-40%. There wasn’t even dust on the engine when I pulled it out of the case.

It’ll be interesting to open the oil filter canister in a few days...
 

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Discussion Starter #960
Engines have long been built in lots, stored, and put into service many years later. If one is considering decades of storage, as I was, care must be taken on how to pickle the engine. Care, also, on commissioning.

Anyway..

Got B started without drama. Oil pressure straight to 50% within 3-4 seconds of starting. I might have expected a bit higher, but I’m using the Myron spin-on adapter, and not sure if the high pressure release valve will need adjusting. I had primed everything via a long-term gravity feed into the pressure galley. That’s not a sure fire way to prime the pump, as the oil has to back up through the filter along the way.

However, I had a couple of pin-holed water jacket cover plates. Holes invisible, but evident under pressure. This was the first of the two spare engines I rebuilt a few years ago, and I used the best of my “experienced” plates. For the second engine (A - the recently failed engine) I bought a set of new plates. So, I just swapped a pair off the A engine onto the B. I’ll see how they hold up in the morning.

Apart from the leaks, I could have driven it this afternoon.
 
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