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I have been reading this thread of Davids' misfortune, and the others that have chimed in also having issues with "bad pumps". I have been reading this with interest because many of you know I had a pump self destruct during initial startup of new rebuild. As I always am, I WAS CAREFUL during all phases of the build but I never placed the blame on the pump. I just didnt follow instructions to the letter. I interpreted and assumed that I was doing it correctly. Mine was a catastrophic fail immediately. I believe from reading many similar scenarios that the slightest of tension on the shaft during installation could feasibly cause a failure, maybe many miles in the future. I am not saying this is what happened to any of you, but I am not saying it isn't possible. After following the shop manual to the letter I can see where I made the mistake and certainly will not make it again but also see that it is incredibly easy to put a minute amount of strain on the shaft during assembly and not even notice it.
 

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I was certainly ready to accept "installer error" as the cause of my issue until I learned about the numerous others, including some noted Alfa race-engine builders, that had the exact same failure. And not just members that have chimed in on this thread. Also, David's pump was installed by an Alfa specialist. To me, the numerous identical failures all at the same time with the same replacement pump is too coincidental to be an installation issue.
 

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SO FAR!!!!
These seem well made pumps. We will see if there are other issues. The binding on installation is a common assembly failure and will kill a pump, either slowly or quickly.
 

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I addressed that point back in post #52, when I wrote:

When you don't follow the procedure CA outlines, the failure mode is different (from the one David experienced). In that case, the steel shaft of the oil pump will fracture, usually where the hole is drilled to accept the roll pin that attaches the drive gear. I learned this lesson the hard way, with one of my early Alfa engine rebuilds, well before the internet made this information available.

Even when you follow CA's installation procedure, it won't help if the pump gear is made out of material that is too soft or is poorly machined. CA's procedure addresses a weak point in the design of the engine: because the oil pump can rock a bit on that O ring, and has such a long shaft, if it gets mounted a fraction of a degree off-axis, the shaft will bend as it rotates and fail due to fatigue fairly quickly.

My guess is that the cause of David's problem is one that is fairly well-known and was discussed on the BB a year or so ago. Apparently someone made a batch of pumps with gears whose material was too soft, or that weren't machined correctly.
mine did not shear the pin, it ate up the gear, and it was my fault.
 

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One of the first three to be reported was in an Alfa race car at Road Atlanta. The motor was built by Apex Racing mechanics who are second to none. The pump was bad.
 

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There is a bit of special tooling required to replace the bad bronze gear, as well as a bit of tolerance correction on the 2L OEM replacement. Not a DIY job.
Gordon:

Thanks for clarifying that. So a DIY mechanic (like myself) can't just buy one of these inexpensive pumps, swap in the gear from his worn OE pump, and save $XXX over the cost of the higher-quality alternative. Darn!
 

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How would you get the drive gear off the main shaft to be able to get the shaft out of the body to remove the bronze gear? The drive gear is an interference fit, and if you use heat on the gear to expand the hub, it stays expanded... forever. The only correct way to get it apart is using the correct holding fixture for the body in a hydraulic press. Got the fixture? Most DIY builders of one pump could never afford one. Alfa oil pump building isn't easy.
 
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Sounds as though the engineers had their ducks in a row here, but if the design is not followed we have a problem
 

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How would you get the drive gear off the main shaft to be able to get the shaft out of the body to remove the bronze gear? The drive gear is an interference fit, and if you use heat on the gear to expand the hub, it stays expanded... forever. The only correct way to get it apart is using the correct holding fixture for the body in a hydraulic press. Got the fixture? Most DIY builders of one pump could never afford one.
Gordon:

Yes, I understand. I was agreeing with you in post #106 when I wrote "So a DIY mechanic (like myself) can't just buy one of these inexpensive pumps, swap in the gear, and...". Maybe you're just not accustomed to people agreeing with you here on the BB. :D
 

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There are TWO choices. Buy a GOOD pump, or buy a VERY good pump. One more possibility is to have one built. They will NOT be $100!
 

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Here is the latest from Jim Steck.

"Got home from Mid-Ohio last night and found your package in the mailbox. The hardness is indeed different ... Rockwell B 67 versus RB 78. The other concerning feature is a difference in root diameter of almost one millimeter, with the failed gear being smaller. I have suspected improperly machined gears as a contributing factor to the failures and this adds to my concern.

I would like to measure pitch diameter and major diameter of the gears of one of the suspect pumps to see if that would be a way to sort the good from the bad. Do you know a source of the gear (pump) you sent me?

Tomorrow I'll be taking the gears to a met lab for an alloy identification ... hardness alone isn't enough identify the problem. Is it within forum rules to ask for donations to help with the cost ... probably $150-$200?"

SO. We have SOFT gears. What are they made of, and why? I'm sending Jim $75 to find out. Anyone else curious? If so contact me with a discussion message or art my e-mail.
We are beginning to have some useful information here now. How far should we go in providing information to CA and Paul Spruell? Will this information get to the actual manufacturer to CORRECT THE ISSUE? I do not know how to do that. Volunteers?
Again, this seems a good pump, with ISSUES. Corrected, it will be useful to BB members and others. Uncorrected, we sadly get to hear about more ruined engines.
Best, Gordon
 
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It is sad that the people who are making money selling these things have not followed up like you have Gordon. The problem has been known for long enough.
 
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Discussion Starter #114
David OD, in for $30. Gordon, pls PM your paypal address to me.

My shredded-gear pump is still at the Alfa shop, pending discussions with CA.
 

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Ok guys, Here is how we do it. Jim just wrote me a note.
" If they want to contribute directly, it's [email protected]. Stop it if it gets to $200. I'm just trying to cover the direct cost. The research is my contribution to the community."
I'm sending him my $75 soon as I post this. The rest of the contributors should follow, ASAP. I'm forwarding this to Jim Steck so he will tell us STOP when we get to $200. Send $ "friends & family" so you don't get charged. Note that it's for "Oil Pump Materials analysis".
I feel this VERY worthwhile, because I do not want to be the Alfa worlds builder of all good oil pumps! I'm too old to handle the job. We ALL need QUALITY pumps for the many different vintage Alfa engines. Jim himself is working on a lobed rotor design which has value for multiple applications. For those of you that do not have my e-mail address, it's <[email protected]>. However send me NO $. Only to Jim please!
Thanks! Gordon
 

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That would be a BIG help. This is a most interesting BB group effort.
 
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