365 GTC/4 water pump bearing

Hello all,

This is my first post here, although I have been lurking here for a little bit. I have been working on a 1972 365 GTC/4 cam, engine reseal/refurbish and a bunch of other stuff as well. This is my first foray into vintage Ferraris, I've spent most of my career on Porsches. It has been quite the learning experience.

My question regards the water pump/ oil pump assembly. Upon disassembly, I found the water pump shaft key way all buggered up. I replaced the shaft and drive sprocket, and all the seals and bearings for the water pump. The new bearings for the water pump are sealed bearings, as opposed to the open bearings originally fit. There is a hole on the top of the boss, above the shaft and bearings, I assume to splash feed oil to the open water pump bearings. Since I am running the sealed bearings, I covered that in epoxy. My thought was that i don't want oil filling up the gap between the bearings with no direct way to get out (thru the bearings themselves) and coming from the Porsche world of IMS bearing failure (if you know you know)...

Is this a bad idea? I haven't installed the pump assembly yet, so I can remove the epoxy if needed.

Thanks in advance,
Jesse

 

I'd have to say "yes, seems kind of strange, and you should really have a good reference for making this change". Are you sure that you've got the correct bearings. Both versions of 365GTC/4 water pump diagrams at the MCP website show an open bearing is used:

https://www.ferrariparts.co.uk/diagram/ferrari/365-gtc4/016-water-oil-pump
https://www.ferrariparts.co.uk/diagram/ferrari/365-gtc4/016a-water-oil-pump-revision-oct-1972

Not uncommon for a manufacturer to change a design from an open bearing to a sealed bearing (and have two different overall designs), but very uncommon IMO for a parts vendor to supply a sealed bearing for something designed to use an open bearing.

(A sealed and open bearing of the same size will have very similar part numbers with most of the initial numbers/letters being the same -- very easy for these to get mixed-up/mis-ordered in inventory of a parts supplier.)

 

Steve,

Thanks for the reply. I got the bearings in a water pump rebuild kit from AW Italian out of New Jersey. The bearing numbers are 6002 RSR. Dimensions are the same as the removed bearings. Only difference I can see is the seals. They are rubber contact seals. Putting that number into Grainger gets me a close match of 6002 2RS, states that the grease is GJN grease.

I will talk to AW and see if they have any recommendations about these bearings, although I suspect they just get close equivalents, like you mentioned.

Outside of running what came out of the car, do you have any thoughts on running the sealed and greased bearings in a oil heavy environment?

Cheers,
jesse

 

Not good and not necessary if the oil supply is proper. An open bearing running in recirculating clean oil has better life than a sealed bearing filled with one-time lifetime grease. For example, on 308 when they changed from an open bearing to a sealed bearing for the cam drive sprocket, it was to solve a geometry load problem (and involved mechanical changes to relocate the bearing) while accepting that the lubrication of a sealed bearing is not quite as good as an open bearing running in recirculating oil -- it wasn't just doing a direct substitution.

 

I agree. I made the decision to disassemble. The bearings look the same except the dust shields.

 

Just pull the seals off the bearing and run them open. The bearing is the same. I do this all the time in many different situations, I have found sealed bearings easier to find than open. When I raced go-karts, quarter midgets, & mini sprints I pulled seals all the time. On the mini spring we had run seals as it was a dirt car. We would service the bearing and put the seal back in.
Long story but if the bearing is correct, rip out the seals.

 

Thats my plan. Thanks.

 

Jess
Did you replace the chain tensioner? The older ones, mine was14973, used an old version tensioner.. plastic base. The replacement is the all metal tensioner used in the timing chain tensioners.

modifications must be made to the timing chain covers which the oil/water pump chain also is part of.

It must be milled out to allow for the larger metal tensioner to function.. otherwise, the new tensioner will self destruct within 500+ miles.. not to mention it will be extremely hard to get the timing chest cover to fit.

 

Dbone,
I did install the new style, all metal oil/water pump chain tensioner. The original plastic one showed wear on the pad.

Luckily, the parts house sent me two metal tensioners. The first one self destructed when I went to release it. I had to remove the timing chest after having degreed in the cams, argh. On the second, i removed material from the pad to allow some room for the tensioner to function. It did not occur to me to take material off the inside of the timing chain housing. Do you have any info/documentation on fitting the updated tensioner?

Thanks,
Jesse

 

When I had my C/4 motor rebuilt in 2009, I drove the car approximately 40 miles to my home when the job was finished. I immediately noticed that the the oil filler was full of "mayonnaise" and trailered the car back to the shop. The oil sump was contaminated with coolant and the engine was pulled for an inspection. According to the the chief mechanic, the water pump seal had been installed backwards.... at least that was his opinion. A complete tear-down was in order and the news was not good, as one can imagine. The shop outsourced a complete rebuild to a guy named Bill Rudd, who found many items had been done incorrectly. After a year of frustration, the motor went back in the car and all seemed good. The shop eventually went out of business, however until that point they were a well established southern California shop. The lead technician still operates his own shop out of Costa Mesa, California. It was a painful experience to say the least. I did not witness the tear-down the second time around as I was working overseas, so I cannot verify the story about the water-pump seal going in backwards.
Just thought I would pass along this information. I sold the car a year later and it went to Germany, so I don't know if the motor suffered any further ills. The shop had made such a mess of things that I lost interest in the car.
Bought another C/4 in 2021..... and really love it. An original 35K mile car. Engine has never been pulled.

 

Jesse,
I will find some pic’s of the modification to the chest. As you now know, the replacement tensioner is larger than the factory plastic version. Consequently, there is zero room for that tensioner to properly release… it was always applying full tension on the chain eventually the pad gets chewed up.. by 400 miles its almost gone but the damage is already done..

Zanny’s C4 may have had the same issue..

As the chain was being over tensioned, it must put pressure on the shaft that goes into the water pump/oil pump. Once the shaft it stressed, the bearings get stressed and all the seals go. “Mayonnaise” is created…
. Zanny… I had the same issue.

I have pictures of the -stupid-crap-poor designed-achilles heal- on these C4’s- maybe the later ones had a metal tensioner… the older one were time bombs with that plastic tensioner.

 

I'll try to upload 9 pictures - it may take several posts:

post 1: tensioner on left is the new, the one on the right is the factory plastic - note size.
pic two is the new tensioner - opened
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post 2 - the over view of the location where it was milled out.
View attachment 2547743

 

post 3:- two pictures- top view and side view: the new tensioner fitted - before milling out. Note that the tensioner is not released creating full tension on a chain
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post 4 - milled out -- two views
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post 5 of 5:
note how the tensioner now has room to release.

The before and After

- Sorry I do not have any measurements as these were the photos taken by the Master tech when he rebuilt and corrected my engine after two different shops failed to recognize the issue. I went through two replacement tensioners before it got taken care of correctly.
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my apologies if I sent duplicate pictures.. I tried to edit them out..

 

That is very helpful, thank you very much. Hopefully, i have enough play in the setup to allow the chain tensioner to function properly. The engine is back together and in the car. There is quite the learning curve on Ferraris. Finding good information has been difficult, and I really appreciate all the help I have gotten from this forum.

Cheers,
Jesse

 

Jesse,
When needing info on these C4’s you should also look at www.365gtc4.com. That is a dedicated site for C4’s. A lot of very good tech help from owners, many service their own cars like you. Many years of accumulated data.

Good luck and enjoy these wonderful understated cars