1998 550 Maranello "sorting" thread--DIY

Disassembling my pump was a PITA. Getting that graphite seal out of the inner part of the pump is a very destructive endeavor.

Pulley removed with a standard pulley remover (Photo 1)

Snap ring removed to allow shaft to be removed (Photo 2)

I removed my shaft in a 10 ton press, and there was an amazing amount of effort required. When I originally installed it, I put it in dry, with no lubricant of any kind. In addition, I had chilled the shaft in the freezer prior to inserting so there was a layer of condensation on it. There was rust fretting visible on both surfaces (Photo 3) I am thinking maybe that's why it was so hard to get out. What do the experts think about a light layer of assembly lube on the inner race of the pump?
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Here is the new shaft, fresh from the Italian bearing factory! (Photo 1).

You can also see in the photo the key that the pulley slots over. Mine is misshapen and dinged a bit, so I will replace the key.
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So in this picture you can see the lock washer ring by the circlip and the later style impeller. That was from my 550 a few months ago. I don't think it matters much but there you have it. You can heat the case and the bearing will fall right out no force or very little.
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FBB- I see your funky washer, too.

Pete- If you do not have overheating problems, I would not change anything.

 

Pete, I used redline assembly lube to press the shaft with not much effort. For seal assembly I was told and used Permatex high tempreture anaerobic flange sealant part # 51031. Lubricate the seal well and press down gently with a lighter press if you have at once with that special tool. If you do not have the seal tool let me know I will ship to you. Then examine the seal with a magnifying glass for any micro cracks before you proceed. As you know seal is super fragile therefore cracks Easley and leaks. The rust on shaft may be as the result of coolant
leakage. When you are ready to put back the pump, apply good amount of silicon grease on the big O ring and housing and thighten the nuts evenly to push back the housing to prevent damaging to the O ring.

 

Sark, I had purchased the seal tool also...thank you for the offer.

Terry, I am going to update the impeller while using the original pulley. I figure if I can get a little better coolant flow that isn't a bad thing, no?

 

Pete you'll need to trim the height of the 575M impeller down a bit for it to fit in our 550 pump housing. It's not a direct fit. Too, it's a bit smaller in diameter than our 550 impeller, so I'm not sure it really did anything for me. Probably if I'd changed the main pump body, pulley, and impeller all together it would have achieved something. Honestly, if I were you, and I wasn't having any overheating issues, I'd leave it alone and use your regular 550 impeller.

Too, I've experienced some cavitation issues with my liners - not near what Ron Furzeland experienced with his, but still worrisome, and so I'm having a pump expert redesign the impeller and dyno the entire pump as part of my relinering rebuild. And (biting my tongue) I'm also going to give Evans coolant a try.

I've been against using this stuff for years because of its very low specific heat capacity and higher density/viscosity, meaning you have to have a well oversized cooling system in order to use it, else you'll be running much higher top tank temperatures. However, its two big advantages over water based coolants are:

1. It will not boil or cavitate

2. No water = no corrosion issues

So for these and only these two reasons, I'm going to try it, but with an upgraded cooling system.

 

Did you or Ron ever come up with a theory as to why you guys have cavitation?

 

Carl, Ron's cooling system had a lot of internal issues. I don't want to speak for him, so hopefully he'll chime in here and expand on it, but it's no wonder he had overheating & cavitation issues, and they had obviously been at work for quite awhile, judging by the advanced state of the corrosion in/around the cavitation pits.

Mine was and still is an enigma. Internally, my cooling system was clean as a whistle, and the nitrite levels to inhibit cavitation were quite high, etc. The only odd thing, internally I found a big chunk of casting slag in the main coolant gallery just opposite cylinders 3&4, whose liners also coincidentally showed the highest levels of cavitation. This slag wasn't loose, but I had to remove it via a die grinder with an extension shaft.

Also, and although I don't like to admit it, and I don't know that it's the actual case, in my quest for more fluid flow with the pump mods, the cavitation issues may have been self induced. When you're doing impeller and drive pulley mods on high flow pumps with low NPSH as our system has, you're in dangerous territory, and any additional system restrictions on either the suction or discharge can induce cavitation, particularly if the fluid is already on the verge of boiling anyway. I knew this, but went there anyway.

So this is why I'm going to Evans. Do I think it's a good heat transfer fluid? No not at all. Is it a good solution for a hot running car with a marginal cooling system in a hot climate like Houston? No, it's a terrible solution under those conditions, but for me, and my 550, if I can get the cooling system overbuilt and with sufficient reserve capacity to overcome Evans' poor heat transfer characteristics, then its other advantages will outweigh its disadvantages.

Some might say I'm overthinking this, and I should just put a 50/50 solution of Prestone or Zerex in it and call it good. Well, the car's history of running as high as 240 degrees outlet temps with a 50/50 solution of Prestone, and now 10 liners with cavitation damage are proof enough for me there's something not right either with this engine, or with this engine running in the Houston climate (and I believe it's the latter.) Frankly, every 355/456/550 Ferrari owner that I know (and I'll admit I don't know them all) here in Houston has had overheating or simply "running hot" issues with their cars.

So my advice to all the other 456/550 owners is this: if you have overheating issues, chase the air side of the cooling system and try to improve the air flow/shrouding first, before meddling with the water pump and coolant flow, as there be dragons there......

 

I had similar overheating problems, I suggest to try 10% coolant and 90% tap water.

Distilled water is not recommended, actually Mercedes Benz clearly says to use tap water.

Water has a natural tendency to draw ions, so if you use de-ionized water, it will "pull" them from the medium it is in (liners, casing, etc.).

 

Water is still unbeatable in heat transfer - the SHC (Specific Heat Capacity) of Water/Vapor one of the highest.

 

Not sure there are many that would agree...

Distilled Water - Safe for Engine?

 

Trying not to divert Pete's thread too much, but I drank the "pure water" kool aid for many years and still believe in it. With pure water's specific heat capacity of 1.0, and everything else being a fraction of that, there's no argument that it's the best natural heat transfer fluid on the planet. However its boiling point is just too close to the running temperatures of our engines. The only way to counteract that is to mix it with antifreeze (which reduces its specific heat capacity) or raise the pressure of the system. And that's well and good, but what happens when the pressure drops, say at the suction of the water pump?

The current pure water mantra is not to use distilled or tap, but to use reverse osmosis purified drinking water as the basis for a pure water based coolant. The NoRosion site has a very informative technical FAQ written here: No-Rosion Products Technical Questions and Answers and the owner of the company isn't just some bubba, but a degreed chemist with decades of experience in water treatment systems.

I believe and support what this guy writes as he has both the credentials and experience to back it up.

 

I learn something everyday...That's great info John. Thanks

 

This is all great discussion. I have never had any cooling issues with this car and would often drive it on hot Virginia days. I have and will continue to use 50:50 Zerex G-05 and distilled water.

 

Hello, actually, there is a very effective way to increase the boiling point: pressure. At the pressure that our coolant systems are operating, the boiling point is much higher than 100.

 

I think you may have misunderstood me. I was referring to the dynamic situation caused by our system having a very low NPSH for the coolant pump. This undesirable situation sets the system up for cavitation to occur.

If you are an engineer, you may wish to review a few articles about the effects of low NPSH on centrifugal pumps.

 

John,
Well Pete is sort of like a scientist the way he is attacking his 550 so I think it is OK to take a topic sidebar. Not being an engineer maybe you can clarify a few things. 1st I get the problem of NPSH pump vs. NPSH needed to prevent cavitation at spec temp and pressure. But because this is a closed loop and the outflow of the pump having to return to the pump is different from just a pump with intake and exhaust in an open system so doesn't that effect of a closed loop sort of negate or reduce the NPSH issue? Also, even if there was cavitation at the pump that would just kill flow and only damage at the pump. You would see cavitation damage in the pump right? Also, you would see and even higher temp at the gauge than with the old impeller and you would know you went in the wrong direction. So even if you saw a small positive change in temps can't you assume cavitation at the pump is a non-issue and your changes OK?

Then there is the issue of what really is cavitation. With diesels cavitation is a known issue and many forms of coolant additive made to help stop it. The reasons given are combustion high frequency vibrations causing cavitation and or vapor pressure boiling issues at liner surfaces. Which is or which is more important or if both really the cause, I don't know but diesel world answer is coolant additives. It is also known that high nitrates like you had in your system mixing with solder in the aluminum radiators form goos that plug the fine passages of said radiator. That will increase the temps seen. I do not know if you checked for that.

So...why not take a more traditional path to solving a possible cavitation issue with just a supplemental coolant additive specifically for cavitation in diesels compatible with the metals in our systems?

 

Carl, you make some good points. My concern with cavitation at the pump is that once it begins, it becomes the catalyst for the vibration induced cavitation elsewhere in the system. But do I have any scientific basis for this? No, just a gut feel, but after many years of working with rotating machinery, I've learned to trust my gut sometimes more than my engineering degree It's true what you say about the system being closed, however having the pump so high on the engine while the fluid it's pumping is below it, is just poor design. Depending on the pump itself to deliver the head back to the suction just isn't wise. You can ignore lots of things in pump design, but you can't ignore gravity or NPSH.

On the nitirite levels, I've been advised that mine weren't high enough to cause the reactions you speak of. Mine were around 2300 ppm IIRC, and they'd need to be >4000 to be damaging.

Still, going with conventional additives to combat cavitation is definitely an approach worth considering for others in a similar situation; I guess you could say my pendulum has swung completely that way by going with Evans. Rather than combating it, I'm hoping to eliminate the possibility of it occurring.

 

What exactly is Evans Coolant?? (I mean what is it made from)

 

Propylene glycol.

Here's the corporate website: Home » Evans Cooling

And a dealer website in the UK, which I find more informative, with far less BS than the corporate: Evans Waterless Engine Coolants | Pre-War Car Parts | Official Distributors & Stockists.

I don't like their marketing approach, and I don't think they objectively present their product's disadvantages and advantages, but once you carve through their BS, it may meet certain special needs that some of us have.

 

Great, thanks John. So what would be the different between this and running 100% regular Ethylene glycol?

 

Nothing, but AFAIK, no one is nuts enough to run 100% ethylene glycol, and I didn't think for a long time anyone would be nuts enough to run 100% propylene glycol either, and now I'm about to.

More seriously, the ethylene glycol is deadly toxic to humans and animals. Only small amounts ingested will cause serious sickness and/or death, depending on the size/weight of the victim. Propylene glycol is supposed to be far less toxic.

I think most racetracks don't allow either product to be used in the cars' cooling systems, because if/when it leaks, it makes for a very slippery surface.

Guess I wouldn't be a very good salesman for the stuff.

 

Correct, a lot of tracks want you to be on pure water, not the other way around!

 

Waterpump rebuild had a few surprises for me.

This time around, I decided to bake the pump housing at 350 degrees F for 30 minutes in the oven, and then removed it and was able to drop the new shaft bearing right in. (Photo 1)

I then coated the inner and outer races of the new waterpump seal with a very thin layer of HondaBond HT. (Photo 2)

Using the 10 ton press and the waterpump seal tool from Ricambi, I pressed the seal into place. (Photo 3)

This is what it looked like afterwards (Photo 4)
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