914-4 engine main bearings wear?

[Windisch]

When I acquired my carb-converted car, there was pretty extensive water contamination/dilution of the engine oil (so much so that the oil had a uniform 'mocha white' coloration to it), probably caused by water entrainment due to someone unknowingly cleaning the engine bay with a pressure sprayer.

I changed out the engine oil and filter ASAP and although the oil pressure appears to be good and there aren't any apparent oil leaks anywhere (other than the usual small seeps that air-cooled VW type engines typically have), there is a strange sort of noise that can best be described as a 'low rumble/grinding' sound that seems to come from the engine. The noise is of somewhat low intensity and slightly variable in noticeability while the engine is operating but the thought occurs to me that perhaps the main bearings suffered some abnormal wear from being run with the H20-contaminated oil.

I'd appreciate inputs and opinions on this from other experienced 914 people. Further, are there any effective means of determining whether or not there is any main bearing damage other than a tear-down? Is this possibility capable of being ruled out by a competent Porsche shop?

Additionally, are there any oil additives that would help ameliorate any possible existing excessive wear, proactively? I am presently using full-synthetic oil but I have been advised to switch to an oil that has ZDDP additives (ZINC-DIALKYL-DITHIOPHOSPHATE), since apparently flat-tappet engines (such as the Type-4) benefit from use that type of oil.

Thanks!
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1973 Standard Beetle, 1974 VW/Porsche 914-4, 1.8 liter
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Der Volkswagen ist ein Ausdruck der deutschen Kultur der Allrad Art ...

[The only irrefutable evidence we have that intelligent life truly exists elsewhere in the Universe is the fact that so far it has NOT contacted humanity...]

[Wolfgangdieter]

My go-to oil for VW/Porsche air-cooled engines is Valvoline VR2 Racing Oil. It has a high zinc and phosphorus formula. It is readily available and not expensive. I don't use synthetic oil in air cooled engines - it seems to leak more than old dino oil.
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CMC '57 Porsche Speedster Replica and Dolphin boat tailed full pan VW MOD-T Street Buggy

[raygreenwood]

[Windisch]

[/quote]

Record the sound and post it.

As for the oil, yes, it should have THE RIGHT AMOUNT of ZDDP.

I posted a link to this a couple of weeks ago. Lake speed Jr is the bomb on oil technologvy. Great video that explains why not enough ZDDP is bad and also why excessive ZDDP is just as bad or worse.


https://www.thesamba.com/vw/forum/viewtopic.php?t=791567


Ray[/quote]

Thanks for that, Ray. I'll try to capture the sound and post, as you suggest. May take me a few days to do so, however. I recently began using CASTROL EDGE EUROCAR full synthetic 5w40 oil in my 914-4 engine and I've sent off an inquiry to CASTROL about ZDDP, but have not heard from them in reply just yet. [I am told that VALVOLINE RACING OIL and the STP additive are both good bets for ZDDP protection but that it's probably a good idea to switch back to mineral-based oil with ZDDP in it, from what all the indicators seem to suggest.
_________________
1973 Standard Beetle, 1974 VW/Porsche 914-4, 1.8 liter
----------------------
Der Volkswagen ist ein Ausdruck der deutschen Kultur der Allrad Art ...

[The only irrefutable evidence we have that intelligent life truly exists elsewhere in the Universe is the fact that so far it has NOT contacted humanity...]

[raygreenwood]

If you have not watched that link in My last post you should.

One of the problems with Ester based synthetic oils that seem to be close to having enough zinc and phosphorous....is that they typically have too much detergent which fights the zddp and causes issues with OUR applications so you have to choose carefully. Ray

[Windisch]

Hi Ray. Yes, as regards the deleterious effect of detergents on zinc/phosphate efficacy, that certainly seems to be true (I did watch that video you mentioned and it is excellent). I've been looking into all this a bit over the past several hours and of the best oils generally recommended for flat-tappet, older engines, VALVOLINE VR-1 Racing Oil seem to be at the top of the heap with a ZDDP rating of about 1300 ppm. Second best appears to be LUCAS Hot Rod Oil for older racing machines, although it has ZDDP ratings of closer to 1800-2000, which may be too much (apparently due to a tendency for too-high Zinc/Phosphate levels to suffer problems such as undesired viscosity increases and oil-channel clogging due to detergent interactions, etc.).

Word has it that most full-synthetic oils now have a ZZDP rating of around 800 ppm, but a natural mineral oil base with about 1200 ppm (ZDDP) or so (10w30) would appear to be the better choice for an older street machine.

Still haven't found out what the Zinc/Phosphate additive rating of the CASTROL EDGE EUROCAR oil I currently use in my car is but I would expect when I hear back from Castrol, it will likely turn out to be in that 800 ppm range just like most of the other modern synth. oils.

Most interesting information, Ray, and I must admit that heretofore I was completely ignorant of the critical nature of and need for Zinc/Phosphate additives in older engine motor oils. Just goes to show me that despite all our (my) knowledge ("shade-tree" in my case), there's still a vast amount of often crucial awareness that remains hidden beyond our (my) personal experiential horizons! Thanks for opening that particular chapter for me in 'The Care & Feeding of Older Vintage Air-sucker Engines.'!
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1973 Standard Beetle, 1974 VW/Porsche 914-4, 1.8 liter
----------------------
Der Volkswagen ist ein Ausdruck der deutschen Kultur der Allrad Art ...

[The only irrefutable evidence we have that intelligent life truly exists elsewhere in the Universe is the fact that so far it has NOT contacted humanity...]

[raygreenwood]

[Windisch]

Yeah, Ray, I'd be interested in hearing about anything you discover in that regard. Even if my engine's main bearings DO have a bit of premature wear (due to that H20-in-oil matter I went into earlier in this thread and others), I'm hoping that use of the perfectly suited oil for my 914 may help to ameliorate and overcome any possible adverse possibilities. Have a memorable Memorial Day!
_________________
1973 Standard Beetle, 1974 VW/Porsche 914-4, 1.8 liter
----------------------
Der Volkswagen ist ein Ausdruck der deutschen Kultur der Allrad Art ...

[The only irrefutable evidence we have that intelligent life truly exists elsewhere in the Universe is the fact that so far it has NOT contacted humanity...]

[Windisch]

I use CASTROL EDGE (Eurocar) full-synthetic oil in my 914's engine, so I sent oiff an inquiry requesting more specific information on that oil's ZZDP (zinc/phos) content to CASTROL's HQ. Below is their reply:
-----------------------------------------------------------

Thank you for contacting Castrol North America.

Classic cars with flat tappet cam engines represent a special case in regard to engine oil lubrication. These engines have valve train configurations that require elevated levels of ZDDP (zinc dialkyl dithiophosphate) anti-wear for proper protection of the flat tappet camshaft and its lifters. Insufficient concentration of ZDDP will lead to premature wear and failure of the camshaft and lifters. Current ILSAC GF-5 and GF-6 fuel economy grade engine oils are designed for the extended life of the catalytic converters in modern passenger cars and have industry-mandated limitations on the amount of sulfur and phosphorus within the oil.

Castrol EDGE Euro 5W-40 A3/B4 contains a typical Zinc level of 1000 ppm and a typical Phosphorus level of 900 ppm.

The following Castrol oils are blended with a high zinc and phosphorus content to help prevent premature aging, wear, and metal fatigue on engines with high-tension valve springs or performance modifications that create high contact pressure and extreme internal temperatures:

• Castrol GTX Classic 20W-50 (Conventional Oil Formula)
Features/Benefits:
Zinc (1400 ppm)
Specially formulated to provide unsurpassed wear protection for classic and collector cars, as well as racing applications
Compatible with gasoline and alcohol-based fuels

• Castrol EDGE 5W-50 (Full Synthetic Oil Formula)
Features/Benefits:
Zinc (1250 ppm)
Excellent cold temperature properties
High-temperature viscosity (SAE 50) is suitable for use in many classic car applications

Castrol always recommends following the guidelines of the engine manufacturer for the recommended oil (i.e., SAE grade, API rating, and manufacturer specifications) specific to your application. Please consult your mechanic/engine rebuilder regarding the suitability of the 20W-50 or 5W-50 viscosity grade in your engine.

Thank you again for contacting Castrol; we value your patronage!

Castrol Customer Relations
1-888-CASTROL (1-888-227-8765)
Hours of Operation: Mon – Fri: 9 am - 7 pm ET
----------------------------------------------------------

Looks as if CASTROL EDGE has just about the perfect levels of ZZDP in it for our older, flat-tappet engines!
_________________
1973 Standard Beetle, 1974 VW/Porsche 914-4, 1.8 liter
----------------------
Der Volkswagen ist ein Ausdruck der deutschen Kultur der Allrad Art ...

[The only irrefutable evidence we have that intelligent life truly exists elsewhere in the Universe is the fact that so far it has NOT contacted humanity...]

[raygreenwood]

[Windisch]

Copy all that, Ray, and thanks. I'll do a bit of reading-up on those sources.
_________________
1973 Standard Beetle, 1974 VW/Porsche 914-4, 1.8 liter
----------------------
Der Volkswagen ist ein Ausdruck der deutschen Kultur der Allrad Art ...

[The only irrefutable evidence we have that intelligent life truly exists elsewhere in the Universe is the fact that so far it has NOT contacted humanity...]

[Windisch]

By the way, I recently contacted a local area engine modifier & rebuilder of some repute (Bryan, at Late Night Air Cooled VW, in Chico, CA) with a question about what sort of oil he recommends to his VW clients. His response was that he prefers synthetic of the 20w50 grade, not 10w30, for his engines. Of course Chico (CA) is situated in a very hot part of the Sacramento Great Valley, so high-quality synthetic (with the right Zinc/Phos. composition) of that weight would seem to be better suited to summer's often 105+ ambient temps there.

The range of air-temps encountered in the particular area one lives in would, to the perfectionist, have some significant bearing upon matters such as what oil would be preferable to use in one's VW/Porsche AC-engined car, of course. Just sayin'...
_________________
1973 Standard Beetle, 1974 VW/Porsche 914-4, 1.8 liter
----------------------
Der Volkswagen ist ein Ausdruck der deutschen Kultur der Allrad Art ...

[The only irrefutable evidence we have that intelligent life truly exists elsewhere in the Universe is the fact that so far it has NOT contacted humanity...]

[[email protected]]

you could raise the idle to 2500 rpm then pull one plug wire at a time and see which cylinder lessens the noise. Could be anything even a valve out of adjustment, a loose guide, an exhaust leak, but at least this way you could localize it

[Windisch]

[raygreenwood]

[Windisch]

Bryan at Midnight Air-Cooled in Chico (CA) principally rebuilds and and modifies Type-1 engines. Uncertain about Type-2s but I rather suspect he does those. Without actual word from him on Type-4s, I am reasonably certain he doesn't normally work on Type-4s, though. [Not sure about Type-3s.]

I admit I was surprised to hear of his recommendation for 20w50 myself! I would have instinctively grabbed 10w40. Speaking of engine heating effects, my 914 engine had the so-called Type-4 'Cooling flaps' removed from the rebuild, something that was apparently popular back in the late 80s period. I intend to have a set (and governing thermostat) reinstalled on my engine at the earliest afforded opportunity.
_________________
1973 Standard Beetle, 1974 VW/Porsche 914-4, 1.8 liter
----------------------
Der Volkswagen ist ein Ausdruck der deutschen Kultur der Allrad Art ...

[The only irrefutable evidence we have that intelligent life truly exists elsewhere in the Universe is the fact that so far it has NOT contacted humanity...]