Dear friends,
I remember that someone told me synthetic oils can destroy seals in older cars. Some people here who are collecting classic (german or british) cars use a so called "Classic Oil" like this: Castrol 20W-50 (Classic). What kind of oil do you use for your early zedds?

Thorsten

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T. Link
Germany
1971 240z (HLS30-16506)

Thor ~

When my 1970 240Z was finished, I began using Mobil-1 synthetic oil in the rebuilt engine. I did get oil leaks, especially in the front case seal.

Simultaneously, I changed the oil to Valvoline VR-1 20/50, AND changed the seal (which was slightly damaged). Now the leaks have all stopped.

The Mobil-1 was dirty after only 2,000 miles, with an excellent filter.

I will remain with Valvoline VR-1 oil from now on. It is designated as a "racing oil", but I don't race. Every part of my engine is new and the 4-core radiator is completely rebuilt, so my temperature NEVER reaches the half-way point on my temperature gauge. Therefor, heat is not an issue for me (yet). I get HUGE oil pressure except at low idle. My engine seems very happy with VR-1, so I will keep it.

Our member Bryan Little writes the excellent Website, "THE DATSUN Z GARAGE". He has a very good section there about Z engine oils, and he actually recommends VR-1. On our Homepage, look on the left margin. Press on his DATSUN Z GARAGE icon to read his very informative information.

Tut tut~
Frank

Frank, thanks, perfect. The Valvoline is also here available!

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T. Link
Germany
1971 240z (HLS30-16506)

I use Valvoline 10/30

Hi Frank:
I hope you didn't use Mobile 1 during the break in period on a rebuilt engine. New and rebuilt engines should be broken in using natural Oil - the synthetics don't allow enough friction to seat the rings.

Personally - I use Mobile 1 in every car I own. Have never had a problem with "old seals" leaking. I think that was a problem with the synthetics in the early days of their development.

I use Mobile 1 because of the heat here in Florida. When I rebuilt my last L28, it ran hot even after break-in. Everything was new in the cooling system - but in the Summer here as the outside temp's approached 90 degrees F - - sitting in stop and go traffic - the engine temp's would creep up to the point at which I would worry about overheating...

I switched to Moble 1 - and it dropped the engine temp's about 15 degrees F - then I added Red Line Water Wetter and that dropped the temp.'s another 10 degrees. At that point I could and indeed did set in stop and go traffic {in Atlanta circa 1995} in 102 Degree Temps - and the temperature gauge stayed right at normal.

Another important advantage of the synthetics is they coat moving parts for a far greater period of time when the engine sits idle. I found this to be the case in the older Muscle Cars I restored. Running natural oil, if the cars sat for a month without being started/ran - you could hear the lifters clatter like crazy on start up and for the first few seconds - until oil pressure came up in the engine. That was not the case once I switched to Mobile 1.

If I lived in a much cooler area and if I drove my Z's more or less every day - I'd use Valvoline VR1 Racing Oil, as I had ran Valvoline oil for years in my Z's {they were a BRE Sponsor after all:-)... Also Valvoline is produced by Ashland Oil - and I'm from Ashland, Ohio anyway!!

The truth is you can run just about any quality motor oil today in the L24's - the important part is keeping fresh oil and filters in the engine. Even a slightly rich mixture on your air/fuel ratio's will result in raw gasoline diluting the engine oil over time, especially in colder area's where using the manual choke is necessary. Engines run far cleaner today so carbon and lead that used to contaminate engine oils - are no longer the main problem.

While the high zinc/phosphorus content in VR1 is very important in the older Porsches and MB's - Nissan's hardened surfaces on their cam lobs and rockers have never had the problems the older Porsches/MB's and a few other British and Italian cars did. However prolonged periods of sitting idle can result in these surfaces being dry or oil drained, and that will cause unnecessary wear - in that case the synthetics are better.

Just my experience and opinion...
FWIW,
Carl B.

Carl ~ I got the engine back with fewer than 2,000 miles on a total rebuild and the PO said he used Castrol. I swapped to Mobil-1 for the exact reasons your cited but it found every leak. I ended up changing it out ($65 down the drain) while it was still clean. Engine's happy with VR-1 at less than half that price.

I'm sure Thor's beautiful car will do fine im Deutschland with either VR-1 or Mobil-1, and I suspect Thor and the previous owner (PO) will communicate about this car for many years.

Thanks again Carl ~ you MUST write that book!

In my experience, use of synthetic oil in "older" cars that pre-date synthetic motor oils, will cause seepage. I doubt that the synthetic oil attacks the seals and gaskets, it is just much better at flowing, so it finds it's way out the old gaskets and seals. Especially OLD gaskets and seals.

When I refreshed my L28ET, I changed all the external gaskets and seals with new OEM ones to prevent seepage of the Mobile 1 that I planned on using. I also coated both sides of gaskets with Permatex#2 gasket sealant. In 6 years of running Mobile 1, the L28ET is still bone dry and squeeky clean.

Permatex#2 is great stuff. It's black and gooey which helps to hold the gaskets in place while positioning. It dries overnight to a hard, licorice like consistency. It never bonds with the metal so removal is easy later on. It's easy to clean up, looks factory, unlike RTV, and is O2 sensor safe.

Follow the instructions on the tube.

http://www.permatex.com/products/Automo ... ealant.htm

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-Dave
76Z Turbo'd
72 In Progress---DONE!

Synthetic Oils all the way.

As long as tolerances are tight, and engine is cared for properly, you will have better performance from synthetics in regards to heat and friction wear.

I use Catrol Syntec myself. They got me back in the Sega Rally days, before I could drive.

In the beginning Mobil 1 was a 5wt...then 5w10.

Today they make 10w30 and 10w40.

I've been using it since late 70's.

I'm still experimenting with some different oils and compiling consensus. I used to use Valvoline VR1 for my old engine. Now I have a turbo L28 so I use synthetic. I've tried both Castrol Edge and Penzoil full synthetic. Both have worked well so far.

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-Chris