engine and drivetrain engine oil opinions

[prosado]

On a rebuilt tii engine what motor oil do you use/prefer?

10/30

or

20/50

A little background. I recently had the engine rebuilt on my euro tii (thus 10:1 compression ratio). The mechanic that rebuilt the engine (whom I trust and is very reputable in our circle) used 10/30. I have since done one oil change also using 10/30.

I had a local shop perform some maintenance and requested they perform an oil change while they were at it. I provided the oil (10/30). When I pick up my car I notice the write-up said 20/50. When questioned about it I was told that was the oil BMW used when the cars were new. It's also the same oil they used when they rebuilt the shop owners tii years ago.

I currently have the tii scheduled for them to redo the oil change with the 10/30. But I'd love to get your feedback.

Thanks,

Pete

[jrhone]

10/30 is too thin for most older small engined cars....20/50 is what most suggest for 2002s...10/40 is also not bad, but 10/30 seems very thin.

[Paul7002]

20/50 Castrol GTX or Valvoline VR are my choices. 10/40 in the Winter if you live where it regularly gets below freezing.

[c.d.iesel]

and this assuming you have driven the "rebuilt" motor

at least 600 - 900 miles on the 10w/30 break-in oil ?

you may now go to full synthetic if you wish (MOBIL 1 15W/50 )

[prosado]

c.d. : yes I've put between 500-600 miles on the rebuilt motor.

[nicktahoe]

I run Royal Purple 20/50 and I'm super happy with it. Kinda pricey but i think its the best.

[///mChris]

My experience is don't use synthetic unless you want it to leak out.

[prosado]

Right.

I should have mentioned that I'm talking about dinosaur oil (non-synthetic).

But does the weight matter with a rebuilt engine?

[nbristow01]

Yeah I burn dead dinosaurs too 20/50

[jrhone]

Right.

I should have mentioned that I'm talking about dinosaur oil (non-synthetic).

But does the weight matter with a rebuilt engine?

Yes...because its been rebuilt to factory tolerances. So you should use what the factory designed the engine for. Newer engines have tighter tolerances because of modern building technology. So newer cars can use thinner oil. Older cars are built with larger spaces between moving parts and the thicker oil makes it run better. Too thin and you dont get enough lubrication on moving parts. You also should probably be using an oil with zinc in it. Older engines use the zinc for coating the lifters (?) Someone correct me if I am wrong, but its something in the valvetrain. Some have blamed that on engine failures of freshly rebuilt engines. Do some googling on old cars and zinc oil and you will have alot of good reading to do. Most modern oils have removed it as it will harm catalytic converters. There are a few 20/50 oils out there with high zinc content. Valvoline VR1 Racing oil does as does most racing oils. Synthetics do not and MOST over the counter oils do not. Diesel oil does AND has more detergent for cleaning the inside of engines. The thickest it comes in is 15w-40. Thats a pretty good option. Its also designed not to break down quickly...I bought some rated at a million miles! I would NEVER EVER think of going more than 3000 miles on any oil in a 2002.

[hrg88]

Right.

I should have mentioned that I'm talking about dinosaur oil (non-synthetic).

But does the weight matter with a rebuilt engine?

I run Joe Gibbs Racing BR (which is a 15W50 High Zink Break In Oil) on a new engine. After about 100 miles of HARD break in, I switch to Amsoil 20W50. This is a vintage racer and sometimes street car. If I was going to run the car as a daily driver in winter, I might consider a 10W40 with a ZDDP additive, depending on the oil pressure I was seeing. The zink is very important to the cam lobes on our type of engine, especially during break in. The oils approved for modern engines (API SH - SN) in xW30 weight or lighter do not have anywhere enough zink for us so I would not use any oil lighter than a 10W40 even if the engine made enough oil pressure with it.

I have also never had a leakage or consumption problem on any engine using synthetics, including a Corvair I raced. I lost no oil except when parts launched out of the block which was a common occurrence. I use Mobil 1 synthetic in every other 4 cycle engine at my house (all non-race cars, motorhome, lawnmotors and generators).

[rover1]

i use Valvoline 20/50 full synthetic in my black beauty 76, and it works awesome i rev my motor up to 6000 rpm regularly. i use conventional castrol 20/50 in my 85' 911

[Napes]

Because of the zinc concerns outlined above I run Brad Penn 20W/50. If you're interested here is a supplier. Several who race 2002s use this oil.

www.RestorationStuff.com

Bob Napier

[jimk]

My experience is don't use synthetic unless you want it to leak out.

You have bad gaskets. It aint any thinner than dino. It will wash the dino crud out and show you where the bad gaskets are at. I have no leaks and haven't used dino since 1978.

[jimk]

Right.

I should have mentioned that I'm talking about dinosaur oil (non-synthetic).

But does the weight matter with a rebuilt engine?

I run Joe Gibbs Racing BR (which is a 15W50 High Zink Break In Oil) on a new engine. After about 100 miles of HARD break in, I switch to Amsoil 20W50. This is a vintage racer and sometimes street car. If I was going to run the car as a daily driver in winter, I might consider a 10W40 with a ZDDP additive, depending on the oil pressure I was seeing. The zink is very important to the cam lobes on our type of engine, especially during break in. The oils approved for modern engines (API SH - SN) in xW30 weight or lighter do not have anywhere enough zink for us so I would not use any oil lighter than a 10W40 even if the engine made enough oil pressure with it.

I have also never had a leakage or consumption problem on any engine using synthetics, including a Corvair I raced. I lost no oil except when parts launched out of the block which was a common occurrence. I use Mobil 1 synthetic in every other 4 cycle engine at my house (all non-race cars, motorhome, lawnmotors and generators).

Why not go with Amsoil 10W-40 high zinc oil if you are looking towards a 10W-40? That's all I have ever used. Check their web site.