Best oil for Racing an early 911

[Vintage911Racer]

With a lot of Oil talk going on in here. What is the best oil for using in a Vintage race car. 1967 911S 2.0L. Any recomendations?

Thanks

[ErVikingo]

In the past I have used Castrol Racing, Valvoline Racing and Quaker State (all dyno oils!).

I tried synthetic and it leaked a bit plus I drain it VERY often so I don't need either the extreme SPI ratings nor the "longevity" of the oil. Not to mention at over 4 gallons every change.....

I'll check and see what my mechanic is recommending for the new engine. I'll post anything else

[304065]

I use Mobil 1 15W-50. I change it after every race weekend, like 6 hours of use if a sprint race, longer if enduro is run. The car sits for weeks, sometimes months after a race, and my preference is to not have all the acids caused by combustion sitting in the oil system for that long.

[Vintage911Racer]

Why do the synthetics tend to leak more? Aren't they supposed to hold up better at Higher temps? Not break down as fast. You would think if they did not break down as fast they would not leak more.

[Vintage911Racer]

John, I use the Mobil 1 15-50 as well. I change it after every race weekend as well. Is it true that the synthetics leak more than non synthetics? ANd do the synthetics help with keeping the car a bit cooler. I have heard that but find it hard to beleive.

[Emission]

Synthetics leak in older cars because their detergents tend to break down deposits. Those deposits are preventing leaks. I run synthetic in all of my cars. The only one which has ever leaked is the 129,000 mile Porsche.

My car doesn't run any cooler on synthetic, and I don't see why it would. The only advantage to synthetic is high temp stability, and better flow when cold.

[Vintage911Racer]

Thanks for the input. I have used the synthetics for the past 4 years in the race car, and I love them. Never had any problems.

[campbellcj]

Mobil1 15-50 (is there an echo in here?)

I have previously used Valvoline Racing 20-50 too.

Keeping it cool and changing it often (enough) are essential.

[Sonic dB]

Do people use Valvoline Racing 20-50 just because it has the word "Racing" in the title?

[Chuck Moreland]

A recent thread talked about 10w-60 oils speced for BMWs. Has anyone tried these?

Seems like the broader viscosity range could only be good, especially for hot running race cars.

[Doug Zielke]

At the Seattle Historic Races a couple of weeks ago, I saw a lot of Kendall bottles in the pits.

[walt]

The narrower the viscosity range the better the quality of oil. Viscosity improvers added to the oils work agansit "lubricity". For example a 10/30 is superior to a 10/40.

[Vintage911Racer]

What about 15\50 Mobil one

[walt]

The narrower the viscosity ranges on petroleum oils the better. Not sure about synthetics.

[Zeke]

Air cooled off roaders like Kendall

[TimT]

Shell Rotella-T

It meets specs that havent been invented yet

[Vintage911Racer]

Isn't Rotella A Diesel Truck Oil? And they only have a 5-40 synthetic don't they?

[Wil Ferch]

Rotella T comes in a mineral oil of 15W-40 and a synthetic of 5W-40.

Good stuff too..stopped the leaks I had with Mobil 1 15W-50 in my 85 Carrera. Then again, it's summertime and my car leaks less ( or not at all) during this season, but leaves a *big* spot during the winter hibernation in a 40+ degF garage...even when I run it occasionally.

--Wil Ferch

[Vintage911Racer]

Which do you use. 15W-40 or the 5W-40

Castrol RS 10W-60?