firstvett69

I was reading a post earlier this morning about what type of engine oil people were using in there early corvettes, I have had and steal do have and build off road buggies and sand cars. My buggies are normally vw 2.2 liter 9.5-1 To 2.5 liter 12.0-1 and I use Valvoline 20-50 racing oil in them never have had a failure, due to this particular oil. In a couple of sand cars I built with early LS1 I used 10-40 dello with relieved oil journals and high volume oil pumps with no oil related problems. So in my 69 350/350 with 68,157 miles on it I'm using the Valvoline 20-50 racing oil, I'm in CA high desert hot in the summer 100s and the winters we can get snow, I always make sure the temp is up before I start to drive it, as so with my off road cars. What is everyone's take on using the 20-50 in my 69, when cold oil psi is at 45, when temp is worm cruising at 55 turning 2250 rpm its 30 to 35 when the ambient temp is around 100 car runs at 170-180 and oil psi is at 30. All the engine's i normally build, or have bought are all flat tap type. The PO of my 69 used 10-40 Valvoline, reason I use Valvoline 20-50 I get it free, not a bad deal for me but i don't want to hurt my baby. Ill appreciate all comments. THANKS

baxsom

20w is very thick for cold weather. i wouldnt try to start it if there is snow on the ground with that thick of oil in it. Your winter weight(what the W actually stands for) is almost as thick as some oils normal operating temp weight.

noonie

I would check the oil pressures with a known accurate gauge first.
If proven to be the same, then that oil should be fine.
If really concerned, add an accumulator.

fwillison

20W50 is too thick both at start up and at operating temp.
I personally use 5W30, and it makes no difference what you winter temps are.

See here:
http://www.ferrarichat.com/forum/faq...=haas_articles
very educational and accurate

Fred

dochorsepower

Just don't use a synthetic like Mobil 1 with a flat tappet cam, unless you need a reason to replace a worn out cam.

fwillison

Synthetic Vs mineral oil has no bearing on the issue of sliding surface wear and associated camshaft failure. It is the ZDDP in either type of oil that protects against this

jackson

most don't drive C3 on snow days.

free VRace 20W-50?

run it but don't crank C3 on snow days.

... I removed Qjet choke ... requires patting gas pedal to cold-crank ... I spin starter over 'til I see op rise ... then I pat the gas & fire-up. Area CT racers do likewise.

jordan89

There's nothing wrong with running synthetic motor oil on a flat tappet cam engine. As long as there is enough ZDDP in there, you're good. I've been running Royal Purple in my '78 Z28 for about three years now and have never had a problem. Have you seen the sticky about oil for flat tappet cams? I've heard a lot of good things about Mobil 1 15W-50 and that's what will be going in my Vette.

fwillison

15W50 is far too viscous for any street engine, particularly at start up, when 90% of engine wear occurs.
The thinnest oil currently available 0W-xx is still too thick at startup, but is the best available. 0 or 5W 30-40 will be optimal viscosity. Then you need at least 1000 ppm zinc. I use Mobil 1 Turbo Diesel Truck 5W-40.
ZDDP is not the only consideration!
See the link to Dr. Haas' discussion of oil viscosity that I previously posted. Few people understand the oil grade ratings and engine viscosity requirements at start up and operating temp. The link will explain it correctly.

Fred