ovidoman

I just bought a 1969 fastback. Theres a pic up in the "introduce yourself and your car" sections. Well this car has a bored out 351 Cleaveland w/ a mild cam. Edlebrock intake, ported heads, 850cfm Holley. The guy i got it from said he used 20W-50 oil. Valvoline was the brand of oil he used. Does this sound right to you guys. Anyone with any suggestions, if you could please let me know i would greatly appreciate it. Thanks in advance.

jc69Stang

Valvoline is a good brand, however, for my ride it is Mobil 1 5W-30 synthetic.

You will notice a difference right away after swapping to it.

ovidoman

Thanks for the info, i was thinking of trying Royal Purple. If anyone out there uses it, does it really make a big difference over, say valvoline or mobil 1 synthetic oils.

ravenblack67

There is no significant difference between oil brands for normal use They all meet the same SAE requirements. The weight is something else. 20W-50 is a bit heavy. I would switch to 10W-30. Synthetic? That depends on how tight the engine tolerances are. There is some advantage but the price is high. As with anything else, you will get a variety of opinions. My '67 gets cheap 10W-30. Then again, I only put on 1,000 miles per year at the maximum.

ovidoman

Well the motor in questions is a slightly built up cleveland with maybe 2000 miles on it. I thought 20W-50 didnt sound quite right, but i thought since the engine isnt stock and has low milage this might be right. I have heard on these older engines you should use 10W-30 or 10W-40. Any more suggestions would be greatly appreciated. Thanks again, you guys have been a great help.

harleybill

I use royal purple (used to use mobil1 but I had heard that they took out some additives that had reduced the quality. I will try and find more on that)... Older engines especially need synthetic and when they aren't used that often, an extra advantage is that they put a nice coating on that lasts much longer than standard oil. I wouldn't use anything but full syn. Weight would be 20w-40 unless you live in a desert and then 20-50 might be ok.

jc69Stang

20W-50 used to be very common for hot rodders to get a little extra protection from running the heck out of their motors. Unless you live in a very hot climate it isn't necessary.

The reason I run Mobile 1 is the availability. you can buy the stuff at any Walmart etc..
Thats hard to beat when you are low and there are no spare quarts in your garage.

ALL ENGINES should run synthetic. Plain and simple it is better. You pay more but the oil changes double in mileage so it balances out.

I ran normal oil in my 02 F150 that my wife drives. I changed over to synthetic and she later asked me what I did to make the truck run better.
If she noticed, anyone would, especially us car guys.

Rolay Purple has a good reputation as well, again its availability that keeps me from trying it.

Good luck

ovidoman

Thanks a lot guys. You were a big help. I went with Valvoline 20W-50 Full Synthetic. The car feels great. I figured its not super hot out here on the west coast, but i better go with the extra protection. Thanks again. I got a lot of useful information.

LMan

can you define "run better?"

jc69Stang

The truck is much smoother through the RPM's, seems to strain alot less at full throttle. And the mileage has picked up slightly. Synthetic oil is worth every penny, not to mention it has proven to be worth HP on the dynos as well.

codeman94

I use Castrol Syntec 10W-30

copasspupil

Try this link...

www.boss302.com/oil.htm


I don't believe the part of the high mpg however.

beneman

A timely topic for me. I had my car's 289 rebuilt last fall, and it has been wrapped up ever since. I plan on installing it next month. The motor has a mild cam, .10 over bore, standard compression, and I live in the AZ.

Having never used synthetic oil before, is it recommended for motors that have just been rebuilt, and never run? ( I imagine it is, but I wanted to make sure). 20W-50 sounds like the way to go for me.

ovidoman

I got this from the royal purple website (FAQ's) about putting their stuff into a brand new engine.


"Can I put Royal Purple® into my brand new car?

Yes. Royal Purple® currently offers many viscosity grades of API Licensed Motor Oils. (See the Royal Purple® Motor Oil Product Page or visit the API Engine Oil Licensing and Certification Website for more information). To allow for proper break in of the engine, Royal Purple® recommends waiting until the manufacturer's first scheduled oil change or a minimum of 2,000 miles in new gasoline engines. Allow 8,000 to 10,000 miles before using Royal Purple® in diesel engines."

67shelby

I agree with most of this statement, however, there are subtle differences that can cause problems with the use of certain oils with certain cleareances and certain configurations, etc.

Some of what I will spout here is theory, but a theory based on certain experiences. I have a 289 4V .040 over, mild cam, very few modifications except Pertronix (concours car). I ran a 10W-30 or 5W-30 or more "modern" oil and had very high oil consumption (1 quart over 200 miles or everytime I filled up, I added a quart). No real signs, didn't blow blue at anytime. A slight hint when I backed off, but other than that, no real signs of oil usage. I did some research and found that the oil brands have a different "flashpoint" or the measurement of the flammability of motor oil:

With Pertronix, you run a hotter coil and can run more gap. You basically have more fire, which in turn is hotter, which in turn hits the flashpoint of the oil and you burn very slight amounts.

So, over a course of an 800 mile drive from KC to Dearborn, MI, I changed from the 5W-30 (I think this is what I was using because I used it in a 96 4.6L GT) to 10W40 by changing 1 quart every fillup. By the time I came home, I wasn't buring oil. The point being that I believe (very firmly) that the use of Pertronix and oils with lower flashpoints will cause oil consumption. There isn't any reason you shouldn't use 10W40 in an occasional driven car of your vintage.

As is stated, you will get many opinions, but if you use Pertronix and have oil consumption, you should try a different oil.

Hows that for theory?

jc69Stang

There are a lot of people that say not to use synthetic in a brand new motor. I used conventional as well in mine.

I agree with that, you need to break in the piston rings and get a good tight seal, then switch over to the good stuff. As an example on my engine, I changed the oil at least 3 times before changing over to synthetic, but I do not clock mileage with it, I just check it periodically and as soon as it starts to change color, get it out of there. My car gets very little driving so time is more of a factor than mileage.

This does not mean you cannot run syn in a new engine, but I like to stick to reccomendations that have been around for quite sometime.

beneman

Thanks for the tip. Conventional 20-50 is where I will start. The drivetrain will be going in on 12th of August. I can't wait to get back on the road after a two year restoration. I have been spending bigtime cash to finish this car recently, but I know it will all be worth it.

bob

Y'know how tight was the engine built (to standard specs, bearing clearence and the like), this has alot to do with the viscosity oil, you should use. Extremely tight engines (ie; very modern engines) utilize and benefit from very thin oils, on the other hand a loose engine (ie; an old desiel engine) would have oil pressure problems if you used the same thin oil.

Also oils are formulated not only for engine clearences but the types of materials and building methods employed. It is in your best interest to make sure the oil meets your engine application or even with good oil, rapid engine wear can occur.