Thread: What oil is right for a 429?

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Hey guys, I wanted to know what oil I should be running in the 429, the guy that we bought it from said a straight 40 or 50 weight racing oil. I hear that racing oils though don't have detergents and allow sludge to build up.

real sorry to ask something so simple, sadly I can't search for the answer as the forum won't search 3 letter words, like oil.

Thanks!

Red

I don't know how many miles are on it, I would GUESS at less than 15k, probably less than 10k. I should say that is what I would guess since the rebuild, but I don't know what machine work was done at that time. He said it had been "clearanced" for hi performance and that because of that I needed to run the straight heavy weight oils. i don't know what the hell that means though.

If the "clearancing" was really done to this engine, it means that the bore was loosened more to the piston than they should be compared to street trim. The bearings have been set looser by either grinding the crank on the "outside" or the bearings were hand rubbed to make a looser fit. Rings were gapped a bit more than required. These are old school and have no place in today's building world. Run the oil you feel comfortable with. I personally like the 20/50 atittude. I have started old engines in sub zero weather with no problems. I have included a chart that is current as of 5/10/07 that contains properties of branded oils. First line is the name; second, viscosity; third, Phosphorus; fourth, Zinc; fifth, Boron; sixth, detergents; seventh, API rating. Look for the best of the third, fourth, and fifth column lines for best combo.

so is that essientally mean that it was a bad idea to clearance it? means it's sloppy? I will go with the 20w-50. I'll have to try and blow the chart up later, on my screen it is too tiny for me to read, and I do have my glasses on.

I appreciate the help.

Red

I apologise for the fuzzies you are seeing. My moniter is a big 22 incher (Old age requires a bigger view). I would love it if Denny would come and clean it up for us. I am computer challenged when it comes to making the PC world a bit clearer and brighter.

The which oil thing is an interesting question. In my earlier days I was a bearing designer. Internal combustion engines use a combo of hydrodynamic (bearings) and boundary layer (cylinders, valve guides, lifters) lubrication. Across the board I would say that as an engine wears more viscosity is better. If you are in a hot environment and like to punch it a 20W50 is usually appropriate. However the synthetics behave better than the old oils. A 5W30 synthetic may in fact perfrom as well as Castrol GTX 20W50 in terms of wear and still reduce friction compared to the 20W50.

I will break my 502 in on 5W30 dino grease and then switch to 5W30 synthetic at 1000 miles. GM swears the 5W30 is the way to go. That seems a little light for my taste, unless it's synthetic .................

Kitz

I like the synthetic oils, Mobil 1 is my personal choice. Even with synthetic, I loosen up the rod bearings on my Windosor's, get them to tight and they heat the rod big end. Last FE I did I went stock spec on all the bearings, broke it in on conventional oil and went to Mobil 1 after 2,500 miles. It's still going strong with great oil pressure some 10 years and 40,000 miles later....

i have always just used castrol 20-50

I read an interesting article on synthetic oil and breakin on Ducatti's website. It basicly said that once the rings seat, any interferance problems should have the slipperiest oil. The rings should seat immediately and if they don't the glaze will never go away. There is no need to wait hundreds of miles. That's why Viper,Vette Z06, ...come with synthetic from the factory. I use mobil 15w50 in the hp &-turbo stuff,10w40 in the regular stuff-older. 5W in anything new.

Denny has your backdoor on this one. Heat is crucial also. Don't forget to heat sink the rings. Thanks for the help on the charts Denny. One day I'm gonna master this XP setup.

Do you guys like any additives to the oil during break in, other than cam and beariing lube that you use during installation?


Don

GM EoS is highly recommended for new engine break-in.

Kitz

One area that is almost always over-looked is the piston rings.
If someone goes to sny. oil to early when using a moly type rings the rings will take forever to seat.
An example would be the JE plasma rings or the Speed Pro Hell fire rings.
I have had a few customers that switched over to early to the syn. oil.
Even after 20 hard dyno pulls at 7,500 rpm's or more a good moly ring like the ones listed above have not fully seated.
In the dirt burner engines I build even after hot laps, the main and the feature you will still see a very small amount of smoke coming out of the breathers.
In a street car with a good moly ring I would not switch over until you had a min. of 3,000 miles on the engine.
When you do switch over don't be surprised if you see the engine use a little more oil also.

Denny, I too tend to err on the side of caution. I start new engines on mineral oil and run them for a short period ensuring compression. I then switch them to syn. The Ducati folks use a dyno break in on all their engines and can control the pressure loading on the new rings. Their engines never see mineral oil in the crank. I have worked on performance engines that never used syn. and had a bad hole due to rings. I am an ASE tech and a gear head so I like this type of info sharing..

We didn't do the break in on this, (by the way although we haven't had to add any my uncle I think is going with straight 40 racing, his car so I said "fine").

I had a mechanic once that I talked to about break in, the only thing he said was, "drive it like you intend to from the beginning". he believed that if you broke them in easy then when it came time that you wanted your foot in it they would not have been correctly broke in for that type of driving.

What is your thoughts on that?

Red