First oil to use after ring seating... Synthetic okay?

[jenkins71]

Hey guys. I am about to reach my first 500 mile oil change for my 440. Been letting the rings break in.
Is it okay to now use Royal Purple Synthetic? 10w-30. Up until now I have used VR1 oil for the cam break in, changed that and the filter, and swapped in more VR1. Now it's time to "regular interval" oil changes. So... Synthetic okay, or not? Flat tappets, normal motor.
Thanks!

 

[Dennis H]

I'd run it to maybe 1,500 or more then use Amsoil Signature 10-40 synthetic. It is high-zinc. My brand and weight choice after a 30 over rebuild in the 440. Royal Purple is good as well. I prefer the 40 due to sever demand and heat. Annual change. Add about a quart to 1200 romping miles.

 

[69Bee]

I tell my customers to do 2 regular oil changes after break-in before they go to synthetic.

 

[GetX'd]

How long would you consider a break in period - or how many miles. My car was dynoed and then now just start and stopped in the shop while other work is being done. No,real,road miles....

 

[lewtot184]

i've never been able to get my mind around why synthetic can't be used in a new engine. i don't use synthetics but i just don't understand or believe the break-in mystery.

 

[mmissile]

I like using dino or blends. Synthetics always seem to leak like hell. Maybe not initially, but always find a way. I change my oil frequently....it's cheap insurance.

 

[eric383]

I remember back when the synthetics came out engine manufacturers said the rings would not seat due to the properties in the syn. Back then they recommended 3000 miles before going to syn. I personally don't use it due to possible leaks on my old stuff. To each his own.

 

[mmissile]

I threw synthetic oil in my 03 CTD, too early. I actually felt the power go down. After about 5K miles and 2 more oil changes it felt stronger all the time. The exhaust smelled different, also.

 

[BBishere2]

Back in my auto parts store days, I talked to the reps about the differences in synthetics vs 'regular' motor oil about the leak complaints.

Their response was that the different type of oils affect the various seals in a different way - they all said if you want to run synthetic oils then to use them and stick with them - the same for the petroleum based oils - if you start using them in the motor, stick with them.
They didn't seem to think that if you were breaking in an engine with a petroleum based oil, there would be a problem if you switched to a synthetic, if you stuck with the synthetic, once you changed over the oil types. They all pretty much agreed that if you had ran a petroleum based oil for a period of time and wanted to switch over to a synthetic, you'd be better off pulling the motor and rebuild it before switching over - at the very least - replacing all of the seals.

I've not switched types of oils, so I have no experience with it - but this is what the lubricant reps and chemical reps came up with when asked.

 

[moparedtn]

Flat tappet cams need zinc. Flat tappet cam failures have been damn near epidemic at times since zinc was removed from motor oils (presumably zinc is bad for emissions equipment), a part of the reason so many manufacturers have gone to roller cams.
I learned all this after researching why my engines' purpleshaft wiped 3 lobes pretty darn quickly after break-in - and yes, synthetic was probably introduced to the engine too soon (approx. 500 miles from rebuild).
Zinc. Can't say it enough.
If not in the oil itself, certainly in an additive to said oil.

 

[67 B-body]

Brad Penn.....
Only oil I will use in my 440 with solid lifter camshaft....

 

[lewtot184]

it's my understanding that nobody has figured out how to synthesize a petroleum molecule. if thats true, and i don't know absolutely that it is, then there really isn't any such thing as "synthetic oil".

 

[GrabberOrange69]

I don't use synthetics in any of my older cars, rebuilt engines or not. I have flat tappet cams and I'm worried about the zinc content. At least a few places offer oils for "hot rods" that have the zinc in them, use one of those and you'll be glad you did. I know there are a couple of zinc added synthetics out there now - those should be fine if you like the advantages of synthetics.

In my new cars, I run the car until it has a couple of oil changes under its belt, no earlier than around 3k miles - then switch to Mobile1, grade appropriate for the vehicle. I had a turbo PT Cruiser that I leaned on regularly and when I traded it at 168k it was still no puff, no consumption between changes. The stuff works.

I just don't like the leaks and lack of zinc with synthetics in my older cars.

 

[moparedtn]

Yep, in all 3 of my late-model hemi's, I run full synthetic. Had a 5.0 Mustang (Ed dodges rocks here) I bought new
and always ran Mobil1 in - at 250k miles, you could not tell the engine had worn at all.
Same with a couple 2.2 turbo Shelby critters I had in the 80's - cars fell apart but the engines showed little wear.

By the way, after a lot of research on here and elsewhere, when I installed my new Comp Cams cam & lifters, I used DRIVEN oil. Excellent information on the need for zinc in engine oil here:
http://www.drivenracingoil.com/news/dro/training-center/articles/zinc-in-motor-oil/

 

[1967gtx]

When I purchased my 95 Caddy ETC which had 42 mi on it when I drove it home and after the recommended period for break in, I change too Valvoline Syn-Power 20/50 and I am pushing 250K mi and it still runs like rocket. On my 67 GTX I am using Valvoline 50 wt racing oil since the motor was done. I will be running the same oil in my 452 Max Wedge motor that I am building. So for me the old hot rods get oil and the new ones(post 92) it's a crap shoot!!!

 

[cdr]

vr1