full synthetic oil?

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beebeeri000

beebeeri000

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hi im rebuilding a 360 and i was thinking about going to full synthetic oil. what are everyones thoughts on full synthetic oil?
 
In my case all bad. perfect 383 69' Coronet. It started up ran on eight, then it after 100 miles or so it would shudder, run erratic and die. Start it again, go down the road, and all over again the same thing. I got it home, and tested for compression, which was 70-90 all around. Also, I had an oil leak around the pump, that wouldn't quit. I called the engine shop, and asked what is the deal. The first question was, what oil? I told him, and he said get that crap out, NOW. I ran Rotella 15-40 in it Immediately. The engine smoothed out within minutes. The engine ran like a million bucks, and the oil leak quit. 5,000 miles later, it drives better every time I start it up. Synthetic won't seat rings. Several restorations later, I always use Diesel oil with Lucas #10036 for lifters. No problems since.
 
Synthetic oil is good, but I wouldnt use it until the motor has a few miles on it first, apparently it can slow down ring seating.

Oldmopardude just beat me too it! But I use exactly the same thing as he does and havent had any issues.
 
Hi, after your initial break in time for your engine using oil with high zinc and phosphorous amounts up around 1250-1500 ppm then yeah full synthetic is fine for new engines. I have been running full synthetic oil in almost every car I have owned since the mid 90's with the exception to my old tired engines lol. They like heavy oils with high zinc and phosphorous to keep things from grinding up lol. Now if you are building a high performance 360 with solid lifter cam/roller cam then you need to run oils with the zinc and phosphorous in them or use the additive in your oil just to be safe. I am sure other members will have experiences to share or opinions by the truck load here at FABO so get ready for a wide range of theories and ideas on whats best. They will ask you whats in your engine, how hard will you drive it, and a whole slew of other questions in order for them to scientifically narrow down exactly which oil is best for your application LOL!! All kidding aside though full synthetic or a blend is good for new rebuilt street engines.
 
Don't see a problem. some say it will develop leaks on older engines, but you are rebuilding your motor, so even if it was true, you wouldn't have to worry about it because you will have new seals.

I Run it in all my cars and motorcycles.
 
k thanks everyone im just gonna run regular hydraulic lifters since its street strip. should i aim for a certin gasket brand if i go with synthetic? or should i just add a little extra rtv
 
X2^
I got a pretty hot 340. Im talkin bout 400 horse
I run mobil one 15w50 full syn and was recommended by my engine builder.
But id leave break in oil in there for 500 miles or so then change but its all personal preference.
But you want a oil with high zinc and phosphate ppm counts
The higher the zinc and phosphate count in ppm or parts per million is what your looking for.
A lot of the oils are geared to new vehicles and have low zinc and phosphate ppm levels due to regulations and emmision control statutes however there are oils out there geared towards flat tappet applications where a high level of zinc and phosphate is ideal for longevity of components.
Heres a list of mobil ones oils, but lucas has some muscle car oils that are pretty high in zinc and phosphate and so does royal purple. But as far as i know mobil one 15w50 full syn has the highest levels of zinc and phosphate in ppm.


[ame]http://www.mobiloil.com/USA-English/MotorOil/Files/Mobil_1_Product_Guide.pdf[/ame]
 
On my race motors the rings are seated by the time I get the valves set, I put full syn in EVERYTHING I own, it does like to find a place to leak out of, no biggie I just put more in and or fix the leak.
 
I ran Mobil 1 15-50 in my DD truck since I did the first oil change on it, 351K miles ago, about 2 oil changes ago I put 10-40 in it...man what a difference that made, it starts and gets to a clean idle much faster and I can tell the motor isnt working as hard to pump it thru its tired old veins!!!
 
After break in full syn 12,000 on this 340 and 100's of thousands on my other cars over 30 years , never had a problem . 340 does not burn any oil between changes .
 
i actually don't think there is much difference between the two. the 340 demon gets VR1 10/30, 12K and no problems engine is a clean as when i installed it. 03 Dakota has 213K oil psi is perfect and doesn't burn a drop, i did use Mobil 1 between 10K and 30K didn't notice any thing different so went back to dino juice.
 
dinosaur oil with zinc additive for the first 1500 miles after that synthetic is fine rings need to be seated before the oil switch
 
You want the new lifters to rotate properly as well. Dont be in too much of a hurry. 3 or even 5 thousand miles isnt alot to ask. What did racers do in the 60's before synthetic? Those engines ran just fine.
 
I use the Valvoline VR1 20W-50 at the parts stores (silver bottle) since my engine has bigger bearing clearances it works great... I don't think it's synthetic but it's designed for high performance flat-tappet engines with plenty of zinc, etc. It's also cheaper than 'normal' synthetic. Timely oil changes are important with this oil I've heard...

The thick Mobil 1 is a step up in quality claimed to be full synthetic with the stuff for flat-tappet engines as well.

If you know you need thinner oil in your engine the choices are more limited to the expensive stuff (Royal Purple, Brad Penn, etc.) unless you use an additive with a 'normal' synthetic oil.
 
As most suggest, break in the engine with conventional high zinc oil and added break-in lube mainly for the cam & lifters. Run it for a while. But Amsoil has a break-in specific oil as well. Then full synthetic will help provide an extra level of protection.

I use Amsoil in my race engines and have actually had to reduce the idle when switching from conventional 40wt or 15w-40 for break-in to synthetic 5w-20 Dominator. Some of it may be because of the viscosity difference, but some is from better lubrication. My engine builders have always liked what they saw when disassembling the engine for a refresh.

Here is a wide range of choices to choose from at www.amsoil.com :

[ame]http://www.amsoil.com/techservicesbulletin/MotorOil/TSB%20MO-2007-08-08%20Flat%20Tappet.pdf[/ame]
 
Here's the Mobil 1 link to their zinc and phosphorous numbers. [ame]http://www.mobiloil.com/USA-English/MotorOil/Files/Mobil_1_Product_Guide.pdf[/ame]

The shop that built my car put Mobil 1 15W-50 in it after break in because it was easier to get than the other high ZDDP oils. I'm not sure about running 50 weight oil, but I haven't had any problems yet. I'll probably switch to Valvoline VR-1 at some point because it is a little bit cheaper.
 
Mobil 1 0w-40 or 5w-40 turbo diesel oil with no additives. Break in on Joe Gibbs. Left in for 500 miles. 12 years on engine.

There is no dispute on this, synthetic is better. Period. If your engine leaks, it isn't the oils fault.
 
I run cheaper conventional oils for my plow and car, most mixed use performance engines can run anything once the rings are seated. I'd give a fresh street or street/strip engine 500-1K miles before you switch it to synthetic and use one that works with your clearances. Race cars get a little more attention and I wouldn't worry about running synthetic after a few passes to seat the rings.
 
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