soonercruiser
Well-Known Member
I use Mobile 1 in all my other MOPARS.
Is synthetic OK to use in my old 318??
Is synthetic OK to use in my old 318??
WHAT TYPE OF OIL??
- Thread starter soonercruiser
- Start date
-
It will work fine, BUT it may show up leaks a bit more than dino oil simply because the synthetic flows so much better. It won't "cause" a leak. It just may "leak a little more" where small leaks may already exist.
Agree with above.
Sometimes on an old engine they Really
Leak a bunch more with the Synthetic Oil.
Sometimes on an old engine they Really
Leak a bunch more with the Synthetic Oil.
soonercruiser
Well-Known Member
Same benefit changing dino oil regularly gives you, yes.But, the benefit is hopefully longer engine life!
soonercruiser
Well-Known Member
It would probably disappoint some that I actually change my synthetic at the same interval as Dino oil.
That would be way more than "I" want to be concerned with. lol
You need zinc for the cam and tappets. I have 300,000 on a 273 with conventional oil, Valvoline racing 20w50, changes every 3,000 miles. Still runs like new. How long do you want your engine to last?
I would say synthetic doesnt do much benefit wise for our older engines. Make sure it has zinc/zddp. I use Rotella 15/40 with Lucas additive
Sorry to deviate from the subject but how many miles is break in oil used prior to oil change (500 miles?). Has only seen the dyno at this point. Don't see this car getting very many miles on it prior to me changing diff. Drive train is incomplete so will sit in garage for extended period of time once I remove the 7.25 diff. Will see engine runs at monthly intervals but not on the street.
soonercruiser
Well-Known Member
I believe that a normal break-in period is 500 miles.
Thanks for the response.
soonercruiser
Well-Known Member
For me, even if I end up selling the car, I want the engine to last the life of the body!
That's just how I fly.
Scody21
Just send it
You can run it up to 500, but really, once the motor is through break in on the dyno, you can dump the oil and put in the regular oil before the power pulls. As by the time the break-in is done the motor is on its way to full pulls. Break in oil does not have the rust inhibitor and additive package that the normal oil has. The other good reason to dump the break in oil is, the break-in oil pushes any FOD ie crap left in the motor during the rebuild into the filter. You can then look at the oil and cut the filter to inspect for silver and such… also, the 500 mile thing is because the manufactures back in the day did not dyno cars as they rolled off the line. Most cars today are cold dyno’d as they move off the line.
Scody21
Just send it
Changing the oil every 3-5 thousands and using a good oil is the best to make it last.
In no order these are the oils I would use. Dino or partial synthetic is just fine for our 50 year old cars. These motors were not designed for synthetic oils.
Penn Grade
Driven
Amsoil
ZR1
Lots of good info here.............Thanks
So after the dyno pulls the engine is considered broken in. Got it. Thanks for the response.
With modern rings and machine work it's broken in as soon as it's up to temp, pretty much.
You don't need synthetic oil to have an engine last forever. Old engines, new engines it really does not matter.
OTR trucks routinely see one million miles on a given engine build. New engines and rebuilds are expensive, so they try to make them last. THey were doing it a long time before synthetic came "into vogue". I'm not against synthetics, I'm just saying they aren't necessary in order to make one last. All that's necessary is keeping one maintained.
I'm partial to using conventional oil on these older cars.
Scody21
Just send it
This is the process we follow. Start motor, run between 2000-3000 rpm for about 20 minutes. Dump the break-in oil and let motor sit over night to cool down. Add standard oil, warm up motor. Shut off and let sit 45 to an hour to heat sink. Start motor and get to proper oil / water temp and then to a base line pull to 6-7/10 of rev limit. Check things and adjust tuning as necessary and then keep upping the rev limit on the dyno. Most engines we run have between 10-20 power pulls, which is really in 10-20 shifts. Let motor cool down and check valve lash and do a leak down test. By this time the motors is either broken in and ready for the races or is junk. There is no middle ground.
QuickDart360
Well-Known Member
Synthetic not needed. Conventional with zinc be happy!
Before the rebuild, the synthetic caused seepage in many places. So conventional oil was in it. After the rebuild its been Mobil1 and STP oil treatment to add zinc for over a decade.
-
