Synthetic oils?

[mlrailguy]

I would like to use Amsoil in my sandrail, but was told that this was not a good idea. Was told the magnesium in the case reacts with it. I'm using the aftermarket aluminum case, so thinking it shouldn't be any problem. What are your thoughts and opinions?

[ps2375]

Never heard that before. My father had synthetic oil in his motor (w/ a stock case) before he parked it for 20yrs, and when I got it and tore it down, there were no signs of any damage, in fact the motor internals came out looking like new. I don't know what brand of oil he had in it, but I'll be switching over to a synth oil next spring.

[Marc]

Don't use "standard" Amsoil for break-in. Biggest reason is that flat-tappet engines need ZDDP (a zinc-phosphorus additive package) to facilitate break-in of the cam lobes & followers; many feel that a "too-slippery" oil will delay break-in of the piston rings/cylinderwalls as well.

Personally I'd use a high-ZDDP conventional oil for break-in ('cuz they're cheaper and I'm frugal) but if you'd rather stay loyal to the brand Amsoil offers an SAE 30 Break-In Oil. They recommend using it for no more than the first 1000mi (2 or 3 times longer than most ACVW engine builders recommend before initial change).

[Marc]

Amsoil also offers 10W-30 and 20W-50 "Z-Rod" oil, with higher zinc content for flat-tappet engines. I have no personal experience with it, but it looks to be a better choice for our engines. http://www.amsoil.com/shop/by-product/m ... 2fzrt.aspx

[craigvwdude]

I've used synthetics and dino oil (VR1). Have had excellent luck with both.
Synthetics will take longer for motor break-in.
Could use VR1 for break-in and then switch to synthetic after a few hundred miles.

[helowrench]

Deisel synthetics in my Ghia for ~80,000 miles now.
No negative results.
Mostly Rotella

[Tony Z]

I had the new batch of Shell Rimula R4X 15W40 analyzed for work this week. Turns out its got 1250ppm ZDDP which is about perfect.
Yes, its a diesel oil.
Yes, I use diesel oils in my bug and bus

[Piledriver]

Have used Rotella HD or VR1 dino oil for break in, but once run in everything gets 5W-40 Rotella T6 at my house.
(also ~1250 ppm zinc/~1000 phos based on most reports)
The cats object but they'll get over it..

Yes, its diesel oil.
I reused the main bearings in my current motor with a fresher crank, as they were still in spec at >400K miles.
Oddly the crank was worn more, not sure how that worked, but clearance was in spec with the new crank.
(was still well within wear limits with old crank, my have always been that way)