got some questions on a engine rebuild

[backfoot100]

I know these are a few (as of right now) that can be used:
Valvaline VR1 20W-50
Shell Rotella T-1 30W
Shell Rotella T-1 40W
Mobil1 15W-50
Amsoil Z-ROD 10W-30
Amsoil Z-ROD 20W-50

I'm sure there are more but definitely do some homework before switching to anything new.

By the way, this list is confirmed by users at CCFan. Several of them use the Valveline and Rotella. I personally used the M1 since I've owned the boat in '92.

To give you an idea about what I'm talking about, I was always a tried and true user of the M1 10W-30 until I found out that the ZDDP levels had dropped considerably in most of their oils. I started using the 15W-50 at that point as that is the only M1 (readily available anyway) that has enough ZDDP. In fact, the Mobil website stated that the ZDDP levels even in the 15W-50 had dropped from 1800 PPM to 1200 PPM but that it was still plenty for a flat tappet motor. Let me caveat the following statement that THIS IS PURELY MY PERSONAL OPINION:   To this day, I have some reservations about the M1 and I personally think that it was at least partially the reason for my engine needing a rebuild but there is no way that I can prove it one way or another. Since my rebuild I have been running the Amsoil Z-ROD 10W-30 even though my engine no longer needs the higher ZDDP levels with a roller valve train. The higher ZDDP levels equate to better lubrication and protection properties overall and that is the reasoning for my use. I'm just no longer confident about the M1 but it still is the oil used in at least two friends boats with flat tappet motors.

[Mike Harry]

I agree with Eddie. Just to thow another name out there, Royal Purple makes a great oil that is high in ZDDP. I have run that for years both in race applications (cars) and in my boats and personal vehicles.

Just FYI

[Joel]

NAPA usually has their NAPA brand (made by Valvoline) on sale.  I purchased a case of their 15W50 synthetic for pennies on the dollar as compared to the Valvoline Syn.  It is the same as the Valvoline 15W50 Synthetic but is branded NAPA.  Double-check the ZDDP amounts, but I'm pretty sure there is plenty for our use, especially if you change your oil seasonally (if not more often).

Joel

[DustinS]

What exactly does a flat tappet motor mean? Is that cause its just a regular build and not a roller motor? And what is zddp?thanks for everyone's input on the oil its been educational I had no clue I was looking for anything other then brand and weight.

[Mike Harry]

Tappet or "lifter" is what everyone is talking about. The old school motors use a flat bottom lifter where as the newer style motors have rollers on the bottom of the lifters.

This is not the only difference between a flat tappet and a roller motor, but it is why people refer to them as flat tappet and roller.

ZDDP = Zink Dithiophosphate. Good for lubing and engine, bad for the environment. Good for lube is why its needed on flat tappet cams, bad for the environment is why oil companies are taking more and more of it out of their oils. Plus the new roller style engines dont need near as much of it.

Remember, when talking about ZDDP addative, your talking PPM (parts per million). Its in there, but its pretty scarce as it is even at high amounts.

[backfoot100]

Good explaination Mike.

Dustin,
If you want to find out more about it, you can go to bobistheoilguy.com and start reading. Or just do a search on the internet. My only problem is that a lot of guys on bobistheoilguy tend to be very brand loyal so you have to be open minded but there is some really good info there.

[DustinS]

Thanks a bunch guys! I figured that was the difference in motors but the oil I never paid attention to honestly. Thanks again for the heads up or I would of dumped the same oil as before in it now I know what to look for.