ENGINE BREAK IN

[Rasp933]

Hello.ratsun

I have close to 2500 miles on rebuilt l20 b.I have used 30w oil since the break in.now when do I switch the oil to different grade?

[datzenmike]

Modesto? 30's fine leave it. Make sure you have plenty of ZDDP content for the cam and followers.

[ggzilla]

Break-in period is first 2000 miles per Datsun (but some guys say it takes less miles).

 

Now it is time to change the oil. 30W is fine unless you plan on trips to Tahoe or other cold places. But 10W-30 is better:

 

[Rasp933]

Thanx guys

[Rasp933]

Will penzzoil 10w30 do any good?

[datzenmike]

Just an opinion... I wouldn't run 10 anything. Also the ZDDP content has been dropping the last few years because face it, it all ends in the environment or fouls the latest catalytic converters, (that we don't use) and isn't needed with the latest roller cams. (also something we don't use) But we still need the Zinc anti scuffing properties of ZDDP in the oil we use. Diesel oils tend to have higher levels of ZDDP and have a HD rating but are often harshly detergent. Some newer lower detergent diesel oils are not bad. I use the NAPA counterman's recommended 15W40 (Rotella is made by Shell, Delo is made by Chevron) and both are HD rated (so higher ZDDP levels) and diesel and gas useable. I guess I could run thinner 5W oil but I don't drive my Datsuns in the winter up hear and cold cranking isn't a problem for me.

 

You can also opt for a racing oil (specifically made with flat tappet cam protecting ZDDP levels) or a synthetic but you will have to resarch this.

 

 

Just go into a NAPA and tell them you have a flat tappet cam motor and need an oil with lots of ZDDP and they'll know what to recommend.

[EricJB]

if I remember correctly, the NAPA and Carquest store brand oil is really valvoline. Also the NAPA and Carquest filter are really Wix. good stuff a bit cheaper.

[ggzilla]

Why do we need the extreme ZDDP additive levels? My engines run fine on valvoline regular 10W-30 with no scuffing. The level of ZDDP and/or other additives must be sufficient.

 

this is the important part to remember - available research shows that more zinc does not give you more protection, it merely prolongs the protection if the rate of metal-to-metal contact is abnormally high or extended. So unless you plan on spending a couple of hours dragging your knee at Laguna Seca, adding extra zinc compounds to your oil is usually a waste. Also, keep in mind that high zinc content can lead to deposit formation on your valves, and spark plug fouling.

 

http://www.baileycar.com/oil_additives_html.htm

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[datzenmike]

That was referring to motorcycles (probably not 40 year old motorcycles either) adding extra zinc to already adequate  regular oils. The ZDDP level used to be higher 40, 30 even 20 years ago to protect motors of that day.  Motors have moved on and are designed differently and so has the oil. Today's oil may not protect a 40 year old motor well enough. Today's lower ZDDP oil may be like running a fram filter. I don't know, but I'm going to take advantage of all the protection I can.

[ggzilla]

Are you prepared to take advantage of all the excessive zinc deposits as well?

 

For highest protection, use Synthetic oil. Then the engine will last 175,000 miles instead of 150,000 miles before new valve guides are needed.

[datzenmike]

Well it won't be any worse than what it was back in the 70s or 80s.

[metalmonkey47]

Why do we need the extreme ZDDP additive levels? My engines run fine on valvoline regular 10W-30 with no scuffing. The level of ZDDP and/or other additives must be sufficient.

 

Valvoline has a higher ZDDP count then most other oils. I think the VR-1 is the highest for the price. I use 20W50 here when it's 30 degrees outside with no issue. I love my valvoline. 

[datsunaholic]

The worry isn't the valve guides or the cylinder walls, or even the bearings.  It's the cam to follower, which is steel-to-steel.  Modern engines don't use a flat steel-to-steel cam follower, they generally use roller cams.  The problem was first noticed on flat tappet cam engines, which were any flathead engine or solid-lifter OHV engines.  I have no idea the profile of an A-series tappet or follower, though I know they don't use roller tappets in stock applications. 

 

The L-series OHC engine doesn't have the same profile, since it's OHC and the "rockers" move.  You have instead a dynamic "tappet" surface.  But it's still a straight Steel-to-Steel (or iron) interface, and modern, thin, ZDDP-free oils eventually leave a nice little indentation in the cam follower and wear down the cam.  You don't have the "gouging" effect that flat tappets can have (particularly on aggressive cams) but the wear can still happen.  You can compensate for the lack of ZDDP by running heavier oil, or adding more oiling capacity to the cam, but the first robs fuel mileage and the second is expensive to get tge proper part for, as it's a racing mod.

 

Still, Nissan used very good metallurgy in creating the cams and followers.  You're still looking at needing hundred(s) of thousands of miles.  You just won't get the 250,000+ miles on a factory cam/followers using modern oil, which old 70s/80s oil had no problems allowing.

 

Also, most modern oils, adding a "ZDDP booster" won't do any good- and may actually be worse.

 

Me, I just run Diesel oil.  Since I have a couple ex-Military diesels, it's no point in buying 2-3 different oils.  And after a couple changes my engines are nice and clean inside.

[72240z]

Just an opinion... I wouldn't run 10 anything. Also the ZDDP content has been dropping the last few years because face it, it all ends in the environment or fouls the latest catalytic converters, (that we don't use) and isn't needed with the latest roller cams. (also something we don't use) But we still need the Zinc anti scuffing properties of ZDDP in the oil we use. Diesel oils tend to have higher levels of ZDDP and have a HD rating but are often harshly detergent. Some newer lower detergent diesel oils are not bad. I use the NAPA counterman's recommended 15W40 (Rotella is made by Shell, Delo is made by Chevron) and both are HD rated (so higher ZDDP levels) and diesel and gas useable. I guess I could run thinner 5W oil but I don't drive my Datsuns in the winter up hear and cold cranking isn't a problem for me.

 

You can also opt for a racing oil (specifically made with flat tappet cam protecting ZDDP levels) or a synthetic but you will have to resarch this.

 

 

Just go into a NAPA and tell them you have a flat tappet cam motor and need an oil with lots of ZDDP and they'll know what to recommend.

 

I use Valvoline zr1 sae 60 racing oil. They claim 1300ppm ZDDP, which is pretty high, I believe the highest regularly available one they sell. There is higher for cheaper out there but not that I can find locally or that makes it worth taking the trouble to order it.  

 

Looking at the break in on the motors I have used zr1 I really think its a great option. 

[ggzilla]

OEM car applications did not use roller tappets or roller followers before the mid-80s.

 

Regarding "protection" in general (not ZDDP in particular), on many Datsun engines the valve guides are the first wear out, as evidence by a cloud of smoke on starting.

 

Cam follower wear was a big issue in 80s after OHC engines had become common for 10 years or so. Ford did a famous study and found that all 10W-30 oil met their specs, but some of the 10W-40 oils did not. Since then oils have been re-formulated (but then so has the metallurgy).

[HRH]

While I use diesel rating oil in my KAZ24, it doesn't need it.  However, the weight is what I want, and it does have extra zinc for diesels.  I broke it in with NAPA 30w.  (No zinc, valvoline's base stock minus their additive package)  For an L motor, I've never, ever, had a cam flatten with regular non ZDDP oil.  Big V8s with pushrods?  Damn straight, I've heard horror story after horror story on those.  L motors are just more advanced. :D

 

And Pennzoil sucks.  Use Valvoline or Castrol or Schaeffers, or Royal Purple.  Something decent.

[ggzilla]

Today's Pennzoil is totally different from the 1980s Pennzoil. It is now reportedly a good oil.

[Dantheman]

I have not read anyone using Brad Penn. I was following advice from ISKY CAMS. Supposed to be the old Kendall Green. I have run into a number of shops that work on older tech. engines that seem to like it.

[zed]

I read on the Castrol spec sheets that the diesel oils - like 15w40, which I use in all my engines - have a much higher viscosity at high temps than oils designed for spark ignition engines. Much higher than for example GTX 20W50. They say such high viscosity oils give less protection when the motor is running at sustained high speed. Which is a concern if you do a lot of highway driving like I do these days

[datzenmike]

I think they all run about the same viscosity at engine temps (about boiling point of water) but they do get thicker when they cool down. This is why a straight 40W isn't good for starting at 0 F.