1977 Datsun 620 Oil change interval

[Oyvind]

Hello all, I just bought a 1977 Datsun 620 with the L20B and the 4 speed and was curious on the oil change interval. I’m used to Subarus so I was thinking every 3k miles but it’s best to ask the experts 

 

I checked everywhere including the online PDFs of the service manual so I do apologize if the question has been asked before, thank you in advance.

[]2eDeYe]

Welcome.

Every 3-5k is the interval. Check the level at every gas up until you know if there is any oil consumption. 

[datzenmike]

Better yet the oil itself is important. Oil made since '92 has slowly been reduced in the amount of ZDDP that is used. Before this as in when your truck was new the levels were not below 1,000 PPM but today all gasoline oils are 500-600 PPM. You should look up the ZDDP controversy for your self and decide. ZDDP is an important anti scuff additive that is not good for today's catalytic converters so it has slowly year by year been reduced. Today's cars don't need as much but our old Datsun valve trains do to protect them from wear. What to do? Well you can buy ZDDP and add it during oil changes but costly and messy and hard to calculate the amount when topping up. What I do is simply buy a diesel oil that is still high in ZDDP. For this I get Shell Rotella T4 in 10w30 or 15w40. It's ZDDP level is 1,200 PPM. Chevron Delo 400 is also good and there are others. Any over the counter oils used for racing are also high in ZDDP.  

[Oyvind]

25 minutes ago, ]2eDeYe said:

Every 3-5k is the interval.

So I should be good to just change it every 4k just about?

[Oyvind]

1 minute ago, datzenmike said:

What I do is simply buy a diesel oil that is still high in ZDDP. For this I get Shell Rotella T4 in 10w30 or 15w40. Its ZDDP level is 1,200 PPM. Chevron Delo 400 is also good and there are others. Any over the counter oils used for racing are also high in ZDDP.  

Oh interesting. I’ve been mainly a castrol user so I was thinking of just using 10W-30 Castrol edge high mileage. I used the 5W-30 and 5W-40 in my WRX and Saabaru and those engines performed great so I was just thinking of sticking with Castrol haha

[Jskinny]

I use Castrol 10w30 in my corolla, and Valvoline VR1 racing oil in my 75 620.

[datzenmike]

I thing those are also high in ZDDP.

[banzai510(hainz)]

I do every 6months if not a oil burner, say FUCK it

[EDM620]

10 hours ago, Oyvind said:

So I should be good to just change it every 4k just about?

The color of your oil will tell you if you need to change sooner. A loose running engine will dirty up the oil fast, and that's bad stuff. Check color every 2nd fill of gas until you know about how long it can go. Then you'll know if you need to change at 3k, 4k or 5k, maybe earlier if really loose engine (bad seals, bad rings, loose bearings etc).

[banzai510(hainz)]

On 3/6/2024 at 4:50 PM, EDM620 said:

maybe earlier if really loose engine (bad seals, bad rings, loose bearings etc).

Usually at this point hes adding new oil all the time as most goes out the back.

When your using 50 weight then you really know it time for a rebuild

[EDM620]

STP - engine glue 🤣

[datzenmike]

Never use that shit, ever!

[Stinky]

High mileage oil may have stuff in it to make your seals swell.  Stay away from it.  I like old-fashioned dino oil.

 

W/today's oil, 5K is plenty often.

 

I have not had an oil related engine failure in a long time.

 

I have 2 Camrys w/over 250K on them (one over 300), a 720 w/210K, a Honda CRv w/a bunch, a Hyundai Tucson w/212K....they all get changed at 5K....when the mileage comes up to a 0, or a 5, on the thousands, I change it.

 

Camrys have an oil filter that points up, like an erection.  They have to fill it up, every cold start.  I haven't seen that it matters. 

 

My FIL had an '84 Camry.  He used to get it changed every 10K.  I told him, what the heck, he says that is what the manual calls for.  We sold that car at 212K, and it ran like a top.  That was with dino-oil, of 40 years ago.

Edited April 20 by Stinky