synthetic or regular for our old engines?

[captaingamez]

This spurted from a conversation yesterday in the "overheating" thread, but I got curious.

 

can you run synthetic in an L series? or an A series?, or any of our old motors for that matter? obviously the engines were not designed for synthetic oils, but are synthetic oils okay to run for these engines?

 

I am sure that running synthetic in a KA series engine is fine, and they have similar oil pumps to the l series, but do synthetics work well with everything else in the engine.

 

reason I ask is that I have had bad experience with synthetics bubbling and cavitating in old motorcycle engines.

 

Synthetics are better oils we all know this, but that does not mean they may be better for our engines.

 

share your experience, 

 

are you running synthetic? why?, how has your experience been with it?

 

are you running regular oil? why? whats your experience?

 

 

[nerdistmonk]

i went all synthetic for my engine, transmission and rear-diff.

 

It moves alot smoother and doesnt drag like it did before and my engine is very clean on the inside after 2 changes of that synthetic.

 

The only bad is if your seals are old the synthetic will clean off any false seals and will cause the seal to seep very slowly (or quickly just depends)

 

but i love synthetic wont be going back to the old stuff.

[captaingamez]

my experience with synthetic is this

 

I bought my Civic SI with about 135k miles (K20A3 engine) and did nothing but synthetic Mobil 1 from day one,

 

interestingly the previous owner used Royal Purple which I find to actually be very low quality oil (do your research before commenting on that opinion) so bad it actually caused damage to the cams in my engine, I noticed galling on the NO. 4 exhaust cam lobe only 10,000 miles after I bought the car, and it was onthere for longer than 10,000 miles. so it had nothing to do with the mobil 1. If you have ever used Royal Purple then you know how thin it is when it comes out, IDK how that protects your engine, it also has the tendency to dye everything purple, disgusting crap. DONT EVER USE THEIR WATER WETTER PRODUCT!!!!!!! unless you want a purple cooling system, and no I dont mean the water, I mean dyed Purple.

 

Anyways, I used Mobil 1 and left the galled cam alone, thickened the oil a bit but thats it (went from 5w20 to 10w30). and the engine lasted me until 250,000, when the head gasket got a slight leak, pulled it apart and  the cam looked exactly the same, haha. but the inside of engine was very clean for 250,000 miles and it still actually ran awesome.

 

Conversely I had a few bikes, one was a CB750 one was a TT500, both of them caused Synthetic to cavitate and bubble badly, it could have been the oil but it was two different oils, I took the TT for a ride down the highway for maybe 50 miles, got off the freeway, popped the oil cap and bubbles cam out everywhere. took it back to the shop, changed the oil out with the cheap walmart stuff (old bikes LOVE THAT SHIT) and never had the issue again. only thing i could think was the oil pump was not designed for the extra slipperyness.

 

 

and yes if you just switch to synthetics, its likely you will get a leak, I always replace all the outside rubber seals when I go to synthetic, main seals are one of the main culprits here.

[nerdistmonk]

my experience with synthetic is this

 

I bought my Civic SI with about 135k miles (K20A3 engine) and did nothing but synthetic Mobil 1 from day one,

 

interestingly the previous owner used Royal Purple which I find to actually be very low quality oil (do your research before commenting on that opinion) so bad it actually caused damage to the cams in my engine, I noticed galling on the NO. 4 exhaust cam lobe only 10,000 miles after I bought the car, and it was onthere for longer than 10,000 miles. so it had nothing to do with the mobil 1. If you have ever used Royal Purple then you know how thin it is when it comes out, IDK how that protects your engine, it also has the tendency to dye everything purple, disgusting crap. DONT EVER USE THEIR WATER WETTER PRODUCT!!!!!!! unless you want a purple cooling system, and no I dont mean the water, I mean dyed Purple.

 

Anyways, I used Mobil 1 and left the galled cam alone, thickened the oil a bit but thats it (went from 5w20 to 10w30). and the engine lasted me until 250,000, when the head gasket got a slight leak, pulled it apart and  the cam looked exactly the same, haha. but the inside of engine was very clean for 250,000 miles and it still actually ran awesome.

 

Conversely I had a few bikes, one was a CB750 one was a TT500, both of them caused Synthetic to cavitate and bubble badly, it could have been the oil but it was two different oils, I took the TT for a ride down the highway for maybe 50 miles, got off the freeway, popped the oil cap and bubbles cam out everywhere. took it back to the shop, changed the oil out with the cheap walmart stuff (old bikes LOVE THAT SHIT) and never had the issue again. only thing i could think was the oil pump was not designed for the extra slipperyness.

 

 

and yes if you just switch to synthetics, its likely you will get a leak, I always replace all the outside rubber seals when I go to synthetic, main seals are one of the main culprits here.

 

I put lucas oil synthetic in this time around and as for the back its all redline synthetic

[HRH]

I've run Royal Purple and Schaeffers in the L motor when I had it.  No issues with either.  Any time you get into a top tier oil, you really can't go wrong.  I don't like Mobil 1, as it tends to go past rings more, but that was on the Miata.

 

If your engine is in good condition with good seals, use synthetic.  If it's not, stick to regular oil.  Synthetic will indeed clean out the gunk holding old crappy seals from leaking, and make leaks worse.

 

Lol gamez, the dye disappears in oil.  Not the radiator, but after 3000 miles there's no purple sheen left.  Schaeffer's is dyed green, it comes out oil colored too when draining.

[Str8_69]

I run good petroleum oils in older engines, unless they are fresh rebuilds, then syn would be OK, but too spendy for me, so meh. Trans and diff I always flush and switch to Lucas. Redline is crap.

[captaingamez]

I have wanted to try the Lucas oil, but NOBODY near me has it, they have everything else Lucas, but not the actual oil. I am dying to try Amsoil, but its sooooo expensive.

 

read the oil analyses of Royal purple, most people have found that it is great until about 1000 miles and then it breaks down and does not do a good job of protecting you engine, at least thats what I have see in the OAs I have looked at.

 

but Royal purple is designed for racing, so you should not keep it in for 1000 miles anyway according to what I have been told.

 

and the purple block thing is unacceptable to me, I have taken apart two engines that were purple inside.

[nerdistmonk]

I run good petroleum oils in older engines, unless they are fresh rebuilds, then syn would be OK, but too spendy for me, so meh. Trans and diff I always flush and switch to Lucas. Redline is crap.

 

 

You have to run GL4 oil in the transmission thats why i put redline in, it has to be PURE GL4 not that gl4-gl5 compatible junk otherwise kiss the transmission goodbye after 65,000 miles.

(it will eat up the brass synchros)

[captaingamez]

this is actually the first time I have EVER read anything bad about REDLINE, I havent ever used the stuff, but I never heard someone say its crap, actually all the racers I know swear by it.

[Str8_69]

this is actually the first time I have EVER read anything bad about REDLINE, I havent ever used the stuff, but I never heard someone say its crap, actually all the racers I know swear by it.

 

It's a racing oil. Not intended to run thousands of miles between changes, comes out like water.

[captaingamez]

good point, It is designed for racing so I guess you should apply the same logic as to Royal Purple. I dont know many people running Redline on the street.

 

but Im still waiting for someone to chime in and say if their running synthetic on theiir L series or A series or not?

[nerdistmonk]

from what ive seen it seems like synthetic motor oil goes in like water so whats the difference? Synthetic _is_ thinner than dino oil, thats its design.

 

It is what it is i guess. when my odo hits 228,500 i will change it again.

[Str8_69]

You have to run GL4 oil in the transmission thats why i put redline in, it has to be PURE GL4 not that gl4-gl5 compatible junk otherwise kiss the transmission goodbye after 65,000 miles.

(it will eat up the brass synchros)

 

Huh, interesting. So that 100K tranny I put in my truck 30K ago only has 35K left on it now? FML........  :rofl:

[captaingamez]

other thing I was curious about is what are you guys using as oil change intervals? for synthetic they say you can run higher, and I have put 6,000 miles regularly between changes on my SI, and according to the OA its still good when it comes out (not great and brand new but good) but its also a very much newer engine design too.

[nerdistmonk]

laugh it up, its your vehicle, ill keep gl-4 in my transmission, the shop manual makes that clear also but meh

 

 

edit: for me its still 3,000 miles maybe less on changes i dont run any oil that long

[HRH]

I run 6000 miles on Schaeffer's oil, but I change the filter every 3000.

[captaingamez]

in the d21 or the 510? that is what I was considering doing with my L28 maxima.

 

from what I read the filter type is almost more important than the oil, almost.

[HRH]

Any Datsun transmission that's been rebuilt recently doesn't seem to have any problem with GL5 oils I've found.  It's true, active sulfur pits brass.  However, almost all the new synchro kits are going to be of a material that's coated or better quality anyway.  Much less, my transmission rebuilder specifies 10-40 for his transmissions for warranty purposes.  I used to ignore him and just put in 75-90 weight as specified, but if you look at the viscosity scale, you'll find 40 weight is almost the same as 90 weight.  Difference is motor oil vs. drivetrain oil.

 

Heavy truck with brass drives, yes, that needs GL4 or a drivetrain oil rated for yellow metals.  

[HRH]

in the d21 or the 510? that is what I was considering doing with my L28 maxima.

 

from what I read the filter type is almost more important than the oil, almost.

 

In the D21.  The L motor ran a bit dirtier since I had a huge cam with lots of overlap.  I changed it every 3000 as it just plain needed it.  The KA runs a bit cleaner, especially only having a mild cam.

[72240z]

I swear by full synthetic valvoline vr1 20w50, its got the highest levels of zddp that I can find and holds up extremely well to abuse, heat cycles, time etc... 

Its a little surprising zddp hasn't been mentioned yet as imho its more important then synthetic vs convention in a regular L series engine. Using top of the line synthetic with no zddp is going to be great for bearing wear but the cam and tappets are going to be for shit in the long run. 

[DanielC]

As far as engine oils go, the problem is not that the oil wears out.  It gets contaminated with combustion byproducts.  Every engine uses oil. If the engine did not use oil, the rings would quickly wear out, because there would be no oil on the cylinder walls, protecting the walls and rings.  "But my engine does not use oil," you say.  It does.  It is just the combustion byproducts that are taking the place of the oil being used.  Unburnt gas, water, who knows what.

 

I think a more important issue with the older engines is the anti-wear additives in the oil.  A zinc and phosphorous, ZPPD is used in many engine oils.  This additive helps reduce wear on the surface of the camshaft lobes, and lifters, or in our case rocker arms.   This is more of an issue with V-8 pushrod high revving engines, but can also affect the lighter L-series valve train.

 

One of the problem with the ZDDP additive is that if the engine is burning a lot of oil, the ZDDP is hard on catalytic converters.  Because of this, the levels of this additive have been reduced in modern oils.  In turn, modern engine are being designed with roller lifters, to eliminate the wear problem on the lifters. 

 

But the L-engine is not a modern engine.  It needs anti-wear additives.  There is probably many L-engines that are not running a catalytic converter.   My choice for an engine oil is based on having the ZDDP, not if it is synthetic, or conventional.

 

I use Valvoline VR-1 Racing oil.  It is a conventional oil, and I also use a straight 30W oil.  I also have a boat, with a 5.8 Ford V-8  I use Valvoline VR-1 oil in it too.  The oil got changed in the Datsun about every 3000 miles.  The oil in the boat gets changed about every 50 hours. 

 

I have noticed with the boat, that if I let the oil drain out overnight, more dirty oil cones out of the engine, and the new oil stays cleaner looking longer.

[nerdistmonk]

when i first got my truck, i put synthetic in it, i believe it was whatever the autohut had for sale, ran it a while then it came time that i needed to put my new valve cover and oil pan gaskets on

 

I got a flash light and had a look at the inside of the motor, it was spotlessly clean, i reach up in the motor and gave all the mechanical bits a tug to see if there was any wear, solid as i rock, no play and no slack in the timing chain, so i put my new gaskets on and filled the engine with 4qts of that lucas oil, and thats how it is as of now.

 

i believe i got 5w40 in there, i want to go to 10w40 this next time around though.

[devilsbullet]

I've ran both the synthetic and regular version of valvolines vr-1 racing oil in my z and 510, both work great, I seem to burn/leak less than other oils, and I've yet to see/feel a difference between the 2 in looks, performance, and the rate of it disappearing.  everything else I seem to lose a quart every 1000 miles or so, vr1 I lose a quart every 2500, which is about where I change it.

[captaingamez]

good stuff guys, I am especially interested in the ZDDP information, I found out that my Mobil 1 has 800ppm of phosphorus, and 900 ppm or zinc, which is great for my k20a3 engine in the Civic, but probably need more for the L series. I might have to try the Valvoline VR1 stuff when I get to installing the L28.

 

 

heres a good one though, You have just built a new engine, new rings, new bearings, and new seals and every wear item,

 

what do you use for break in oil?

[72240z]

I use lucas break in oil. It has extremely high zddp levels and I trust lucas after reading various studies and comparisons.