oil type and oil pump

[fixkick]

always do what bob says. (but your oil gauge will prove him right or wrong, sure will. if pressure falls on a very hot day, watch out, I use gauges on old engines.
after all who knows the wear inside. not bob. not me. (you alone and your added gauge)

keep mind, a 1980 or 90s engine is not like a 2016 engine. and is vastly more worn.. (the clearances add up too, due to there run parallel.)
IN the summer, i'd be wondering how good my pressure is , at idle.. and if low who well it gets to the cam , through that tiny 0.050" head orifice.
the cam needs pressure and good flow....

i think the new coolants now mix, with the old dexcool it turns to Jello.
getting the green out of rear water jackets can take an hr of flushing (the laws of diminishing returns) ive cust it too, many times.
there is a block drain, but getting it out, oh boy, near impossible.

grade:
when the temperatures are mild they all work,see. ?
The manual is clear, what to run, why buck the engineers book, ? (he well knew all grades made, sure did) but climate matters, What to do in Norway, well , read the guide.
but a nice gauge will let you know what's up, at 120f in the shade.

[kthnos]

bob says (at least thats what i read on his site) that engineers didn`t knew (and couldn`t possibly know) the tech/quality of todays` oils in the 90s (when they wrote the manuals of their cars/trucks).

now regarding the wear of the engine: (100% hypothetical/theoretic question)
is it possible to offset the wear-out (and thus restore the tolerances) with just a set of new pistons (and a head gasket maybe)? or the wear on the block is irreversible?

[fixkick]

really bob is right
the engineer is dead or retired, and now is well worn out. no?

here is your rod. clearance (note the 1 thou variance new and then the limit.)
min max limit
.0008 .0019 .0031"

so if you are at or beyond .003 limit, it might have issues. at 5000 rpm . (too old oil or too thing for any reasons)
main is 0.0023 max

what matters most is oil pressure at 5000 rpm this car run 3000 to 5000 ,

buy an oil pressure gage
run 5w-30 in it, the 30 number at 212F is what matters, (it should do well.) but how can i say that?, ive not miked your bearings.
but my pressure gauge never lies, and have my own custom low limit set to 10PSI, stock is 3psi, lamp on, (min)
this lube in dino form , failed in 1998. thus the warning. failed at the cam shaft.
my engine here, runs roller rockers to avoid all that.

look at dino oil
they take 5w oil (API rules) and add plastic VII to it , so at 212F acts like 30w.
Some oils dont go the distance here. (called shear rates)
Like folks driving 20k miles cuz mobil1 said to.

[kthnos]

well, i guess oil conversations is 'the chicken and the egg' sort of discussion. everyone can advocate both sufficient data and logic reasoning to prove the opposite.
like gandi`s 'spiritual contradictions', lol ('being able to prove white is black and black is white as long as you use the same quality and quantity of reasoning for both equations').

according to mr.Bob, flow is that matters; not pressure. so high pressure isn`t always an indication of sufficient flow. he advocates that low pressure (via thinner oil) might get better flow and thus lubrication. i know the camshaft (SOHC in our case) is up high, but still...

anyway, another oil-question here:
bro-science scientists/technicians (in my area) claim that adding 1 cup of diesel fuel inside the engine`s oil compartment/pan, then running the engine for 1 minute and then flushing out the oil (before every oil change) makes a huge difference in engine/passage cleaning-ness.
your opinion on this please? dangerous practice? efficient practice?

[fixkick]

if engine is tight and good and climate mild
all those work;
even brands are not an issue. today, most are overkill, for a drive to Church or to Walmart.
if changed frequently.
most brands are good;
just avoid this. (old distilled, not Hydra-cracked pure base) makes sludge fast.

[kthnos]

anyway, another oil-question here:
bro-science scientists/technicians (in my area) claim that adding 1 cup of diesel fuel inside the engine`s oil compartment/pan, then running the engine for 1 minute and then flushing out the oil (before every oil change) makes a huge difference in engine/passage cleaning-ness.
your opinion on this please? dangerous practice? efficient practice?

any ideas? i usually avoid bro-science at all, but this sounded interesting. should clean up some stuff?

[fixkick]

1cup to about a 20:1 ratio, so is small.
i'd not do it, i'd go more freq. oil changes, for a while.... let the great detergents clean the engine naturally.
they sell engine pre cleaners in the store, i think way more radial, kerosene? in it or Stoddard solvents.(close to paint thinner)
those scare me, but if done short time. at idle, nothing like this is harmful.
but id be watching oil pressure like crazy,,, see that it does not drop.
most engines are cleaner, due to better oils that dont sludge up like in old days, with distilled nasty engine oils.

[fixkick]

99% of most people their auto service shop decides this, or may off a list of choices of oil.(or worse the quick lube shops (not name , but generic) use bulk oil that is not as claimed, see API warnings,,,in the news.
see warnings here. (MOM sections)
http://www.aa1car.com/library/motor_oil_605.htm

in most cases it don't even matter, what matters most is they went there, before the oil is bad, or full of dirt.
the oil does get dirty, for many reasons, carbon bits, and sand grit sucked in past that K/N.
the other %1 are the more risky..
1: they buy what the TV guy said to buy.
2: what "some autos store clerk said" (he gets spiffs and commissions...so....)
3: a pure religion, of brand, loyalty. (avoid all conversations here. , anger can rear it;'s ugly head, but not me, no oil company loyalty here.)
4: then others go a bit wild , into a near paranoia , sector , running the most expensive synthetic oil they can find, some are super expensive. and GOOD.
5: Don't ask me ,i'm in the change oil often camp, and any brand works. LOL and any 10w-30 runs and lasts 300k miles (changed regularly) or more... many do.
6: omg, those running oil 20,000 miles because some synthetic oil maker said , it lasts this long....
7: picking oil just on one factor, lower carbon foot print, see #3...

the real question is this, is 16valve, which oil sold, does not do like seen below, back in 1998, are there oils, that still do this bad thing>?
are you willing to bet engine on this guess?
see that 16v notch and warning, bob the oil guy tells you, this is gone now..... but is it? , can anyone say that, for all brands, and dino/syn/blends.>? its GONE ?

my guess? (FWIW) is that in 89-98' the 5w-30 oil , when over 3000 miles old, would not make 30w spec, at 212F, hot, due to shear effects. if truth, many syn oils do not do this, thing, (but some do)

So if some DO shear still, then which ones DON'T?, (ask your friendly oil engineer)
This Suzuki warning is about the CAM. (and 8 extra valves and lobes), my guess is they had cam failures, and the cam has no bearings, its just machined aluminum. and tend be loose after 20 years, and rebuilt heads you dont get good clearances here, just so-so...
the limit here is .0047 " (huge) so if .0046 the head is a good core.
so if all bearing leak bad here, tell me how much oil gets there, and keeps pressure high, past the head oil gallery "orifice plug", 0.050" in diameter, i bet this is the cause of Suzuki engineer worry here. IMO.

try to understand the engineer spec'd. the oil not just on new engines, but for the life of engine... (a whole other matter, if you think about bearing wear, and with really hot oil, and the vast array of bottles SOLD OTC)
Oil temps can go as high as 250F , on a hot day.... this is where you need to focus, this is the limit of Dino oils, (many) and syn. goes 300f easy. (most times oil is near 180F or 200F (thermostat temp)
but not always.
the 2 numbers that matter here, are HTHS Viscosity, (the 100C and 150C{302F}) rating. ASTM- D4683. "2.6" is the minimum for 30 grade (the key facts you need hot)
many oils back in 90s did not pass the 4683 test. and that is what i think caused the below warning.... IMO (note that , some 0w-40 pass this spec !)
as seen here.
http://www.kewengineering.co.uk/Auto_oil...lained.htm



so look up your bottle of oil and read the data sheet on that oil (all oil makers offer it for free, all do, or RUN !)
ASTM- D4683.
here is one SHEET and that passes this spec. and is sold at walmart at $26 a jug. (5qt)

http://pds.mobil.com/USA-English/Lubes/P...5W-30.aspx

[fixkick]

warning, I picked a brand, by rolling dice.

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i had to look up the word
Broscience is the predominant brand of reasoning in bodybuilding circles where the anecdotal reports of jacked dudes are considered more credible than scientific research.

huh?
you can read anything you want on the internet. its infinite this...."a super nova like cloud"
best is to ask specific questions.
like , a specific brand and exact product and ask questions.
If this product ok for my old car. when fully or extra hot? using this X grade of product.?
some are not.
and can change every 6 months, in the new world products evolve fast, Green oil, low carbon foot print oil, animal fat oil. and near endless choices.
I say go main stream, what your local store sells, and is used by the most people. and has a full data sheet.
(not to mention uSA gov meddling in ever every walk of life )

[kthnos]

10w-30 brand name oil changed once a year (at spring).
annual mileage: ~7000km (roughly 5k miles).
90% city driving with short 5km trips at most times.
this is my plan.
(its Eneos 10w-30 premium plus for the time being.)

feedback?

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i`ve heard that short trips (like 5km x2 daily) require more frequent oil change intervals. does the FSM specify what is 'short intervals'?