Rhoads Lifters On Solid Lifter Cam - Setting Valve Lash
I read through this, and since you were kind enough to post up a thoughful response, I wanted to do you the same turn. A response like yours DESERVES a thoughtful response. Pretty rare when you can articulate what you did so clearly in a few words. I wish I had the gift of brevity!! So here it goes.
There is no such thing as an engine that is designed for a synthetic or mineral oil. The bores are essentially all the same materiel. That's cast iron. I can suppose that some manufacturers may have gone to some form of nickel based coating on the bores, but even then, that shouldn't matter.
Piston rings are also in the same boat. There are relatively few ring materials in use today, and most engines come with a pretty dang nice ring package. Modern rings will pretty much seal under almost any conditions.
Oil, regardless of where it comes from MUST have additives to make it useful in a crankcase. SAE/API and whatever the euro and jap equivalents are set the minimum for what goes into an oil to make it an engine oil.
There are 5 groups of oils that make up base stocks. In the entire world except for this country (thanks to a bought and paid for Supreme Court that should be wiped out and reformed...but that is a different topic) only TWO of those base stock groups is synthetic. In this country, for the above mentioned illogical ignorance or negligence of SCOTUS, the US recognizes THREE base oils as synthetics.
While this doesn't seem to be a big deal, the reality is that is a HUGE deal. A HUGE deal because now, a company can sell a group III base oil as a synthetic, but it doesn't behave exactly as a synthetic.
Group III base oils are nothing but a highly re-refined mineral oil. That means you can use a Group III base oil on alcohol based fuels and not have an issue, whereas if you use Group IV or V base oils with alcohol base fuels you'll never get ring seal. This is just one of the confusing nightmares this crap has caused.
Ok, so why does this even matter? Because the base stock, how it's refined and how it may be mixed with other base oils will for a great part, determine what the additive package is and how that additive package is put together.
There is no such thing as an engine oil that doesn't have an additive package.
That includes (going off memory here, as I don't feel like dragging out my books to nail it all, but this should give an idea of what's in there) Viscosity Index Improvers (these are, as a general rule, long chain polymers that can take a 5 grade base oil and make it behave and flow like a 50 grade oil at 212 degrees), anti foam, anti corrosion agents, detergents, dispersants, dry film lubrication additives (this would be a full load or more of zinc as one example) and...dang I'm missing stuff, but you get the picture.
So...the base oil(s) and how they are refined and blended with other base oils (IMHO, the very BEST 100% synthetic oils out there are a blend of Group IV and V base oils, and the how tribologist blends the two groups and in what percentages will change what additives you use and at what percentages) will determine what additives are used beyond the set minimums of SAE/API. That's why you can have mineral oils at 4 bucks a quart up to 12 bucks a quart. And synthetics that start at about 7 bucks and go way over 20 bucks a quart (think I'm paying 22 a quart for that I use).
I typed all that to say this: you should be able to use any oil from any manufacturer and not have an issue. Synthetic or not. I can't say what happened to you, but any engine should be able to use any oil and not have a crisis.
When honing a cylinder, I never (and I don't know anyone else who does this either) based how I honed a cylinder based on what oil was going to be used. I was more concerned with what fuel was going to be used. Ring material establishes 95% percent of what the surface geometry should be, and fuel the rest.
Again, it doesn't really matter what name is on the valve cover, it won't know what oil you are using, as far as GRADE you are using. IOW's, you need to chose the GRADE of oil you want use, and THEN set your clearances accordingly. If you want to use a 20w50 (again, I'll never know why anyone at this time would chose that oil, but that's on the end user) then when setting your clearances, you had better be on the big side or over the .001 clearance per inch of diameter of shaft so you have some oil flow at a reasonable pressure. If you chose to use say, a 5w30 oil, then you can close up the clearances, have less oil slinging all over the place and reduce the oil consumption of the engine (meaning how many gallons/hour an engine needs) which are good things.
There is no such world where any engine, regardless of what era we consider (when I do a flat head Ford it gets set up for a 5w30 unless the customer just can get it) that can't benefit from a lower grade oil (grade meaning viscosity...there is no such thing as an oils "weight" even though it is said so much today as being de facto a correct statement) and the same engine can't benefit from a QUALITY 100% synthetic.
Drain intervals are abased upon the additive package, and not the base oil. A QUALITY synthetic base oil doesn't actually wear out. What happens is the additive package gets used up, or wears out and you need to change the oil.
That's another thing that separates cheap oil from QUALITY oils. The additive package and how much they use.
40k drain intervals is nothing for some oils and some oils are crap at 5k.
The point is, before you get married to a specific grade and/or formulation of oil, do a bit more research.
A QUALITY synthetic oil blended for a performance application in a what is considered a lesser grade is a much better investment than 1950's thinking.
Just my .02 on lubrication.
Thanks, yellow rose for your thoughtful response. I appreciate your laying out your points as you have and they are most compelling.
I would just say this. The subject of dino oil versus synthetic is one of personal preference more than anything, really. Do I wear suspenders or do I wear a belt? sort of thing. As you so correctly point out...... There are several grades of both dino and synthetic base oils and there are differing additive packages for both, as well. Not to mention weights (viscosities)
In the end, whichever lubricant type you choose (dino or synthetic based), it is always best to familiarize yourself as you have with the various base oils and additive packages so you can make an informed decision regarding which you prefer for a particular application.
Regarding my statement as to whether a newer engine is designed for synthetic oils...... What I mean by that is......
It will have reduced internal clearances. It will have been machined to higher standards of accuracy using the latest CNC equipment. Bearing journals and cylinder walls will have optimum RA and RZ surface finish for the bearing and piston ring materials utilized. Cylinder prep will include the specific type of honing pattern and crosshatch that the thinner, lower tension rings require in order to seat properly. Engine seals and gaskets will be designed (by material and design) to function not only with synthetic base oils, but with very thin oils regarding viscosity. This will include provisions to better tolerate the deleterious effects of ethanol, as well.
On the other hand, engines such as the '78 360 Chrysler and early '60's 292 Chevy inline 6 I am building for my '62 Dodge Lancer and my '57 Chevy have none of these modern upgrades. Yes, I could have them machined to closer tolerances and use modern thinner, low tension ring designs (and corresponding custom pistons) if I wanted to use the newer thinner weights (viscosities) of synthetic based oils. But there are no bearings nor seals and gaskets available other than the ones used in the past.
Fortunately, the 292 engine shares a few parts with small block Chevy V-8s and there was a better 2-piece rear main seal designed for them around the time the newer production engines were changing over to 1-piece rear main seals in the late 1980's which should work there (if I can find one), but little else. So I will probably set these engines up with internal clearances more suited to thicker weight (viscosity) oils and run dino based oils in them. I realize that there are some synthetic based oils which have an adequate ZDDP content for my flat tappet cams and they can be had in the weights I would need. But I am a strong believer in frequent oil changes to drain the contaminants out of my crankcase and I just do not see the value in running a more expensive synthetic based oil when it is going to be changed at 3,000 to 4,000 mile intervals anyway.
Now my son is building a '96 L31 small block Chevy truck engine with 1-piece rear main seal and roller tappets for his '92 Camaro. He bought this engine in the late 1990's as a new crate engine from GM whilst serving in the Navy. Was going to drop it in his old '88 Camaro but never got around to it. Then he worked his way through college, married, had kids, started a career and it has set here in my garage sealed up and strapped to the pallet all those years. In the interim, I installed an upgraded roller cam and timing gear/chain, replaced the Mickey Mouse (prone to leakage) plastic timing gear cover with an older stamped steel cover and I sold the iron Vortec heads to some circle track guys. Son has some SLP headers designed for the limited production SLP Firehawk which used L-98 'Vette heads (these have angled plugs at very odd angles and his headers won't work with anything else). The good news is that Chevy still uses the L-98 heads on their ZZ3 and ZZ4 crate engines. The bad news is that except for being aluminum and lighter than iron heads...... In the words of Randy Brzezinski...... 'When it comes to flow, L-98 heads suck canal water!' In stock form, they flow worse than the old OEM iron 4bbl heads of the early 1960s.
So he located some AFR heads having the correct L-98 spark plug angles and that is what we are using on his engine along with the factory GM roller tappets. I'm glad he knew about those heads because he is dead set on running the SLP headers.
Son may choose to run a synthetic based oil in his engine. And I will keep an open mind and help him by researching GM tech bulletins from 1996 to 2000 when these engines were made to see if they did well on synthetic oil. But regardless of his choice of oil, I will encourage him to do frequent oil changes for the reasons I stated earlier.
In short...... There are good points to both types of oils (synthetic and dino based). I just feel that synthetic based oils are better used in the later model vehicles that are designed specifically to use them. Especially those which are designed to run the very thin weights (viscosities) of oils.
And conversely, dino based oils make more sense if used in older engines designed to run on them.
Is there overlap? Can synthetics do well in older engines if the correct weight oil and additive package is chosen? Of course. Then it boils down to whether you think its cost effective if you insist on frequent oil changes as I do.
The only caution I would add is that on a very high mileage engine that has always been run on dino oils since new...... Be aware of the possibility that you may encounter what we did when even a synthetic blend is used. My wife's 2003 model car was approaching 200,000 miles when we had our experience with a synthetic blend (smoking, increased oil consumption, seals and gaskets leaking). On the other hand, if you have fewer miles on your engine, it may tolerate the change to synthetic or synthetic blend without issue. At least we were able to get her car straightened out by simply going back to the dino oil within 3 days time. So no harm done. We drove it another 50,000 miles before selling it and would have kept it even longer except that the engine management computer was possessed by demons. But that's another story for another time.
That's my take on synthetic versus dino based oils. Both have their place. Appreciate your comments and even though we have both gotten off topic a bit here (I am old and tend to do that a lot anyway :) )...... I believe its always good to discuss such things and air all sides.
Best regards,
Harry
P.S. >>> Yes, I am looking into Nikasil plating (cylinder walls), new bearing materials and ring designs and materials as well as piston coatings. Just want to educate myself on the choices available. These are my last builds and I want to do them the best that I can, given the tight budget I must keep to. Regarding piston rings...... When I built my first engine 57 years ago (a '53 DeSoto hemi that I swapped into a '53 Henry J and later, a '55 Ford), Mom insisted that I use Grant graphite rings. Mom and Dad had their own automotive machine shop from the late 1920s through the end of WWII. She did all the mic work and rebabitted rods (before insert bearings came along for some engines). Until her dying day, she could quote from memory the journal diameters and clearances of any American made engine from the Model T's through those built at the beginning of the war when civilian car production ended.
Sure wish I could find some graphite rings like Mr. Grant used to make. They seated straight away and endured all the crazy things a teenage kid hell bent for leather can do when running an engine mostly flat out for 3 straight years. 4 years later (1970) after I was home from the service, I went out to the barn and turned that engine over by hand with a large screw driver on the flywheel teeth. Turned over freely. I gave it to the owner of the wrecking yard where I had worked after school, weekends and summers before leaving for the service. He dropped it in his old Dodge wrecker (boom truck) and last I heard (1978), it was still running fine.
