Well yes, you do. But the general claim that all flat tappet cams need it is incorrect.

...so I have a 'data point' I'll add to this thread, and while it isn't a synthetic vs dino thing it is a 'viscosity' thing, and this is just additional info that may be useful.

So I recently refreshed my 02 Mag 360 engine - it had ~129k miles on it and ran good 3 years ago - has sat until last November when I got into it - took it down to the rear main seal, but left the short block otherwise unopened. The heads were freshened up and had new seals installed with the Comp springs to match the Comp 20-745-9: 212-218 (264/270), .480/.480, on a 114* LSA - basically a biggish 'truck' cam I put in. Rockers and roller lifters were restored and reused. Holley Sniper 2300 2bbl on an Eddy 7577 intake. Runs good, but it was making what I considered an above-average amount of 'chatter'; it also had about 18-20 psi of oil pressure when fully warmed up - not awesome but still 'okay'. Installed a slightly longer set of pushrods, which did not make it quieter - maybe a hair but very hard to really tell - it still was 'noisy'. I've rear and I believe that the flat-bottom air-gap intakes like the 7577 'amplify' lifter operational noise, so I figured it just was what it was.

I've been really frustrated with how much 'noise' the engine was making - just seemed to have excessive 'chatter'...and I know the 'lowish' hot idle oil pressure wasn't really awesome...but it isn't a new engine - the bearings still have ~129k on them. So...in a bout of frustration...over the weekend I had the thought about draining out the spec 10W30 and just dumping in something thicker - I figured what do I have to lose? - it'll either like it or blow up...and at this point I'm really fine with either because one version means 'better' and the other means 'will be better'...and since we're (hoping to) keep this truck we'll put whatever investment into it that's required...within reason of course. So...I went to O'riellys and just looked over the oils sitting on the shelfs there...and after a few moments of surfing one in particular just looked 'right' - Valvoline 20-50 VR1 - something in me brain just said "do it - it'll like it", and after pouring I have to say it seems to be just what the engine needed, because after putting it in the engine is now noticeably quieter and has double the hot-idle oil pressure - it now idles at about 40-45 psi hot...and maybe 15 psi more cold but not as much of a cold difference as I thought it would (maxes out at about 75 psi).

So - it's quieter, and had better oil pressure - good. Yah I know it's kind of a shortcut...but really not so much - I'll run it as-is now for a while, and if it continues to run good then fabulous, and if the engine ends up needing a rebuild then so be it, but until another reason happens this'll be the oil this 360 uses from now on 👍

I'm figuring the low oil pressure was simply allowing too much 'slack' in the lifters(?), and the higher viscosity enables the system oil pressure to remain high(er)...which by the literal sound of things seems to be just what it wanted. It still makes some 'noise' but it's now more of a normal general 'engine running' sound...like a sewing machine, but it sure seems to have much less 'chatter', and hey if it's this easy and will get me by until I do a full rebuild (if ever) then horray . I know being a roller engine I didn't 'need' the extra ZDDP, but I figure it can't hurt, and VR1 sure has a very good reputation, so there it is.



- Sam

I know someone who put synthetic Mobil 1 in a rebuilt small block Mopar and he ended up with a little less oil pressure and slightly more valvetrain/lifter clatter noise. He tried it as a friction reduction experiment to see if he could get 1-2 more mph out of it at the track to get into the 110 mph club they have for street driven cars. After that one race he drained it and put the standard oil back into it. Not sure it was doing any damage, but it didn't make it any faster.

I had a Ford small block years ago and ran Valvoline synthetic in it. The oil pressure was solid and more than it needed, but the valvetrain was a tad noisy. I attribute some of it to the aluminum valve covers and steel roller tip rockers it had that tend to create a buzzing sound you notice in older cars with minimal firewall insulation.

Rhoads hydraulic lifters were patented in 1975 and updated by Jack Rhoads in 1990,
and I would guess that synthetic oil would make a standard design hyd lifter behave more like a Rhoads type, “leaking down” at low rpm but “tightening up” at high rpm.

https://patentimages.storage.googleapis.com/8b/db/d6/23db2828fb4793/US4913106.pdf

Look at Fig. 4 showing how it is like changing camshaft profiles.

Notice all the other inventors who “tweaked” the idea.

I just sold the 2 cases of that which I had
Guy came quite a ways to come n get it too

I haven't used synthetic oils in any of my "classic cars" over the years. It has always been
conventional oils. In my current 418" small block Duster, (with a Bullet Racing solid cam .250 @.050) I have used Gibbs Driven oils with a Wix filter.

If I can't get Gibbs, I will use Royal Purple with Rislone zinc additive. Oil pressure is great and has zero problems

Any opinion, feedback or experience with Lucas Hot Rod and Classic? Thanks for the information. Interesting post.

If someone knows otherwise....please chime in:

"Synthetic" oil is a bit of a misnomer, the molecules that make up these oils are still petroleum based but they are (more or less) harvested or "Cherry picked" molecules that possess whatever desirable qualities for strength ,lubricity and ability to withstand temperature extremes they are looking for within that particular viscosity...or base oil from which the viscosity is derived from.

It's more likened to making wine or beer than anything "magical" only instead of grapes or hops they are cultivating molecules with the most desirable properties.

"convetional" oils are held to a much wider broad base where the weaker base molecules break down faster from temperature extremes and shear forces when under normal driving conditions.

So it's more like screening and selecting the Varsity team verses a scrimmage team that consists of more (possibly better in a few ways but worse in more other aspects) random skill players.