found a great post about how to break in the new motor. Got all that handled but now its time to settle on a motor oil. synthetic or not? viscosity? its a pretty hefty built 292 but want to make sure i get the right juice in her. thanks in advance

i just broke in a 292 i rebuilt, i got some great advice here. i used shell rotella 15w 40 and gm eos- i had to get it from dealership but you might be able to find it elsewhere. i switched over to a synthetic blend after 500 miles on my last engine i did before this one. you don't have to but i've heard you shouldn't break it in with syn so rings seal. my breakin went great. i am glad i used the shell.

i agree, shell rotella 15/40 and eos Added for breakin. after 500-1000 miles if you want to go to syn, still use 15/40 as it has additives you need for the lifters to survive. tom

from what and the way I understand it is YOU DO NOT use a synthetic oil for Brake in. The RINGS will Not seat like they should. Due to the synthetics after the 500-1000 mile brake Then it is ok to Change over to the synthetic oils.
The Main Object to the synthetic oil is to REDUCE
Friction. Reduceing friction at Brake in would not let the rings seat/seal like they should.

From what info I have gathered.
Some requre up to 1000 miles before switching to synthetic.
Also depends on type of rings used & the finish of your bores.

MBHD

What is GM eos- and is it sold as something else in a parts store ie Napa Autozone??? The last engine I broke in I used John Deere "Break In Oil" 15w-40. JD uses this in all new tractors and combines for the first oil change interval. Worked well for me I ran it for the first 500 miles. No oil usage post breakin period. Just my 2 cents from a farmboy.

EOS is Engine Oil Suppliment, the real stuff is sold by GM dealers in the parts department. I've never seen real EOS anywhere else.
I use Valvoline Synpower 20w-50 in the V8 350 [crate motor] in my '71 Jimmy. It seems to run well on the stuff. I broke it in on organic SAE 30 weight. That engine is about 8 years old in a daily runner. I am thinking of going back to organic [regular] 20w-50 due to the fact that $6 a quart is too much for synthetics. I intend to wean it off the synthetic by running Castrol Syntec blend thru one oil change cycle. But lately the Valvoline Synpower has been on sale, so maybe I'll stay synthetic for a while.
In my '68 C/10, I have a 292 L6, that's been operational since Jan '05. I broke it in on non-detergent Napa 30 weight, then switched to detergent Valvoline SAE 30 after the required 500 miles. Since I had a lot of organic Valvoline 20w-50, I ran the 292 on that for maybe a couple of years. On my last oil change I decided to run straight Valvoline SAE 30, for the summer at least. The change in engine tone was noticable. It sounds better, runs better, feels better. Don't know why. But I'm keeping the 30 weight for now.

The cost of synthetic oil is starting to look like a bargain lately. Have you noticed the prices on conventional oil have finally followed the gas prices? Locally all the name brands like Pennzoil, Quaker State, etc have hit the $3.00 a quart and higher level. The synthetics have pretty much stayed between 5 and 6 bucks. No matter which type you use about the only way to stay ahead of it is to buy oil whenever it is on sale somewhere. Generally the gallon or 5 qt containers work out a little cheaper and seem to be on sale more than the single quarts.

i put the rotella in for now. I think once i get over 1k i might switch to synthetic but i'm liking what i'm hearing about the 30 wt.

From my own personal experiences and from what I hear,if you run a hi performance flat tappet cam for sure use some GM EOS during breakin and add about 1/4 of the container during oil changes.
Synthetic oil is no guarantee of the proper additives to protect the flat tappet cam amd lifters from premature wear.Apparantly Zddp(zinc)is the best additive and many synthetic street engine oils don't contain this additive cause "modern" engines have been designed around the lack of zinc.
Valvoline makes several grades of synthetic and conventional dedicated racing oils with enough zinc.They are labelled as racing only,this is probably to limit claims against using then in engines with catlytic convertors that can be fouled by the zinc.
Most oil manufacters have websites where you can check out the oil and judge for yourself.

Just an old observation, but unless you guys are punishing your engines or driving them a lot of miles I personally would stay away from 20-50 especially if you do a lot of stop and go or in-town driving. An engine needs to properly warm up and then run long enough for it to be of any use. A lighter weight oil is also better for fuel milage. These engines were built with single weight oil in mind when new. The heaviest I use is 10-40 diesel for the mechanical lifters and 1/2 bottle of EOS with every change. Good luck

Dear Johnny;

Your right, stay with the standard grade (SAE 30)unless your in a 'freezing' climate etc.

Multi-grade was developed by the U.S. Army in the 40s for use (worldwide) so they would need only one type of oil. It had higher detergent agents also, because there wasn't time for "regular" servicing.

The Shell 'Rotella' is for commercial usage like the Standard Oil equivelent Dello, which I use. Also; the additives last longer (than regular brands) too.

Happy trails.

Sounds like a mix of straight 30 wt and quarter bottle of EOS might be the ticket. Thanks to all of you for your advice.

I'll throw in my two cents on this topic. TonyP was the first person I know of to begin to connect the dots on recent engine oil formula changes and the corresponding trouble with wiping cams in flat tappet motors. Since his first sniff of this, I have done a great deal of research on this subject and just finished an article for a vintage vehicle magazine on this very topic.

In a nutshell, all of the posts above are spot on and all points are correct. The issues that concern me WITH BREAK IN are sufficient levels of ZDDP to form the necessary and historically experienced bi-metallic barrier on the cam in flat tappet engines. The new gasoline engine oils absolutely do not have sufficient levels to do this because of reductions to save catalytic converters.

Therefore, my opinion (and it is just that; an opinion) is to use Dello, Rotella, or Delvac diesel engine oils ONLY along with GM's EOS during break-in. I have converted 100% of my vintage gasoline engines to diesel engine oil for routine and that is my preference, but I can tell you that this engine oil world today is a whole new playing field from where it was only one year ago.

I have a lot of data from AERA (Automotive Engine Rebuilder's Association) along with a fair amount of technical data to back up my findings. HotRod did a great article on this topic too: http://www.hotrod.com/techarticles/engine/flat_tappet_cam_tech/

So if you're running flat tappets, be very careful about what you do on engine break-in and more importantly cam break-in.

Each comment posted above from the other members in this thread is excellent and needs to be carefully considered. The engine oil world today is very different from what it was just a few years ago and all of it driven by conflicts with either emmissions equipment or emmissions standards.

Thanks Rob. I am nearly broken in and will be hitting the 1000 mile mark soon. Sounds like i should be ok just running the 30 wt rotella with no eos from now on. I live in delaware and truthfully the coupe doesnn't get driven much in the winter. I am also going to run the rotella in my 57 ford y-block as well. Thanks again guys.

Johnny T, The oil concerns for our inline engines are very important but your bring up the Ford Y-block brings me to my youth. As you probably know their rockers are very suspect when it comes to proper oiling. I started with Y's in 1954. My dad had a theroy that alway worked for him and the 3 Y's we had. With every oil change one qt of ATF was included. He believed the added detergent and the lower viscosity was a good thing. I never did it with any late model stuff. Good luck...J.D.

I broke my 292 in, with 10-30 Valvoline and for the last three years it has been running on 5-30 Mobil 1.
Racers use 20-50 becaue they set the clearances up loose and they know they will be tearing them down every couple of races.
I set my engine up with the plan for it to outlast me.

Jimmysix, i don't want to sound like a knucklehead but what is ATF? i was going to add some of the lucas additive, any thoughts on that?

My engine builder recommended using a lighter grade of oil + EOS for my Flat tappet 235 run-in. After 300 miles he recommended a switch to a CL,CL-4+ oil. Our operating temperatures down here are a bit more extreme, so I started hunting for this API rated oil in a straight weight. Couldn't find any...even discovered that Rotella T can be found, that is rated lower. Gotta watch the API stickers or you'll wind up using sl or sm stuff.

Guess it's like the "flat tappet situation"....less demand, fewer manufacturers, fewer choices, more money for the quality stuff.

The Cl,Cl-4+ Rotella was $5.00/quart in 2 gallon jugs, the Delo400 with a CJ-4 was $2.70/qt in gallon jugs so it looks like Delo with a bottle of EOS would economically, be a feasible choice. Will run an oil analysis ($9.00)at 1300 miles and see if my theory works.

Dave

Dear Dave;

It will. Also; if your 'on the road' Dello 400 is sold at every Truck Stop from California to Maine.

Happy trails.

I am finally ready for the initial run and break-in of two engines I have been building for several years (I'm slow) and I do appreciate all this good information. Thanks to all. Sam

ATF is Automatic Trans Fluid. Don't know much about todays additives. Back in the 50's it was common practice to use non-detergent oil in engines with solid lifters. Intown stop and go driving is very hard on vehicles as we all know and non detergent oil makes this worse.. Now days you need to look for that style of oil. Even with detergent oil back then and a solid lifter engine my dad felt keeping the oil passeges clean as possible was real important.
The only additive I use today is Stanadyne fuel additive in my 6.0 Ford diesel truck. Not only has oil had much of the additives removed so has diesel fuel. Good Luck

J-6;

The "Y block" rockers always had problems getting oil. The oil feed (hole) was offset between the block/head to reduce volume. In time it became restricted (sludge) as the opening was just the height of the compressed head gasket.

Some of the later truck heads had a 'relief' in them there.

Sometimes the cam bearing (feed) would wipe over the hole and block the oil flow too.

Happy trails to all.