Synthetic oil question

[jdincau]

Hi all,
     The literature that came with my gapless ring package cautions about using synthetic oils for break in. Coming from a blown alcohol background I am unfamiliar with this concept of "break in". This is an unblown gas engine with roller lifters so I am not worried about any lack of zinc. Anyone have any experience with gapless rings and initial start and run?
Jim in Palmdale

[RichFox]

I use gapless rings and I don't use synthetic oil. Don't know what to tell you. I have been real happy with leak downs. If I wasn't way to cheap to use synthetic for initial fire up maybe I would have some pertinent information. But since it's coming right back out I'm not buying the good stuff.

[jdincau]

Hi Rich,
     Thanks for the reply. Do you mean you drain the oil and change it after initial start up? I have a case of straight 30 wt that I won in a raffle and thats what I thought I might do with it.
Jim

[dick elliott]

Take a look at http://www.bobistheoilguy.com/cms/ to learn all about oil.

[Cajun Kid]

We use Joe Gibbs Break In Oil  or Rotella with a ZDDP  additive for break in and initial dyno pulls,,

Then we drain , change filter and use Mobil One full synthetic from that point forward.

On all motors,, roller or flat tappet cams,,, same procedure all the time, every time.

Charles

[wobblywalrus]

I do pretty much the same thing as Charles and it works good for me, too.  Mobil lists their oil properties on their website and I use one with lots of zinc and phosphorous in my flat tappet engine.     

[Stainless1]

When Castrol brought out their synthetic we put it in the lakester motor right after a rebuild... started it up and it started pushing oil out the tailpipe    Then we called Castrol, they said the rings would not seat with synthetic, too slippery to allow any contact.  They said pull it, put it in a clean container, put in 20 or 30w conventional oil, run it and the rings should seat OK. 
They did, synthetic went back in after a couple of heat cycles and 5 miles of WOT. 
That is our plan these days since we don't see a lot of dyno time, conventional oil for a couple of heat cycles and the first pass, then the BG synthetic goes in. 
I heard one brand of the gapless rings should be assembled dry, turn the motor by hand 6 rotations and the rings are seated.... check the website for yours to see if this is recommended.

[Dean Los Angeles]

Any comments on how long break in takes? I can see where the synthetic oil might interfere with the process. Using non-synthetic oil shouldn't take longer then a few minutes to seat the rings.

Anybody old school enough to have used Bon Ami for quicker break in?

[manta22]

Dean;

"Anybody old school enough to have used Bon Ami for quicker break in?"

I have it on good authority that Aston-Martin used to sprinkle a little into the carbs while running a fresh engine on their dyno; I was told that you could see the HP reading increase as the rings seated.

Regards, Neil  Tucson, AZ

[RichFox]

When I was a kid I did a ring and valve grind on a '40 Ford V8. The wrist pins were loose so I got oversize wrist pins and my dad brought home an expansion reamer from work. He had me ream the rods and pistons somewhat undersize. I don't remember what if anything we used to measure with. And then he made me fit the pins using Bon Ami as an abrasive . Wish I could go back and see what the heck I was doing.

[hotrod]

My understanding is the way to break in gapless rings is with a standard 30 weight oil and using quickseat compound (the modern equivalent of Bon Ami) to ensure a quick problem free break in.

http://www.cbperformance.com/catalog.asp?ProductID=174

To get good piston ring break in you need a combination of a lubricant that does not over protect the bore and ring (ie no synthetic) and progressive series of runs on the engine at progressively higher engine load to get enough cylinder pressure to get the rings to seat properly without scoring the cylinder walls or overheating anything.

As I recall Chrysler advocated a system or progressive load to their Direct Connection customers for their drag racing engines that was something like the following.

(I remember reading this in some hot rod magazine but have not been able to re-locate the article)

Start them up and let them idle at a fast idle 1500 rpm or so for 20 minutes or so. ( most cam shaft manufactures recommend the same for new cam shafts ) Then after checking for leaks etc. let the engine cool down completely.

Next make runs at 1/4 throttle , 1/2 throttle, and 3/4 throttle, each followed by a full cool down. Make a final full throttle pass then go racing.

Several major engine builders describe how they dyno break-in an engine and they also use the same pattern. 30 minutes or so of moderate fast idle to warm things up, followed by brief runs up through the engines rpm range under gradually increasing load, followed by cool down cycles.


Mark Donohue the famous race driver describes how he broke-in race engines after rebuilding them in his book "Unfair Advantage". He liked to take the newly rebuilt engine and let it run at a fast idle for an hour or so, with a garden hose running in the cooling system to keep it cool. Then he would put it back in his car and take it to the track. By the time he finished his tuning laps and time trials for qualification, the engine was ready to race.

Graham Bell author of the book "Four Stroke Performance Tuning" gives an example of a dyno run in process he uses on all his race and rally engines. To make it universal, I converted the numbers to % of maximum torque.

Code: [Select]

rpm      Torque         min
    3500        25%           10
    4000        33%           30
    4500        45%           30
    5000        56%           30
    5500        66%           30


"Anybody old school enough to have used Bon Ami for quicker break in?"

I remember my dad talking about doing it, and I know of a person that swears he saw Smokey  Yunick do it in the pits at a Nascar track.


Larry

[Ron Gibson]

Years ago I saw a mechanic dump a teaspoon of Bon Ami down each side of a two barrel carb. He had it reved up and would sprinkle it down the carb then squirt some oil in to lube it. He said it worked.

My uncle used to work at a John Deere dealership. When they first came up with their inline sixes some of the blocks were too hard for the rings to seat.  The mechanics would take off the intake manifold (non-Turbo) and with the engine idling open a small bag of factory furnished powder in front of each cylinders port. He said the intake would suck it in and that was all they did. He also said it looked a lot like Bon Ami.

YMMV
Ron

[wobblywalrus]

Once or twice I have had a fresh bore, new rings, and an old piston.  I mix some very fine abrasive with oil or toothpaste and push the old piston up and down the bore with the new rings on it by hand.  I take the piston out and check occasionally to see if the rings are seated.  When they are I take them off of the old piston, clean them, and put them on the new piston.  I clean the bores with solvent and then with hot soapy water.  Then I put the engine together.  This is a lot of work and I have done it when there would not be the opportunity to break the rings in properly, such as motors built the night before the race.