Possible alternative for flat tappet motors

[CaptCobrajet]

An engine does need to be loaded to seal up.  Your 20 minute cam break in ( I do three 20 minute cycles) is not going to seal up the rings. 

Hone procedure, and cylinder wall prep is different for a race piece than for a high miler.  I like the 500 mile deal on a street engine for two reasons.  One..... it is not going to seal as quick as a race engine, and two....the extra run time on the mineral oil is only going to insure that the rings are seated before putting the synthetic in there.

We run the heck out of race engines on the dyno.  You can tell when they seal by the numbers it spits out over the first ten or so pulls.  Also, you would lay a gold brick over what the rings cost for some of the race engines.  Just a different set of circumstances.

[Falcon67]

IMHO "diesel oil/Rotella" etc was an old school deal before specific oils like Brad Penn and the like came out.  Most diesel oil is similar to current passenger car oil specs.  Note that all new diesels have to run that low sulfur fuel with additives.  Most current stuff has less need for ZDDP, etc.  So if you think you're saving a dollar, you probably aren't.  Buy the correct oil for your intended use.

That said, any flat tappet break in I've ever done was done with 10w-30 VR1 racing and the additive supplied by the cam mfg.  And for ring break-in, I load the motor against the converter a few times, then it's ready for whatever - driving or racing.  Can't exactly drive 500 miles in the dragster.  With modern moly faced rings and proper bore finish, your rings are pretty much seated before the motor gets hot. 

 

[blykins]

I think modern rings with correct honing techniques goes a long way. 

On the dyno, the rings are seated in about 3-4 good hard pulls.  You can watch the power keep rising and then it will level off.  Then it's time to start tuning. 

[CaptCobrajet]

I think modern rings with correct honing techniques goes a long way. 

On the dyno, the rings are seated in about 3-4 good hard pulls.  You can watch the power keep rising and then it will level off.  Then it's time to start tuning.

Ah yes, but you wouldn't want to run right in there and pour in the synthetic.  I have seen the rings come undone and start losing power if you switch over too soon.  I won't put the synthetic in until the 18-20 dyno pull mark, which is a fair amount of loaded run time after the power stops going up after the initial few pulls.  Those rings need time to find a home before the really slick oil goes in.

[FElony]

I think modern rings with correct honing techniques goes a long way. 

On the dyno, the rings are seated in about 3-4 good hard pulls.  You can watch the power keep rising and then it will level off.  Then it's time to start tuning.

Ah yes, but you wouldn't want to run right in there and pour in the synthetic.  I have seen the rings come undone and start losing power if you switch over too soon.  I won't put the synthetic in until the 18-20 dyno pull mark, which is a fair amount of loaded run time after the power stops going up after the initial few pulls.  Those rings need time to find a home before the really slick oil goes in.

What's the true power difference running non-synthetic? Or a blend like Motorcraft?

[CaptCobrajet]

Power difference depends on oil viscosity and other factors.  I have seen 5 to 20 hp difference, depending on the situation.   There are benefits other than just the power.  I used to be a "never synthetic"-ER.......now I am a "synthetic when the time is right, and the procedure is right"-ER.

[blykins]

I think modern rings with correct honing techniques goes a long way. 

On the dyno, the rings are seated in about 3-4 good hard pulls.  You can watch the power keep rising and then it will level off.  Then it's time to start tuning.

Ah yes, but you wouldn't want to run right in there and pour in the synthetic.  I have seen the rings come undone and start losing power if you switch over too soon.  I won't put the synthetic in until the 18-20 dyno pull mark, which is a fair amount of loaded run time after the power stops going up after the initial few pulls.  Those rings need time to find a home before the really slick oil goes in.

Agreed.  I don’t use synthetic, so I dont have to worry about that.

[FElony]

My engine test stand will have a shorty bell that was hooked to a pump on a 428FT rig. Can I grassroots something up to create a load, or am I a terminal dreamer? 

[plovett]

I once changed from regular to synthetic on the dyno.  I don't remember the weights, but they were similar.  Gained 5 hp, about 1 percent.  We had done somewhere around 16 dyno pulls on the motor so it should have been mostly broken in.  It might have been over 20 pulls.  I like to try stuff on the dyno....we were messing with spacers, jetting, and timing a lot.  And different size headers.

I know that small of a difference could be within the noise of the dyno.  I think it is real, though.

paulie

Oh yeah, using 15W50 Mobil One with over 400 lbs open pressure on a solid flat tappet.

[Joe-JDC]

I use AmsOil break in oil in my flat tappet engines, even though it is expensive.  Haven't lost a camshaft yet with the AmsOil.  The oil will turn black after about 12-15 dyno pulls on break-in, so it should be changed.  I go straight to the oil I am going to run in the engine, either a 10-30W synthetic, or 5-20W synthetic, and haven't had an issue with oil consumption this way.  Going to a lighter oil will give an increase in hp simply due to the oil pump not having to work as hard.  Also, have seen a dyno mule with nearly 300 pulls lose up to 10 hp power slowly, only to have it come back in one pull after a fresh oil and filter change.  Joe-JDC

[blykins]

I'm not really an oil snob, per se.  I use VR-1 for street engines and Brad Penn for my race stuff.  Never have tried Amsoil.  Driven/Joe Gibbs smells like rusty anus.  A 5hp difference on a dyno session can be anything and on higher horsepower engines, a 5hp bump could literally be within the error margin of the dyno. 

What I mainly look at is how the bearings look when engines come back in for freshen up.  If the bearings look like I could leave them in because they look new, then I consider that a success.  I've had some dry sump high rpm engines come back for freshen up and I had to argue with myself whether I should put the bearings right back in and save the customer some money, or charge them for a new set of bearings and re-measure/verify, because $300 of bearings on a $40k engine is kind of a drop in the bucket. 

[frnkeore]

Oh yeah, using 15W50 Mobil One with over 400 lbs open pressure on a solid flat tappet.

Did you brake it in with those springs? If so, what cam and lifters?

Also, what is considered the max spring pressure that can be used on break in and can higher pressures be used with higher zink content?

I've read that the zink, depletes in use.

[plovett]

Oh yeah, using 15W50 Mobil One with over 400 lbs open pressure on a solid flat tappet.

Did you brake it in with those springs? If so, what cam and lifters?

Also, what is considered the max spring pressure that can be used on break in and can higher pressures be used with higher zink content?

I've read that the zink, depletes in use.

I took the inner springs out for break in.  My understanding is that zinc does get used up.

paulie

edit:  I think I used 0.050" taller retainers for brake in, too.  It was a long time ago.

[FElony]

  My understanding is that zinc does get used up.

paulie

Does zinc embed? If so, x amount would do so and "appear" to be depleted. If not, then why not continue using 2200 ppm after break-in? If so, is there an advantage to soaking a cam and lifters with break-in oil for x days prior to assembly.

And for rings, has there been a discussion here on plateau honing?

[66FAIRLANE]

I was told by an oil company tech here in Australia yesterday (Nulon) that ZDDP gets 'used up' as ash. So as it is loaded between surfaces it turns to ash & is carried away by the rest of the oil.
Not saying its true or not. Just what I was told.