Jet Black 496ho Oil..... - Page 5

Anger Management · 12-02-2007, 07:31 PM

Raylar....
If your still on this thread I would like to ask you a question? I was wondering if after a Raylar conversion on the 496 if you noticed any different in the oil color or appearance? Did you run the Mercury oil after, or are you running some other brand of oil that you like better?

Thanks

Raylar · 12-02-2007, 10:13 PM

Anger Management and others:

We have run 496's on many oils, such as the Mercury 25-40, Royal Purple 15-40, Kendall 20-50w and Mobil 1 20-50W. Our various usages seem to show that some oils like the Mercury and Royal Purple seem to turn dark in color sooner than the others, but with oil analysis results showing all the oils maintaining their TBN numbers at 40-50 hours of use. The analysis's above were done on engines that had no internal problems or damage and they did not show high wear numbers in aluminum, iron, tin, copper and such which were backed up on tear down and inspections.
This being said, I know our kit equipped engines seem to run with a little less color shift in the oil and I feel this might be a result of a quicker combustion burn which lessens unburned fuel dilution of the oil. We tend to see less fuel in the oil of our kit equipped engines and this seems to show in oil tests.
But even in Raylar kit equipped 496's the oil will darken after moderate use, 10-20 hours and yet the oil is doing an excellent job with no abnormal wear on teardowns and bad numbers in the oil analysis.
So my conclusion seems to be that based on different brands of oils and types(ie synthetic) there does not seem to be any real corelation between darker oil color and engine wear or damage, unless the oil analysis results or tear downs and inspections show obvious problems.
If your engine oil is being somewhat overheated due to poor oil cooler performance or sizing and the oil temperatures frequently rise above lets say 260-280 degrees, the oil will darken quicker and its lubricating and heat removal qualities will drop quicker. Likewise oil temperatures that are too cool ,lets say under 190 degrees, will tend to accumulate and hold moisture two quickly and also damage the oil quality.
If you are concerned about your oil conditions and engine, get an analysis done of your oil done ( remember to have a sample of unused oil and the used oil tested. If the test comes back with normal range numbers and a good TBN number, stop worrying about oil color and use your boat and enjoy!
If on the other hand the tests show moderatly or substaintial out of range numbers, especially, iron, aluminum, copper, tin, lead and antifreeze indicators, there is probably something not quite right in the motor and furthur inspections, tests and corrections are needed.
As for the black soot on the transoms of todays boats a good deal of that is a result of the newer fuel additives that gasoline refiners are using today and some of it comes from boaters using too high an octane fuel for their motor where the slower burn of the higher octane mix is causing too much unburned fuel during combustion which exits the exhaust and also can contaminate the oil to quickly.
Use the engine manufacturers or builders recommended octane fuel.
Remember that all marine high performance engines run richer that todays automotive engines, they have to or they would burn up under the high loads and extreme usuage they are subjected to. This richened air fuel ratio will also tend to contaminate the oil quicker so keep your oils serviced regularly as 50 hours max., or more often if you subject it to hard usage, high temperatures and extreme conditions.

Just some more facts!

Regards,
Ray @ Raylar

Big Block Billy · 12-02-2007, 11:15 PM

Quote:

Originally Posted by snapontoolsjt

"piston wobble" - - - - - -

we'd have more than dark oil to clean up. there'd be connecting rods flying through that oil pan supposedly full of residual. that's one way to get it all out though.

This is no joke. What this is is the side loading of the piston in the bore and it wants to rock at a part of the stroke and actually in time will cause an uneven wear mark in the cylinder that is reffered as an "Eyebrow"
I have seen it and was going to build a 572 Talldeck 4.5" stroke but was talked out of it into a 4.25 Stroke 540 Talldeck for this very reason. I have seen this on 572's.
They should have made the 496 with more deck height. Only so much room for the Crank counterweights, only so much you can offset the wristpin, only so long can the piston skirts be. All with thinner top rings.
The synthetic is a great thing because it can withstand higher temps without breaking down and cokeing . Synthetic is chemically altered and processed oil and starts oil as a petroleum base. One of my buddies 588's runs high oil temps and oil gets dark quick. Still can't figure it out. We've changed coolers, plumbing , pumps, etc.
Maybe you can use an infared laser thermometer and aim it at the oil pan and see what your real oil temps after a hard run. The gauge may not show the oil temp just right. My 2c BBB

Big Block Billy · 12-02-2007, 11:28 PM

I'm with Raylar on the Running rich. Way better than running lean. I buy alot of 454's mostly 330's and 365 Mag's and some 350's either part them down or rebuild them. What I have especially found is that the ones that had the black oil were usually in better shape with less or no internal issues.
I just bought 2 perfect running 1978 330's from a cabin cruiser and took one apart and it's like new inside. The exhaust ports were black too. I think when I am looking at used motors this may be a good thing to look for.
Especially with todays reduced air fuel ratio due to Ethanol, it appears that black oil is a good thing. Have seen many problems especially in older Vortech motors leaning out and burning head gaskets from detonation.

minxguy · 12-03-2007, 07:20 AM

Quote:

Originally Posted by Big Block Billy

Synthetic is chemically altered and processed oil and starts oil as a petroleum base.

Not necessarily, some synthetics are derived fron natural gas and coal.
Ken

Nova 26 · 12-03-2007, 08:36 AM

I run a 540 n\a in my boat. Big oil cooler, no thermostat so it runs cool. My oil also gets black real fast- within hours after a change.I am a mechanic and I think I know what used oil should look like. It has been a concern and I removed the 30 psi oil bypass in the filter pad on the block thinking that high oil pressure differential was causing the oil to bypass the filter.
The oil still gets black right away. I broke in the engine on the dyno and for the first oil change using Kendall 20-50, then switched to mobil 1 20-50 gold cap.Have changed the oil 3 times with syn. and engine now has 55 hours on it.
I sure would like to find an answer to this, it just makes me uneasy to see such dark oil after a few hours of run time.
The engine was built loose, larger ring gaps etc.for marine use and if that is the answer, I can live with that but I would like to be sure.

Anger Management · 12-03-2007, 07:14 PM

Raylar, thank you for the post that you sent the last time! This helps to explain things more clearly to me and I'm sure others on this thread.

In the spring I will send a fresh oil sample and after 10-20 hrs I'll send another to see what; if anything , is going on inside my motor.
Thanks again