New Engine Oil Change

chrs1961815

chrs1961815

Well-known member
I have a recently rebuilt engine in my car that probably has about 150 miles on it so far. Should I change the oil soon to flush out any metal or debris or wait until the regular interval?
 
I'm assuming you don't have an oil filter. If that is the case, I'd change it soonish, then go to your usual interval
BTW, it's time you retorqued the head
 
Then it is a deal. I have retorqued the head already but it would not hurt to check it again just to make sure everything is right. The thing runs beautifully!
 
More debris enters an engine when its open than ever will when its closed,as your rings seat it sloughs metal off the cylinder walls,timing gears mate up and all kinds of things occur.Oil is cheap and changing it often on a new engine is beneficial.I change it after first run in,the first day its fired up..do it again at 100 miles,do it again at 250,then 500.

Modern detergent engine oils hold debris in suspension,so they don't deposit on parts and the debris is flushed out during the oil change..don't leave the assembly/break in debris circulating in your new engine
 
When my motor was rebuilt, they recommended changing at 50 miles, , at 200 miles, at 500 miles. Then every 500 miles.


They recommended not using synthetic until motor was broke in - according to them at least 5,000 miles. For break-in they suggested Rotella T4 since it is higher detergent with some zinc in it, then use whatever I want to. 6000 and the motor seems to continue to run smoother (less vibration) as more miles are put on it. One thing I have noticed is the T4 seems to get blacker quicker that the oil I was using previously - looks really black at 500 miles (not running an oil filter).
 
Black is good,that means the carbon is being held in suspension basically the detergent is working.The proper name for the effect is entrainment,the oils ability to hold debris instead of depositing it on bearings
 
Jack Shaft said:
Black is good,that means the carbon is being held in suspension basically the detergent is working.The proper name for the effect is entrainment,the oils ability to hold debris instead of depositing it on bearings
Click to expand...


I agree, but I still will not extend oil changes beyond 500 miles. I figure instead it collecting on surfaces, it continues to go through the bearings and other moving friction points.. The oil may be good, but the contaminants are still there. Like above oil is cheaper than replacing a motor with a shortened life. If I am wrong, prefer to error on the safe side.
 
Well I agree more often is more better than not often enough. Just the oil with no additives.
For what its worth, [not much], I use Rotella 15-40. This engine was last done in 1961.
 
Engines shed a lot of metallic particles, rag lint, and sealant squeeze out during the bedding in process. Lycoming recommends an oil change after the first 10-hours now days. This is a change over from earlier years where the oil was changed every 25-hours when only a filter screen is used. They have all pretty much gone to 50-hours now as long as they have a spin on filter which most now have.

I'd change it. As was mentioned already, oil is cheap compared to the cost of repairs and overhauls. If it has detergent oil in it, warm it up good before you change it. Detergent oils hold the crud in suspension and you want all that crud to go out the drain plug.
 
Unless you are a real stickler for originality, I'd install a filter. I have one on all of my 4 Model As which have been set up for long distance touring where help can be hundreds of miles away.
All that crud people are talking about in the oil is removed and although one might cast a few $, it works out cheaper in the long run, either by extending your oil change intervals or by increasing the life of the engine - likely both.
 
the full flow filter and a small lube line from the pump body to the center main bearing..the filter media provides enough resistance to flow to 'pressurize' the bearing
 
Jack Shaft said:
the full flow filter and a small lube line from the pump body to the center main bearing..the filter media provides enough resistance to flow to 'pressurize' the bearing
Click to expand...

How much pressure do you think that would give? I suspect only a couple of psi at best unless the filter is nearly blocked.
I run a Bill Stipe high volume, high pressure pump with direct feed tot he middle main bearing but I made my own relief valve to limit the pressure to 25 psi. The higher the pressure, the greater the load on the distributor/oil pump drive on the cam shaft.
 
I always change the oil and filter if it has one on any engine I run for the first time.
Most of the time they run for at least an hour. Its cheap insurance.
 
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