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ShawnG
ShawnG UltimaDork
12/20/20 11:53 a.m.

Oil is cheap compared to all the stuff that it keeps from wearing  out.

Use what whoever designed your engine recommends.

Change it lots.

That's all you need to be concerned about with engine oil.

03Panther
03Panther SuperDork
12/20/20 2:11 p.m.
Ransom said:
rdcyclist said:

Lessee:

February. Check.

Colder than Berk over most of the North American continent. Check.

Oil thread. Check.

This thread is approved for the season.

I disagree. I think we should be running a lighter-weight topic this time of year.

Good one!

03Panther
03Panther SuperDork
12/20/20 2:26 p.m.

I'm mostly just guessing here, going by what I've heard about blueprint engines over the years. My no means should anyone confuse this with facts. 

I imagine that their recommended break in is for the engineered sell that they are marketing to street cars. If they are selling you an engine they know will only be raced, they may say something different. 

Also, manufacturing process are worlds better than when synthetic oils started being popular, and are better than a sloppy rebuild. A proper rebuild could be better, but what percentage are proper ? (not asking for an answer... just food for thought)

One last thought. Dino Oil can be sold as synthetic, if it meets certain standards similar to true synthetic. So do those count as Dino oil for break in (again, not asking for an answer, just food for thought)

Vigo (Forum Supporter)
Vigo (Forum Supporter) MegaDork
12/24/20 1:17 a.m.

It's almost always better to throw more cheaper oil through something than it is to hone in on the exact right thing and leave it in there longer, at least in case of break-in. Use ZDDP if you think you should, but other than that my personal policy is run literally whatever is cheap and/or already sitting around near me and change it out several times in first few hours. There is nothing about viscosity or any other additives that matters more than just being clean when you are just trying to keep a new engine from abrading itself to death with metallic debris in the oil. And ring break-in either makes metal, or doesn't happen, one or the other. So just change the oil several times on a very short schedule with whatever you have, and don't worry about the 'right/best' oil until you're past that part. My schedule is something like <20 mins, <3 hours, 300-500 miles, 2000 miles, then normal. 

The varying rpm thing has become less universal as cam-in-block engines have become a smaller proportion of what's out there, but the basic idea is that the parts of the engine that get splash lube don't get the same splash lube at every rpm, and it's basically impossible to figure out where splash oil is going at different rpms, so the CYA policy is just try all the rpms and don't sit at any one of them for too long at a time, just in case that's the one rpm that sucks for splash lubing one thing or another.  There was an episode of Engine Masters where Steve Brule talked about correlating where splash lube went at different rpms by noticing one engine smoked out one bank at one rpm and smoked out the other bank at another rpm. I thought that was a really interesting anecdote.

benzbaronDaryn
benzbaronDaryn SuperDork
12/24/20 12:25 p.m.

Interesting to hear why the varying rpm would matter, splash lubrication makes sense, I couldn't imagine the rings caring.  The big thing is don't over heat it and glaze the bores.  You can get into it but don't go crazy.   

When I did my bike I just did a lot of engine braking in the hills, which doesn't make a lot of heat, changed the oil a few time with cheap diesel oil and had at it.  10 buck a gallon diesel oil is good stuff for short oil changes.  

Toyman01 (Moderately Supportive Dude)
Toyman01 (Moderately Supportive Dude) MegaDork
12/24/20 8:45 p.m.

In reply to benzbaronDaryn :

The word I've heard on varying the rpms is the rings spin on the piston and they can turn in different directions depending on rpm. You want to keep them spinning so they dont stick in one place.

 

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