Brenspeed's Oil Recommendation for B326

[eighty6gt]

are people not reading my post above explaining why they recommend conventional oil?

it is risk mitigation.

 

[Midlife Crises]

If I had 15 or 20 grand tied up in a motor I purchased built I sure as hell would use the oil the builder recommended. Interesting that synthetic isn’t recommended.

 

[1950StangJump$]

are people not reading my post above explaining why they recommend conventional oil?

it is risk mitigation.

I'm all about theoretical, organizational risk mitigation. I just tend to think it falls short to say, "other engines failed with synthetic, so non-synthetic is the answer cause none have failed with it." I would think there would be a MECHANICAL reason for that conclusion, and I hoped someone here could offer a theory or two.

That said, I am 100% onboard with the idea that, absent some other info, I stick with what Brenspeed says. I have not ran anything but convential 10W40. I just want all the info, and I don't apologize for that.

 

[eighty6gt]

You have all of the info! You typed it yourself!

There's no mechanical reason, I'd say at most testing synthetics would cost $50,000.

 

[Rick Simons]

I can't think of a single reason why they would recommend against synthetic oil.

It may have something to do with the combination of cylinder finish and ring type that they're using, but that's just a guess. If I'm not mistaken, the 5W20 was originally specified to improve fuel economy. What's interesting to me is that there is no classification specified, only the oil weight.

 

[Juice]

Kind of a moot point specifying anything other than weight. Whatever oil is sold today is going to be the latest classification available Even if an older classification is recommended, say SG, you can only get whatever we are at today, say SL. (No idea what the latest spec is lol) Thats all you can buy, and hope it exceeds the older spec.

The only thing I ever heard is never to break in a new engine on synthetic. The reasoning being the rings will not seat. As machining technology advanced, machined finishes got more refined and much less break-in is required vs the old day. Where you could damage a new build if you didnt break it in. Today, thats a non issue on factory built engines.
I will not speculate how brenspeed machines their engine blocks. Personally, I would switch the synthetic after a few thousand miles.

 

[chip721]

I've been running a B326 since 2017. Custom cams, ported heads, and E-Force blower. Day one I asked what oil they recommended and why. The answer .. 10W40 'dinosaur' oil. Said they found it maintained better oil pressure. I'm not an engine builder or seasoned mechanic, so I can't offer up a valid engineering explanation. I follow their recommendation and haven't had any issues. A quart of 10W40 is cheap. A failed engine is not. I change my own oil and filter .. often!

 

[Juice]

Oil pressure concern tells me they build with loose tolerances.

 

[1950StangJump$]

Maybe. I can say that, even with a catch can, there was a pretty good amount of blow by during the first few hundred miles. I only got to 700 miles before winter hit, and I didn't break it in hard like people recommend, so I can't say definitively how much it has lessened or will continue to lessen as I drive it more (and harder) in the spring.

The 10W40 weight (and not the conventional oil) was articulated as being about using pressure to overcome the high lift springs when keeping the VCT (with limiters). They even said that, if I locked the cams (which they didn't recommend), I could use lighter oil.