Reading my Sparkplugs

[hansr433]

Since the massive oil loss and the persistent smell of burning oil when running the engine, I decided to pull the plugs. They are Bosch WR7 DC+.  In the attached photo, they are arranged from left-right cylinders 1-6.  They look OK, if a bit too hot to me. What do all you think?

[Benz Dr.]

They look about right to me. The number 4 cylinder is a bit darker but not enough to worry about. Your fuel ratio looks to be good so if you're burning oil you will want to tack down the source.

[hansr433]

Thank you Dan - much appreciated.  I am still trying to track down my poor mileage (almost a full tank for 200miles at 120kph) as well as the sudden oil loss.  Compression and leak down tests are next.

[Benz Dr.]

Yeah, that's probably 8 or 9 MPG less than what you might expect. Odd situation for sure.

[wayne R]

Hans--- looks ok, would like to know what grade , and type of oil you use.

[hansr433]

All, thank you for your posts.  @Wayne, the engine rebuilders in Canada had put in Liqui Moly МoS2, Leichtlauf Oil 10W-40, which is a semi-synthetic, and I replaced this with Motul Classic Mineral 20W-50.
 
I have done 60 miles on the new oil and the plugs were pulled after the oil change.  Something is definitely not right.  The car smokes lightly on cold start, smells a bit of burning oil, but is no longer blowing put any quantities through the dipstick.  Fuel consumption is also higher than I would expect.  I am hesitant to put on serious miles on the car, but am doing short drives in the neighbourhood hoping that the rings will bed in eventually, helped by the old school oil.

[Benz Dr.]

You should not use synthetic oil for engine break-in.  Break-in has to be done carefully using different engine speeds and loads or you can easily end up with high oil consumption.

[hansr433]

Dan, I completely agree.  The guys who did the Dyno run-in and Fuel Pump Adjustments are in your neck of the woods (RSP Motorsports).  I went to see them when my car was on their Dyno.  (It is also my avatar.)  They seemed really competent.  Ray Ouelette, whose shop did my 2 year restoration, sadly passed away before my car was finished and I had to chase a lot of information after delivery.  I called RSP and found out what type oil they used.  I did one oil change with LM oil here in Italy after having done about 2000km since engine rebuild thinking that these guys should know best.  Live and learn.

[Benz Dr.]

Dan, I completely agree.  The guys who did the Dyno run-in and Fuel Pump Adjustments are in your neck of the woods (RSP Motorsports).  I went to see them when my car was on their Dyno.  (It is also my avatar.)  They seemed really competent.  Ray Ouelette, whose shop did my 2 year restoration, sadly passed away before my car was finished and I had to chase a lot of information after delivery.  I called RSP and found out what type oil they used.  I did one oil change with LM oil here in Italy after having done about 2000km since engine rebuild thinking that these guys should know best.  Live and learn.

I'm about a 1/2 hour drive from them and I was acquainted with Ray a little bit. They purchased an input shaft for your transmission so now we have that connection. 

  It' kind of an odd statement but you need enough anti-wear additive to prevent excessive cylinder wear during break-in yet they have to wear enough so that the rings seat nicely.  Too little or too much wear is kind of the factor in this case.
I watch how the fan or crank stops during shut down. On an engine that's fully broke in, the crank will rock backwards a bit on compression as it stops. A tight engine that's not broke in will pretty much stop dead in its tracks. I also watch oil consumption. When that goes down to pretty much nominal that's also a sign that your engine is broke in. Every engine is different and I try to do all of the break-in driving I can before handing the keys over. It's one of the top things to do during the rebuilding process. If you can drive around town for an hour or two before going out on the open road, that helps out a lot. Varying your engine speed and load by increasing amounts is what does the trick.

[hansr433]

Thanks for that important bit of information on breaking a motor in.  I fear that the car was not broken in properly (partially my fault) as I did a lot of highway driving right away. Ray had mentioned that they would be putting on break-in miles, so I assumed that I was safe to drive at a reasonable speed.

Is there something I can do to help the rings bed in?