Z4M S54: Rod bearings replaced again ...

[pal]

I had replaced the rod bearings at 59K miles back in Sep/Oct of 2011 and the last couple of reports of my oil had lead reading that started to jump again. I have done 37 track days since the last bearing change and the car now has 81K+ miles on it (and a total of over 80 track days).

One more point to note is that the last 2 years I have been driving the car better and improving my lap times - this means more full throttle time and more high rpm usage.

59K Rod Bearings Replacement

Since I have multiple upcoming track days including one tomorrow at Watkins Glen, I did not want to risk the motor and decided to get them replaced again. RRT in Dulles, VA were nice enough to come in on Sat morning on Labor Day weekend no less to do the work for me. They even stayed late on Fri night until I got to there shop so they could get my car in and drain the oil and park it inside.

It appears there was enough wear esp on cyl 3 upper bearing that was down to bare metal and I could feel it rough and scratchy with my nails. Cyl 4 top has a little point like that as well so it may be starting to go too.

There is some offset (on the sides) wear on some bearings but there was some on my first set as well. I am guessing its just a manufacturing variance on my motor with how the rods sit on the bearings and some could be possible variance in thickness of the coating on the bearings I had in the car.

I went with OE bearings (no coating) and ARP bolts this time as that is what RRT had in stock.

RRT recommended I switch to Motul 300V Competition 15w50 oil as they have seen better bearing life with it so that's my new oil for now.

[dorifto88]

i am speechless.

could you by any chance share your last few oil change reports? id like to see the increase in lead levels. i am sorry you had to go through this ordeal, again.

[XMetal]

Wow...so the treated bearings didn't do much to decrease the wear?

[seank]

What have you done to put more oil on them. Have you upgraded the oil pump?

[thekurgan]

Maybe with your more aggressive lap times, a dry sump conversion should be considered, Pal.

http://www.vacmotorsports.com/catalo...mp-kit-s54.htm

[seank]

http://www.vacmotorsports.com/catalo...n-oil-pump.htm

[chickdr]

Wow- the dry sump kit costs over $6K???. I think I would just keep doing bearings every 40K.

[beta]

Originally Posted by seank

http://www.vacmotorsports.com/catalo...n-oil-pump.htm

For $500 this might be a good option to try out before a 6k dry sump upgrade.

[inTgr8r]

...anyone here install one yet?

[pal]

I am at Watkins Glen with Chin so will upload and post last 2 reports. Lead was 9 and 15 ppm on the last two and ones before are here. For reference, 60, 514mls was the first report after first set of bearings.

http://dertt.fotki.com/m-coupe/maintenance

The coating seems to have done its job and worn away first. Its not supposed to be a bullet proof solution but an additional layer of protection and sort of a sacrificial layer.

RRT recommended using Motul 300V Comp 15w50 oil. I am guessing this is not only a bit thinner and hence possibly will get in there but being a comp oil, better maintain its stability at high temps.

I need to do these myself going forward every 20K miles or 30-35 track days going forward.

[Shipkiller]

Originally Posted by seank

http://www.vacmotorsports.com/catalo...n-oil-pump.htm

This might be a good upgrade, but I would think if you do not change out the Constant Pressure Valve (CPV) to an upgraded one (not seen one offered), which I think keeps the oil pressure regulated to 58psi (not sure of that value), a higher flowing pump will not make a difference. Could be wrong though.

[seank]

Originally Posted by inTgr8r

...anyone here install one yet?

In an s14. On a track e30m3, you go to larger coated bearings and upgrade the oil pump to flow more oil. The result is better flow. The problem with increasing the oil viscosity, which is what most want to do, is it does not flow as well, so even though it is better to higher temps, it doesn't coat as well. When you upgrade the s14, you are able to run thinner oils, run cooler, and increase oil flow.

Just a thought. I would find out whose setting track records with an s54 and ask them what they have done. Most club guys aren't replacing their motors every year.

[chickdr]

Originally Posted by pal

I am at Watkins Glen with Chin so will upload and post last 2 reports. Lead was 9 and 15 ppm on the last two and ones before are here. For reference, 60, 514mls was the first report after first set of bearings.

http://dertt.fotki.com/m-coupe/maintenance

The coating seems to have done its job and worn away first. Its not supposed to be a bullet proof solution but an additional layer of protection and sort of a sacrificial layer.

RRT recommended using Motul 300V Comp 15w50 oil. I am guessing this is not only a bit thinner and hence possibly will get in there but being a comp oil, better maintain its stability at high temps.

I need to do these myself going forward every 20K miles or 30-35 track days going forward.

In your case the number of track days seems to be the key. You went 60k on the original set, but only had 37 track days. You did over 40 track days in the last 20K miles so they wore out in less miles. You can use the track days like the cars service indicator uses gallons of gas...

[seank]

Originally Posted by chickdr

[/B]

In your case the number of track days seems to be the key. You went 60k on the original set, but only had 37 track days. You did over 40 track days in the last 20K miles so they wore out in less miles. You can use the track days like the cars service indicator uses gallons of gas...

They should last longer. Track cars at the club level and fast drivers last 4 years or 80 track days

[Vanne]

can i ask what it costs to replace the Rod Bearings? all up?

[pungo]

So I wonder what the rod bearings look like on some of these cars with FI in the 445-525 hp range?

[inTgr8r]

Originally Posted by pungo

So I wonder what the rod bearings look like on some of these cars with FI in the 445-525 hp range?

& the torque.

[Shipkiller]

Depends on who does it. It cost me $1600.

[Vanne]

Originally Posted by Shipkiller

Depends on who does it. It cost me $1600.

Shippy, is that you helping out or dropping it off and picking it up?

[Shipkiller]

Dropped the car off, picked it up a couple of days later.

http://www.zpost.com/forums/showthre...ght=shipkiller

[kennyfrc]

The Motul 300V Comp doesn't look spectacular on paper. Very interested to see a UOA on it.

[kennyfrc]

Originally Posted by seank

They should last longer. Track cars at the club level and fast drivers last 4 years or 80 track days

This engine only has 60LB of oil pressure for 8K RPM max.