3.8 Replacement Motors

[The Radium King]

if you read the thread on pistonheads it talks about when Porsche changed linings. from what I understand from that thread it goes like this:

nikasil - pre m96 engines, aftermarket replacement (ie, lne)
lokasil - m96, m97.1 engines
alusil - m97.2 engines

apparently lokasil is the bad one, but the thread also goes on to say:

"Boxsters up to 3.2 and 3.4 996 engines do not suffer the problem (despite also running in Lokasil) and bank one is much less vulnerable ..."

this gives credence to jack's post regarding rod angle; the 3.2 and 3.4 share the same bottom end and just different bores, but the 3.6 strokes it and the 3.8 is a bored 3.6. so the stroking increases rod angle and must dramatically increase scoring. note that the m96 and m97 3.6 share the same crank (ie, the m96 3.6 is not a bored 3.4).

the other thing is the statement regarding banks, which indicates to me that cooling is an issue, and supports the idea that anything you can do to improve cooling is a good thing.

long story short, the 3.6, even the early ones, seem to be as subject to scoring.

ps, i'm not jack. I just read a lot. and have a 3.6 that i'm worrying about.

[Jake Raby]

I was stating that all of the engines that we create exclusively use LN Engineering "Nickies" (Nikisil plated) billet aluminum cylinders.

No engines retain Lokisil bores, or otherwise. This goes for all M96/ M97/ 9A1 (DFI) and Cayenne engines.

I assisted with the founding of LN Engineering and used the very first set of "Nickies" ever manufactured- They reside in the 914 based engine found in my personal 356 Outlaw today.

The only engines that leave this facility with factory cylinders are those that we have repaired that had acceptable cylinder wear and only needed some other extensive "repair" carried out. These are the engines that do not have a budget for reconstruction, or do not require it to resolve their internal issues. A good example of this would be an engine that has low mileage and loses an IMS bearing with limited collateral damages. We would disassemble the entire engine, replace the IMS with our upgraded unit, then install an IMS Solution, upgrade to ARP rod bolts, replace bearings and timing chains and save the owner at least 10K bucks.

Otherwise we use Nickies and I won't even consider any other solution. We developed these products from nothing and have used more than anyone in the world 20X over.

[pk2]

Originally Posted by The Radium King

if you read the thread on pistonheads it talks about when Porsche changed linings. from what I understand from that thread it goes like this:

....

long story short, the 3.6, even the early ones, seem to be as subject to scoring.

ps, i'm not jack. I just read a lot. and have a 3.6 that i'm worrying about.

What then is the symptom of scoring? is it just a gradual loss of compression? or a catastrophic failure. Will a simple compression check Identify evidence of scoring. This motor apparently has 36k miles. At what point does scoring really become an issue.

Regards, PK

[The Radium King]

i'm no expert but i'll start off:

- it'll burn more oil as more oil makes it past the rings
- potential smoke on start-up as oil may seep past the rings into the combustion chamber while sitting
- if the piston gets really loose in there you might start to hear piston slap (you can youtube it to hear what it sounds like)
- if things get really bad something might break.

scoping the bore when doing your next spark plug change is probably the best way to see what, if anything, is going on in there.

so sayeth the armchair mechanic.

[pk2]

Originally Posted by The Radium King

i'm no expert but i'll start off:

- it'll burn more oil as more oil makes it past the rings
- potential smoke on start-up as oil may seep past the rings into the combustion chamber while sitting
- if the piston gets really loose in there you might start to hear piston slap (you can youtube it to hear what it sounds like)
- if things get really bad something might break.

scoping the bore when doing your next spark plug change is probably the best way to see what, if anything, is going on in there.

so sayeth the armchair mechanic.

Thanks,

- At what mileage can you expect slapping, if it's going to occur? (I realize how it's been driven plays a part)

- Do they all do it? Or is this an IMS type thing, some fail and others go a zillion miles?

Regards, PK

[Jake Raby]

Originally Posted by pk2

What then is the symptom of scoring? is it just a gradual loss of compression? or a catastrophic failure. Will a simple compression check Identify evidence of scoring. This motor apparently has 36k miles. At what point does scoring really become an issue.

Regards, PK

The only symptom initially is a noise that sounds just like a bad lifter... Tick..tick..tick.

It will fool even the best pair of "mechanical ears" until the person outfitted with those ears has had it bite them in the ass after a "lifter job" was a waste of time and did not solve the problem. So, you spend 5K+ on a lifter job and the issue is not repaired, because people lack experience and ASSUME that symptoms are something they are not.

I have had these engines make the ticking sounds and never consume oil, never smoke and never lose power and even pass a compression and leak down test and have failed cylinders. It bites shops in the ass all of the time, but luckily we have been able to identify it up front in 100% of the cases.

The reason why the ticking starts first is because the wear occurs at the piston skirt area where friction is greatest. This is well blow the ring sealing area and because of that the engine can fail from this without any of the classic symptoms of a lost cylinder.

[pothole]

Interesting to see Nikasil pitched as the perfect premium solution.

Back in the 90s, BMW has problem with Nikasil bores suffering premature wear in some European territories due to high-sulphur fuel.

They never offered Nikasil bores in the US due to high sulphur fuel being common.

Makes me wonder two things.

1. If Nikasil is so expensive, how did BMW manage to offer it on basic 3 Series cars?
2. Is high sulphur fuel a thing of the past? Because if it isn't...

[pk2]

Originally Posted by Jake Raby

The only symptom initially is a noise that sounds just like a bad lifter... Tick..tick..tick.

...

The reason why the ticking starts first is because the wear occurs at the piston skirt area where friction is greatest. This is well blow the ring sealing area and because of that the engine can fail from this without any of the classic symptoms of a lost cylinder.

Thanks

At what kind of mileage? The car in question apparently has just 36k miles on it. I drive about 1500 miles a year. In 10 yrs the car will be trashed anyway with 50k miles on it. Do I need to sweat about it?

I drove it once for a couple miles and noticed nothing abnormal, no smoke, know rattles, sounded pretty tight.

Regards PK