reducing lead wear numbers?

[JohnBrowning]

I do not think that the difference in cold flow between a synthetic 10W30 and 5w30 is going to be significant in single digit temps. Seeing how I get the exact same time to full oilpressure in the winter with 10W30 M1 as I do in 80F-90F summer weather with M1 15W50 I fail to see the signifacance. Our winters here get into negative numbers and I have never had cold knock on an engine with 10W30 M1 in it. Michigan winters can be preety intense.

I would definately try the M1 10W30 and a shorter interval as well. I would start with 5000-7500 miles and use UOA to guid me from their. Consistency is on the side of M1 10W30.

 

[zoomzoom]

This car is a daily driver(about 50 miles a day), mostly highway 70-80mph..I also have one or two long trips (500miles)in interval...It is geared high so at 80mph engine is at 4000RPM...I will push it from time to time over 100mph and have some pretty hard starts(I would shift just short of redline which is at 7000RPM) but only when car is warmed up. also once or twice a week I will get stuck in stop and go traffic for about 15-20 min.
Do you guys think that M1 0W-40 would protect my engine better given the conditions above?

 

[YZF150]

Good candidate for an A3 oil.

 

[buster]

Yes, I think M1 0w-40 would do much better. Actually this engine might be a good canidate for Amsoil 0w-30. A3 rated like the 0w-40 but thinner so it won't rob HP.

 

[widman]

Questions:
1. period of time these miles were driven
2. was there any period where it sat without driving?
3. any autocross or drag racing?
4. any heavy loads?
lead normally increases in engines that sit around or get super heavy acceleration. Often on engines driven seasonally.
I have one that sits at my second home. gets 100 km a day when I'm there 8 times a year for a week to 3. but the rest of the time it sits or gets started for a while to charge the battery. It shows higher lead than normal.

 

[userfriendly]

Lead content is the first wear metal I look at.
When the lead gets high it tells the story on the tune-up, insufficient fuel octane, pinging, detonation, hot engine oil, too light of an engine oil viscosity, too heavy of a viscosity, the engine's tolerance to horsepower, and driver imput.
See loose tolerance engine and bearing film thickness threads.
Some people think that the main and rod bearing clearances have something to do with the engine oil vscosity selection.

 

[buster]

I think userfriendly is right and I would look into what he suggested. I'd also run AutoRx for a good 1k miles using a dino oil. Then switch back and see what happens.

 

[userfriendly]

???????
What?? what did I suggest?
The lead is comming from the main and rod bearings.

Perhaps the engine needs a better oil pump, maybe a thicker oil, maybe a thinner oil, perhaps the timing needs playing with, higher octane fuel, maybe more fuel, maybe the rod bolts are streching, who knows.
The bottom line is the bearings are in need of more oil for one reason or another.

My question would be >>>Why would anyone extend their oil drain intervals with a high performance vehicle that cost thousands of dollars?
To save the whales?

And my point was>>>> Who ever said that bearing clearance had anything to do with engine oil viscosity?

Engine oils play between 6.5 and 24.5 cSt @100C 99.9% of the time.
That would be aproximatly ISO 46-220 @ 40C.
ISO numbers run from 1-2000.
The engine oils play in a very narrow viscosity range in the big scheme of things.

Now if each of you plotted your engine oil temperatures and cSt viscosities from the time you started your engines to the time you shut them down, every day for a year, I bet the adverage cSt # would be over 200 in the summer and 5 times that in cold winter climates.

If anyone thinks that at 250F, 5W30 oil is going to protect a high performance PRODUCTION engine without special attention at 7000 RPM and 35 LBS of oil pressure, your dreaming.

You need 10 LBS (PSI) for every 1000 RPM to keep your main and rod bearings lubricated.

If your oil pump can't keep up, get a better one.
If the oil gets too thin, use thicker stuff.
Mineral oils go to heck in a handbag after 250F, and by 300F, they are useless as far as the bearings are concerned.

What are the multi-grade minerals doing at those elevated temperatures?
Plain lead bearings HAVE to run on an oil film.
All the ZDDP, moly, tums, antacids, RX treatment are of no use whatsoever if the bearings run dry.

Detonation from whatever the source or cause, can squeeze the oil from a rod bearing in one revolution of the crank.

Think about this guys>>>> How often is your engine oil at 100C or higher?
You are all looking at the viscosity at 100C only and thinking you engine oil is running at that temperature.
What is the cSt of a 0W30 engine oil at -35C? 6,200?
Your engine will start and run without bearing damage with that oil at that temperature with .001" clearance.
So you can forget the tight clearance/viscosity theory when it comes to finding lead in the oil.

 

[buster]

quote:

---

When the lead gets high it tells the story on the tune-up, insufficient fuel octane, pinging, detonation, hot engine oil, too light of an engine oil viscosity, too heavy of a viscosity, the engine's tolerance to horsepower, and driver imput.

---

Oil might not be the sole problem, although it very possible it is. I'd check the above and see if there aren't other problems that are causing high lead.

 

[zoomzoom]

I'm really can't decide now should I go with GC 0W-30 or M1 0W-40...maybe I shoud use GC for winter and M1 for summer?

here are oil pressure specs for this engine:
Specs - 2.5V6 - 28psi @1000rpm, 49-71psi @3000rpm

Also engine architecture(mine is 2.5 V6):

Engineering Data


Mean Piston Speed

- V6 Engines - all-alloy DOHC 24V 60-degree V6 configuration
- Split Crankcase - as 911 flat-6 offers increased rigidity over traditional bearing-cap solutions for high-rpm capability (7800rpm 2.0V6) and low NVH (winning 1992 German engine award)
- Bearings - 4-bolt Mains, with a further pair of bolts at each bearing section. Key journals & bearings are oversized regarding width. Bearings are triple-layer heavy duty
- Crankshaft - Forged, nitrided, triple-lapped, mirror-finished
- Piston Squirters - Upper bearing journals contain piston oil-squirters to aid cooling
- Exhaust-Valves - Stainless steel & sodium cooled
- Pistons - Lightweight to reduce reciprocating mass, piston skirts are moly coated to reduce friction
- Head Gaskets - Stainless steel is used, with torque-to-yield bolts
- Stroke - Very short stroke creates low crank angles & low rod/bearing loads

Engine Dynamic Stress Levels
o Mean Piston Speed, MPS
- 2.5V6 MPS = 0.167 * 2.92 * 7000 = 3170 ft/min at 7000rpm
- 2.0I4 MPS = 0.167 * 3.62 * 6500 = 3929 ft/min at 6500rpm
- F1 engine MPS = 4519 ft/min at 16,400rpm


- As a benchmark, MPS
- under 3,500 ft/min - Good reliability
- 3,500-4,000 ft/min - Stressing
- over 4,000 ft/min - Very short lived


o Bore & Stroke
- 2.0 Bore*Stroke of 83x92mm (3.62" long stroke)
- 2.5 Bore*Stroke of 84.5x74.2mm (just 2.92" stroke)
- For comparison F1 engines have 70x42mm (1.65" stroke)


o Ring Loadings
Top-rings must balance high-rpm capability and wear, a thin ring allows high-rpm capability, too thin and wear becomes an issue. With reduced crank angles from a short stroke ring wear is reduced. A 1.5mm ring is beneficial over a 1.0mm ring for high-rpm.

Maximum-Piston-Acceleration (MPA):
2.5 top-ring - 1.49mm/0.06"
- MPA Permitted = 77,000ft/sec^2
- MPA Experienced = 51,354ft/sec^2 at 7000rpm
2.0 top-ring - 1.17mm/0.046"
- MPA Permitted = 105,000ft/sec^2
- MPA Experienced = 70,157ft/sec^2
- The BMW M5 in comparison experiences MPA of 90,000ft/sec^2 on a 1.5mm ring.



Lighter rings create reduced accelerative forces, reduced ring/piston interface overheating and reduced hammering of the piston-ring-groove. Too light and ring longevity is adversely affected.

MPA = (rpm^2 * stroke"/2189)*(1/2A), A = ratio between rod-length-between-centres to stroke.
2.0 rod-centre-dist = 135mm; stroke = 92.0mm; A = 1.47
- MPS-2.0 = (6500^2*3.62/2189)*(1.2*1.47) = 51,354 ft/sec^2


2.5 rod-centre-dist = 138mm; stroke = 74.2mm; A = 1.87
- MPS-2.5 = (7500^2*2.92/2189)*(1.2*1.87) = 70,157 ft/sec^2


Both the 2.5V6 & 2.0I4 engines are engineered for longevity. The 2.5 engine is likely to be the longer lived engine subject to identical maintenance to the 2.0 engine. Mazda V6 engines are assembled entirely by robots, not humans, at the Osaka engine plant in Japan alongside Rotary engines.

Ford bench testing, with very minor changes, showed the V6 to be capable of continuous running at 8900rpm - well beyond redline 7500rpm.

SAE paper "SAE920677" covers detailed design of the engine.