Determining Competition Engine Life

[teamDFL]

Is there a way to determine the service life of an engine that is used in racing events before it fails and without a tear down?

The reason that I ask is that I have a Focus with a DOHC Zetec that I take to track events. It has approximately 2700 on track miles on the engine and 76000 total. Since I drive the car to work every day, I cannot disable it just to see if things are OK. Nor can I risk grenading the motor. I thought that there was an equation that involved piston speed, but I would really appreciate anyone's experiences or personal guidelines that they use. Thanks.

 

[jason07-1zzfe]

Get with Terry and start a UOA trend.

 

[tom slick]

Used oil analysis is about the only "non-destructive" inspection method to know when your equipment is wearing out.

 

[Steve S]

Track events with your car? then worring about not being able to dissable it . Well Just a guess is that it is a stock engine that only revs to the factory limit there may not need to really worry. When the motor gets real weak you will know it ,maybe the power will drop or burning oil. Then rent a car or buy another one.

 

[tom slick]

I need to edit my previous statement. you can keep a close eye on your spark plug condition to check for detonation. and you can do routine leakdown tests to see if you have a valve, piston ring, or head gasket problem.

 

[teamDFL]

quote:

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Originally posted by Steve S:
Track events with your car? then worring about not being able to dissable it .

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Not sure what you are implying with this, but if the sheet hits the fan, I can manage. However, I would prefer not to have to. For example, if I put the car up on jackstands Friday night, drop the pan and plastigauge the rod bearings, what do I do if they are out of spec? Do I put it back together with parts out of spec? It has been my experience that bearings that are disturbed are not always happy about it. To check the rings, I would have to pull the pan and the head. Again, I am competent enough to do this in a weekend, but there is an element of risk. Rings can crack going back into a cylinder if the upper ring grove on the piston is beat up or if there is a lip on the top of the cylinder (ridge). That risk is what I am trying to avoid by doing non-invasive testing.

quote:

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Originally posted by tom slick:
I need to edit my previous statement. you can keep a close eye on your spark plug condition to check for detonation. and you can do routine leakdown tests to see if you have a valve, piston ring, or head gasket problem.

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Thanks Tom. Any tips on reading plugs? The car has a knock sensor, so I am assuming deto is in check. Leakdown tests sound like a good idea, particularly since it will give a good read on both rings and valve seats.

Still looking for a way to check the bearings.

 

[Steve S]

I am implying that if your car is being pushed to its limit the most you are doing is accelerating wear ,unless the motor grenades when eventing I don't think the motor will fail when commuting,as in my previous post the motor will tell you when it is getting tired. The motor will start loosing oil pressure "lower oil pressure" is the bearings wearing. burning oil is the rings A puff of bluish smoke upon start up valve giudes or seals or the engine will seem to loose power. Rebuilding an engine over the weekend to drive to work on monday is not fun. If there is a ridge in the top of the cyl it has to be reamed before the piston is removed .If the ring grove is beat up the piston is bad. yes if the bearings are worn disturbing them would almost gaurantee a spun bearing . There is no easy way.

 

[tom slick]

quote:

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Still looking for a way to check the bearings.

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That's when the used oil anaylsis comes in. it will tell you if bearing wear is going up, if your head gasket is leaking, if your oil is failing, if you are running too rich, if your rings are wearing out...
if you are getting detonation your plugs will have little metal sparkles on the insulator. you need to look at them with a bright light and good magnifying glass.

 

[1sttruck]

Gauges help, where oil pressure and maybe exhaust gas temp and boost for a turbo make sense as you can monitor boost for a given load to see if it changes much. Regular compression checks, tracking oil consumption, and maybe even regular emmissions checks can also help to monitor wear.