simple question
simple question
(OP)
I am going to advance the cam in my 02 malibu 3100 using a offset key on the crankshaft. will somebody tell me if i'm right or wrong. turnig the cam against rotation using a bushing will advance the cam,so using a offset key on the crank i should rotate the crank with rotation right or wrong. If thats not correct can someone explain the correct way. thanks





RE: simple question
RE: simple question
RE: simple question
It may be your gauge is wrong.
Changes in an engine that was not intentionally changed must be due to accident or wear.
Most likely point of wear is valve train, especially cam lobe wear.
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RE: simple question
For example, in a 3500 lb auto with a 3.0L engine, it MIGHT be running at highway speeds at 9"hg, where as the same vehicle with a 5.7L engine may be running at 16"hg. Guess which one will get better economy?
Cam lobe profile can certainly cause problems as patprimmer indicates, but to add my small and barely significant thoughts, once a camshaft wears to the point where valve lift is compromised enough to cause a loss in power, the valve followers should be rattling like a bucket of rocks, and it just gets worse, fast. Once the camshaft lobe hardened surface is cut through and the followers suffer the same wear rate, the resulting action more closely resembles a bench grinder than a precision engine.
Franz
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RE: simple question
RE: simple question
RE: simple question
Regards
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RE: simple question
RE: simple question
RE: simple question
1) He should not be here.
2) He should neither assemble nor adjust engine components.
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RE: simple question
This may be a little extreme, but have you put your car on a dyno to see if it's actually lacking bottom end power, or if you just feel it is? Lets face it, it's a 2002 Malibu; they weren't exactly known for tearing up the drag strip. It could just be that your car, even in perfect form, had poor performance compared to many other cars on the road.
Make sure your vacuum is actually low, and make sure your cam timing is actually retarded. You should make sure something is broken before you fix it.
Bob
RE: simple question
There may be proven performance benefits from altering the cam, and even retarding or advancing the timing as a whole. It just doesn't seem to me that the OP is going to figure out exactly where the original engineers compromised low rpm torque, if they even did.
When was the last tuneup? How old is the airfilter? There are a whole lot of other things that may be causing your trouble. (is the catalytic converter plugged? I had a VW that just died till 3000rpm, once we cleaned the cat it again could accelerate in 5th from 25mph.)
Nick
I love materials science!
RE: simple question
I think the engineering folks refer to this bit of folk wisdom as "Ockham's razor".