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TaterSalad

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the car wasnt using excessive oil, or coolant. the oil was about a month old before i tore her down, and the coolant was in the car when we bought it, so i dont know if it was the propper mix or not.

i do know that if you look at the bottom of the gasket, you can see a track where fluid left the cylinder and went down into one of the holes going to the oil.

i had a picture of it, but it didnt turn out at all, so i deleted it.

were getting the head milled on monday, and if its done on time, i should be able to get her back together by monday night, or be a little to sick for school tuesday, and finish her up on tues.

i will be keeping an eye on the temp gauge, and the smoke color

 

oh, and all the ring scoring on the cylys are from the camera/flash, looking at it with bare eyes they look almost like mirrors.

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by the picture inside one of the water jackets i can clearly see nice green coolant- and no i don't see any "greening" of the carbon. what i do see are 2 clearly cleaner cylinders- from whichever fluid cleaned them. we have no way of knowing(other than to ask tater) if it used water before- or had plain water, or if the new coolant had just been added prior to head removal. i also didn't like the looks of the ring score visible in cyl #2. to me it's all typical of a mazda with over 180k on it-

 

i think we're both on the right track- although we may disagree about the details. what we're both missing is the other half of the equation. we don't have the engine or cylinder head on the bench in front of us- can't check it for flatness- and there's alot that pictures can't capture that the naked eye can distinguish. between those 2 cylinders there are 2 water passages, the gallery that feeds oil to the top of the head, and the sealing ring for compression. amidst all that, we have a worn engine with a half an inch of gasket missing.

 

anyways- i'm still hopeful that a resurface does the trick. try the easier fix, and hope for the best.

 

I agree on the later...;)

 

I hope tater has learned from this post as it is the mission here at diy-street... with all of the post and info he should be confident enough to get it back together...;) mission accomplished...

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Guest YuKoN

good deal tater- hope it all works out for you. make sure you blow out the head bolt holes so they're clean and empty of oil and water, and use some lube on those threads when you torque 'em back down. this will ensure an accurate torque. i usually use copper based anti-seize- or if those holes enter the coolant jackets(some engines do) i use aviation sealant(it's similar to a brown tar), liquid teflon pipe fitting compound works as well.

 

pay close attention when you time the cams- not sure if you had 1 sprocket or 2 on top but get it right the first time and you'll have no problems.

 

let us know how it goes!

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its dual overhead cam,4 valves per cylinder is impossible with single cam.make sure you get the cams set right,with mazda youll get an immediate code for the belt being off one tooth.itll run smooth but lack power.for dr_bowtie,oil cannot take the place of the fuel charge in any single cylinder,the injectors all fire the same pulse according to the information received from the o2 sensor.if you had an o2 for every cylinder you could have different pulsewidths per injector..when you have excessive oil the resultant misfire will cause excess oxygen,up to 6%. this is seen as a lean mixture so the injector pulse is widened to richen the mixture,for all the cylinders.lean misfire and detonation are different things.detonation or pinging is when the flame front from a preignited charge meets the flame front from the plug fired charge.any misfire, lean, oil fouled,spark, compression related,or coolant, cools the combustion chamber so you cannot have detonation.the pcm cannot see the hydrocarbons,gas or oil in each cylinder,it infers it from the o2 content.too much o2 means lean,not enough fuel to use up the o2,too little o2 means rich, it used up all the o2.oil does not burn efficiently so it will always cause misfire whether you can feel it or not, youll see it on a 4 gas analyzer.

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its dual overhead cam,4 valves per cylinder is impossible with single cam.make sure you get the cams set right,with mazda youll get an immediate code for the belt being off one tooth.itll run smooth but lack power.for dr_bowtie,oil cannot take the place of the fuel charge in any single cylinder,the injectors all fire the same pulse according to the information received from the o2 sensor.if you had an o2 for every cylinder you could have different pulsewidths per injector..when you have excessive oil the resultant misfire will cause excess oxygen,up to 6%. this is seen as a lean mixture so the injector pulse is widened to richen the mixture,for all the cylinders.lean misfire and detonation are different things.detonation or pinging is when the flame front from a preignited charge meets the flame front from the plug fired charge.any misfire, lean, oil fouled,spark, compression related,or coolant, cools the combustion chamber so you cannot have detonation.the pcm cannot see the hydrocarbons,gas or oil in each cylinder,it infers it from the o2 content.too much o2 means lean,not enough fuel to use up the o2,too little o2 means rich, it used up all the o2.oil does not burn efficiently so it will always cause misfire whether you can feel it or not, youll see it on a 4 gas analyzer.

 

you are almost right in theory...

 

Although what you say is in theory how it works in this case just the opposite is true....

 

you will get the same fuel charge per cylinder but when oil is introduced it must take the place of something...

 

With a predeterminded amount of fuel delivery the only other thing is oxygen...the oil rich cylinder(s) will get less oxygen and creates an over rich condition....

 

part of the ECM tries to lean it out but gets confused and ends up enriching it more....Although computers are smart...they arent that smart...they dont come built in with oil consumption maps for ware... nor do they know how to differentiate contaminates in the exhaust...Think about it..

 

O2 sensor tells it it's rich but every other sensor says different...so what happens...it dumps more fuel anyhow...Some ECM might just think the O2 is bad....

 

But neither of that matters....

 

when you have and excessive amount of oil in the cylinders detonation will occur nomatter if it's rich or lean due to the characteristics of the oil properties...Things just get alot more complicated when you add fuel injection to the mix...ECM's are programed for the environments they were designed to run in...not in an contaminated environment with oil...

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the cams havent been moved, and theyr marked, so they will be good.

 

i am going to be tapping the holes for the head bolts, and taking a die to the actual bolts so i can get them torqued right.

 

the heads getting milled tomorrow while im at school, then im having my friend come over, and we will be putting her back together.

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you are almost right in theory...

I diagnose and repair 10-12 cars a day 6 days a week for smog failures,2-3

of them for the California State Consumer Assistance Program.in 30 years not one misdiagnosis .According to the California state BAR stats i am the #1 rated smog diagnosis and repair tech in the state.thats out of the 1000s of gold shield and general repair stations in the state.the 84 CAP stations in the state do 400 cars a month,i do 40 to 60,you do the math.as an ASE Master tech for the last 30 years as well as the california smog program since its inception in the 70s,im pretty sure i know what im talking about. the ONLY sensor that tells the pcm how rich or lean the mixture is, is the o2 sensor.the others may CAUSE a rich or lean condition due to false readings,but they tell it nothing about the fuel levels. Detonation can ONLY occur in a cylinder with overadvanced spark,too lean a mixture,too high a compression,from carbon buildup or using too low an octane gas in a normally high compression engine,or a combustion chamber temp of over 2100 degrees f. high octane gas burns slower so it reduces detonation,which is why it is used in high compression engines.diesel burns slower yet which is why it is used without a spark in a 20 to 1 compression ratio or higher engine.oil burns slower than that which is why it is IMPOSSIBLE for oil to cause detonation.in tatersalads 8-1 compression engine this is doubly impossible.detonation is basically the same as dieseling, combustion due to compression before the spark.as to the oil taking the place of the oxygen, all the cylinders in an engine take in the same air,the ratio of 20.4% oxygen in the air will be the same in every cylinder no matter how much oil there is.misfire and detonation are NOT the same thing.detonation will cause extreme NOx levels,misfire extreme hydrocarbon levels,you can NOT have both at the same time.

to TaterSalad make sure you change the oil and filter before you fire up that engine as its almost impossible to keep coolant out of the oil when you pull the head off,and wipe off the cylinders walls with an oil soaked rag as youll have coolant down in the rings from the spillage out of the head.also use moly engine assembly lube on the cam surfaces since they will be dry till the oil starts pumping.good luck with it.

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the cams havent been moved, and theyr marked, so they will be good.

 

i am going to be tapping the holes for the head bolts, and taking a die to the actual bolts so i can get them torqued right.

 

the heads getting milled tomorrow while im at school, then im having my friend come over, and we will be putting her back together.

 

make sure those are reusable head bolts.if the torque specs say anything about torquing to an angle after a certain torque,they are stretch bolts and should be replaced.

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I diagnose and repair 10-12 cars a day 6 days a week for smog failures,2-3

of them for the California State Consumer Assistance Program.in 30 years not one misdiagnosis .According to the California state BAR stats i am the #1 rated smog diagnosis and repair tech in the state.thats out of the 1000s of gold shield and general repair stations in the state.the 84 CAP stations in the state do 400 cars a month,i do 40 to 60,you do the math.as an ASE Master tech for the last 30 years as well as the california smog program since its inception in the 70s,im pretty sure i know what im talking about. the ONLY sensor that tells the pcm how rich or lean the mixture is, is the o2 sensor.the others may CAUSE a rich or lean condition due to false readings,but they tell it nothing about the fuel levels. Detonation can ONLY occur in a cylinder with overadvanced spark,too lean a mixture,too high a compression,from carbon buildup or using too low an octane gas in a normally high compression engine,or a combustion chamber temp of over 2100 degrees f. high octane gas burns slower so it reduces detonation,which is why it is used in high compression engines.diesel burns slower yet which is why it is used without a spark in a 20 to 1 compression ratio or higher engine.oil burns slower than that which is why it is IMPOSSIBLE for oil to cause detonation.in tatersalads 8-1 compression engine this is doubly impossible.detonation is basically the same as dieseling, combustion due to compression before the spark.as to the oil taking the place of the oxygen, all the cylinders in an engine take in the same air,the ratio of 20.4% oxygen in the air will be the same in every cylinder no matter how much oil there is.misfire and detonation are NOT the same thing.detonation will cause extreme NOx levels,misfire extreme hydrocarbon levels,you can NOT have both at the same time.

to TaterSalad make sure you change the oil and filter before you fire up that engine as its almost impossible to keep coolant out of the oil when you pull the head off,and wipe off the cylinders walls with an oil soaked rag as youll have coolant down in the rings from the spillage out of the head.also use moly engine assembly lube on the cam surfaces since they will be dry till the oil starts pumping.good luck with it.

 

 

There are still discrepancies in your post...although I would be inclined to agree with certain factor most of it is not either fully correct or not a good comparison...

 

Oil in the cylinder will cause detonation regaurdless of of experiance of diagnosis and any certifacation....

 

As an engine builder myself I have seen it in full form...and as for higher octane gas being less likely to detonate...yes and no...

 

here are some links for detonation....

 

 

http://zhome.com/ZCMnL/PICS/detonation/detonation.html

 

 

Another area that's often overlooked is detonation on one or two bores in lieu of all or most cylinders. It really takes a trained ear to determine this by the frequency of the knock and its sound. Then again, there's something particular to those bores only that is causing a problem. An often overlooked area is oil migration into the bore as a cause of detonation. If you're searching for the culprit, carefully examine the spark plugs under a magnifying glass. Oil originating at the valve guide area is a major contributor to single-cylinder detonation. Retarding of the timing may lessen this but will drastically diminish power output in all the normal combustion bores.

 

 

http://www.hastingsmfg.com/ServiceTips/eng..._detonation.htm

 

 

I think the best thing here after is we should agree to disagree and drop it from there...;)

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Guest YuKoN
make sure those are reusable head bolts.if the torque specs say anything about torquing to an angle after a certain torque,they are stretch bolts and should be replaced.

 

if they're "torque to yeild" bolts they'll be easy to spot- there's a shoulder under the head of the bolt, and a narrower shaft of the bolt between the shoulder and threads- if they are torque to yeild then they must be replaced. if they're a standard straight shaft bolt then they can be re-used if threads are good.

 

i forgot to mention this- good call.

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the bolts are strait and reusable.

the machinist found problems with my cam gear pins, so i ordered new ones, and they wont be here till tomorrow. then i can start putting things back together.

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