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> cylinder honing
ruddyboys
post Jul 14 2004, 05:54 AM
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I am probably going to pull the engine this weekend and check the cylinders. I have a bottle hone, and will probably try to hone the cylinders myself. Does anyone have some pics of what a good honing job should look like?
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Joe Ricard
post Jul 14 2004, 06:11 AM
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So why are you going to do this work? Are you losing compression, burning oil? or just bored. If it were me I would put new rings in it after measuring the cylinders to make sure they are still fairly true.

To bottle brush hone use lots of oil and twist the brush as you push in. What you are trying to accomplish is give the cylinders a tooth for the rings to bite into while seating/sealing. Somewhere around 15 degrees. If your cylinders are smooth the rings may never seal.

Sorry if I sound gruff this morning but it started pourig half way to work in the 914. and I only have 1/2 cup of coffee so far.
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ruddyboys
post Jul 14 2004, 07:44 AM
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Joe, I put new rings in about a year ago and honed the cylinders then (first time I ever did this), finnally had the car out a couple of weeks a go for its maiden trip drove about 10 miles on flat roads, then I could not make it up a small hill without stalling, no power. I also had major oil leaks at the pushrod tubes on both sides and on at least one cylinder at the block. figuring if the engine is out to check the oil leaks I can easily pull the jugs and maybe run the hone on them to see if this is the problem with lack of power. The only pic I have seen of honing is in the haynes manual (B&W drawing), so if I can see a real pic I can tell if the honing was done right.
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Jake Raby
post Jul 14 2004, 08:20 AM
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Ensure the cylinders are still in spec before honing. A quick measurement of cylinder/piston clearance will tell this. Worn cylinders cannot be repaired with a honing process.

Does the engine have blowby/oil consumption issues now?
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Joe Ricard
post Jul 14 2004, 10:00 AM
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lack of power would not come from P&C's that have new rings with nearly no miles.
Problem may reside in carburation/injection. or ignition. assuming you are getting air in.
Only takes Air/fuel/spark.
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SLITS
post Jul 14 2004, 10:22 AM
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Honing depends upon the material the ring is made out of. When we used the DEVES Cast Iron Nodular - the "crosshatch" of the honing marks was 45-60 degree angle. No pics, sorry.

For a refresh, I would move the bottle brush in and out about 10 times with a 1/2 drill at half speed. Wanted to just "break" the glaze without removing much metal.
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blabla914
post Jul 14 2004, 10:57 AM
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Before you go pulling things apart figure out what's really going on.

I gather you have no power. Are you certain you know why?

Is the timing right?

Is the fuel pressure right?

Is the air filter OK?

Is the valve adjustment to spec?

Is it smoking a lot? (like besides the smoke from the oil burning off the outside of the heater boxes)

Did you do a compression check hot and check the numbers to the spec?

I understand why you are skeptical of the pistons and cylinders. A quick compression check to the specs will give you a good idea of what's going on there.

Know what you've got BEFORE you take it apart. Once I took a motor apart because it wouldn't run and it turned out to be dirt in the carbs. I don't recommend that approach.

Kelly
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newdeal2
post Jul 14 2004, 11:57 AM
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I think a leak down test may be more revealing.
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Allan
post Jul 14 2004, 12:30 PM
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Speaking of specs for compression, what is the correct spec.? I checked mine a couple of weeks ago and it was reading 130,130,130,115.
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newdeal2
post Jul 14 2004, 01:50 PM
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Those are pretty good numbers but the 115 is a little suspect . Did you check it hot?
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Allan
post Jul 14 2004, 01:53 PM
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Not really. It had only been running for maybe 5-10 minutes. Do they usually seal up a little when hot?
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newdeal2
post Jul 14 2004, 02:28 PM
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I have been told to take the car for a "spirited" run and get it nice and hot.

If it doesn't make a difference it's still a good excuse to go for a ride (IMG:style_emoticons/default/biggrin.gif)
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morph
post Jul 14 2004, 02:58 PM
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if you feel that youre rings are a issue i would do a compression test first b4 you do anything to the motor.then go from there.test b4 you shred youre motor apart or car (IMG:style_emoticons/default/wink.gif)
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SLITS
post Jul 14 2004, 03:08 PM
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To simulate "hot" or good sealing -

take a compression test on each cylinder

Squirt a couple of squirts of oil in the cylinder, turn the engine over a couple of time and then retake the compression. If it is markedly different, rings could be suspect.

As stated, a leakdown test will tell you far more.
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