To deglaze or not to deglaze

[Guest]

I took the engine apart to inspect the rings and cylinders. The cylinders are within spec and so are the rings. Should I deglaze the cylinders before I put everything back together?

[Nessism]

I'm inclined to say no deglaze, although some people do it. Personally, I recommend replacing the rings while an engine is apart unless the engine has less than 20k miles and the compression was good before the tear down.

[old_chopper]

I was taught the same as Nessism, if the rings come out of the cylinders then they get replaced. Of course we were working on automotive engines and the rings are usually pretty inexpensive. If you do put new rings in then I would definitely hone the cylinders.

[razooki]

This is my first engine tear down of any kind so I'm still learning as I go along. I'm wondering why is it that the general consensus is to replace the rings even though they are within the specs of the repair manual? I have seen instances (such as the head gasket) where the book recommends replacing it but nothing about replacing the rings. I would think that the manual would not even bother giving the ring measurements if they need to be replaced whenever the engine is taken apart.

[tkent02]

I'm wondering why is it that the general consensus is to replace the rings even though they are within the specs of the repair manual?

The general consensus is to not take it apart if there's nothing wrong with it.
I would hone the cylinders and reuse the rings, but that's just me.

[spyug]

When I had to pull the head on my kat project engine to free up the stuck rings I was in a bit of quandry of how to proceed. The cylinders were in spec and while I didn't check the rings I had no reason to think they were out of size. Conventional wisdom is that you should do a cylinder hone and re-ring if you get to this stage, however. I chose to merely deglaze the cylinders and put it all back together. I even reused the head gasket despite the recommendations not to.

At first, I thought I had screwed myself as I had a devil of a time starting the engine and when checked it seemed the compression was way too low at 90 psi or less.

Once I was able to start it and allowed it to warm up to operating temps the compression came up to 180+psi in each cylinder. So far no leaks or nasty noises but the real test will be when I get it roadworthy for a spring launch.

In view of my findings, I'd suggest a light hone to deglaze, use the rings and button it back up.

I don't think you will have a problem as these are tough engines with a reputation for being bulletproof.

Good luck with it.

Cheers,
spyug

[razooki]

TKent thanks alot for your customary words of wisdom. I took the engine apart because I was getting some blue smoke and from what I gathered here it was either the valve seals or the rings. I replaced the valve seals and lapped the valves and I thoght prudent to check the condition of the rings and cylinders (but then again what do I know??). I'm not in the habit of taking thinks apart for no reason.

Spyug, thanks for your input. I've been following your project with great interest and I'm happy that you finally got it running. I hope to follow your lead soon and finally hear my bike run - I only wish I had more time to spend in the 'man cave'.

[Spyderman]

The general consensus is to not take it apart if there's nothing wrong with it.
I would hone the cylinders and reuse the rings, but that's just me.

yup i agree with kent if i take cylinders off then i deglaze even if i use the same rings it's just better and safer to do it then you know you'll get a good seat once you run in the engine

[spyug]

Looking back over my many years fiddly farting with sportscars I seem to recall that most cases of blue smoke are a result of leaky valve seals so I think you nailed it.

Out of interest what is the mileage on that engine? If it is getting up there and if you will be keeping it awhile you might think about re-ringing it afterall. If its in the budget that is.

Thanks for your interest in my project too. It was a struggle getting it to fire and it did confound me a time or two. I think you're going to have an easier go of it so I'll be looking forward to hearing about it when you do.

Its a great satisfaction when you bring a bike back to life Enjoy it.

cheers,
Spyug

[tkent02]

I took the engine apart because I was getting some blue smoke and from what I gathered here it was either the valve seals or the rings.

I guess I missed the blue smoke part in your original post.

Seals harden with age, rings wear with use.

Replace what makes sense to you.

[chef1366]

Do you want to ride it for 30k miles? Replace the rings.

[razooki]

I appreciate everyone's input and I don't mean to belabor the point but it seems there is no right answer for this question. I'm an empirical data kind of person which is why I rely on the spec numbers from the repair manual so much and I could find no such data to convince me either way regarding reusing rings and deglazing.

[chef1366]

In my opinion you need to ball hone the cyliners to ensure that the rings will seat. New or used.

[spyug]

You strike me as being very exacting, even meticulous in your approach to issues ( are you an engineer, accountant or scientist by chance). I don't think you are going to have peace of mind until you hone those cylinders and re-ring your pistons.

While I like to think of myself as logical, I do listen closely to my gut and what I would do is not likely to be the same as you.

What does your gut tell you ( besides lunch time).

Let us know what you think you are going to do.

Cheers,
Spyug

[razooki]

Spyug, I'm only meticulous when it comes to certain things especially when I'm doing it for the first time. Here is my train of thought regarding this. Nowhere in the manual does it state that rings should be discarded and replaced if the engine is taken apart. The manual also gives precise measurements regarding end gaps, ring thickness, etc. To my mind they would not do that unless the rings could be reused if within spec. The same goes for deglazing the cylinders. So I'm just going to put everything back together and see what happens. I know there have been alot of opinions expressed here one way or the other but what I am curious to know is has anybody done it one way only to find that it does not work or is it a case of "well if I'm in it this far I might as well do it". I'm a firm believer that if it ain't broken don't fix it that is why I took the engine apart to inspect. Had I found anything out of spec I would most certainly have replaced any parts that needed replacing (i.e. rings).
This is the great unknown for me since I'm doing it for the first time and I hate not finding the precise answer.