A LOT of blowby smoke after engine rebuild

[don_gibb6512]

I've got 317 miles on a rebuilt top end, '80 GS1100ET. Standard sized rings, pistons measured in spec as did cylinders. Cylinders honed and valves done by a professional machine shop. I took the engine apart and re-assembled it myself. I've got a Kerker 4-1 pipe and K&N pods. I used transmission fluid to lube the cylinders, rings and pistons when I re-assembled. Long story short, I didn't finish up the rest of the bike for 4 years after that. I did turn the engine over by hand occasionally and put drops (about a teaspoon full) of oil in each cylinder before I turned it over. Once I was ready to start the engine it fired right up after only 3 times around. I'm running Hondaline 10W-40, non-synthetic. After a quick 25 mile ride today, I'm still getting a continuous stream of white, oily smoke coming out of the breather tube. The tube is long and I've vented it down and out, under and behind the right foot peg. That makes it easy for me to monitor how much smoke is coming from it. Obviously I can only notice this when I'm stopped. I had a friend ride behind me today and it was enough that he could smell it. He did say I would puff out some white smoke when I took off and when I shifted from the exhaust pipe. For break-in, I kept the rpm's under 6K until I got just over 200 miles then I started revving it up to between 7-8K or so before I would shift, but not all the time.

So, that's as much info as I can recall right now. Basically, am I screwed or do I just need to put more miles on this engine before I start to get really worried?

Thanks.

 

[DanTheMan]

I always figure about 1500 miles to break in new rings, especially since it seems like all the companies are manufacturing lately are the stainless ringsets.....

 

[KGB]

"I used transmission fluid to lube the cylinders, rings and pistons when I re-assembled. Long story short, I didn't finish up the rest of the bike for 4 years after that."

Never heard of this. Not saying it's bad, just never heard of it.

You're keeping the rev's down or under 6K, but how much throttle to ge tthere?
1/2--3/4 ? the amount of pressure used , or throttle opening will help seat the rings.
When my 1000 was rebuilt I kept it under 1/2 throttle-most of the time and 6k as you're doing. a once or twice a day wide(r) opeing helps seat the rings

What color does tranny fluid burn ?

 

[mmarshall13098]

just a note...trans fluid will burn white...being an auto mechanic also, i know this is an old trick used my mechanics to clean the top ends of engines (WAY before seafoam)

 

[Guest]

misplaced piston ring?

 

[Guest]

The first minute of running after a rebuild is crucial for ring seating. If you oiled the cylinders before running the motor it set back the seating process. Just ride it. They will seat eventually.

Even if you put the rings sixty degrees apart they do move. If you opened up the engine now they would be different than when you installed.

 

[don_gibb6512]

I'll try to answer all in one set. Didn't misplace the rings when installing, I was meticulous. Good thought though. I used tranny fluid because I knew I wouldn't get the thing done right away, (never imagined it would take as long as it did) and I needed something that wouldn't congeal. Tranny fluid always burns heavy white but I figured it would have burned off right away and I know the smell of tranny fluid and that's not what this is. This is definitely blowby engine oil. Yes, I did add oil before starting it, being overly paranoid about breaking a ring. Probably a mistake. Lesson learned. Thanks for that hint. I missed it.

So, am I just in for a 1000 miles of stink and smoke? Will they seat in eventually? If that's the case, I can live with that easily. I'll just be content with riding alone for awhile. 8-[

 

[tkent02]

Open the throttle more.

 

[tfb]

Yes, a freshly rebuilt engine will burn *a little* more oil then when it's bedded in. But there's no way you should be burning so much oil that you're getting "white" smoke choofing out the back.

misplaced piston ring?

Even though you've discounted it, I think that may be on the right track, I'm afraid... ... it's those oil ring 'expanders' that are easy to install incorrectly, ie. they can be easily 'overlapped' instead of the ring ends butting-up against each other. For example, read points 1 & 2 under 'Ring Installation' below (These instructions are from a Wiseco kit I have used) and look at Illustration 1...

 

[don_gibb6512]

Thanks for the illustration. Unfortunately it's been too long and I don't remember exactly how I did it. I think I butted them correctly but I could have screwed that up. I'll let this engine smoke for a couple hundred more miles and then probably open it up and find out where I went wrong.

 

[Guest]

Oh man, I forgot about the ring gap. If you didn't set this right it may never stop smoking. Put the ring in a vice and use a dremmel.

 

[49er]

Thanks for the illustration. Unfortunately it's been too long and I don't remember exactly how I did it. I think I butted them correctly but I could have screwed that up. I'll let this engine smoke for a couple hundred more miles and then probably open it up and find out where I went wrong.

If you're running it in with synthetic oil it will take forever to settle down.
It is recommended to us 30 grade for the first 1000kms and then switch to 10W40 synthetic.
You may have the rings fitted incorectly as well!!

 

[don_gibb6512]

100 percent sure I didn't measure ring end gap

100 percent sure I didn't measure ring end gap

So, I've read more and thought a lot about how I put that motor back together and I did correctly butt the oil ring expander but I didn't measure ring end gap. The cylinders and pistons measured out within spec so I used standard sized rings. I also did install the rings in the correct order.

What are the chances that the gap was correct right out of the package?

And what exactly happens when the ring end gap isn't correct? (other than smoking a lot)

The motor pulls strong so other than the blowby smoke, (which only happens after the motor is HOT) you'd never know anything might be wrong.

Thanks.

 

[tkent02]

Ring gaps too large, you would never notice, unless the cylinders were worn way too far...slight loss of compression, not much. Race engines use bigger than normal gaps to allow more expansion, they run OK. I have assembled beater car engines with three or four times the specified gap due to bore wear, they sealed up OK and ran fine. Lasted a long time although probably not as long as if it were done correctly. I'll never know.
Ring gaps too small, can cause broken rings, cylinder bore damage, possible seizure... basically no place for them to go when they expand due to heat. This should only happen if the wrong size ring was used, cylinders bored to the wrong diameter, etc.
Just go run the **** out of it, see if you can get it to seal up.
OPEN THE THROTTLE!!!

http://www.mototuneusa.com/break_in_secrets.htm

 

[don_gibb6512]

Ring gaps too large, you would never notice, unless the cylinders were worn way too far...slight loss of compression, not much. <snip>
Ring gaps too small, can cause broken rings, cylinder bore damage, possible seizure... basically no place for them to go when they expand due to heat. This should only happen if the wrong size ring was used, cylinders bored to the wrong diameter, etc.
Just go run the **** out of it, see if you can get it to seal up.
OPEN THE THROTTLE!!!

Thanks man. I got to 200 miles and just couldn't stand to keep it under 6K rpm's any more. So yeah, I've been twisting the throttle as much as I can get away with. My paranoia stems from the "fear of the unknown". I've taken all of this on my own, no mentor, no guide, just had to do it so I did. I tend to make ALL the mistakes possible before I actually get things right. "Bent" Karma I guess. :-D

 

[49er]

Thanks man. I got to 200 miles and just couldn't stand to keep it under 6K rpm's any more. So yeah, I've been twisting the throttle as much as I can get away with. My paranoia stems from the "fear of the unknown". I've taken all of this on my own, no mentor, no guide, just had to do it so I did. I tend to make ALL the mistakes possible before I actually get things right. "Bent" Karma I guess. :-D

It's a learning curve. Lessons learnt the hard way stay with you forever. You will benefit from them in latter years and maybe help others to avoid them on this forum. We have all made them to some degree.
My 850 rebuild resulted in #3 pot not completely settling in until the engine had over 2000kms on it. I think I slightly damaged the oil rings on that piston during assembly. So dont panic.
Enjoy your ride and open that throttle!

 

[BadBillyB]

If you had issues with the oil control rings, you would only have smoke coming from the exhaust system. If you have pressure coming from the crankcase vent (breather cover) that causes oil or smoke to vent from the crankcase to the atmosphere, you have compression sealing problems. Replacing the rings and re-using the pistons and honing the bores is not a top end rebuild. A slight amount of "taper" in the bores combined with loose fitting pistons/rings will cause just what you have.....Excesive "blow-by"......The fact that your motor set up for so long after the work plays into the equation....Try running some Marvel Mystery Oil mixed with the fuel (may unstick "gummed" up rings) for a while and see if you get any good results........Billy

 

[don_gibb6512]

It's a learning curve. Lessons learnt the hard way stay with you forever. You will benefit from them in latter years and maybe help others to avoid them on this forum. We have all made them to some degree.
My 850 rebuild resulted in #3 pot not completely settling in until the engine had over 2000kms on it. I think I slightly damaged the oil rings on that piston during assembly. So dont panic.
Enjoy your ride and open that throttle!

Thanks for the support. I appreciate it. I figure at this point I don't have much to loose so I'm just going to ride like I would anyway which is pretty much thrashing it. :-D

And good idea Billy. Won't hurt to try some Marvel. Thanks.

 

[Nessism]

If you're running it in with synthetic oil it will take forever to settle down.
It is recommended to us 30 grade for the first 1000kms and then switch to 10W40 synthetic.

My understanding is that synthetic oil is not more slippery than dino oil, thus it should not affect the break-in process. In support of that line of thinking, some OE car manufacturers, such as BMW and Chevrolet with the Corvette, supply synthetic oil in the engine from new.

 

[tkent02]

My understanding is that synthetic oil is not more slippery than dino oil, thus it should not affect the break-in process. In support of that line of thinking, some OE car manufacturers, such as BMW and Chevrolet with the Corvette, supply synthetic oil in the engine from new.

It's not more slippery, but it keeps the parts from wearing better, not what you want. The new engines which use synthetic from the start are machined to much tighter tolerances, in effect need no break in at all.