[Nixter420]

Okay I just finished rebuilding my 87 samurai. I seem to be burning a little oil nothing drastic though. I would like to think it is because I just rebuilt it and there is only 90 miles on it thus far. I rebuilt it because the rings were broke in the old one which made it smoke real bad. Along with the rebuild I installed a new weber 32 36 carb and took away all the emissions. I still have blue smoke coming out of the exhaust though. I have all NEW parts except for the 2 shafts. I also replaced my pcv valve and it still occurs.. Please help. I did a compression check head is sealed all the way no leaks I am wondering if the new carb is too much compression for the g13a

 

[Max]

Did you hone the cylinders? Have scored cylinders now (ie broken rings found)? Did you check the piston to bore clearance for excessive readings (diameter and taper)? Check / fit the ring gap? Reuse worn pistons (ring lands) ?

Do a compression check to confirm adequate compression after you run it a bit more, on the chance that the rings have not seated (or to confirm that you have ring issues).

Did it smoke prior to this work? Did you rebuild the head to include valve stem fit check and new stem seals?

 

[Nixter420]

Yes the cylinders were honed out from a machine shop. The head was also rebuilt with all new compenents and within taper limits. It did smoke heavy when the rings blew before the rebuild. I mean thick and I did drive it for a while.

 

[Max]

Then IF your smoking situation doesn't improve with the (hopefully) breaking in of the new rings, then something was missed during the overhaul.

 

[zooki4x4]

Your exhaust most likely is coated in oil and will take awhile to burn out. Run it a little longer and see if it improves any. Rich fuel usually burns a black smoke and smells like fuel.

 

[Azelgin]

Has the smoking cleared up yet?

Does it smoke on acceleration, deceleration, or , both?

Did you assemble the engine, or, did someone else?

Was the engine block cleaned (I mean REALLY cleaned) after the machine work was done?

What brand of piston rings did you use?

Is it running fuel rich?

I had a similar problem on a rebuild, that was part related. I hope your problem is different from mine.

It drove me nuts for a year and 6k miles.

 

[Max]

I had a similar problem on a rebuild, that was part related.

What specifically? :huh:

 

[Azelgin]

What specifically? :huh:

If someone had told me this was their problem, I never would have believed them;

The piston rings were not round!

I did a compression test at several mileage intervals. Dry to wet numbers were always 30lbs. apart. There was no improvement from 1000, to 6000 miles. All the cylinders were within less than 2lbs. variance each.

I figured I must have screwed up something, as the rings refused to seat in. After running it for a year and 6000 miles, I decided to pull it out, tear it down and start over. I thought either I hadn't gotten the bores clean enough and the cylinder walls glazed over, or, maybe I put the rings in upside down, or, the carb was too rich and glazed the walls, or. . . . ?

Cylinder walls were perfect and looked as good as the day I assembled it. The cross hatch had no signs of anything fishy going on.

Upon closer inspection, I could see uneven wear on the compression rings. Most noticeably on the second ring, as its wider. There were large dark (unpolished) spaces along the rings, where they never contacted the cylinder walls. After looking closely at the thin top rings, I could see they were worn just as uneven. Polished width varied from normal, to almost none.

I gave it a light hone, cleaned it up, put in some top quality rings (Seal Power/Perfect Circle brand), reassembled and tried again. No smoke and no oil usage in 900 miles. I mean not an ounce of oil usage!

Before the "re-rebuild", I was going through a quart every 800~1200 miles. The oil was getting dark, by 2000 miles.

Who knew?

I saved the old rings, so when my friends tell me I'm full of BS, I can show them the proof.

 

[Max]

Interesting!

My first thought while reading your post was that the bores weren't power honed (just deglazed) nor bored, thus the cylinders were egg-shaped or tapered, thus not in spec. But if the 2nd set of rings seemed to do the trick, then maybe all was well with the block and the first set of rings WERE suspect.

 

[Azelgin]

When I did the rebuild, I had it bored .020 over. I picked a machine shop with one of the best reputations in Tucson. I was sure to ask if they did their boring with a bolted on top block. They do, so, the bores should have been as good as it gets.
They had some pretty exotic engines laying around, so, that gave me confidence that they might know what they were doing.