77 CJ7 with rebuilt 350 smoking out of one side

[seanmcnunn]

I need help. I've read several threads on this site and have always found them to be very helpful. Here's my problem in short.

Background:

1977 CJ7 Base I bought from a farmer dude as a rebuilt for my daughter's sweet 16. He claims that in the rebuild they took it down to the block, bored it out .10 over, did the heads and all that. Iffy on the valves but he claims that at least they had them honed or cleaned or whatever the basic is without replacing them.

Jeep "Buster" had 20+ miles on it when I got it a year ago. I've been working on the body, wiring and interior for the last 8 months or so.

Started it up and it smokes LIKE IT'S GETTING PAID TO DO IT. but only out of the driver side.

I've changed out the oil to 30 weight and new filter, put a brand new Holley 4160 on it cause I thought it was running rich and didn't care to rebuild, replaced the plugs yesterday and ran it for about an hour in the garage. Still SMOKES OUT OF THE DRIVERS SIDE LIKE IT'S ANGRY AT MOTHER NATURE.

The smoke originally stung my eyes which made me think fuel so I replaced the carb. replaced the fuel filter, new fuel lines and so on.

I pulled the plugs today and #1 was wet and oily but the rest were sort of suit covered. Passenger side looked pretty good. I can post pictures if it helps but definately went to the touch on #1 and some oil in the threads.

went and got a compression tester and the dry results are:

Driver side front to back
200
190
190
205

Passenger side front to back
210
200
190
215

Adjusted the mixture screws on the carb 1/2 turn in and ran it for another hout today. Same smoking out of the drivers side. Now about the smoke. It appears to be blueish white. I'm not using anti freeze and it doesn't smell or taste sweet. The oil off the dipstick doesn't smell gassy and looks fairly clean still but it's only been about 20 miles / 1 hour with the new oil.

It doesn't start out too bad, but after it warms up it really really smokes up. Then if you let it idle for a bit it will calm down but still smoke and if you rev it up a bit the smoke comes out and clouds the entire neighborhood. Then if you let it idle it seems to settle down to a little trickle of smoke (still not acceptable but very noticibly different). Then you can up the RPM and the smoke comes back till you let it settle down again.

I don't think it's fuel because of the new carb but could be wrong there. I think it's valve seals but the Chevy guys I talk to say it wouldn't smoke when hot... just at start up and then only just a puff. Might be the intake or head gasket but I can't see anything visible and it actually runs great other than the smoke. One additional data point is that it seems to over gas on a cold start and shoot fuel up thru the top of the carb and barf a bit but once running at temp will start and stop with no drama.

Any thoughts or tests I can run?

 

[dunebuggy18]

Does it smoke when decelerating as well? Sounds like oil burn to me. Could the PO who rebuilt it have screwed up on the ring alignment? If the ring gaps are not properly off-set, you will get oil blow-by.

 

[rr41mag]

X2 :madjeep:

 

[seanmcnunn]

It does smoke when it decellerates as well. If you hold it at a specific RPM high or low it will eventually decrease the amount of smoke. Then when you go up or down from there it's starts up.

I'm hoping for anything but rings because that means I'm rebuilding the motor. Do you think it makes sense that it's only one side? How about valve seals in your opinion? Think it's worth new seals and gaskets before I just pull the motor or is that just tossing money at a problem that is more than likely rings? Any way to know for sure without taking the motor out?

 

[Old Dog]

I have to agree with the other guys in that valve seals usually only blow a little smoke at start up and than quit.
The compression looks good. It seems strange that you only have one oil fouled plug and yet seem to be blowing so much smoke.
Maybe the intake gasket is bad on the inside and sucking oil from the valley.

 

[Torxhead]

I would think that the blow-by on your "Just rebuilt" engine is just as bad.

 

[seanmcnunn]

Thanks everybody. I'm not going to be able to keep testing or working on this till the weekend now, but you've all given me some food for thought. One last question to the group. I've never done a leakdown test but the guy at Napa recommended it. Will that definitively tell me it's rings or just confirm what I already think I know which is rings and or one of the many gaskets. I'm thinking of doing the test and then planning on intake gaskets, cover and head gaskets to see if that fixes it before I go full monty and pull it. If you can't tell.... I don't want it to be rings.

And yes there will be some difficult conversations with the guy who sold me the jeep with the "just rebuilt engine" If I have to rebuild it after an hour or so of run time it seems like somebody should contribute some wrench time or money.

Thanks for all the thoughts.

 

[dunebuggy18]

I definitely would take this one step at a time: Start by pulling the heads for an inspection - take a good look at your gaskets for signs of failure. Who knows, you might get lucky! If it is rings, (which is my bet - Sorry) someone was probably asleep at the wheel when they put them in and did not off-set the gaps - not the first time that has happened! OK, you got some work ahead of you, but it's not that big of a deal if all else was done right.

Sounds like time to invite some buds over for a wrench party and a beer! Ok, several beers!:booze:

 

[rr41mag]

I'm leaning towards the rings too. After building several 350's it would be easy to put the rings on upside down. It's not the valve seals, I do now that.