Smoking Engine

[1965fastback]

We just put a new Autolite 1100 from Pony Carbs on a 200. The carb is tuned in but the engine is still smoking alot. The compression test showed an average of 155-158 psi. What is making it smoke, if the rings are bad the compression would be low, right? What do you guys think is causing it to smoke? Thanks.

 

[fordconvert]

Could still be rings, other than the compression rings there is usually a oil control ring. How long have you run it with the smoking? Keep running it doing extra frequent oil changes. The detergents in the fresh oil will clean things up. Other and fairly likely option is valve guide seals. They would be plastic or rubber, either way if they are more than about 10 years old they would be shot. If the motor has lots of miles on it the guides likely are worn which would make it even worse. Does it somke the most on a hot restart? Thats oil leaking down the guide and sitting on the valve. If its been going on a long time its likely built up along with a bunch of carbon.

 

[grocery getter]

like fordconvert said,
there's compression rings as well as scraper rings.

bad valve guides or seals can cause an engine to smoke.


to be clear, what color is the smoke?

how does it run with the new carb ? ( aside from the smoke)

 

[JackFish]

If you put oil in the chambers for a compression test perhaps it's just not quite fully burned off, and you still have some oil in the chambers?

 

[1965fastback]

Okay, well I think I figured out the smoking problem. Today me, my dad, and my grandpa pulled the engine out of the car and took the head off. The block looks good, there are still honing marks on the cylinder walls except for one spot in each piston.It looks like the cylinders have been sleeved. The spot is the same for all 6 cylinders. There is alot of oil on the valves on #5 cylinder.

 

[addo]

Is each piston notch or arrow towards the thermostat end of your block? Sounds a bit like either side loads or piston slap.

 

[1965fastback]

To be more accurate, the first time we started this motor, it smoked some, but not a lot. Even though it was smoking, when we test drove it, it ran great and had lots of power. It looks like the cylinders have been sleeved. The most oil was on the valves on #5 cylinder. What would be the best plan of action for this motor, ouverhaul the head, or completely rebuild the motor?

 

[1965fastback]

Fordconvert, it does smoke on a hot restart, but no more than normal. We ran it for 20-30 min. and it smoked the same the whole time. It looks like the bottom end of the engine has been rebuilt, but not the topside.

Grocery getter, the smoke is a grayish color. It ran great with the new carb.

We pulled the head because we broke an exhaust manifolt bolt off in the head.We are considering just rebuilding the head and putting it on the motor to see if it runs better. Would that be a good idea or should we go through the whole motor since the history on it is unknown?

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[fordconvert]

Since you have it apart cc things and see if things are close to stock. You can get close just picking up a syringe. I had one from one of the pets. Auto stores also sell them for mixing 2 cycle oil. Get the block as level as you can, crank it to TDC and see how much fluid it takes to fill it. I used ATF just because it was around. Same thing with the head turn it upside down and fill the chamber. You may need a little grease around the valves to help them seal. This wont be an exact test but it will tell you if there has been a lot of work done. With my setup my valves and seats were shot but the bottom end was fairly clean and tight. I figured I would get a later (better) head and have that rebuilt for my bottom instead of dumping money into the older head. Turns out that I must have non typical pistons and someone did a lot of work on the head to give a decent low compression ratio. Any other stockish head (even the early ones) would give be around 7:1 compression. Rather than getting rid of the good looking block I just ended up getting the original head redone. There was more I could have done to the head but I only had them do what it would take to last as long as the bottom. The other parts are just waiting for the next project. If your head & block are still fairly close to stock I would think about just doing the head. If the block turns out to be bad you can always move the head to another block. It does not seem like someone would bother to sleeve all 6 in an engine like that. From what I read and hear they were always fairly common. How does the cam look? Dont forget if you take the lifters out to id them so you can get them back in the same locations. Not a bad idea for the pushrods either. Were all the pushrods the same length?