Replacing Piston rings in car

[rockin86ranger]

My friend has an 89 festiva that has bad blowby on the #3 cylinder. How much hassle would it be to replace just the piston rings on the piston in the car. Can you just drop the oil pan and pull the piston out the bottom and then reinstall it from the bottom. How long should it take to replace them?

It is just a car to get him around town in to save gas and he doesn't want to do a full rebuild. If he doesn't want to fix it I might buy it and replace the rings myself and sell my other Festiva.

[newcomb]

I have always put the pistons back in threw the top with the compressor (easiest) and you cauld drop the pan and pull jead and do that way it cstelle had a set of piston and rings for 25 bucks brandnew and u buy the oil pan gasket and upper gasket kit you would be in good shap probaly set you back around 100 bucks

[jjk1224]

You cant pull the pistons from the bottom, the structure of the block prevents it.

[Festiva_Fred]

Yep, only way they'll come out fromt the bottom is if you pull the crank out first...

[rockin86ranger]

That's what i was afraid of. I don't want to mess with pulling the top end. If i went through all that trouble i would just swap it for the motor in my parts car.

[Movin]

Not even with the crank out..the bore is champhered at the top
and the bore has obstructions to facilitate pull through out the bottom.
The champher makes it possible to compress rings and install from
the top, not the bottom.
Pretty much standard for all engines.

[Christ]

^^^That

I've only ever worked on two engines that you could pull the pistons through the bottom, and one of them was an insanely large boat (think cruise ship) engine, the other was a steam engine that was hand built by the owner.

There are always obstructions because there's "meat" there that's meant to keep the cylinders from flexing at the bottoms due to pressure on the main bearings from side-loading the crank (along it's spinning axis). On some engines, you can pull the crank and swap rods without pulling the head, but only because there's enough clearance and the gudgeon pin is low enough that the piston will come down and you can expose the pin by turning the piston in the bore. Again, those engines are few and far between, and I've never seen one for automotive use.

[blkfordsedan]

Chances are, if 3 cylinders hold good compression and 1 cylinder has bad blow-by, just pulling the piston out and putting in new rings probably wouldn't fix it anyway. Good chance it has a broken piston, worn cylinder walls or will need other attention. Pulling the head (or entire engine) would be less hassle in the long run, IMO. Good luck!

[htchbck]

In my experience a B3 with decent comp on all but one cylinder usually has a burnt valve. What makes you say you have blowby on #3? Have you done a leakdown test?

The last B3 I worked on that had low comp on #3 was due to a burnt exhaust valve. Which means pulling the head anyway. Its not terribly complicated to do on these engines though... to me pulling the head is easier than pulling the oil pan, at least with the engine still in the car lol.

[rockin86ranger]

I have not even seen the car, he is telling me now that the engine blows oil out of the #3 cylinder. Like i said not really wanting to put a lot of time or money into it, he got it hoping it would have a decent engine in it when he got it running.

[htchbck]

Go look at it if its not too far away, and do a compression check on it. That will tell you a lot. And maybe ask him where its blowing oil of of cyl 3? Is the spark plug out of it? Or the exhaust manifold off? Hard to tell which cylinder is blowing oil unless something is taken apart.

[WmWatt]

I was wondering about that myself. Had low compression on #3 and it was carbon buildup on the exhaust valve. Fixed with chemical cleaner. How I knew? Carbon deposits on underside of valve cover over #3.

[rockin86ranger]

He said it blows oil out of the exhaust on number three. It is only about fifteen miles from me but after working seventy hours a week i don't really feel like looking at another project. I think i am fixing to trade my festiva in on a 74 ford f100. I tried to sell him my parts car but he b didn't want to put that much time into it. It needs all new tires too.

[htchbck]

Wow, you don't want another project, yet you are taking on a '74 F100? Unless everything plastic and rubber (esp fuel/brake lines) has already been recently replaced I'd think that might be more of a project! Not knocking the old F series trucks I love them, just saying something that old usually becomes more of a project than it seems starting out... that truck is pushing 40 years old now. Best of luck to ya whichever way you end up going!

[Christ]

I got lucky... my 78/74 F150 4x4 sat in a field for 10 years and started on the gas that had been in it the whole time! The tires even held air when we pumped them up, and they're not terribly rotten!