Hey-
Sorry if this message is getting posted twice. I don't think it worked the first time.

I'm rebuilding a 225 on a 73 Scamp and would like to know first of all what you think is wrong, second of all I'm having a minor problem with the rebuild itself.

Some background. This is a low mileage engine, ~30,000 miles. I am having a problem with the engien burning a LOT of oil, like a quart every 200 miles. The oil also gets very BLACK within about 300 or so miles. Some history on the engine:

The original owner only drove the car on short trips around town, about 1000 miles a year. I have maintenance records that indicate that the oil was changed yearly at about 1000 miles.

I am using the car for shows, so I do mostly interstate driving with it. Early on, I noticed the engine burned a quart of oil every 200 miles, and that the oil turned very black rather quickly. I began doing oil changes every 500 miles or so (10W-40 motor oil). I also noticed qa problem with blowby. The oil filter would get coated with oil from fumes backing up from the breather.

I figured frequent oil changes + highway driving would eventually resolve the engine's oil burning issues, but it has not. I forgot to say that this engine runs GREAT and has good compression.

At first I thought it was the valve seals. I replaced these, and when doing so, I noticed a lot of black gooey crud all over that I needed to clean out- all over the rockers and all that.

New valve seals did not help things. I thought fuel must be getting into the oil, so I first rebuilt the carb in case it was running rich, and later replaced the fuel pump (in case the diaphrgam was leaking).

This did not resolve things. I finally decided a rebuild was in order, thinking that the oil control rings must be plugged with debris. I now have the cylinder head and oil pan off. The oil pan had a lot of burned on crud but not lots of sludge like I might have thought.

Here's the problem. When I go to take the piston and connecting rod out through the top, there is a little lip of metal on the bottom of the rod that prevents the rod from being pulled through the bore. I assume this is not normally a problem?? What do I do about this, grind it off? I don't have a lot of clearance to do that if I needed to.

I have one piston out far enough to see the rings. Neither the compression rings nor the oil control ring are stuck on the piston like I would have thought. Also, the oil control ring is NOT full of debris like I would have thought!

I don't know what to think at this point, since none of the problems I thought existed are there. I'm going to do a re-ring anyway, since I did all this work already. But I can't hone out the cylinder unless I can get the connecting rod out of the bore, and I don't know what to do about that.
I don't want to proceed with the other pistons unless I can figure out what is wrong with the first one.

If you have any thoughts or ideas I'd appreciate hearing them.

Thanks,
Scott

What you're saying doesn't really make any sense (not that I don't believe you.) The crank end of the rod is small enough to easily pass through the bore unless something is terribly amiss. If the crank is not turned so that the throw is directly under the bore, or close to it, the rod can be difficult to extract. Could that be your problem? If not, perhaps a picture would clear up the mystery.

As for the cause of your oil consumption, a clogged PCV valve can do that to you and you're describing a lot of the symtoms of that.

_________________
David Kight
'62 Valiant Signet, White
'98 Dodge Dakota
'06 Jeep Liberty

Growing older is unavoidable but growing up is strictly optional.

That HAS to be it. Just turn the crank. If not it. You have a strange engine

Ok, I will check to make sure the crank is centered properly. I hope that's all it is. And you're right, it doesn't make any sense.

Though I have done top end work on engines before, this is the first time I'm attempting a re-ring. Whenever I try something new, I always seem to run into some kind of unusual problem.

By the way, I have checked the PCV valve before and have replaced it, so I made sure it was not something like that before doing something as major as this.

I've had this problem for YEARS now, and only now concluded I had to do a rebuild. I've done many, many things to the car to make sure it was not something simple. e.g. tune ups, adjusted the valves, carb rebuild, etc. I would never undertake something this major without checking the simpler stuff first.

Thanks.

The PCV hose and PCV inlet in the carburetor & manifold can also get clogged with deposits, causing these symptoms. Best thing would have been to check with the engine still running that there was plenty of suction and air flow through the PCV valve, running with the PCV valve pulled out of the valve cover. Otherwise, if the engine had ever overheated, the piston rings could have lost their temper, but still seem good otherwise. Sometimes if an engine sits long enough without being run, some rust forms on the cylinder walls, then you get a big oil burner even without much apparent cylinder wear.

_________________
1964 Dart 225 1966 Valiant 225
1966 Dart 273 1966 Barracuda 273
1969 Dart 225
'64-170 engine '66-170 engine
(two) 198 crank/rod sets in custom-fitted wooden boxes

wooden motor scooter with hybrid-electric drive

I used to work in a wrecking yard and saw alot of SL6 engines in the same condition. They would come from some older person who either never drove it or if they did never over 35 mph and just around town.

I would add a couple of quarts of transmission fluid and let it idle for several hours letting it smoke. If the rings were good the smoke would stop and things would clear up after a few oil changes. Change the thermostat so it gets up to temp to clean things out. Take it on a long trip (more than 2 hours) to get it up to speed and throughly warmed up. It will clear up and oil consumption will go down and possibly stop.

I have done this to several motors. If tranny fluid seams to much of a shock or you don't have the time, throw in a quart of Rislone and drive it. It will do the same thing, but will take longer.

Good luck!

_________________
Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

I'll bet you'll find your oil rings are clogged with so much crud they no longer expand. Short trips are murder on engines.

I'm sure the PCV system was working, as it did have good suction from the valve when I disconnected it from the valve cover.

I had tried putting in one quart of trans fluid in place of one quart of oil a few times when I changed the oil. I didn't try using transmission fluid alone as I would have thought the viscosity of the stuff would be too thin.

And in fact, it WAS an older person who hardly ever went over 35 mph and hardly ever drove it.

I never thought about cylinder walls rusting from lack of use, but I suppose that could have happened.

Well, I will have to check the other pistons to see how they look.
Thanks.

I ran a mix of oil, not all transmission fluid. Also, this was done in a no load situation, idling only, no driving. The new tranny fluid is pretty good as a solvent and will clean out the holes in the piston behind the oil rings over time. Once the rings are unstuck so to speak they will start to seal again and the compression will come back. You may have to flush the motor (repeat the process) several times to bring it back to life. It is worth a shot and is very easy to do short of a total rebuild.

_________________
Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

You pulled out the pistons out, and the rings looked fine, right? What about the cylinder walls? I don't know what glazing looks like, but maybe they need to just get a quick hone?

Can one reuse rings in this case, or is it SOP to just replace rings in this case?

The cylinder walls look OK to me.
I think a quick hone would help.

I don't think you are supposed to re-use rings once you've hoend the cylindes, even a little bit. I think you're supposed to put new ones in.

Rings are so cheap compared to the effort required to change them that it makes no sense to try to reuse them even if you could.

_________________
David Kight
'62 Valiant Signet, White
'98 Dodge Dakota
'06 Jeep Liberty

Growing older is unavoidable but growing up is strictly optional.

OK! I was able to get the rod and piston out.
I think the rod was slid too far over on the wrist pin, and it got stuck in the cylinder bore. I got the piston out now.

So far I have 2 pistons out. #5 and #2.
#5 is just fine- looks normal in every way.

But guess what happened with #2!!
The top compression ring was BROKEN!!!

How does a ring get broken in an engine?
Could that cause the excessive blow-by?

I'll have to get the other four pistons out tomorrow night and see how they look.

hi,make sure that there is no ring ridge at the top of the bore. you will break the rings and/or piston ring lands trying to push the pistons out of the block. ron

OK!