[steve25]

Once again let me repost what the info that the op posted up, that being that he hears air going into the crankcase when he does a test for leakage.

So why then Half Inch Stud could his issue not be a broken ring in your mind?

It does not take ping or knock to crack a ring , too little ring gap causing them to butt up will crack them also!

[Firebob]

Ah! Marvel Mystery Oil. I saw it on the shelf at the parts store when I was looking at all the rest of the snake oils. It could very well have broken rings. I would imagine the comp would be a whole lot lower if it wasn't blowing by so much oil. But like I said, so few miles put on a year it's hardly worth the effort until things become dire.

[steve25]

If your loss of compression is due to a broken second ring then whenever you run the motor its making more and more damage to that cylinder wall.

I would find a machanic / repair shop that has a Bore scope and have him look in the plug hole to check for scratchs now before you find that you need to sleeve that cylinder.

[track73]

In my experience with broken rings I have seen compressions of 30 psi or less. Not 125. But that's me.

[Schurkey]

Originally Posted by track73

In my experience with broken rings I have seen compressions of 30 psi or less. Not 125. But that's me.

Thank you.

At 125, that cylinder should still run. I had an 80 psi cylinder on my boat 454 that ran. My step-nephew had a 400 Ford with a cylinder at 50 psi, dead at idle, but ran when the revs came up and the throttle opened.

[hurryinhoosier62]

Originally Posted by Schurkey

Thank you.

At 125, that cylinder should still run. I had an 80 psi cylinder on my boat 454 that ran. My step-nephew had a 400 Ford with a cylinder at 50 psi, dead at idle, but ran when the revs came up and the throttle opened.

X 2. Broken rings normally indicate by blowing air into the crankcase during a differential compression check. 125 most likely indicates a ring that has begun to lose its seating. MMO should help take care of this.

[Firebob]

I'm going to check the comp next week and see if anything has changed from the 125#s I got before.
Shirley, the crankcase is where the MMO goes correct? How many ounces? Maybe a pint of it added to the fresh oil change?

[Schurkey]

Originally Posted by Firebob

Shirley, the crankcase is where the MMO goes correct? How many ounces? Maybe a pint of it added to the fresh oil change?

https://www.youtube.com/watch?v=Qo7qoonzTCE
And don't call me Shirley.

I don't think I've ever used MMO. I imagine it's just like Seafoam.

[racegto65]

I did the bonami trick years ago on a Ford 292 Y block that had sat for years and smoked like the devil.
I actually used a small eye dropper and put it straight in each cylinder.
The smoke actually stopped after putting some miles on the car.

[hurryinhoosier62]

Originally Posted by Firebob

I'm going to check the comp next week and see if anything has changed from the 125#s I got before.
Shirley, the crankcase is where the MMO goes correct? How many ounces? Maybe a pint of it added to the fresh oil change?

MMO goes directly into the crankcase. One quart per oil change. It can be used in the fuel system. Add the required amount listed on the bottle into the fuel tank. I’ve seen many engines that had a simple case of stuck or rings that have lost their seating have restored static compression after a treatment of MMO.

[Firebob]

Ok so I check the comp in the one cylinder that was at 125 before running a whole can of Seafoam down the carb, changing the oil and adding some rislone oil additive that is supposed to aid in reseating old rings. Put about 300 miles on it during the weekend drive. Rechecked that cylinder a couple of days after we got home. No change in compression. Still reads 125. (Surprise)
I may give the mystery oil treatment a shot at some point but I'm not holding out hope for any miracles. As it is it runs fine so basically I'll get me where I'm going and back. I'm not overly thrilled but I'm no worse off than I was. Just wanted to post the update because I said I would.

[steve25]

Sorry to hear nothing improved for you, but like you said it was worth the try!

[Firebob]

Yeah I was able to figure out that one of the intake gaskets had slipped out of position( still not sure how that happens) and created a vacuum leak. Found it with some carb cleaner spray. New gasket and it runs a lot better so that's a happy thing. I'll live with the other issue. It's only about a 20% loss in comp in that one hole. Not tragic.
Thanks for all the suggestions.

[HWYSTR455]

Leave some MMO in the crank case and put some miles on it, it may just take more time.

On a positive note, if you have the means, could rebuild, and then know what you've got. And how long you will get it to last.


.

[HWYSTR455]

So just to say, MMO is a detergent, and removes build up, rislone is also a detergent, but it's not as aggressive as MMO. Or as thin.

In the 'day', a pint of ATF used to be a good substitute for MMO. The detergent package is roughly the same.

Only thing I've even seen as a side effect of using ATF is that it can make seals grow. Never had that issue with MMO tho.


.

[jamaca85]

i dont think anythings going to work. i would leave it alone. you only drive it 1000 miles a year. but if i owned it i would tear it down and fix it. its always good to have a fresh motor and no worries down the road.