#2 cylinder dead in my y block. no problems found?

i got a 59 edsel with a 292. compression test showed 90 psi in all but the #2 cylinder which blew a 30. bleed down test confirmed that it was bleeding into the crank case.

so i stripped off the head and pulled the #2 piston out of my y today. to my surprise the there were no holes in the piston, no apparent damage to the walls or rings at all not to mention any thing that would seem to cause the 66% drop in compression. i inspected the head gasket and noticed that the funky oil journal was less than a half inch away from the cylinder but did not find evidence of the gasket blowing out into this journal... basically i found nothing to make me think that it was the problem, it all looked pretty sound...

at this point i think i'm going to re-ring the whole engine since i have it this far apart. new head gasket and hope for the best, basically cover all bases.

I'm curious though if anyone has run into this or something like this before? or if anyone has any knowledge on this thing that i might be missing out on. cause really it has me stumped. what ever is/was wrong should have been pretty obvious to be giving such a terrible number.

 

If what you say is correct then the only way the air from a cylinder leakage test can get into the crankcase is via the rings.
If you had a hole in the piston you would not register any compression on that cylinder at all.

This suggests to me the rings are shot. Rings can loose their radial tension over time and particularly from overheating. Given that you have torn it down then remove the ridge in the bore hone and fit new rings.

You should also check your valves in the cylinder head since they are off and make sure there are no valves burning out or on their last legs.

 

+1 on the stuck rings or valve. Also, I used to have the same car with the same engine. Had a strange piece of aluminum (don't know what the hell it was) stuck between one of the valves and the head, preventing the valve from closing all the way. I seriously doubt that's what your issue is, but it goes to show that it could be any weird ****. Check everything.

 

were the rings free to wiggle around on the #2 piston?, may have been over heated and took the tension out of the rings.

 

yeah it had been sitting for who knows how long. I'm guessing 10-15 years since it was regularly driven. who knows how long it was out ran till i bought it. then I've been driving it for almost a year with a dead cylinder.

the heads looked ok. but it was definitely leaking into the bottom end so it was not a head issue.

 

it did not smoke, it did not seem to burn oil.

the plug in that cylinder actually seemed to show a slight lean condition.

however it did have some blow by, I could see it from the dipstick tube.

 

Put a bore gage in that hole to make sure it's round. JC

 

i removed the one piston from the bad cylinder. there does not seem to be a ridge, anywhere. the wall is smooth as gl***.

i have not measured the cylinder as of yet.

 

It's hard to believe 30 psi and all of it going past the rings..and not seeing anything MAJOR wrong.

Are you positive that there was no leakage at that exh valve, as well as going to the crankcase? Honestly, I pull the valves on that cyl. Simple to do and worth it.

 

I never had a problem with it over heating. but that doesn't mean it didn't have problems before got my hands on it...

honing and throwing rings in it does not bother me, actually I'd be happy just to keep from boring it...

 

yeah, I'm going to take the head to the shop tomorrow and have them check it out, just to be sure. but they looked fine to me.

 

any possiblity that all the ring gaps were lined up?

 

Sorting the wheat from the chaff. One step at a time. We're not fixing it yet, just diagnosing.

Glaze is good, that's normal. No ridge is also good news. No need to remove any more of the pistons, those readings are good.
Remove the rings from the piston you have removed, you will never need them again no matter what you do. Clean the top of the piston carefully to determine the size of the bore on ALL pistons. Look for a number, like .010, .020, .030, .040
If it wasn't burning oil it makes no sense to do the entire motor.
Measure the bore, top and bottom of ring travel(glazed), and again 90 degrees from first measurement, top and bottom.
Come back with the measurements.

 

Dude i found this out the hard way too same exact problem did a bunch of research found out that head gasket was up side down cutting off one of the cooling p***ages this caused the heat which made the rings lose tension and caused compression to be pushed past rings into crankcase and out roag draft tube!!! Now have several articals on y-block rebuild and they both point this problem out. Trouble is that head gaskets are all most always one color on one side and another on the other ,so most people put them on with same color up or down not kwowing that it will close off a cooling p***age. Can make articale availible to you if you want has other little known secrects on making y-blocks oil better for long life and for high hp motors the maestro 937-835-3349 937-609-2290

 

this happened to you on the same cylinder? (#2 using ford numbering?)

if you have the article I'd be interested in checking it out. can you email it?

i was planning on buying the y block book before i started putting it back together mostly because i need the torque specs for the rod and head.

 

i would say it would be very difficult to look at piston rings and tell they are good or bad.

you should see the **** some people get away with, .005 taper, .010 cylinder wear, pits in a cylinder wall, out of roundness. so if it is a bit, just hone it and put a new set of rings in it.

rings or a valve is not seating. usually a good head shop will have a little vacuum pump to pull vacuum on each individual port, it will point out a problem in a real hurry.

JEFF

 

XNoctemNacimur ya the very same and yes i will try this here computer thing is a new trick fdr this old dog!!! or find march 2002 rod & custom how to get vintage power also ford builder august 2005 y-block perf. build up

 

XNoctemNacimur you can call me here in ohio 937-835-3349 937- 609-2290 maestro

 

did you by chance do the leak down more than one time?

 

I can believe that; I've seen it happen in auto engines and have had a real "up-close and personal" experience with it in an aircraft engine.

 

Only because the valve wasn't closed the first time lol.

We pulled the valve cover to be sure it wasn't something weird where it was leaking from the cylinder to the valve cover to the crank case. It was definenately leaking to the crank case.

 

I'll try to track these issues down after work tonight.

Honestly this makes the most sense to me.

However I looked at the gasket and it was installed with what was marked as front installed correctly. And as I flip it over the one difference I see is one p***age is blocked or unblocked but its toward the outside (front or back) of the head. So its wouldn't seem to effect the #2 cylinder.

 

Is the cam OK? opening the valves all the way? valve springs OK?

90 psi on the rest of the cylinders sounds a tad low....

 

Its a stock 50 year old motor (though it looks like its been rebuilt the bearings on the rod showed no scoring at all which also supports the head gasket theory) its not the higher compression heads either.

 

i got the rod and custom on its way i cant find the ford builder though.

 

I checked in one of my old National service manuals and the compression pressure for a 292 should be 155 for the 8.0 compression engine an 160 for the 8.4 compression engine.

I'd highly suggest doing a full rering job and having the valves at least checked out.

 

that was the plan, thanks for the specs though.

I've heard of a couple Ys running well at 90psi.

i had the one head i have pulled checked out, he said the guides aren't bad, and the seats seal but they aren't hardened so if i were to do the seats might as well do it all. though nothing would stop it from being a good running motor if i just slapped it together as is, though the seats will eventually be a problem.

if I'm going to spend the money on seats and a valve job i want the higher compression heads.

 

sounds like it's been answered, so I'm gonna jump on the bandwagon.

check the bore to make sure it's within spec so the pistons don't rock. if it's good, through a bottle hone it to knock off the glaze. Re-reing the pistons and drop them in. Be sure to get file fit rings and fit them to the bore. using the piston to get them square.

bolt it up and enjoy you new V-8 instead of your old v-7.5

 

I have some interest in this thread. I recently bought a Lincoln 317 Y block and the person I bought it from said it had a dead cylinder, curious if it is #2 cylinder. I am planning on tearing it down soon, so I may find something to contribute to this matter.