A burr on cylinder #4.

[Geeshik]

Today i was cleaning up the deck of the engine for my new heads, and after i got all the rust and old gasket material off, i found a few little flecks of metal stuck to the top edge of the cylinder wall. This piston had a whole lot more carbon built up on it than the others, and because of that, i am pretty sure the rings are shot. As far as i can tell, the little ridges are just on the top part of the cylinder.

Is this as bad as i think? i'm worried that i have to get a junkyard engine now. What do you guys think? Here are some photos i took of it tonight. The fluid in the cylinder is WD-40. i used it with a scotch brite pad to get rid of the surface rust that was on everything.

 

[killacal]

From the pictures that looks like a very mild case of piston ring ridge. It's hard to tell from the pictures, but it doesn't look like the cylinder walls are scored, and hell I can actually see the cross hatches in that close up picture. I think that you're worrying too much, everything looks ok.

 

[Sevensecondsuv]

Yeah it looks like piston ring ridge. Autozone will rent you a tool that gets rid of the ring while the pistons are still in the cylinders. I used it when I put new heads on my 4.0 at 165,000 and it worked great.

 

[Geeshik]

Ridge reamer.

Is that tool called a ridge reamer? i have one somewhere, i guess i have to find it. i've had it a while, and i've never had to use it.

So what causes the burrs? Is it left-over material from the piston rings? If it is, then the rings are shot anyway, right?

 

[rurouni20xx]

ring ridge is caused by wear on the cylinder and the rings dont travel up that far, it is essential that you remove this ridge because when a ring hits the ridge it will break the ring. broken ring fragments and poof theres the cylinder and that goes into the oil pump ruining the motor. just clean up the ridge and youll be fine, just be thankful you caught it b4 something catastrophic happens.

 

[killacal]

Is that tool called a ridge reamer? i have one somewhere, i guess i have to find it. i've had it a while, and i've never had to use it.

So what causes the burrs? Is it left-over material from the piston rings? If it is, then the rings are shot anyway, right?

Yes the tool is called a ridge reamer. The ridge your seeing at the top is carbon build up left over from combustion, and is common on high mileage motors.

 

[Geeshik]

Carbon?

i thought carbon was a dense, black element. Why are the ridges shiny and silver metallic? i've cleaned lots of carbon, but nothing that looked like that before.

Something catastrophic did happen. That's how i bought the truck. It had failed head gasket and a cracked cylinder head on the side with the ridge. The other cylinder bank had a badly burned valve on #2 cylinder. i'm just trying to avoid having to tear it all down a second time. (see http://www.therangerstation.com/forums/showthread.php?t=36403)

Anyway, there was probably 1/16 of an inch of carbon on the top of that one piston. It was pitted and crater-like before i scrubbed it. The top of the piston was very rough. The other pistons were very near clean; like you see in the photos. What would cause one cylinder to look like this? Is there a chance that the cylinder already has bad rings?

 

[rurouni20xx]

if the carbon is heavy and uneven theres a possibility you have a bad cylinder, the best way to know is measure the bore and check your measurements versus stock and max alllowed, if its beyond itll have to be bored. just turn the engine til that cylinder is bdc and measure the center of the cylinder. (cylinders wear in an egg shape this will be the farthest area out of round) another way to check is to get a feeler gauge and turn the crank and measure the piston to cylinder clearance that way, then divide the number in half and that is your piston to cylinder clearance you measure (say the measurement is .020, you have .010 piston to cylinder clearance) and compare that to the max allowed in the book.

 

[Geeshik]

Cylinder 4...

i cleaned all the carbon off of it today. When i was scrubbing, i noticed the piston moving around in the cylinder. None of the other cylinders moved like that. i also used a ridge reamer and took care of that metal on the cylinder wall. i remembered that when i pulled the heads off, i found that one of the spark plugs (i can't remember which cylinder) was missing it's electrode. i think that metal on the cylinder wall was the result. But at this point, i think i'm going to put it together and take my chances. This truck won't see daily use, so it's not as vital. It's mostly for 'truck stuff' anyway.

i'm just hoping that it will last long enough for me to be done with school and in my new job making big money so i can swap in a JDM diesel and convert it to a 4-door.

 

[Wicked_Sludge]

your worrying far too much. plop the heads back on the engine and drive it for another 150,000 miles.

 

[Geeshik]

i got a quick question about a dipstick. The one for the engine oil... Nowhere online have i been able to locate one, and i've had no luck with dealerships. i know from experience (i once had a 2.9 with a rusted through dipstick tube) that the junkyard ones aren't going to be any better.

i noticed that Jegs sells a multitude of dipsticks for V-8 applications. Could i maybe use one from a 302 and make it work? Does anyone know the outer diameter of the tubing used on 302s? I know i could cut and bend it to work. i just need to know if the sizes are compatible. Also, what is the measurement in length of the original 3.0 dipstick tube? i have the dipstick, and was wondering if i could reuse it.

 

[Wicked_Sludge]

if the dealership cant find a dipstick tube then id try another dealer (call around, you can always have them mail one if the dealer is far away).

i would still at least check the junkyards. dipstick tubes arent a common rust victim...so you can likely find one thats just fine.

i dont know about the 302 tubes.

 

[Geeshik]

I found it!

I went to a different dealer and was SHOCKED to see that they could order a dipstick tube. $37 at ford; a little pricey, but worth it to avoid the headache of trying to make one work from something else. i'll post the part # when i pick it up for anyone else who lives in the rust belt and is having problems with it.

Also, i lost my lower intake manifold bolts, so i had more ordered, and my exhaust manifold bolts/studs were way too crusty to reuse (the bolts and studs were almost rotted off). i was thrilled that they could order those too.

So since there are alot of people doing heads on 3.0s, maybe we could post those part numbers to help some people out in the future. With nicer weather here again, i'm excited to get this thing on the road soon.