Opinion on cylinder condition (1 Viewer)

[nagrom46]

Well it all started when I wanted to get this engine leak free and baseline it. Now I have a stripped down block on an engine stand. Funny how that happens.

Anyways, this is the deepest I’ve gone into engine work. I wasn’t planning on going this far so I do not have any compression numbers, no knowledge of oil consumption, or completed any leak down tests. I’ve driven the cruiser approximately 10 miles before surgery began. Seemed to run just fine.

Here is what cylinder #6 looks like. #1-5 look great.

Seems to be excessive carbon build up/staining. Looking for education regarding this so I can further my knowledge.

 

[JoeCova]

@Fj80oregon might know, he rebuilds these a lot

 

[cahill]

I am here to learn too. It looks kind of unevenly scored and shiny about 1cm from the I very top and maybe a little pitted lower down on the left side of the cylinder wall. I am not knowledgeable but that is what stands out to me.

 

[Broski]

First it would be helpful to know what motor we’re looking at.
On my 1FZ at 250k miles all the factory hatch markings were still present. With no lip at the top of the cylinders.
I’m no expert but it doesn’t look good.

 

[nagrom46]

That would be helpful. 1FZ. 218k miles.

 

[Rusty Marlin]

The cross hatching is gone and cyclinder is glazed.
I would say, that cyclinder, it needs a hone at minimum or the block needs a bore out to the next piston/ring size.

 

[nagrom46]

Any idea what would be the culprit? Head gasket leak? I’m pretty sure the truck sat for a very long time

 

[Broski]

Most likely the rings were frozen to the piston

 

[Fj80oregon]

This is what It should look like, that’s a bored out .50mm bore. That cylinder needs to be bored. Yes you could maybe hone it and clean it up but why risk it? Now’s the time to do a full rebuild get .50mm over pistons and all new bearings, deck the block, get new timing components and rebuild the head. Probably looking at 3-5k. The glazing ( no cross hatching) is caused by lack of oiling and you rings getting worn out or stuck and not moving freely.

 

[Fj80oregon]

Keep your pistons and bearings in order as you disassemble each bearing is specific and has a number marked on it for that journal.

 

[manofthewoods]

Any idea what would be the culprit? Head gasket leak? I’m pretty sure the truck sat for a very long time

A good formula for rust. Iron, moisture and time.
Have a trusted engine machinist look and measure. I'm betting a hone won't be enough on that cylinder.
Lucky you (seriously). You are on your way to a "new" engine after the rebuild is complete. To quote Martha Stewart, "it's a good thing."

 

[Broski]

Most likely the rings were frozen to the piston

 

[manofthewoods]

Keep your pistons and bearings in order as you disassemble each bearing is specific and has a number marked on it for that journal.

EXCELLENT posts from a man who knows. On mine all rod and main bearings were the same - easy peasy.

 

[nagrom46]

Appreciate the information. I’ve got it all organized and plastigauged all bearings. All looked good and in spec. I’ve already purchased all seals/gaskets/timing components/hoses. Was about to purchase new bearings until I discovered the shape of this cylinder.

Shame as the closest machine shop is 3 hours away.

 

[DIRTBIKEUSA]

Let’s see the piston!

Check your piston for wear as this will tell you how it was riding in the cylinder. If there is HEAVY wear anywhere on the piston, call your machinist..if not and the the cylinder isn’t gouged or damaged from broken piston/valve/ring.. You can de-glaze it with a spring hone and cutting oil and cut in some new cross hatching with a ball hone.

Take some measurements after all that and see if it specs out. You will need some t gauges and micrometers but you might be able to borrow them. It will be fun.

 

[nagrom46]

I’ll get some photos tomorrow. I removed the rings and cleaned them up tonight. All rings were free. No real visible damage that I can see.

My next step was to take measurements as per the FSM. I know that’s a specialized skill in itself but figured I’d give it a shot.

Been really enjoying this process

Appreciate the input!

 

[Kernal]

@nagrom : What can you feel when running your fingers over the cylinder wall? A few areas appear to be pitted.

 

[nagrom46]

I believe you are correct. Initially I thought it was excessive build up but after spending some time cleaning it, there is pitting that I can feel.

 

[DIRTBIKEUSA]

I’ll get some photos tomorrow. I removed the rings and cleaned them up tonight. All rings were free. No real visible damage that I can see.

My next step was to take measurements as per the FSM. I know that’s a specialized skill in itself but figured I’d give it a shot.

Been really enjoying this process

Appreciate the input!

Good man! Take your time learning the techniques and you will be good to go.