Pulled the heads. What's is supposed to look like inside?

[UNGN]

I pulled my motor out today for head swap, timing chain and rear main seal. Unbolted the heads and it took almost exactly 65 ftlbs to break the bolts free. Stock Head gaskets looked like they were sealing perfectly. Heads were 100% stock and unmodified in anyway, so 118 mph with a TA49 and bluetops doesn't require any motor mods.

Since I try not to make it a habit to tear these things apart, I have questions about the look of the cylinders, pistons, etc:


The pistons have a slight dish and have a rough texture on them. I'm guessing it deposites of some sort or the piston tops melting is this normal?

The cylinder bores have a smooth feel, but are dull in appearance and are "dry" rather than oily. Is that normal?

when the piston is down in the bore, I can see a lot of ring. I mean a lot of ring, like 1/16th of an inch around the piston. Is that normal? The rings are shiny and the pistons are dull so maybe I notice them more, but it still looks weird to me.

Thanks for the help.

 

[REDS HOT AIR]

sounds about right...

for seeing so much ring the piston is smalle from the top ring up and half of what your actually seeing is the reflection on the cyl wall too making it look like more that what is actually visable.

stock pistons that ive seen have a alil hole in them on the surface not very deep but you might have to clean then since the holes are probly filled with carbon.

 

[FJM568]

1. pistons...yes, they will look a little rough...

2. cyl. bores...smooth...Can you still see any crosshatching in the cyl walls??? How many miles on the motor???

3. yes, the top of the piston above the top ring is smaller than the skirted area by the pin and below, so you will be able to see the top ring...

All in all...sounds normal to me...

 

[UNGN]

Originally posted by REDS HOT AIR
stock pistons that ive seen have a alil hole in them on the surface not very deep but you might have to clean then since the holes are probly filled with carbon.

I saw that little dimple and went "crap!" then I saw the other 2 in the same place and was relieved.

I didn't see crosshatching, but I did see a rusty area in the bore near the top in one cylinder bore. The original owner of my car burned an exhaust valve when a splitfire sparkplug electrode broke off and bounced around the cylinder before coming to rest on the exhaust seat. I'm guessing that the rusty area was damage caused by the electrode. It's 8 years old and the car burns no oil so the damage stays.

I knew one head had been off the car when I bought it (why I got it for so cheap) and I thought maybe they did some head work while it was off, but all the as cast ugliness was still intact. They did port the headers when they had the cracks welded so that was a lucky surprise for me that will save me an hour or two.

So for a 95K motor this sounds about right? that makes me feel better. I'm curious to see what the timing chain looks like. Anyone want to guess?

Thanks for the help.

 

[Ken Cunningham]

The tops of my pistons were covered in crusty deposits. I cleaned them up (still in the block) with a Dremel-type wire wheel. I was overjoyed to see the original concentric circles on the tops. In other words, the pistons had _gained_ material, not _lost_ material. BTW, if you choose to clean up your pistons like I did, be sure to cover the rest of the cylinders and the lifter valley when you're blasting off the grunge. I did not do this and cringe when I think of all those deposits going up into the air, then settling down into the valley. I cleaned it up as best I could, but prevention would have been a better way to go.

 

[pracingrev1140]

timeing chain

hi itook my 90,ooomile gn down for a timeing chain change and was surprised to see that it it looked new i mean no stress cracks no teeth missing or any such wear i must say iwas impressed the car did come from kirbans so i wouldnt wear to much about your chain being too bad good luck RR

 

[UNGN]

I got a better look at my pistons today. A large chunck is missing from the #6 piston (about 1.5" long circumferencially and tapering from no wear to about 1/16" missing at the greatest point) The head has some corresponding marks in the shape of splitfire spark plug electrode. These motors can take some abuse as it was done atleast 8 years and 400 drag strip passes ago. The rest of the pistons look fine. I guess I'll start gathering parts for a full rebuild when it desides to let go.

 

[salvageV6]

Both my cars had brand new looking timing gears, and decent chains.

112K and 123K respectively.

I think the oil was changed regularly that should help.

Let us know.

 

[Toady]

UNGN, I did my headgaskets almost 2 years ago. This was before I knew to check for little things like deteriorating y-hoses...it's amazing how much boost the stock turbo can make when one of those hoses lets go on an on-ramp...

I have some pics of the top end when it was apart. I'll try to scan them at work tomorrow and send them to you. My motor was at 155k at the time. Other than carbon build-up on the piston tops and lifter valley, it looked brand new. The crosshatch on the bores was plain as day. Lifters and cam looked very good. Sounds like you're in good shape.

Side note: I took my heads to the shop that did Ryan Guy's motor. The owner asked if I wanted to have the same CNC program used to port Ryan's heads...man, if I'd had the money!

 

[Toady]

The pix didn't have enough detail of the cylinder bores...

 

[1badTTA]

UNGN, Sounds exactly like mine when I pulled it apart with only 36,062miles I blew a headgasket and looked down the bore at a piston that was missing the edge from about 9 O'clock to 6 O'clock, it was rounded and rough instead of being machined square. I did go ahead and change pistons to TRW forged (for a GN which raised my CR to 9.27) but looking back, I could have left it and still slept fine at night. The damage is caused from detonation. Just like everybody else, it was the back cylinder from running leaner than the rest. Guess I need the RJC power plate

 

[HEROTIME]

UNGN
Sounds like its all good inside, be glad you didn't get a suprize like me. Block bored 60 over and a NON Turbo crank
I got a new engine on the way, I'd like for you and Mitch to come over and help me out. Could be good practice for you as well
Later buddy
Frank

 

[UNGN]

Got to my timing chain tonight. Three words... Like Brand New.

I guess mobil 1 since new really works. Now a few days of parts cleaning and scraping gaskets and then I can think about slapping it all back together (I just have to do it before I forget where everything goes...Oops, too late.)

I made some pretty cool tools:

Styrofoam egg cartons make great places to store your lifters in order. Close it up, put it on a shelf, flip the motor over on the engine stand without fear of lifter dumping disaster.

Make two, 22" long pieces of 1" pvc water pipe, Drill two 3/8" diameter holes, 20.5" apart. Saw it down the middle, perpendicular to and past the holes, making about 3" of "half pipe" on each end. Have the two half pipes be on opposite sides. Now unscrew and replace your hood shocks with these and the hood will remain almost vertical and hoisting the motor out is a snap.

For removing the front shocks don't waste ANY time trying to use a tiny 1/4" wrench on the shock shaft... Instead, add two more nuts to the shaft, bind them together and use a wrench on top "bound" nut and one on the shock nut to loosen and remove the nut. With rusty or air rachet installed shock nuts, you'll break every 1/4" wrench you have and the nut still won't budge if you try to use the shaft. Ask me how I know