ok, this has been racking my brain for a while now. Unfortunately its winter here where I live so my car is down for the time being. Any way, when I tore my engine apart I had a bunch of vertical scratches up and down on the cylinder walls. At first I thought it was tuning. So I honed and reringed the walls/pistons, and made sure I tuned imidiately after start up. A/F ratios were great. mid 13's at WOT and 14's at partial throttle. I have since tore the engine apart again and the lines are back again. some of them can catch your finger nail. Now Im not using this block this season, so I not too concerned but I would still like to know wtf is going on here. YES THE MOTOR BURNED OIL. about 1quart every 1k miles.

possibilities:

1. molycoating rubbing off skirts from over expanding pistons (but I was tuned).

2. cylinder is outta round. (nope, checked that before the rering)

3. pistons are outta round.(nope, new topline itr cast pistons)

4. cylinder wall is outta spec.(nope, checked that also before/afetr rering/hone)

5. rings are gapped too tight/or loose (nope, i checked that also)

6. rings are installed incorrect/ or spaced incorrect (nope, made sure perfect).

7. Tons of detonation (nope, spark plugs show or piston tops show no signs, rod bearings look great)

8. EXCESSIVE OIL/CARBON DEPOSITES ARE GETTING LOGGED IN THE RINGS/CYLINDER WALL AND CAUSING VERTICAL SCRATCHES.

Ive been thinking long and hard about what it could be. My leakdown numbers were great and compression numbers were very consistant with each other. When I was playing with the carbon buildup it almost felt like dirt. Almost hardened, and I cant help but to think thats whats going on here.

sorry for the long post, but all opinions are welcome, and hopefully this thread can be used to help other H-T members trouble shoot there oil buring/cylinder wall scratching problems.

 

up for some ideas.

 

I know you have already excluded these possibilities but I am going to ask anyway....

1) What was your ring gap set at- all three rings

2) What was your wall to skirt clearence?

3) Where did you place your ring gaps?

 

honestly, I dont remember. I made sure everything was to spec with my helms manuel/ or manufacturers spec. The ring gaps were positioned just like helms said. I used hastings rings when I reringed it and they were real good. I remember them being in spec. Honestly though, I dont think I checked piston to wall clearance because if anything it woulda been lose since I rehoned. Also because the ring gaps were perfect in spec.

 

piston/wall clearence

overheating will cause piston/wall issues, but if its too tight, itll have issues from the get go. can u get some pics, and show us some of the scratches.

 

How about good old dirt.Does it still have the stock air box.Some of the aftermarket air cleaners are very coarse.Ive driven on some of your dirt roads and I've found that red clay silt in my car everywhere.
Glenn

 

im always thinking of the more complicated stuff first

 

yea, I am interested in what you find out. about 65K ago I put in a new ITR block and another GSR head in my car. I waited 1000 miles to get into it. I babied it for 1000 miles. As soon as I got into it, I saw that the motor lost oil almost immediately. 2-3 quart per oil change and it got progressively worse. now, I burn a quart every 800-1000 miles depending on my habits. I plan on tearing into my motor as well to see whats going on in there. I hope everything goes well for you man. please post pics as you progress

 

ill try to get some pics, but its gunna be hard to get the scratches to show up. I ran a velocity stack at the track, and a cone style filter on the streets. The problems that I speek of were imidiately after turn key. Like I said, to avoid any kinda over heating/expanding I maid suer i tund it witha a wideband the next time I started it. That time the oil burning was alot better from the original.