Hey All,

It's been a long time since I've been around here. Just wanted to check in with everyone. The combination of a bunch of crazy work stuff and some serious health issues with my wife pretty much took me off the radar scope for awhile. We have 7 children between us and it was difficult to say the least while my wife was unable to do anything. My wife had surgery and after a few weeks mending she's much better.

Obviously, the truck hasn't received a lot of attention either. If anyone remembers, I had rebuilt my 390/C6 and rear end. I had it back running but really hadn't had the opportunity to really run it in yet. It turns out the engine was not right. It ran good but continually smoked. I really wasn't too worried about it as I really hadn't got to run it much. Last week I had to go out of town yet again and I drove the truck to the airport....about 40 miles from my house. It used 3 quarts of oil going up there....whew!! After running it all week it just got worse. After some discussion, I decided the rings wouldn't seat and it must be my fault because I coated the cylinder walls with assembly lubricant when I assembled the engine. I pulled the engine today. The engine was bored .060 over, new pistons and new steel rings...not chrome moly. When I disassembled, the rings were shiny like chrome moly rings, the cylinders were shiny but you could see area on the cylinders that had a healthy coating of oil...in fact the cylinders were very slippery...I wonder if the engine assembly lubricant could have been the root cause? The worst thing is that I have 2 cylinders that have score marks...one of them it really bad...I think the block is ruined as it's already bored .060 over. For now I think I'm on the search for another 390 block to put all my stuff in.

Hopefully I'll be keeping up with FTE from now on!

Tracy

 

Egad! That sucks. It sounds like you used the wrong size of rings for the bore; they'll do exactly that. Did you have any overlapped oil rings?

I do have a couple spare 390 blocks I could part with if you're interested. With shipping, you're probably better off to locate one locally though. Junkyard time.

 

I'm no expert, but I would not suspect the assembly lube. I'm with Kurt, sounds like somthing wasn't quite the right size.

Glas to hear the wife is getting healthy.

 

3rd vote for wrong size, i vote for wrong size pistons and/or rings. Assembly lub will not cause it to use oil!

the standard spec is .004 end gap for every inch of bore, so a FE needs about .016 for the top ring, the second ring can be as low as .012.

But, the oil rings are supposed to stop the oil, so i suspect that to be a problem. I know trw/speedpro have a red and black tab for standard moly rings. This lets you verify that the ends have not overlapped or anything.

When you tear it apart, measure the bore, piston width, and ring end gaps for all three rings.

 

Sounds like to me there might have been some crap in the 2 cylinder's that had oil pumping,,,Meaning some junk was in the ring lans and not allowing the rings to seat in those 2 Holes..thus cause the oil to get past them and smoke..and hence the scoring of the walls!! JMO!

Russ

 

Heck if I know what's going on. The Pistons are .060 over they are marked .060....the block is bored .060 over...the pistons fit very nicely in the bore. The rings came out of a box that said .060 over. I didn't get a chance to go back and put the rings in the bore yet...maybe that is the problem. I thought that it would have to be the oil ring that is the problem but they all look assembled correctly. How do you measure the ring end gap on the oil ring? I'm guessing you just put the outer band in the cylinder and measure the gap? I suppose it's a mute point as I think I have to change to block anyway now...still I'd like to understand what went wrong. I plan to take the whole thing over to an engine expert I know and let him take a look. I'm off on yet another business trip for a couple of days...maybe I'll get back to this before the weekend. If anyone has a complete engine built and ready to go I'd be interested at this point....I'm tired of working on it.

Tracy

 

i found out the hard way to always check your piston end gap... i bought some .060 over rings and just put them on the pistons and insstalled them.. same problem- smoked like a fire and used about 1 qt of oil every 25 miles or so.... ran the motor a total of 150 mile before i pulled it apart and had 3 slightly scored cylinders.. i was able to just hone it out though... so we can tell where my vote lays, mismarked parts.. JMO glad your wife is doing better and hope she has a speedy full recovery- best wishes..