Alpine951

I spent a year last year burning oil and having the oil pan start leaking. After researching on here I figured the leaking pan was due to blowby. My car has 80k miles on it. The chips I had in it ran rich last year. I got the head off today and here is what i saw on #2 and #3. I did compression and leakdown before surgery:

compression leakdown
#1-130 3%
#2- 116 17%
#3- 133 7%
#4- 135 9%

All the audible air loss on the leakdown was coming through the oiler filler tube.

The first pic is #2 and the second is #3. I havnt turned the motor yet for the others. What will happen if all I do is a ring job. I will of course pop the pistons out and measure the bore and pistons as well as the rings. I guess once I do these measurements I will know better how to approach it. I don't want to go the bore and oversize piston route. Maybe I will do it down the road. What does it mean "catch a fingernail" on the scoring. When I drag my fingernail accros the scoring I can feel the unevenness but its not like my nail gets stuck.

hosrom_951

Both look bad, #2 being especially bad, now you found the oil consumption problem.

I can just barley feel some extremely minor scoring with my fingernail on my block, so minor that you have to look really close to see the marks. If you're fingernail catches, then the scores are deep.

Replacing the rings wouldn't do any good, it looks like you need to go oversize, but only when you measured how deep those score marks and bores.

Ski

What's the budget?

Pull it and have it polished and refinished and install new rings. Understand that even with new rings, you will be over the new spec but well under the wear limit. Or, you can get new 100.5 pistons and bored and finished. Are you going to do the labor?

lart951

# 2 don't look too good. If you don't have the budge to polish and refinish a good short block could be the solution as well.

OriginalSterm

you could also try the nikasil route...

Alpine951

Whats the budget?

Not sure. probably not thousands right now. What is polished and refinished? I am not afraid to do the labor myself. It just means the car is out a commission for a good while during 2006.

Alpine951

I'm wondering if I can just clean it up, put rings in, do the rods, oil pan, and save up to do something more involved ($$$) down the road . I'll admit i don't even know what has to be done to put new rings on the pistons. I am trying to educate myself on all of this.

Ski

I'll pm a guy and see if he might be able to help.

Rings for standard bore, $110/set
Main bearings 149, rod bearings, 50, lower seal kit 169, upper gasket set 150, rod nuts 15, pressure plate bolts 15, flywheel bolts 28, pilot bearing 8. Probably add a clutch or at least the disc, check the needle bearings in the fork as well. I've been keeping a pretty good write up on Rhobs rebuild, from start to finish, would be happy to send it to you once we're through if that would help.

DanD

This is probably a good time to update a similar thread about my cylinder woes.
Take a look at the pictures on this thread.

https://rennlist.com/forums/showthre...light=cylinder

I put the engine back together with new rings and bearings 2 years ago. It had poor compression. About 120 across. When I pulled it out last month it still had about the same compression. 115 to 119. I used the car as a 3rd vehicle, driving it whever and also doing a few autocrosses. The only real problem I had was a buildup on the drain plug magnet. I would wipe it off and the next oil change it would be filled up with a pasty silver substance.

Anyway, when I pulled the head to look at the cylinders, I thought they would be wasted. Not the case. It still looks basically the same as it did 2 years ago. The thing that is most odd is that I thought the oil pan would be filled up with this pasty substance. It was clean. Very odd.

Anyway, it ran fine for those 2 years, but it was down on power.

I'll fire up another thread on my NA block project.

DanD

hosrom_951

Honing and finishing the bores with silica paste (factory finish), you could be lucky, and by just honing the bores the scores could go if they are not too deep, a rennlister here did that and the scores went away.

Ski

You can see #3 has some scratches, not bad at all, no finger nail scratch and you could just feel them with your forefinger. However, I knew if we just put in new rings that that cylinder would wear faster than the others. Rhob decided to pull it and we worked with a local machine shop here who had used on his sons Mustang Mach I. I didn't want to use him but he had the Sunnen Machine and holders, all we had to do was get the procedure, which we did from the FSM and the KS - Reconditioning Aluminum Engine guide off of either Mahle or KS (kloberschmidt) site. This did open up the rings just a bit, as the cylinder in question, new gap is .020 - .040 and this one was .046. All the other were in just under the .040, like .034-.038. Wear limit is around .080 IIC

hosrom_951

Question is, if there are bad scores on the piston(s) themselves.