I got a car and piston ring question. Need your opinion

Modding_out

Modding_out

#1
#1
Hey guys I wanna throw something by you.
A few months ago I rebuilt my car engine, new pistons rings decked the head cut valves. ported and polished with a port Match, lighter crank and flywheel. Any way it ran great but I forgot the check the main bearing and it trashed my crank and all bearings in the motor as well as my oil pump. So I replaced it all put a fresh crank in it and all is well in the lower end.

Now here is my problem. I didn't do a re ring after I trashed the crank cause the fresh piston rings were already seated nicely and i didnt want to disturb them. But 4000 miles later I've come to realize my oil rings are completely smoked from the main bearing failure...how ever! I have great compression and no blowby at all.

Now hear's my question.
Can I pull the head and replace just the oil rings the compression rings are still working like new. I really don't want to do another re-hone or rip out the moter. That's 2mo of work and I need it as my daily driver, if I can pull the head and drop the pan that's a weekend of work
 
H

Hent

New Member
#2
#2
Modding_out said:
Hey guys I wanna throw something by you.
A few months ago I rebuilt my car engine, new pistons rings decked the head cut valves. ported and polished with a port Match, lighter crank and flywheel. Any way it ran great but I forgot the check the main bearing and it trashed my crank and all bearings in the motor as well as my oil pump. So I replaced it all put a fresh crank in it and all is well in the lower end.

Now here is my problem. I didn't do a re ring after I trashed the crank cause the fresh piston rings were already seated nicely and i didnt want to disturb them. But 4000 miles later I've come to realize my oil rings are completely smoked from the main bearing failure...how ever! I have great compression and no blowby at all.

Now hear's my question.
Can I pull the head and replace just the oil rings the compression rings are still working like new. I really don't want to do another re-hone or rip out the moter. That's 2mo of work and I need it as my daily driver, if I can pull the head and drop the pan that's a weekend of work
Click to expand...
tl;dr

better question, why werent you at windber?
 
45t

45t

Well-Known Member
#4
#4
In my experience if you don't pull it and redo it, you'll constantly be chasing gremlins until you've replaced everything. :shrug:
 
Modding_out

Modding_out

#5
#5
Hent said:
tl;dr

better question, why werent you at windber?
Click to expand...
Haha i kinda deserve that one but do i get a pass for being a poor nursing student? :laugh: To be honest school runs on a trimester and it landed on a test week plus my dads truck is dying of old age. Hopefully i can bumm some beer from the community ice chest next year. (finally turned 21 this past march)
 
W

WLB

Active Member
#6
#6
What kind if engine is it? You mentioned new pistons, did you bore the cylinders and fit over size pistons or just put new pistons in the original bore? If you have no blowby why do you think the oil rings are shot?
 
Modding_out

Modding_out

#7
#7
Saturn sl2 inline 4. Hone and re-ring std. Bore. Compression was awesome before rebuilt at 210 stone cold. I had a hole in #1 that started this whole mess

I'm gonna run another compression test and preform another leak down test this week end. I think the oil rings are bad cause i'm burning 1qt every 250 miles. the guys on the saturn forum say that's a sign of completely failed oil rings. And my main bearing would have thrown its metal shavings right into the bores were the oils rings would have been the first to contact. To give u and idea of how much crap was in my engine the crank was worn .030" in or about a
Pennies with into the surface. and all the bearings had .006 to .008 slop from the grit.
It trash my cams too... I had to do some
Machine voodoo to bring the cam bearing/caps (one piece) back into speck as they are made of "unobtanium"
 
M

Mikez3202

New Member
#8
#8
Unfortunately if you say metal shavings got into the bore then your going to have to re-hone it. I would re-hone it regardless because after replacing any rings you need that nice 45 degree angle cross hatch in the bore to cut and seat them properly. If not then you run the risk of the rings glazing over and your engine will still burn oil. In my opinion I would replace all of the rings again. I wouldn't risk the potential problems down the road of the compression rings possibly failing. In my shop that's what I would do. But before doing all of this I would closely inspect all of the rings to make sure that there no good. They might be fine. After the crank went you might of just scratched up the bores pretty good with metal shavings and the oil could be seeping through those deep scratches. Either way its going to need to be honed again for sure. Just my 2 cents. Hope this helps you out.
 
Neck

Neck

Growing up is optional
#9
#9
It sounds to me that this engine is doomed, and as said before you may be money (and time) ahead by finding a replacement engine, either used or remanufactured.
 
W

WLB

Active Member
#10
#10
Wow, that was major damage. Did you ever find out why you holed the #1 in the first place? Was the hole frosted looking or just fractured looking. With all that damage I would agree with Neck, you are likely chasing your tail with that engine particularly since time is important.
 
toomanytoys

toomanytoys

Well-Known Member
#11
#11
You are rich if your cam bearing caps are made from unobtanium

It is a room-temperature superconductor for energy, which makes it very valuable; it is worth $20 million per kilogram (2.2 lbs) unrefined (worth $40 million per kilogram refined) on Earth
Click to expand...
 
MB165

MB165

Active Member
#12
#12
Yeah, what hent said.....:laugh: we missed ya at winder......

Unfortunatley, I feel you have more problems than just oil rings now. I wouldnt be surprised to see alot of other components beyond specs. I cant belive it held together with that clearance on the crank journal, If it were mine Id plan on boring the cylinders to get proper clearances. Are your bores aluminum, cast iron??
If you luck out, and the bores arent trashed.....be careful, there are a ton of stone choices for hones, you can eat a set of new rings in a few hundred miles if the bore finish isnt compatible with the rings.
wouldnt hurt to use hot soap and water to clean the bores, get a bunch of brake cleaner and flush out evrything you can get to.
 
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