Putting new rings in a motor.

[boostedinaz]

In my quest to bring back my old Galant I found a new 6 bolt for it with a catch....it has really bad compression in one cylinder. From basic text conversations he says it just needs new rings and it should be good to go. Of course I'm going to compression test with and without oil as well as a leak down test to see what's really going on.

My question is for those who have simply run a hone up and down then tossed in new rings. How succesful was it? I'm not building a monster just need to car to be a daily for now so reliability is key.

 

[chrisfullwood]

I personally haven't done that, but i would think, as long as the cylinder walls were still in good shape, and there wasn't the step at the top of the cylinder, where the walls are worn, you'd probably be OK, I would prepare to bore it out, and put new pistons in it, just in case though, hope for the best, plan for the worst.

How many miles are on the motor? how has it been driven, frequency of oil changes, MODs, etc. Those are important questions to ask, when looking at a replacement engine that's been used. to help ascertain what caused the failures it exhibits.

 

[DR1665]

I re-ringed the lump in 195/2000 a couple months before the Kia Incident. No problems. Dropped the exhaust, pan and tcase, then yanked the head and manifolds. Popped the pistons up through the top, ran a bar hone through the cylinders (even though they still looked great), and buttoned it back up with new rings and bearings. Ran like a champ.

A complete rebuild might get you another 200,000 miles out of it, but if a simple ring job would get you half that much, it's stall far longer than most of us keep these things anyway. Certainly last until you have a proper engine for it, ya know?

 

[boostedinaz]

What was the compression on the motor before tossing rings on it Brian? After?

 

[DR1665]

Oh dude, I can't remember. It's been like three years. Still, it sounded great, ran great, didn't over heat, and got 25mpg around town (unlike 464, which gets closer to 21). Not like you're going to just hamfist some rings in there and call it a day. I'm sure you'll pull it apart, measure twice, (cut once), and do it up right.

The engine YOU halfass will run longer than the one some of our vendors "blueprint."

 

[rdomeck]

I have re-ringed a lot of engines without having them bored. I have also had to bore a lot of them that only had a little wear. You should run a dial bore gauge down in them to see that they are round and tappered. The factory specs are in the Chiltons and Haynes manuals. I wouldn't through rings at one with out checking the wear and looking to see if any scoring has happened. It all depends on if the low compression was caused by low oil levels or over boosting or overheating, etc. If you don't have a dial bore gauge or haven't read one before run it by a machine shop and have them check it for you.

I just put my engine together and it had .0008" taper and right at the factory piston to cylinder clearance. I can't remember what the clearance was, but I do remember being happy to know that a rebore wasn't going to take place. The compression was low on #1 and I believe it was due to over boosting it from one of the previous owner's. it had 140 on 2,3,4 and 110 on 1.

 

[PreskitVR4]

I agree with Brian, quick/dirty/nasty FTW! I've done horribly half-ass't things to 4G63s that last way longer than they should... hone 'n' go, polish the crank, clean clean clean! then clean some more.

 

[chrisfullwood]

i think it has to be said, that horribly half assed, if you have a clue what you are doing at all, is still a lot better, than a complete hack job, done to the best of an idiots ability.... for examples, please come view the handiwork done by the previous owner's of my car.... so with everything, it has to be taken into context, always stay well within your own ability, and see guidance and advice for those things you are not comfortable doing /ubbthreads/images/graemlins/smile.gif

 

[alansupra94]

If you plan on running alot of boost, run the rings a little on the loose side. They will seal and expand better under boost.

 

[toybreaker]

Michael,

Do you have access to a borescope?

It'll tell the tale better than anything else.

It's scratches/gouges/damage in the bore that will kill any chance of a re-ring.

Leakdown test will tell you a lot about what's going on, but it won;t tell you if the bores will take a re-ring successfully.

At any rate, if the rings were worn enough to lose their seal in the bore, the piston ring lands are probably junk, so plan on firing in a new/used set of pistons.

Be a good time to go 2g on the pistons and score a lil more compression. /ubbthreads/images/graemlins/smile.gif



I freshen up every used motor I buy with rings/bearings, and most of them have gone over 200k without needing anything but oil changes and a t-belt every now and then.

My advice would be to find a good used high mileage motor and freshen it up, or a motor with dinged valves, and swap the rods/pistons and build a head for it.

Might cost a little more up front but the results will pay off in the long run.

 

[boostedinaz]

I'm trying to find someone who has a borescope but not sure if I'll have any luck with it. The guy only wants a 100 bucks for the motor and some help pulling it and installing his old motor so the price is right even if the motor needs more work.

I did see a guy selling 2G pistong fitted to 1G rods for cheap but then I gotta add in the machine work and my budget daily driver is way over budget. Hopefully I wont have to go down that path but we'll see.

 

[donniekak]

Most 4g's i see with really low compression in only 1 cylinder either have a cracked ringland, or need a valve job. Taking the shrader valve out of the compression tester adapter, and pumping 100psi of air into the one in question will quickly show where it's leaking.
I would never just re-ring an engine that had any piston/cylinder wall damage. But, i have re-ringed many 4g63's and have yet to blow a dipstick. Just a 3 arm hone, and plenty of cleaning later they come out nice.

 

a)If you need it, I have a borescope.
b)I have ringed pistons before with no problems after a quick hone to break down the varnish on non-turbo applications many times.
c)King balancing in phoenix does good machine work cheap if you tell them you go to UTI. I have a spare shirt you can borrow. =) Vatted, bored .030 over, honed to my pisotns, decked, balanced and all clearances double checked out the door for $175. They are *cash* only.
d)Go through this guy for bearings and seals and such. His prices are excellent, his service is top notch, and he can have stuff couriered to you in the vally for same day for cheaper than ground UPS. (You must ask for this service, it isn't mentioned on the site.)
e)good luck getting a motor with taper within spec. I have taken my bore gauge with my on several motor buys and not a single one was within spec. The spec for taper is essentially none, .0001" I believe. You will have to decide how much taper and oor you can accept.

 

[boostedinaz]

^^^^
That IS pretty cheap although I'm not looking to build a motor at this point. I will keep them in mind for the future though.

I went for a ride in the car the motor will be coming out of and supprisingly it runs damn good. Pulls 20" of vaccum at idle, idles dead nuts on at 750-800 ish, doesn't smoke, and pulls nice and smooth. To be honest I am thinking of just tossing it in and starting to find parts to build another motor. A little half ass and against my whole being but until we get a house every dollar counts.

 

[donniekak]

If it's the one i think it is, it has a new water pump. Should have had a new timing belt, but napa sold the right box, with the wrong belt. /ubbthreads/images/graemlins/banghead.gif