Printable Version of Topic

Posted by: orcadigital May 8 2007, 03:35 PM

Due to some poor leak down numbers, mostly ring related, i was wondering what was entailed in replacing piston rings.

I have a cylinder hone and plan on honing the cylinders, then checking for taper or anything worrisome (i have 2 complete sets of pistons and cylinders, used but no scarring or any visible damage), then installing new rings. I am wondering what concerns or things i should check.

Also, as car as a ring compressor. I have a band type, but usually you put it on, then lightly hammer the piston into the cylinder. As this setup is a tad different (the sleeve slides over the piston), is there anything i need to worry about?

I am in a bit of a time crunch, thus i am going this way, while i build up an engine that i can swap in later in the year, which will have new P's and C's.

Thanks!

Posted by: smontanaro May 8 2007, 08:15 PM

In my 356 days I believe I used to just compress the rings by hand one-by-one and slide the cylinder over them. Never had a problem, but that was a long time ago. Maybe I misremember my exact technique.

Skip

Posted by: Jake Raby May 8 2007, 08:43 PM

ensure that the cylinders have not seen heat damage and gone out of round/ tapered. All too often people re-ring pistons and still have issues that stem from worn ring lands or out of round/tapered cylinders.

Posted by: Mike914 May 8 2007, 09:30 PM

What Jake said...

If your ring compressor is a solid band you can still use it if you put the pistons into the cylinders BEFORE putting the pistons onto the rods. Just poke them out the bottom to put the wrist pins in. I've seen people do this to brand new piston/cylinder sets so they did not even need a ring compressor. Not recommended due to balancing issues and not getting the ring gaps lined up properly obviously. Not to mention, you should clean the "stuff" off new pistons, right?

Posted by: brant May 8 2007, 11:36 PM

grant,

does this mean your motor wasn't fatal?
that would sure be good news as I heard it may have been fatal

brant

Posted by: TROJANMAN May 8 2007, 11:41 PM

is this the one you are building from 3?

let me know if you need any 2.0 stuff

Posted by: So.Cal.914 May 8 2007, 11:57 PM

You can use your ring compressor with the piston on the rod. They have a release,

Just put it over your piston rings and tap the jug on (I use a small piece of 2X4

and a rubber mallet) just past the rings. Then release the compressor and pull it

out from behind the jug. Tap the jug into place, I used them many times.

Posted by: orcadigital May 9 2007, 11:28 AM

Thanks for all the responses!

Jake, I definately agree, and the only reason i am doing this is to have a car going in 2 weeks. I have 2 other blocks that are waiting for attention, and will be treated with new parts and gone through properly. I ran my parts car at the last autoX, which while interesting (and i did win my class) is not something i want to run on the track.

Brant, Nope, not fatal at all. It looked bad by the sparkplug, but really wasnt. The head developed 2 cracks at the spark plug hole on #3, but being the cylinder it was, tended to seem worse then it was. I have a good set of heads (just gone through professionally, and new valve job) ready to bolt on, but i wanted to attempt to fix a little bit of my leakdown numbers. I was the worst on #2, and 3 wouldnt read with the cracks around the hole.

The question is, and keeping in mind this is an engine to last 6 months tops, should i hone all 4, and rering them? Or just swap in a matched jug and piston on the 2 questionable cylinders (from another engine with fairly low mileage) and bolt it back together?

I was actually contemplating swapping in the 1.7 from my parts car, but then i lose my daily driver, and with $3+ a gallon gas, i dont want to go back to my truck for my 40 mile each way commute.

Any colorado folks coming to La Junta May 19th?

Grant

Posted by: TROJANMAN May 9 2007, 11:31 AM

unlikely. Probably Pueblo in June

Posted by: Jake Raby May 9 2007, 12:34 PM

Jake, I definately agree, and the only reason i am doing this is to have a car going in 2 weeks.

NEVER, ever alow time constraints to dictate your engine plans- doing so is almost guaranteed failure.

Posted by: orcadigital May 10 2007, 12:31 PM

I will be measuring for taper tonight when i get home from work, and see what i am dealing with. I was just worried that if i took things apart, that i wouldn't be able to put them back together again.

Never like the time crunch, no more so then the financial one.

I would run the parts car before i put damaged parts back together though.

Grant