I'm in the process of rebuilding an engine. I've got it back from the machine shop and I am currently assemblying it. Thus far it has been the assembly from hell.

I'm not even to short block stage and I've got another problem.

Is there ANY secrets to using a piston ring compression tool? I'm on my second style tool and while it seems to compress the rings and such uniformly, I still can't get the FAWKING piston into the cylinder. I've tried the gentle circumferance tap in... I've tried the quick center hit. And it still gets hung up.

Do I need to do some mystical chant or some funky ass holding technique to get it to work? Or do I need to spend more than $15 on a compression tool?

Thanks in advance for any useful help and have a merry Christmas.

John

Take the rings off the piston. Push one of the rings in the cylinder using the piston to make sure it is square. Measure the end gap of the ring using feeler gauges. You should have about .003"-.004" for every 1" of bore.

EX - 4.000" = .012"-.016"

If that is ok and the piston fits in the cylinder ok, learn how to use the fawking ring compressor.:flipoff2:

Yup ...I think you should ckeck every ring for end gap about 1 inch down from the deck in the cylinder it will be running in.
You need to use lots of engine oil on the rings and tighten the compressor real tight.

I checked the ring clearance before I put them on the piston. They were definately in spec.

Thanks for the input.

Be a man, use your fingers..... Otherwise ask your wife/girlfriend/daughter to do it for you :flipoff2:

It's probably a POS ring compressor that's giving you all the trouble......or operator error.

Originally posted by Nobody
It's probably a POS ring compressor that's giving you all the trouble......or operator error.

I wouldn't be suprised if it were either:flipoff2: This is Kragen's second cheapest ring compressor:D :D

As such, the instructions are a little light:p So, I may be not quite using it right :(

The best kind of ring compressors I have used are the ones that have a steel band and handles that look like vice grips. Once you set them up on the first piston it works perfectly for the rest. Another kind I have seen, but not used, is a machined donut with a taper on the inside. Supposedly you line the donut over the piston hole in the block, wide end up, guide the piston down until the rings sit in the taper, then gently tap in the piston with a rubber mallet. I watched a NASCAR engine crew doing a quick buildup with this tool.
Make sure you dip your piston into a clean container of oil before inserting. And also put some sleeves ove the rod bolts so you dont scratch your crank....
One of the things that alot of people look over is cleanliness. You must keep everything spotless, or you will destroy an engine as soon as you fire it up.
I always clean the block when I get it back from the machine shop with hot soapy water. Use brushes to throughly clean the oil galleys. Wipe out the cylinders with acetone and lint free rags. Never use the red shop towels, they leave tons of lint. Clean the crank journals, and run pipe cleaners through the crank oil holes.
I have never got a block from the machine shop that was clean, even though it was hot tanked. You will be suprised at the ammount of grit you get off the cyl walls wiping them off with acetone and a white lint free cloth. I have even removed metal shaving from oil galleys from the left over machineing processes.
Clean, Clean, Clean, your engine will last along time if you do a good job here!:skull:

I've probably rebuilt 200 engines.

The way I do it, is to put the rings on the piston (with a ring installer) and set the gaps where I want them. Then I put vacuum line on the rod bolts. I then dip the piston in a coffee can of oil and put on the ring compressor.

The compressor I like:

http://www.lislecorp.com/images/specialty/catalog/ring/21700l.gif

http://www.lislecorp.com/images/specialty/catalog/ring/21700in.gif

Tighten the adjustment tight enough to get the rings into the cylinder, but not so tight that it is difficult to get the piston out of the compressor. With this type compressor, you only need to set it for the first piston. Also, the wrinkles in the band offer less resistance than other types of compressors. Then I reach under the block, and guide the rod to the journal as I tap the piston in with a hammer handle.

Originally posted by ranger
The best kind of ring compressors I have used are the ones that have a steel band and handles that look like vice grips. Once you set them up on the first piston it works perfectly for the rest. Another kind I have seen, but not used, is a machined donut with a taper on the inside. Supposedly you line the donut over the piston hole in the block, wide end up, guide the piston down until the rings sit in the taper, then gently tap in the piston with a rubber mallet. I watched a NASCAR engine crew doing a quick buildup with this tool.
Make sure you dip your piston into a clean container of oil before inserting. And also put some sleeves ove the rod bolts so you dont scratch your crank....
One of the things that alot of people look over is cleanliness. You must keep everything spotless, or you will destroy an engine as soon as you fire it up.
I always clean the block when I get it back from the machine shop with hot soapy water. Use brushes to throughly clean the oil galleys. Wipe out the cylinders with acetone and lint free rags. Never use the red shop towels, they leave tons of lint. Clean the crank journals, and run pipe cleaners through the crank oil holes.
I have never got a block from the machine shop that was clean, even though it was hot tanked. You will be suprised at the ammount of grit you get off the cyl walls wiping them off with acetone and a white lint free cloth. I have even removed metal shaving from oil galleys from the left over machineing processes.
Clean, Clean, Clean, your engine will last along time if you do a good job here!:skull:

He knows what he's talking about. ;)

I have use the ring compressor shown in the previous post on more than one occasion. They are inexpensive, and work well.

I'm with Ranger on this one... clean clean clean!

StephenW I use that same compressor... works great, quick, and cheap.

Try test fitting a piston on it's own without the rings... if it Won't fit or is too tight, it may be the wrong oversize.

Sometimes the oil control ring separators are wrong for the pistons... or need to be trimmed to fit, this is very rare, I've only run into this problem on racing motorcycles.

Also, are you sure that the rods aren't hanging up on anything down below? Some tubing on the rod bolts will save the crank and cylinder bore.

As for clean.. one of the things I do is wipe each bore down with motor oil, then wipe 'em clean, and repeat until the "wipe clean" rag comes back *clean* and not dirty.

As for the rings/piston.. I use the wrinkle type shown.

I found it to work best by dropping the piston into the bore and "sitting" on the rings, then put the compressor in place, lift the piston up just a touch, and snap the ring compressor onto the piston.

I then use the rubber coated handle of a hammer to coax the piston into the bore.