im reinstalling the pistons back in my 350. they came out just fine, but with the new rings i cant seem to get them back in. ive used to different compressors and neither seemed to do the job. i dont think i need to use a ridge cutter, but maybe i do. any ideas or tricks i can try?

 

a ridge reamer is a must . did you check end gap on the rings ?

 

end gap is fine, within tolerances .003 or so. so should i find a ridge reamer and cut the top down a bit, will that help.

 

You don't need a ridge reamer. Ridge reamers are for getting the pistons out of a heavily worn block, and for turning good blocks into trash in inexperienced hands.

What types of ring compressor have you tried?

I hope that's a typo.

 

a couple of different band style compressors. ive tightened them down as tight as i can get them, still no luck. as soon as the first metal ring goes in it gets caught up. its like i cant keep the clamp even enough or something.

 

Did it look like this?


If so, toss it in the trash.

Try a set that looks like this


or this


Make sure you keep it tight against the block as you push the piston in.

 

just curious whats wrong with the first one i havent ever installed pistons. sorry for the noob question

 

i tried one like the first band style, then the one on the bottom, no go.

 

The steel band overlaps itself so it's not perfectly round on the inside, you need about four hands to tighten the band while you keep the rings in their proper locations, the edge of the compressor easily slips into the bore, or the edge of the ring slips out and gets caught above the bore.
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What's your actual ring gap? Which ring is it getting hung up on?

 

thanks

 

i dont actually have a feeler guage so i will have to pick one up tomorrow, i just used the little paper guage i got with the rings,and obviously that is not the proper way to do it, i need to try and find one of those plier style compressors too.

 

piston ring end gap should be .010-.020 , .003 is just too little . ring gap should be measured at the lower part of cylinder bore . if you have a ridge of carbon & crud build-up on the top of the cylinder bores , it should be a no brainer . it has to go . many people have used the clamp type ring compressor for years with good results . i know i have . common sense is one of the best tools you can have . good luck .

 

my end gap is .030. a little more than it should be i guess. seems like the clamps im using are cheap and the rings want to pop out, i can get the lower set of rings in, then the middle ring wants to hang up. maybe i better quality clamp would work.

 

I used to use one of those. I ended up buying a bore specific one of these and kick myself in the *** for not getting one sooner. They work great!

 

I wouldn't mind having a whole set of fixed-size compressors like that.

These don't look too bad:

 

The ring my neighbor chipped using the POS band style clamp ended up costing more than the correct one bore size only tool. The pistons drop in like butter. Best $25 I ever spent on an engine tool.

 

I have always used the one in the first pic with no problems... I have built a ton of motors using that style... One trick to using them is to make sure the piston is square in the compressor... tapping the sides with a wooden hammer handle works to getting the clamp to tighten up evenly...