Resize or new sleeve/piston
04-10-2005, 06:02 PM
#1
Resize or new sleeve/piston
Hey all, I recentally picked up a Novarossi RX21-R engine 2nd hand. The engine was susposed to be barely run. Once I recieved it. It is very easy to turn over by hand with the glow plug out (no pinch). With the glow plug in it, it has compression.... Nothing like my other Rx21. Judging by the oil that was dripping out of the pipe (was included with the engine) it was run in way to rich.
Is a "pinched" sleeve (alot cheaper) just as reliable as a new piston/sleeve combo. The sleeve on this engine has no hot spots,gouges,etc.... just no pinch. I would like to hear from those who have had a engine "pinched" and what they though about it.
Is a "pinched" sleeve (alot cheaper) just as reliable as a new piston/sleeve combo. The sleeve on this engine has no hot spots,gouges,etc.... just no pinch. I would like to hear from those who have had a engine "pinched" and what they though about it.
04-14-2005, 08:39 AM
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RE: Resize or new sleeve/piston
I have had good luck using pinching tools. I have pinched an rb 21, ofna hyper 21 and a mach 26, all with excellent results.
Starting with clean, dry piston and sleeve, I followed the instructions that came with the pinch ring and did just a little at a time until the pistion felt snug at about 85 percent into the sleeve (3/32 to 1/8 from the top dead center). I changed the bearings, and did my normal breakin. and have not had any issues what so ever with any of the engines.
Starting with clean, dry piston and sleeve, I followed the instructions that came with the pinch ring and did just a little at a time until the pistion felt snug at about 85 percent into the sleeve (3/32 to 1/8 from the top dead center). I changed the bearings, and did my normal breakin. and have not had any issues what so ever with any of the engines.
04-15-2005, 02:29 PM
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RE: Resize or new sleeve/piston
what is a pinching tool ? and were can i see a picture of one..
and were can i get one
sorry for all the stupid questions
but i dont know
and were can i get one
sorry for all the stupid questions
but i dont know
04-15-2005, 10:08 PM
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RE: Resize or new sleeve/piston
I have a pinching tool also.I honed mine out to accept the largest o.d. sleeve i had and made insert spacers so i could pinch them all regardless of size.(.21-.26).I'm glad i'm a pack rat and saved all of my old sleeves.I now have way more running engines than i have cars. .I only pinch a sleeve back to about 75% of the factory fit.This greatly reduces the wear on the chrome/piston and the stress on the rod.I have a ws7II on its 3rd pinch and about 15-20 gals.Same p/s/rod.I have replaced the front bearing a couple of times.Front engine bearing slop is the main culprit in crank pin wear so keep an eye on that.And DONT spend $30-50 on a bearing.I get high quality(better then most factory)SKF bearings for $18.Shipping included.If you cant find them click on my name and send me an email.I'll hook you up.
.I only pinch a sleeve back to about 75% of the factory fit.This greatly reduces the wear on the chrome/piston and the stress on the rod.I have a ws7II on its 3rd pinch and about 15-20 gals.Same p/s/rod.I have replaced the front bearing a couple of times.Front engine bearing slop is the main culprit in crank pin wear so keep an eye on that.And DONT spend $30-50 on a bearing.I get high quality(better then most factory)SKF bearings for $18.Shipping included.If you cant find them click on my name and send me an email.I'll hook you up.
