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| Author: | soflah2b [ Sat Oct 17, 2015 3:15 pm ] |
| Post subject: | Broken piston |
My 73 Z1 turbo started fouling the number one plug. Thought it was the head gasket. Unfortunately it wasn't. Broke the top ring landing off. What a bummer. Its a 1015 kit which aren't produced anymore. No damage to the sleeve or the exhaust side of the turbo impeller. Hate to go to a 1075. Any suggestions? 
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| Author: | Ja-Moo [ Sat Oct 17, 2015 4:50 pm ] |
| Post subject: | Re: Broken piston |
There are a few Z1 pages on facebook, lots of parts. You might ask there. |
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| Author: | H2RTuner [ Sat Oct 17, 2015 6:49 pm ] |
| Post subject: | Re: Broken piston |
When Hurley and I had the shop around the corner from American Turbo-Pak eons ago, and when I worked for RC Engineering, we saw a bit of this occurring when the pistons weren't sourced well. At RC, I had to fix a supercharged CBX that did this, the guy lived in Las Vegas, and also had a turbo CBX. What to look for in a piston is one that has a very thin top ring, and the ring land be cut down farther from its top deck on the piston face, instead of at the regular point for a naturally aspirated engine. Two factors are in play here, detonation/pinging, and heat. With the normally aspirated pistons, it doesn't take much more heat than made by the regular engine to induce detonation, with ring land to deck land failures, as seen in the pictures. Also, if you find a set, or have a set made that have the lowered ring grooves in them, have the piston guru cut the face area from the top of the upper ring groove to deck at a 1 degree inward angle. What that cut will do is to allow more cooling mixture to get down to the top of the upper ring, and along the area between the upper face of the piston, and bore wall. An added benefit is that on pistons run with giant clearances to the bore walls, the upper edge of the piston doesn't scrape the bore wall. I do the 1 degree cut on just about every piston I install, including car, 4 and 2 stroke, and especially the triple stuff I do. Ever see a piston from upper ring to deck have top to bottom scrape marks, along with the bore? this is because the piston, at rock over is hitting the bore, and that ain't good. The 1 degree cut eliminates that, along with helping the cooling, and mixture fill in the area. Also, keeping the piston to bore clearance low helps, too, from a lot less piston rock over. |
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| Author: | Jeff [ Sun Oct 18, 2015 7:19 am ] |
| Post subject: | Re: Broken piston |
soflah2b wrote: My 73 Z1 turbo started fouling the number one plug. Thought it was the head gasket. Unfortunately it wasn't. Broke the top ring landing off. What a bummer. Its a 1015 kit which aren't produced anymore. No damage to the sleeve or the exhaust side of the turbo impeller. Hate to go to a 1075. Any suggestions? If it will work for you, I have a cylinder bank with pistons from a 1980 kz1000. It's an 1100 kit with 73mm Wiseco pistons. Came off a running motor. Cylinder bank says 1015 on it and I believe that the 1100 kit was just an overbore, but I might be wrong about that. I'll let it go relatively cheap. Jeff |
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| Author: | H2RTuner [ Sun Oct 18, 2015 1:54 pm ] |
| Post subject: | Re: Broken piston |
If I remember my Z/KZ stuff, 1,000 cc was 70mm bore stock, actually 1,015 cc's. On first 900's, 66mm bore was stock, 903 cc's. Been a long time for all this 4 striker early insanity. On the over bores, 72mm was 1075 cc's, 73mm was 1,098 cc's, marketed as an 1,103 cc bore kit. 900's wouldn't go all the way to 1015 without issues, sleeves way too thin to go to 70 mm bore, used to use CB450 Honda twin pistons/rings, came out near 1,084 cc's or so. |
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| Author: | JohnnyO [ Sun Oct 18, 2015 8:19 pm ] |
| Post subject: | Re: Broken piston |
http://pages.ebay.com/link/?nav=item.vi ... ID=EBAY-US Will this work ?? |
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| Author: | H2RTuner [ Sun Oct 18, 2015 8:37 pm ] |
| Post subject: | Re: Broken piston |
If all else is OK, I think I'd look into a specialty set of pistons and rings, ones designed for turbo or supercharger use, with the ring packs designed and placed for that application. If they cannot be found, have a set made. That cylinder/piston set in the E Bay sale is nothing special, could to the same as what you already have, and yours doesn't have a broken fin on the cylinder. |
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| Author: | Ja-Moo [ Mon Oct 19, 2015 1:10 am ] |
| Post subject: | Re: Broken piston |
Good gosh, there are probably 100's of turboed motors around with stock pistons. How many miles you have on the Motor? A bunch I bet............ |
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| Author: | H2RTuner [ Mon Oct 19, 2015 12:44 pm ] |
| Post subject: | Re: Broken piston |
Just a simple question, John, how many have you actually hands-on worked on internally, either Z1R-TC, RC, American Turbo-Pak, other? I've worked on quite a few between the shops I have worked at, ATP and RC Engineering, not only Kawasaki, but a lot of other brands and models. For very low boost, stock pistons, tight clearances, are OK, anything with more boost, better pistons with lower ring groove placements IS the rule to go by. All it takes is a stuck waste gate to over boost a stock piston set into just the failure in the picture above. |
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| Author: | Ja-Moo [ Mon Oct 19, 2015 9:52 pm ] |
| Post subject: | Re: Broken piston |
Simple answer Dave, his question was, is there a 1015 piston available. Not have custom pistons made.......... |
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