| Ducati TT1, Ducati TT2 and Ducati 750 F1 Forum http://ducatittandf1.com/ |
|
| breaking in new rings http://ducatittandf1.com/viewtopic.php?f=10&t=11430 |
Page 1 of 1 |
| Author: | ptenax [ Fri Sep 16, 2016 11:56 am ] |
| Post subject: | breaking in new rings |
Hi there, I had new pistons/rings (high compression Carrillo) put into my 1983 600SL engine. Received just a little advice on breaking them in from the mechanic before riding the bike home, read a bit more online later. One strong opinion was to give some reasonable revving and throttle shut-off under load in the first few kilometres after a brief warm up. At handover time from the mechanic today, the bike had a minute or two to warm up, and then maybe 5 km of normal riding in suburbs (several brief start/stops at intersections), before running it for 15km on the freeway below 5000rpm (90km/hr), followed by a bit more start/stop on main roads with traffic lights. Noticed oil leak within first 2km of running after parking for a few minutes, and some dripping upon reaching home. Not sure, but it might be coming from the right side cover - have to track it down further. So, I would like to know thoughts on ideal break-in of new rings/pistons, and whether I might be observing oil leaks because of blow-by (or an unrelated problem). What would be a good next step? - a compression test (what values in hPa or kg/cm2?)? Tell-tale signs of blow-by and improperly seated new rings? Since the new pistons have done about 25 km, I suppose an oil change with non-synthetic oil is a good idea about now? Would I have done some damage already? - the oil leak is disquieting, and the bike will suddenly cut out when idling from 1600rpm to zero almost instantly. Any expanded thoughts and advice very welcome. ptenax |
|
| Author: | danomar [ Fri Sep 16, 2016 4:38 pm ] |
| Post subject: | Re: breaking in new rings |
The idea behind providing a bit more deceleration (shut-off) throttle is to get new rings to seat both in the tops and bottoms of their piston grooves. For a race motor, one wants to avoid seating the rings with mostly compression. For street use, it might be less relevant. Probably the best advice with new rings is to avoid continuous revs for a prolonged time. The leak might be something else. If you see blue smoke out the exhaust, oil is getting past the rings or there is other wear such as in the valve guides. If you do not see oil in the exhaust, then there is something leaking, probably from the rebuild. Did you get the heads refurbished with the new rings? The stronger seal on new rings can sometimes cause older, worn valve seat and guides to show their wear. |
|
| Author: | ptenax [ Fri Sep 16, 2016 7:07 pm ] |
| Post subject: | Re: breaking in new rings |
Thanks danomar, One barrel was replated with Nikisil, the other barrel was left alone (I think). The replating and piston change was necessary because a main bearing fell to bits and scored those parts. There is no blue smoke and in fact the exhaust is clean and clear. So perhaps I will do an oil change, a little bit of up and down the rev range under load, and look for other causes of oil leaks? I thought the explanation on this website sounded logical to me. http://www.mototuneusa.com/break_in_secrets.htm ptenax |
|
| Author: | brad black [ Sun Sep 18, 2016 4:18 am ] |
| Post subject: | Re: breaking in new rings |
if they're old cylinders i get them hot then let cool once to stress relieve the pistons. then take it out and give it some shit. done. replated cylinders i might keep the rpm down for a little while. |
|
| Author: | ptenax [ Tue Sep 20, 2016 5:33 am ] |
| Post subject: | Re: breaking in new rings |
Thanks brad black, One of the cylinders is old, the other has new Nikisil. I got some other advice to not give it too much revs until after 500-1000 km, and not to overheat the new pistons - so shorter rides with a little rest to cool things down. Like you say, seems like it is best to take things a bit easier for a while (at least 500 km) in case I seize it and to make sure the rings bed in nice and evenly. Appreciate all the advice. ptenax |
|
| Page 1 of 1 | All times are UTC - 5 hours [ DST ] |
| Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group http://www.phpbb.com/ |
|