Moorron
|
 posted on 14/5/08 at 11:47 AM |
|
|
starting a rebuilt engine
Getting scared now.
Sounds funny but I am starting to feel the pressure of having to start up my rebuild CBR1000F after I cracked the head earlier this year (pretty sure
I ran out of water!). I have fitted a new oil pump, cam chain tensioner, head, pistons, rings and a honed set of liners. It’s the first engine I have
taken apart although I am good at mechanics I have the feeling something isn’t going to work and I will have to do it all again. Is this normal?
Things that cross my mind going wrong are mainly the piston rings, I had great trouble trying to get the last ring (oil control) to go into the bore,
it turns by hand fine but I did get heavy handed with them. The head came off a spare engine so its condition is unknown and I didn’t want it skimmed
because I didn’t want to lower the CR by any amount, it was also very dirty inside the inlet and exhaust ports and I have blown them out with
compressed air but it still doesn’t look nice and shiny inside. I am starting it up (or trying) in the morning, but after letting it idle to fan
operating temp, what do I need to do afterwards?
Will it be hard to start?
Do I need to re torque the head after it has cooled over night? What about the valve clearances?
Also, and I know this has been talked about a lot, but should I run the engine in or ‘nail’ it like some bike engine experts suggest. Take note it is
turbo charged so is under a lot more stress then it was designed for.
So by tomorrow dinner time I will be over the moon or a little grouchy.
Sorry about my spelling, im an engineer and only work in numbers.
|
|
|
|
|
smart51
|
| posted on 14/5/08 at 11:51 AM |
|
|
Fill the oil filter with new oil, so that the engine primes sooner.
Turn it over by hand once or twice to make sure it is free
turn it over for tens of seconds on the starter motor, with the plugs removed and the fuel off. This pumps oil through the engine and builds up oil
pressure.
Once your pressure is up, refit the plugs and fuel. start up normally for a few seconds to make sure it runs OK.
Switch off and check everything.
|
|
|
dubstar_04
|
| posted on 14/5/08 at 11:53 AM |
|
|
Amen,
You can't get any better advice than that!!
Good luck
|
|
|
worX
|
| posted on 14/5/08 at 12:01 PM |
|
|
As above and above!
Also, the nailing the engine doesn't really apply to you as it's not a new engine (which is the more specifically debated topic)
Steve
|
|
|
82 Locost
|
| posted on 14/5/08 at 01:12 PM |
|
|
NEW RINGS?
I believe there's a requirement to run the rings in? 2000rpm for an hour? Can somebody confirm or deny this please?
Mike
|
|
|
02GF74
|
| posted on 14/5/08 at 01:39 PM |
|
|
any head can be cleaned out, using oven clean to shift the carbon or brushing but would need valves to be removed.
with what sounds like a s/h head, you removed vales to check seat and do a light regrind if necessary.
as for nailing it - there is an ongoing debate - also done if bores are honed and new rings fitted - apparently it is the hard driving that beds them
in best.
|
|
|
smart51
|
| posted on 14/5/08 at 02:27 PM |
|
|
The Yamaha manual for the R1 said start off with revs below 5000 RPM for, I can't remember, 1000 miles or so, with no more than, I think 50%
throttle. [/vague mode]. After that, build up the revs and throttle gradually until you're using 100% throttle and all the revs.
Car manuals used to say not sticking to any one engine speed or throttle opening for any length of time to ensure a nice bedding in.
I think that the middle ground sounds best. Don't go too hard too soon, causing lots of wear whilst the engine is "new", but not
being too gentle and not bedding in the bores. I guess that's what the building up is for. Slow in the beginnning to get things going then
harder and faster to bed it in.
I replaced the crank and big end bearings in mine last year. I figured that the bores and top end were all nicely bedded in and that the new bearings
run on a film of oil. I ran it as per Yamaha's advice but dividing the milage by 5. I was still running it in on the way to Stoneligh last
year so my top speed was 50 for part of the way there.
|
|
|
motorcycle_mayhem
|
| posted on 14/5/08 at 03:42 PM |
|
|
I've NEVER managed to see any oil pressure when cranking a rebuilt bike engine, so if you're looking and waiting, it's probably not
going to happen. The car engines have all given lots of reassuring pressure on a plugless starter episode.
My competition engines (from Mistral) don't get a lot of gentle run-in, but then longevity isn't an issue..... I normally give them a very
gentle period on a track test day for a while, change the oil/filter and explore the upper limits. Touch wood....
My road-bike experiences are that engines will soon let you know if they aren't integrally good!
|
|
|
Coose
|
| posted on 14/5/08 at 07:21 PM |
|
|
Rings and bores need minimal running-in. Just go easy for the first 50 miles or so and you'll be ok.
Spin 'er off Well...
|
|
|
