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poor compression
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Re: poor compression
NYC
- Flx48
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Re: poor compression
Your update is most appreciated.
It's a great example for the rest of us, of how a thread can be successfully concluded to the benefit of all.
Many lessons in life are learned from mistakes, (at least in my little world) and hearing of those made by others is always welcomed, if just for the off-chance my brain might actually be awake and listening..
Were it me, at this point I'd be following the advice given earlier by James- ride it hard a while and then retest, before considering other courses of action. (but do retorque heads/readjust valves)
Best-
George
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Re: poor compression
I don't have much choice at this point. I've never had such low compression in a fresh motor. Guess there's a first time for everything. Will give an update after a few hundred miles.
Frank.
NYC.
NYC
- Discogodfather
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Re: poor compression
Did you cross hatch it before the assembly, or was it as it was given to you by the shop?
San Francisco, CA
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Re: poor compression
NYC
Re: poor compression
- Micha
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Re: poor compression
I also do not think it is worthwhile to treat it too gently at first.
What we want to do in the running-in process, is wear-fit between the piston ring and the honing scratches on the cylinder walls.
Do not forget that the abrasion between them is not uniform as the piston rings are made of a different material than the metal of the bore.
Proper running-in will result in a better engine and better oil carry-over sealing.
Of course just as you push the engine, you also need to know how to give it rest and coolness by driving calmly here and there.
R51/3 1952
Engine Nr. 529466
- jwonder
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Re: poor compression
So, no real break in other than changing and checking oil early and often.
Vice President, Vintage BMW Motorcycle Owners
2022 BMW Friend Of the Marque
Long Island, New York
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Re: poor compression
- Discogodfather
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Re: poor compression
I hear you, but the problem is this- you have to check the piston ring gap at the bottom of its stroke and then compare that measurement to the reading at the top of the stroke. The gap goes to practically zero tolerance at the TDC. Also was there any way to check and verify that the cylinder boring was actually tapered correctly?dellatorre6708 wrote: ↑Tue Jun 01, 2021 7:03 amNew pistons and rings, sent to millennium tech for fitting. Cross hatch was done by MT. When I received them, checked ring gap and installed. This couldn't be more by the book. I'll ride it a bit and see if things improve.
San Francisco, CA