BMW Luxury Touring Community banner
1 - 16 of 16 Posts

·
Registered
Joined
·
106 Posts
Discussion Starter · #1 ·
I'll try to make this question as simple as possible, and avoid quantum mechanical theory and the like...

Pic 1: Question: will this mark on the cam sprocket come up more than once in a complete "engine rotation"?
Same question for pic 2.
 

Attachments

·
Registered
Joined
·
4,536 Posts
The cam shaft will turn one complete revolution for every 2 complete revolutions of the engine crankshaft so that mark if it is directly attached to the cam shaft will only line up once for every two revolutions of the engine.
 

·
Registered
Joined
·
106 Posts
Discussion Starter · #3 ·
The cam shaft will turn one complete revolution for every 2 complete revolutions of the engine crankshaft so that mark if it is directly attached to the cam shaft will only line up once for every two revolutions of the engine.
Guess I'm confused. But that's prob obvious, since I'm asking the question :)

Would have thought crank once, cam twice. Seems like other engines I've fooled with were that way anyway. Still getting familiar with this boxer stuff.
 

·
Registered
Joined
·
1,339 Posts
I'll try to make this question as simple as possible, and avoid quantum mechanical theory and the like...

Pic 1: Question: will this mark on the cam sprocket come up more than once in a complete "engine rotation"?
Same question for pic 2.
Unless you have invented a new type of combustion engine (grin), in all "normal" 4 stroke engines the camshaft(s) will make 1/2 (one half) of a turn for every complete turn of the crankshaft (360 degrees).

Hence, to answer your question: of course you would need to make 2 complete turns on the CRANKSHAFT to see this camshaft mark once (single turn of camshaft). Relationship is always 2 to 1 (or 1/2 the other way) irrelevant of having ONE camshaft or TWO overhead camshafts to operate ALL intake / exhaust valves.


ANOTHER WAY to REMEMBER this principle are these 3 facts:
- a 4 strokes engine needs 2 full CRANKSHAFT revolution to complete a full combustion cycle

- the camshaft lobes will only make a single revolution to complete a full combustion cycle for this engine (for example, the intake valve will open only once in a full combustion cycle)

- thus the gearing is such that there is exactly 1/2 turn of the CamShaft for every CrankShaft revolution (360 degrees).
 

·
Registered
Joined
·
106 Posts
Discussion Starter · #5 ·
Unless you have invented a new type of combustion engine (grin), in all "normal" 4 stroke engines the camshaft(s) will make 1/2 (one half) of a turn for every complete turn of the crankshaft (360 degrees).

Hence, to answer your question: of course you would need to make 2 complete turns on the CRANKSHAFT to see this camshaft mark once (single turn of camshaft). Relationship is always 2 to 1 irrelevant of having ONE camshaft or TWO overhead camshafts to operate ALL intake / exhaust valves.
Clearly we are both aware that I haven't invented a new type of engine. I really do appreciate the response and the knowledge, but not as happy with the condescension.
 

·
Registered
Joined
·
1,339 Posts
Clearly we are both aware that I haven't invented a new type of engine. I really do appreciate the response and the knowledge, but not as happy with the condescension.
I am very sorry that you took it this way... I only saw this as adding humor for those that might come up with funny theory about other combustion engines (2 strokes, rotary ...)

Those who know me for many years on the K1200LT sub-forum would say that I am anything but "condescension". In the future, I will avoid visiting this "RT series" forum and helping out.
 
  • Like
Reactions: BB 1200RT

·
Registered
Joined
·
106 Posts
Discussion Starter · #7 ·
I am very sorry that you took it this way... I only saw this as adding humor for those that might come up with funny theory about other combustion engines (2 strokes, rotary ...)

Those who know me for many years on the K1200LT sub-forum would say that I am anything but "condescension". In the future, I will avoid visiting this "RT series" forum and helping out.
Sounds a bit of an over-reaction to avoid an entire forum based on a reaction to one of your posts. I don't plan to avoid the forum based on one post. Sorry you feel that way.
Again, thanks for the knowledge.
 

·
Registered
Joined
·
4,536 Posts
Clearly we are both aware that I haven't invented a new type of engine. I really do appreciate the response and the knowledge, but not as happy with the condescension.
John is Canadian. Need I say more >:)

English isn't his first language but I thought he did rather well with the humorous intro to his answer. :) He is probably one of our greatest technical resources on this forum. Hope you got your answer and understand now. If not, we can certainly get into the "quantum mechanical theory" if necessary. All in good fun. Merry Christmas.
 

·
Registered
Joined
·
106 Posts
Discussion Starter · #9 ·
John is Canadian. Need I say more >:)

English isn't his first language but I thought he did rather well with the humorous intro to his answer. :) He is probably one of our greatest technical resources on this forum. Hope you got your answer and understand now. If not, we can certainly get into the "quantum mechanical theory" if necessary. All in good fun. Merry Christmas.
Ok, understood. I am a huge fan of Fortnine on youtube, so I guess the Canadian humor now makes sense there. Apologies to all for any misunderstandings.
 
1 - 16 of 16 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top