- Posts
- 2,101
- Location
- Mull of Kintyre
To go from No. 1 TDC on power stroke to No.1 TDC on power stroke ie one rev of the engine requires two turns of the crankshaft
P38A Thor engine RPM
- Thread starter kermit_rr
- Start date
This site contains affiliate links for which LandyZone may be compensated if you make a purchase.
- Posts
- 33,601
- Location
- North Shropshire
Just to be really annoying, the engine doesn't actually turn!! Unless it's an old plane engine 
- Posts
- 2,101
- Location
- Mull of Kintyre
OK, I didnt know that but that is not engine revs
Just to be really annoying, the engine doesn't actually turn!! Unless it's an old plane rotary engine
Now let’s not start on rotaries
J
- Posts
- 33,601
- Location
- North Shropshire
A revolution is 360 degrees
- Posts
- 2,101
- Location
- Mull of Kintyre
Oh yes it does
Ooops wrong season
Ooops wrong season
- Posts
- 33,601
- Location
- North Shropshire
Not 720A revolution is 360 degrees
- Posts
- 33,601
- Location
- North Shropshire
A single 4 stroke cycle is 2 revs
tomcat59alan
Well-Known Member
- Posts
- 18,611
- Location
- wirral and triquivijate
Rpm is the number of times the crankshaft turns along its longitudinal axis per minute and is double the number of power strokes on a four stroke engine and the same on a two stroke.
- Posts
- 2,101
- Location
- Mull of Kintyre
Yes it is
But engine revs are not crank revs but I am not sure what the rev counter measures
Is a single cycle not an engine revolution?
- Posts
- 2,101
- Location
- Mull of Kintyre
I agree with Alan and a cycle is a power stroke to power stroke and if the rev counter measure cycles eg no. 1 spark to no 1. spark then that is two crank revs.
Ignore the redundant spark bit
Ignore the redundant spark bit
- Posts
- 33,601
- Location
- North Shropshire
Now about my target engine speed being 4x actual..
- Posts
- 2,101
- Location
- Mull of Kintyre
Is one engine rev not a full cycle>
In old days the rev counter was taken from the spark which would be one rev of engine
In old days the rev counter was taken from the spark which would be one rev of engine
- Posts
- 33,601
- Location
- North Shropshire
I still think i should tap the crank sensor.. what's the worst that could happen, another wrong value? Surely i won't fry anything..
- Posts
- 2,101
- Location
- Mull of Kintyre
I have no idea where the 4x comes from
- Posts
- 33,601
- Location
- North Shropshire
There were several ways to measure revs.. spark being one of them, but the electrical gubbins that measured the spark, adjusted the value to actual RPM
- Posts
- 33,601
- Location
- North Shropshire
Nor me unless it just 'looks' 4x to the eyeI have no idea where the 4x comes from
