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5 BTDC vs 5 ATDC
5 BTDC vs 5 ATDC
Apologies if this is a really, really thick question, but the manual for the timing on my auto N12, says 5 degrees BTDC. That's what I've been using.
Anyway, I checked the timing and such yesterday, just moseying around the engine, and found that the mechanic who last worked on it put it 5 degree AFTER TDC, i.e. the first mark clockwise on the pulley (anti-clockwise has five marks: 0 . 10 . 20. I was using the second mark on this.)
I'm presuming it's for more power....but why change it?
Anyway, I checked the timing and such yesterday, just moseying around the engine, and found that the mechanic who last worked on it put it 5 degree AFTER TDC, i.e. the first mark clockwise on the pulley (anti-clockwise has five marks: 0 . 10 . 20. I was using the second mark on this.)
I'm presuming it's for more power....but why change it?
Sorry, is that so! According to which manual?sgs wrote: five degree before TDC not after
Damo
Do humanity a favor, use your brain and fight the forces of WOO WOO!
http://www.youtube.com/watch?v=G1mrbxhWU5Y
http://www.youtube.com/watch?v=G1mrbxhWU5Y
- tassuperkart
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If you have a look at the emissions placard under the bonnet, it will show you ignition timing it should run. Any E15 carby engine sold in this country runs a setup timing of from 5-7deg ATDC! This does move a long way back into BTDC with the vac line hooked back up after tune up checks, but factory timing is ATDC.sgs wrote:when the heel on my points worn off due to lack of oil, it dropped back to exactly TDC, car was guttless and backfired when i buttoned off the trottle. i would hate imagine what five degrees after TDC would be like
Damo
Do humanity a favor, use your brain and fight the forces of WOO WOO!
http://www.youtube.com/watch?v=G1mrbxhWU5Y
http://www.youtube.com/watch?v=G1mrbxhWU5Y
Damo
Interesting point. I just checked my Gregorys (Australian) manual, and it says 5deg BTDC, but my official Nissan Australia manual workshop says 5deg ATDC.
Okay, back to basics for me; the marks on the auto N12 are, anti-clockwise; (mark) 10, (mark) 20. In other words, four marks indicating 5, 10, 15, 20. Clockwise, just on mark that corresponds to 5deg.
So, let me get this right; the single mark clockwise is 5deg BTDC, and the rest are ATDC?
If that is so, I made a mistake in my opening post; the timing set by the mechanics is actually the 5deg single mark going clockwise.
I've been timing it at the 5deg mark in the anti-clockwise.
Interesting point. I just checked my Gregorys (Australian) manual, and it says 5deg BTDC, but my official Nissan Australia manual workshop says 5deg ATDC.
Okay, back to basics for me; the marks on the auto N12 are, anti-clockwise; (mark) 10, (mark) 20. In other words, four marks indicating 5, 10, 15, 20. Clockwise, just on mark that corresponds to 5deg.
So, let me get this right; the single mark clockwise is 5deg BTDC, and the rest are ATDC?
If that is so, I made a mistake in my opening post; the timing set by the mechanics is actually the 5deg single mark going clockwise.
I've been timing it at the 5deg mark in the anti-clockwise.
Damo,
i'v change my timing to 5deg ATDC, car is running mint. It now makes more down bottom end nothing strange happening, has alot lot better exhaust note also. i have a feeling im gonna save heaps of gas!
well we learn something new everyday! Thanks Damo
btw, are nissan E series engines unique in this way because everybody i talked to about it looked at me kinda side ways
i'v change my timing to 5deg ATDC, car is running mint. It now makes more down bottom end nothing strange happening, has alot lot better exhaust note also. i have a feeling im gonna save heaps of gas!
well we learn something new everyday! Thanks Damo
btw, are nissan E series engines unique in this way because everybody i talked to about it looked at me kinda side ways
holy thread revival Batman.
Figured I'd bump this since I just ran across this 'fun' today. Manual for N/A version does state timing @ 5° ATDC when dizzy vac line disconnected
It is 5° BTDC when vac line is connected. Which is the mark to the left of the 0° timing mark (counter clockwise when looking in from the drivers side wheel well)
After driving around with what amounted to 10° of retard, I now know how important timing is... absolutely no power, hesitates whenever you press the accelerator. Returned the timing to 5° BTDC and she's much more responsive and back to her usual self.
Figured I'd bump this since I just ran across this 'fun' today. Manual for N/A version does state timing @ 5° ATDC when dizzy vac line disconnected
It is 5° BTDC when vac line is connected. Which is the mark to the left of the 0° timing mark (counter clockwise when looking in from the drivers side wheel well)
After driving around with what amounted to 10° of retard, I now know how important timing is... absolutely no power, hesitates whenever you press the accelerator. Returned the timing to 5° BTDC and she's much more responsive and back to her usual self.