07-03-2015, 09:42 AM
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#11 (permalink)
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Not Doug
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Two weeks after I had the timing belt replaced on Bacon it began driving very roughly. The shop that did the work said that the timing belt was off by one tooth and it was "firing on two cylinders." I do not want any part of that ever again.
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07-03-2015, 10:06 AM
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#12 (permalink)
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EcoModding Apprentice
Join Date: Apr 2011
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none - '98 Honda Civic HX none - '00 Chevy (Geo) Metro base none - '00 Saturn SL1 base
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degree per tooth
Quote:
Originally Posted by MetroMPG
For consideration: 40 teeth on a stock 1998 Metro/Suzukiclone G10 1.0L SOCH cam sprocket = 9 degrees per tooth.
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You have to double that because of the 2 to 1 ratio cam to crankshaft, makes 1 tooth effectively 18 degrees. |
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07-03-2015, 10:17 AM
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#13 (permalink)
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Administrator
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The Metro guys actually do have an adjustable cam pulley. I think you can get it in variants of +6, +8 and even +10 which seems to be quite popular as 2000mc posted. I don't know what I'd go with.
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07-03-2015, 10:23 AM
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#14 (permalink)
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Batman Junior
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It also doesn't look like it would be hard to modify the stock cam sprocket.
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07-03-2015, 10:28 AM
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#15 (permalink)
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Batman Junior
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Quote:
Originally Posted by iveyjh
You have to double that because of the 2 to 1 ratio cam to crankshaft, makes 1 tooth effectively 18 degrees.
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Got it - thanks. I'll edit my post. |
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07-03-2015, 10:58 AM
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#16 (permalink)
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Administrator
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Quote:
Originally Posted by MetroMPG
It also doesn't look like it would be hard to modify the stock cam sprocket.
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Yeah, thats kind of what I had in mind. At least give it a try. |
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07-03-2015, 12:05 PM
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#17 (permalink)
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herp derp Apprentice
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Quote:
Originally Posted by iveyjh
You have to double that because of the 2 to 1 ratio cam to crankshaft, makes 1 tooth effectively 18 degrees.
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Spitballin late at night, I thought it was weird people would pay for a 10deg mod if they could get 9deg for free... Obviously not firing on all cyls over here |
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07-03-2015, 12:19 PM
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#18 (permalink)
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Cyborg ECU
Join Date: Mar 2011
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I deleted my earlier post because you are asking about cam timing and I wrote about ignition timing. However, if you adust the cam timing and your distributor is connected to the cam, I suppose you'll want to adjust ignition timing too, unless the cumulative effect works for your plan...
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See my car's mod & maintenance thread and my electric bicycle's thread for ongoing projects. I will rebuild Black and Green over decades as parts die, until it becomes a different car of roughly the same shape and color. My minimum fuel economy goal is 55 mpg while averaging posted speed limits. I generally top 60 mpg. See also my Honda manual transmission specs thread.
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07-03-2015, 12:21 PM
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#19 (permalink)
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Administrator
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Yep, after cam timing has been adjusted, ignition timing should be updated to optimize the change.
As it is, I'm running stock ignition timing and that could definitely be changed for a bump in efficiency.
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07-03-2015, 12:33 PM
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#20 (permalink)
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Cyborg ECU
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Quote:
Originally Posted by Daox
Yep, after cam timing has been adjusted, ignition timing should be updated to optimize the change.
As it is, I'm running stock ignition timing and that could definitely be changed for a bump in efficiency.
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Sounds cool. If I did things like this to my car, and it sounds interesting, I would likely fail California emissions testing. I am not complaining about emissions, just observing the limits for anyone in a US state that has adopted Cali standards (about 30 states, I am told...).
__________________
See my car's mod & maintenance thread and my electric bicycle's thread for ongoing projects. I will rebuild Black and Green over decades as parts die, until it becomes a different car of roughly the same shape and color. My minimum fuel economy goal is 55 mpg while averaging posted speed limits. I generally top 60 mpg. See also my Honda manual transmission specs thread.
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