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Location:
Colac, Victoria
Registered:
May 2002
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WTD: 2t timing curve graph
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Sun, 21 July 2002 06:14
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Need a timing graph or info on timing curve or similar for a 2t motor , so i can get my 2tb Set up properly with my weber and hopeful cam swap
Anyone able to help .. It seems to be way out
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Location:
Finland
Registered:
June 2002
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Re: WTD: 2t timing curve graph
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Sun, 21 July 2002 13:59
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Somewhere in the net is accurate info on how to diy std distributor for twin carbs & hot cam.
In short:
- std dizzy gives too wide band of advance variation
- hot cam & twin carbs like only about 20 degrees of advance on top of idle advance
- disassemble std dizzy, observe how to limit advance travel
- install weaker springs to mechanical advance unit
- set idle adv to about 13-15 degrees, and limit total max advance to about 34 degrees.
- check with timing light & rev counter that total advance (= 34degrees) comes in at about 3500-3800rpm
This will give you very good starting point to start investigating what advance your engine likes and dislikes. If it knocks heavily under acceleration at certain rpm range - you have too much advance there.
Good source books, see anything written by:
- Des Hammill
- A. Graham Bell
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Location:
New Zealand
Registered:
May 2002
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Re: WTD: 2t timing curve graph
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Mon, 22 July 2002 02:29
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hmm, this is very interesting.
I'm going to wire up the Jaycar programmable ignition kit for my 2TGEU next week, and I'll need some sort of figures for it.
So....
Base advance on 2TGEU is about 12 deg.
What is the full advance amount?
When does it come in at?
Is the advance curve linear or exponential?
Thanks,
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Location:
Colac, Victoria
Registered:
May 2002
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Re: WTD: 2t timing curve graph
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Mon, 22 July 2002 02:45
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these days a 2tgeu would be a godsend - 80 % of mechanics these days rely on a damn computer to tune a motor - rather then their skills ..
makes you wonder sometimes .....
thanks for the info on setting it up in a nutshell - though im running a single 45 in leu of duels .. shouldnt make much difference overall
stuart
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Location:
Tasmania
Registered:
May 2002
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Re: WTD: 2t timing curve graph
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Tue, 23 July 2002 01:22
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So are we saying, that with big cams/ carbie etc, you should have weeker advance springs so the advance comes on early, and then stays advanced (limited) for the rest of the rev range? If you want the advance to come on so early and stay there, you may as well bring up the idle and fix the advance. ??
I would have thought it would be better to use stiffer advance springs, so the advance would come on progressively with rpm. ??? no?
I think the base advance setting would depend alot of what idle speed you wanted.
I wonder what I should do when I get a 290 degrees cams for the 2TG?
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Location:
Finland
Registered:
June 2002
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Re: WTD: 2t timing curve graph
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Wed, 24 July 2002 16:51
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There seemed to be some interest towards the subject at hand, so I decided to plough through my hectic array of bookmarks. Maybe this would be the day to do the lottery as well - I found the link I wish to pass onto you all.
This site has a lot of good information. Here is the main index:
http://hometown.aol.com/dvandrews/
Here is a shortcut (from the said index page) to read on how to modify ignition advance:
http://hometown.aol.com/dvandrews/timing.htm
---
I know it can be tiresome when people are posting endless stream of (afterall worthless) links to all kindsa rubbish. I stand behind my first class(?) judgement and urge all gearheads to explore also this addy - happy & informative readings to all.
http://www.pumaracing.co.uk/mainmenu.htm
(note - while there, do not miss their link section - be sure to visit "SDS tech page")
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