Date: Sun, 29 Dec 2013 18:02:45 -0800
Reply-To: Alistair Bell <albell@SHAW.CA>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Alistair Bell <albell@SHAW.CA>
Subject: Re: Timing Issues
In-Reply-To: <52C0C0CF.7000806@gmail.com>
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I like using tencentlife's method, here it is from the samba ( no tach needed)
Alistair
10cent likes 40*
tencentlife wrote:
It wll be all in by 3000rpm at the most.
Surfalia, there should be two marks on your rear pulley: a "V" notch on the forward rim nearest the engine case, and a shallow "U" dish on the next rim back, about 1/4" counterclockwise from the V when you view it at rest. The U is actual TDC, the V is 5deg. advanced from there (the pulley spins clockwise, so the V will reach the witness mark 5deg. before the U, get it?).
So, at idle, everything hooked up and engine warm, if you point your Flintstones timing strobe at the crankcase center seam, you'll see the V notch aligned with the seam, but it will dance around a bit.
You can do the method in Bentley, but myself, I find it bogus. What matters most in an engine is total advance. If you set it to total, all else should fall into line well enough.
So, 40deg. advance happens to be exactly 2" clockwise on the forward rim of the pulley from the V notch. Bring your pulley to TDC, and measure with a cloth tape or marked strip of paper the 2" to the right of the V, and make a new mark. I use a center punch on the edge of the rim, then fill the punch hole with some light-colored chalk, crayon, paint, nail polish, whatever. Then you just hook up your strobe, warm up the motor, and point your strobe while revving the motor to 3000rpm or higher. Your new mark should be seen aligned with the case seam. Make small adjustments to the diz position until you have it right.
If your principal driving altitude is over 4000 feet ASL, you can add one degree of additional advance for every 1000ft. more than 4000ft. (i.e. at 7000ft. ASL, you would add 3deg.).
With additional advance, you will be seeing the mark to the left of the case seam under the strobe light. The width of the case tab that sticks out is about 10 degrees, so you can eyeball it using that. The margin of error is minus 5deg. but shoot for the full 40 for best performance.
Test drive and check for pinging after tuning. I find it best to remove the engine cover so I can really hear it. With the motor hot, drive up a slope and put the pedal down, but not all the way to the floor. You want to avoid the WOT throttle switch enrichment. With the engine under load but just shy of WOT, you should not hear anything that sounds like a little dwarf that lives in your engine who likes to hammer at the walls. If you hear him hammering, back off the timing a couple degrees, and road test again.
> On Dec 29, 2013, at 4:39 PM, JRodgers <jrodgers113@GMAIL.COM> wrote:
>
> Thanks Mark.
>
> I don't understand the temp II issue. For what purpose would it be
> unplugged if it runs crappy at idle when trying to set the timing with
> the light?
>
> I learn something new about these beasties everytime theres a problem
> and have to find a fix!
>
> Thanks again.
>
> John
>
>> On 12/29/2013 6:21 PM, mark drillock wrote:
>> Just set the timing at idle without unplugging the Temp II. I should
>> have said that I guess.
>>
>> That should get you close enough for it to run alright unless something
>> else is wrong.
>>
>> Mark
>>
>> JRodgers wrote:
>>> Mark, thanks.
>>>
>>> Bentley says warm up, disconnect Temp II, rev to 2000/2500, set timing.
>>> I needed the tach to do that. And it won't stay running long enough
>>> under those conditions to get the timing adjusted. Can't get any rpm out
>>> of it with the Temp II disconnected. Clearly - I must be approaching
>>> this wrong or misinterpreting something.
>>>
>>>
>>
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