Timing Question: Any Harm in Increasing the Advance?

[Phaedrus]

As the title says. Curious. Playing around with the timing after a full tune, I noticed a marked difference in pep advancing about 4 degrees past 37 btdc. Nothing crazy, but just a little bit quicker response. Didnt really notice much difference on hills. Idle was a bit high though, maybe 900-1k. Set her back to 37 degrees, proper idle.

Question is, does it hurt the engine in any way to increase the advance? What are the downsides? I.e. why should I not go past 37 btdc?
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1986 WBX (Tin Top Camper)

[captcory]

too much advanced timing will cause pinging "detonation" and can burn a hole in the top of your piston.
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Cory Cotherman

[Phaedrus]

K, but how much is too much? Ive heard the wbx is pretty resilient to pinging. How much room do we have to play with? 4 degrees, 10 degrees, 20? Gimmie more to ruminate on.
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1986 WBX (Tin Top Camper)

[Ahwahnee]

I've run 40° BTDC all-in with all hoses connected for many years w/o issue - this on a GoWesty 2.2L Digijet.

The risk is pinging as noted. You can listen for pinging at low speed (accelerating hard in 4th to create a load).

The problem is a ping at high speed -- you'll probably never hear it -- and that is the ping that will get you.

[UrS6Vanagon]

I advanced my timing an additional 4 degrees to help compensate for the high elevation where I live (8500 ft). Most of my driving is in the 7k-12k ft range, and from what I've read it's safe to advance it a few degrees if your normally above 4k-5kft. It's helped the engine feel a little more lively and I haven't had any pinging.
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1986 Westfalia Weekender
2019 VW Golf R
1995 Audi S6
1987 Audi 4000 quattro
2011 Nissan Pro-4x

[bluebus86]

[Phaedrus]

Ah, yes, but the prophet hath spoken to the Vanagon God and doth bequeath us with His knowledge:

[UrS6Vanagon]

Yeah, I mean I haven't heard any pinging. I've been driving it this way for about 10 years without any issues. The need for higher octanes to reduce pinging also decreases with elevation, however I've always used 91. I wouldn't run too much advance at sea level but for my application it runs better overall. Apples to Oranges but my 2011 Nissan truck has the option to advance the timing 2 degrees. This can be done at the dealership or with an aftermarket programmer. Why didn't Nissan just make all of their Frontiers run the additional 2 degrees if they can safely handle it?
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1986 Westfalia Weekender
2019 VW Golf R
1995 Audi S6
1987 Audi 4000 quattro
2011 Nissan Pro-4x

[nemobuscaptain]

Digifant:
Timing Set At:: 5deg BTDC @ 2000 rpm w/strobe. Thermotime Sensor (Digifant ECU Temp Sensor II) must be disconnected when performing timing adjustment. Engine Oil Temperature must be at 80c (176F) minimum.
Advance/Retard Range: Digifant ECU Controlled: 35deg @ 3000 rpm (+ or - 5deg)

Digijet apparently had up to 47 degrees max
Timing Set At:: 5deg ATDC @ 850 rpm w/strobe, vacuum hose(s) connected. Idle Stabilizer must be disconnected and it's plugs directly connected together (bypassing the Stabilizer) for accurate timing with strobe. Reconnect Idle Stabilizer when timing is set.
Advance/Retard Range: Vacuum: 12-16deg Adv @ 10.6 In. Hg, 9-11deg Ret @ 10.6 In. Hg; Centrifugal: 16-20deg @ 2400 rpm, 21-25deg @ 3800 rpm


http://www.oldvolkshome.com/ignition.htm#V8691
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Ohio Valley Tribe, Full Moon Bus Club https://www.facebook.com/groups/294422277314227/

https://www.facebook.com/groups/FullMoonBusClub

RIP Bob Hoover https://www.thesamba.com/vw/forum/viewtopic.php?t=427791
Hoover Sermons: https://www.vwsage.com/images/vwsage/Bob%20Hoovers%20Sermons.pdf

[danfromsyr]

you can always add a stand alone knock sensor monitor and then adjust accordingly.

it's best to be educated when messing away from factory settings.
https://www.google.com/webhp?sourceid=chrome-insta...k%20sensor
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[jberger]

The WBX is resistant to knock.. however it is quite a bit less so if you have Brazilian Piston sets or some other hackery that increases deck height.. That being said, the Digifant protraining manual states something about checking total advance after setting idle timing that it must advance 35° over the initial setting +or- 5°.. so I have always taken that to mean 45° of advance at 3000rpm is safe for stock engines. And indeed I have driven them timed like that for Thousands and thousands of miles. YRMV.

As a side note, as can be read in some of my engine build threads I have also experienced severe knock\pinging in non stock engines, over time\miles and the heads of the pistons were just fine. The only results... rod bearings that will fall off the rod when disassembled from the hammering action. Not damaged or spun mind you, just un-sprung

[DenCon]

I just set my '85 to 40° BTDC (everything connected, ≈3K RPM). Woke that Vanny right up and it starts more easily and I haven't heard detonation.

[jackbombay]