Timing type 4, 2.0 L dual dellorto 40’s w/ Petronix ignition

[buzz cut hippie]

Not having luck finding timing information when I search on the forums. Tips or pointers on how to search? Links? And yes I know this question has probably been answered and discussed thousands of times on the Samba but I can’t seem to find those threads. Would like to set proper dynamic (and static) timing on my type 4, 2.0 L engine with dual 40’s dellortos. Thank you in advance to all responses!

[skills@eurocarsplus]

you want about 30-32* @ 3200 RPM, vacuum hose disconnected and plugged. where it falls at idle doesn't matter...unless you have to pass emissions testing
_________________

[buzz cut hippie]

Right on. Thank you. Curious about why the number 3200 rpm is used as the reference point to set dynamic timing? Is that the power point or responsive range of acceleration on the engine?
At a highway speed of 65 mph I believe my rpm is between 3500 to 3800 depending on conditions— wind, incline, cargo weight etc

[buzz cut hippie]

What should the static timing be set at?

[SGKent]

Disconnect the vacuum advance hose then run the engine up to where the timing stops advancing. That is around 3200 RPM +. Then set the timing at 29 - 30 BTDC. You'll have power and the engine will run cooler than 32 BTDC. Make sure your timing scale is accurate. You don't time a VW engine statically except to start it the first time, and then you immediately set the timing. When you are done reconnect the vacuum advance and BE SURE it is connected to the ported vacuum meaning above the throttle plate. These instructions have been given some 45,000 times by 3500 different members here so I call BS on you couldn't find it.
_________________
"Most people don't know what they're doing, and a lot of them are really good at it." - George Carlin

[buzz cut hippie]

Thank you kindly for the accurate information. When you call “bs” on I couldn’t find it, are you saying that 45,000 other people had the same problem I did? Lol 😉

[Wildthings]

Since SLC is 4000+ feet in elevation I would tend to use the slightly more advanced timing that Skills suggests, it is within book specs for sea level and should be just about right for your elevation.

In answer to your question about the timing to go with your carbs, timing doesn't vary much between various fuel systems, the ignition system makes no difference assuming the timing curve is the same. Pretty much you want your burn completed at around 11 degrees after top dead center no matter the make of the engine, fuel system, or cam. The fastest burn for the mixture is near stochiometric and as you lean out from there the burn slows which is part of the reason to have a vacuum advance setup. A richer mixture than stochiometric will be more stable and thus less prone to knock and to a point will put out more power than a stochiometric mixture.

[buzz cut hippie]

Wow very grateful for your fascinating and valuable information

[SGKent]

[KentABQ]

[SGKent]

[KentABQ]

[alman72]

me too. that guy was the bomb. at least his threads of knowledge still exist to help others.

[CarlosZ]

Happy new year everyone. Am I supposed to A)plug the vacuum port on the carb while leaving the distributor end open or B)Leave both ends unplugged while timing an svda with 40 IDFs? I’m assuming (A) but it’s been described so many different ways and lingo varies a bit.

SkillS states “disconnected and plugged” while SGKent says “disconnect the vacuum hose”

Don’t meant to beat a dead horse with a stick but I’ve always wondered if I did it correctly. Thanks!

Type 4
SVDA
40IDFs
Petronix

[busdaddy]

On models with advance only there's usually no need to plug anything, plugging is required on a retard line (carb end) because it causes a huge vacuum leak and won't idle correctly (or at all).
IDF's should idle fine with the hose disconnected and left open since they shouldn't start making vacuum until you open the throttle, by that time a small leak doesn't effect anything that concerns you for just setting the timing.
If you do notice a change when you pull off the hose you should confirm your throttle plates are closing fully before proceeding further, that's going to cause problems if you leave it alone.
_________________
Rust NEVER sleeps and stock never goes out of style.

Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!

Слава Україні!

[TomWesty]

Plug the carb port so no vacuum leaks. Distributor end open so no vacuum signal to distributor.
_________________
If you haven't bled on them, you haven't worked on them.
Visit: www.tomcoryell.com and check out my music!