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Sun Nov 08, 2009 1:21 am

I've a 0-231-168-005 distributor on a man trans '77 2L bus. I've been timing it statically for ages and never had any issues but recently come across arguments calling for timing with a strobe. I thought I'd give it a try, as soon as I can get a strobe light, but am having trouble interpreting the data given on OldVolksHome: viz.

Timing Set At:: 7.5deg BTDC @ 850-950 rpm (Man Trans), 900-1000 rpm (Auto Trans) w/strobe, vacuum hose connected
Advance/Retard Range: Vacuum: 8.5-11deg Adv @ 7.9 In. Hg; Centrifugal: 8-13deg @ 1600 rpm, 20.5-24.5 @ 3400 rpm

Would the procedure according to the data above be: statically time to 7.5*BTDC with engine off. Start and warm engine; adjust idle to 850-950rpm. Disconnect vacuum hose - check and adjust timing to 20.5-24.5* at maximum advance (3400rpm). Check advance (8-13* w/- vacuum disconnected) at 1600rpm and again at idle (8.5-11*) with vacuum hose connected. Check maximum advance with vacuum hose connected and make sure the advance is not above 32*BTDC? (Can't say where I remember getting the last figure from.)

As a side note: in Muir's book he says to time the engine statically **cold**. At AircooledTech.com however they say to warm the engine up before timing statically. Any comments?

Just another question: I've also got a 1600 (single port I believe) '61 beetle with a 28PICT carb and ZV/PAU 4R5 distributor. I've heard that the carb is not good for the engine but it seems to run well enough. Question is, with the timing stats from OldVolksHome being:

Timing Set At: 10deg BTDC Static or @ 800-950rpm w/strobe w/vacuum hose disconnected and plugged, Advance/Retard Range: Vacuum Advance Only: 10deg @ 1.3 In. Hg, 15-21deg @ 2.8 In. Hg

Does this mean that it's best timed statically?

Sun Nov 08, 2009 8:50 am

Two different questions regarding two different systems here.
For the 77 bus the mechanical advance is really all you have to be concerned with, the vacuum sorts itself out.
The 20.5-24.5 @ 3400 RPM gets added to the 7.5 deg base setting for a total of 28-32 deg max @ 3400+ RPM. With the vacuum hoses off you are looking for those numbers at or near 3400 RPM (exact RPM not important, rev it until the mark stops moving). Check it with the hoses on if you like but it'll be more than the 28-32 and different every time.

Timing the 61 Beetle is a little different as there is no mechanical advance and it's difficult to simulate all engine loads and throttle settings in the driveway so static is likely the better option here but check it with a light anyways. Same deal with the math though 10+21=31max (seeing a trend here?).

Sun Nov 08, 2009 9:12 am

They give you all the extra timing numbers so you kind of know what the timing curve is supposed to look like. If you are not having problems then just timing it at full mechanical advance will do fine, as Busdaddy said the exact rpm isn't important, just rev it until the advance stops. I don't know where the idea that static timing will not work for a T-4 motor came from. If you know what you are doing and the dizzy isn't so worn out it should be tossed, it will work absolutely fine. Timing an engine at idle with a strobe seems to be beyond many people, experience has shown me that an awful lot of people end up with their timing way off using a strobe at idle.

I check my own timing curve with a strobe every few years to make sure the dizzy is operating properly and the rest of the time I just check it statically. Checking the timing statically only takes a wrench to turn the engine, and not even that if the fan inlet screen is missing so you can turn the engine by grabbing the fan hub.

Sun Nov 08, 2009 10:10 am

Wildthings wrote: I don't know where the idea that static timing will not work for a T-4 motor came from. If you know what you are doing and the dizzy isn't so worn out it should be tossed, it will work absolutely fine.

Exactly, there's no reason it won't work if you know what you are doing and you know the distributor is working properly, but a noob with a questionable distributor can't really screw up 28-32 @3000+ with the hoses off and you can always check it at idle or static after. The bottom line is timing at speed though and that reading/setting has priority over all the others, your bus isn't idling when it's going down the highway.

Sun Nov 08, 2009 10:37 am

When your engine runs at idle at cruise speed, static timing will be effective..

Ignition timing is critical.

Mon Nov 09, 2009 2:53 pm

Jake Raby wrote: When your engine runs at idle at cruise speed, static timing will be effective..

Ignition timing is critical.

Every thing has it time and place. By using static timing I can check my timing in seconds with zero tools. Just put the tranny in neutral, turn the ignition on, walk back to the engine compartment, remove the coil wire and then turn the engine over by hand while watching the marks and listening for the spark. Reinsert the coil wire and I am done, no tools, no wasted effort. If it is shown to be different from what it was the last time I checked it and set it, only then is it time to get out the tools.

I check the timing on my own bus very frequently because doing it statically is so very easy to do, if I had to grab a timing light to check it I would check it infrequently like just about everyone else.

Timing is critical and in order to know if it has changed or not you need to check it, here static timing just plain rules.