someone please help timing on 69

[clubryde]

Ok here's the deal i have a type 1 1600. I've been trying to get my timing right on the car and i know you have to match the dizzy to the motor. But if my block number says D0373245 (which is a aftermarket replacement block) if i'm correct. Then what should i set the timing mark too? As far a the dizzy i have a 0231-178-009 with a pertronix ignition kits. I know this might be all over the place i hope it makes sense im just trying to figure am i suppose to be setting the timing at idle or setting it at adv. between 28-30?

[Marc]

That engine ID goes to a 1968 1200cc engine. With a little machinework and longer head studs it could easily be used to build a 1500 or 1600, and would arguably be better than the original 1969 H5xxxxxx case (they were made from a soft alloy which was infamous for failures).
Do you know what timing marks you have on the pulley? If there are two very close together the left one is 7.5°BTDC and the right one is 10°BTDC - your initial timing will probably end up around 10, but you are correct in surmising that best practice is to set it for ~30° total when the the advance is "all in" above 2500 RPM. Since this distributor has only a centrifugal advance mechanism, it can't respond to engine load/throttle position; with no connection to the carburetor or manifold vacuum, that timing procedure can be used on almost any engine equipped with it.
There's not much consistency between "009"s, so set it for 30° and take what you get at idle. If the gas you're burning has sufficient octane for the compression ratio it was built with, you might even be able to fudge it up to 32°...but if you hear any "pinging" (marbles-in-a-coffee-can sound) under load, back down on the timing until it goes away.

[clubryde]

ty so much sir. this helps alot.

[Phil69]

Sorry for hijacking the OP's thread.
H5 code cases are allot softer than other serial numbers.
They suffer from pulled studs and the middle journal tend to get out of shape pretty quick.
Any ideas why Marc?

[Marc]

The `68 1500SP H5 (and 1600SP B5 Bus) were VW's first effort at an emission-controlled engine for the US market. They concentrated on leaning the fuel-air mixture, with the result that the just-rich-enough-to-run engine's operating temperatures went up. They attempted to compensate by using a less-dense alloy in order to improve heat transfer through the case, and the rest is history (as are most H5/B5 blocks - these things were generating warranty replacements when they were nearly new, and they don't improve with age).
Recognizing the failure of this approach, VW then redesigned the oil pressure control system - they incorporated larger passages in the B6 case, pump/pickup, and cooler and added a second control valve to protect the cooler from overpressure when cold, and ditched the "cottage cheese" alloy. The carburetor design was changed, too. Unlike the `68/`69 30PICT-2 carb, the `70 30PICT-3 could be adjusted for a richer idle mixture than was used to squeak through federal testing - but the distributor remained essentially unchanged.
With the introduction of the dualport engine for `71, the cooling system received sweeping modifications - most notable was the placement of the oil cooler outside of the airstream to the LH cylinders; it was given its own air supply with an enlarged fan to supply it. Again the carb was changed (essentially the same basic concept as the 30PICT-3, but larger for the higher-performance aspirations of the dualport) and the distributor incorporated a mechanism to retard the timing severely at idle in order to reduce HC emissions. Early `71 (AE) cases were essentially leftover B6s but later ones have distinctive washboard ribs cast into the flat panel above the dipstick; in my experience those tend to be found in better shape than the "non-ribbed" ones, but I'm uncertain as to why. Possibly just because the compression ratio was lowered with dished pistons on the later engines, or because the oil pump was enlarged (from 21mm to 26mm gears)...but I suspect that the alloy and/or casting process was subtly changed on the ribbed cases.

Bottom line is that the H5/B5 cases were barely adequate as a a foundation for a low-output 15/1600SP; the last thing you should do with one is to build it into anything with higher performance...adding DP heads to one is the kiss of death. If you happen to own one of the few that's still in service, be nice to it in deference to its frailty and start saving your pennies for its inevitable replacement.

[clubryde]

=/ I guess i should start saving. Whomever had the car before i got it did the dp setup on this case. I set the timing to 30btdc and turn the idle air screw all the way until it almost died then back it out 3 revolutions. Now by doing that did i mess up the fuel mixture. Or should i have just set the timing to 10btc and adj the idle screw to til it met the proper idling rpms?

[Marc]

3 turns out from lean stumble is most likely richer than needed...it varies from carb to carb, but as little as a half-turn out from that point is often adequate. Make the idle mixture adjustment at full normal operating temperature; the idle speed should be ~875 RPM. What model is the carburetor? On "two-screw" carbs (like the 30PICT-3, 34PICT-3, H30/31PICT) the speed is set with the large bypass screw on the LH side of the carb - the throttle arm screw should only be barely in contact with the fast-idle cam on those. Dualports are more sensitive than singleports to insufficient intake manifold heat because the airflow is slower through the larger intake tract, and it's more common for them to have complaints of hesitation on acceleration when set to lean-best-idle. The 009 tends to exacerbate the problem compared to a vacuum-advance distributor; a slightly richer mixture is often used to improve driveability.
You need a strobe lamp to verify what the total timing is above 2500 RPM; odds are you're OK at 10° BTDC initial but it's never wise to assume - manufacturing tolerance on 009s is pretty sloppy, I've seen them with curves anywhere from 12 to 24+ degrees wide.
Your `68 D0 case shouldn't be cast from the "bad" alloy that they used in the H5/B5s - once machined out for the larger cylinders it's essentially the same as the `66/`67 F0/H0 cases. Still not a great idea to make one into a dualport IMO (because of the small oil passages) but at least the metallurgy should be halfway decent. If your cooling system is in order I wouldn't lose any sleep over it.

[clubryde]

Marc thankyou so much my carb is a 34pict-3 and the screw that i adj. was the bypass screw sorry i meant to correct my message.

[Marc]

http://vw-resource.com/34pict3.html#carb

[clubryde]

thank you again

[Piledriver]

http://vw-resource.com/34pict3.html#carb

(step 7) ...Next set the volume of gas available at idle speeds. This is done using the Volume Control Screw. Please note that the Volume Control Screw controls the AIR volume, not the fuel volume. Screwing it in reduces the air and makes the fuel/air mixture richer. And of course turning the Volume Control Screw out increases the concentration of air and makes the mixture leaner.

This has a fundamental procedural oops, they are using different names for the same screw in various parts of the procedure. (they call it the "bypass screw" later)

I always think of them by what they DO, the big one sets idle air flow, the little one is idle fuel.

The gist of the procedure is correct if you keep that in mind.

The initial fast idle stop setting at the beginning is one very common cause for off idle stumble.
Just because its the obvious adjustment some folks cant resist to use it for idle speed, and then they cannot figure out why nothing else works right anymore.

[aussiebug]

http://vw-resource.com/34pict3.html#carb

(step 7) ...Next set the volume of gas available at idle speeds. This is done using the Volume Control Screw. Please note that the Volume Control Screw controls the AIR volume, not the fuel volume. Screwing it in reduces the air and makes the fuel/air mixture richer. And of course turning the Volume Control Screw out increases the concentration of air and makes the mixture leaner.

This has a fundamental procedural oops, they are using different names for the same screw in various parts of the procedure. (they call it the "bypass screw" later)

I always think of them by what they DO, the big one sets idle air flow, the little one is idle fuel.

The gist of the procedure is correct if you keep that in mind.

The initial fast idle stop setting at the beginning is one very common cause for off idle stumble.
Just because its the obvious adjustment some folks cant resist to use it for idle speed, and then they cannot figure out why nothing else works right anymore.

I just had a careful read through my own procedure there, and I can't find the error you mention. Can you point me to the step where you think the error lies and I'll reword it if it looks wrong/confusing.

[Piledriver]

I re-re-read it and the oops was mostly mine, but that in itself shows that it could probably use a bit of massaging.

[aussiebug]

Thanks

I'm doing a very slow review of all articles on the site, looking for improved wording