Daf 33 Timing marks - someone confirm please???

[spunkymonkey]

Just done a service on Betty, and I think I may have got the timing wrong last time.

The (oh so clear) Autodata book mentions a single mark on the pulley, which indicates TDC when it's aligned with the crank case joint and that the timing should be set either 4mm before, or after, the joint depending on the exact model.

Betty is the "later" timing of 5 deg ATDC, so that (apparently) puts the mark 5mm past the joint for correct timing.

Last time, I found a single mark and duly lined it up 5mm past the joint. Seemed ok.

This time, with a little cleaning, I discovered there are TWO marks on the pulley. One is scribed on both flanges (both sides of the belt) and there's another one - the one I found before - which is just on the flange nearest the engine block.

Now, I guess that the double mark is TDC and the second is one that they added to show the later timing. So I've re-timed as shown in the photo (about 5 degrees more advance than before) and, again, it seems happy enough. This puts what I assume to be the TDC mark 5mm past the joint, as specified by Autodata.

But, for peace of mind, can anyone confirm that I've got it right this time???

Thanks,

Joe

[jeremy]

Joe, I've always taken the view that the "book" figures are just a starting point. All engines vary and petrol formulations change with time - I suppose the book figures were for 2 star leaded and now we have 95RON unleaded. I would advance it until it starts to pink ("ping for John - one of those rare case where the American English is more descriptive than real English!) under load, then back it off a degree or so.
What I'm waffling my way around to is that if it doesn't pink in the new advanced position, then that's fine.
An old friend of mine was able to flick open the throttle with his head under the bonnet and hear the pinking but I prefer to depress the throttle sharply on the road and listen.
An advantage of setting the timing this way is that you get all the benefits of the fuel, engine tolerance etc which translate into fuel economy or low CO2 emissions.
Jeremy.

[spunkymonkey]

That's how I've generally set timing in the past, Jeremy. Select a slightly high gear, put it under load, and see how it sounds.

Trouble is, it doesn't seem to work too well with the variomatic - you can advance it to the point it'll barely run but when you floor it, instead of pinking, it just changes down through the ratios !!!

[jeremy]

That's interesting, I would have thought that the pinking would show up in the short interval before the ratio changes. I wonder if the lack of a water jacket makes the pinging harder to hear?

On my old 101 Land Rover, I could reach the dizzy from the drivers seat (honestly). This was great fun as I could wind the timing around for max power - although it was better to get a passenger to do it as a belt from the HT is not conducive to steering the beast.

Jeremy.

[daf44]

hi there.

i treat timing marks on old vehicles as vague guidelines and agree with jeremy that they are only a "starting point".

30 year old timing figures can be up to 10degrees out with new fuels.

i set the timing using a vacuum guage where possible, and by ear when i have to.
you can also listen for pinking by reving the engine in neutral.

DAFs DO have a neutral gear. according to my owners manual, it is used for "diagnostic purposes".

basically, my advice is:- ignore the timing marks. set it by vacuum guage or by ear


paul44

[spunkymonkey]

Again, Paul, nice idea but stumped a little by the technology. Having the Eco Friendly "emmision control" version with a 5 degree AFTER tdc idle setting, it actually idles most happily wound up to about 2 degrees BEFORE tdc - although really doesn't like starting at that !!!!!.

Trouble is, as soon as you start to drive, it dials itself lots of advance from the basic to counter the ridiculous idle setting. So, if you set it to max vacuum at idle, as soon as you pull away it becomes gutlessly over advanced on the road (but still no pinking)

The current setting seems ok for starting and for running, so I guess it's a case of see how it goes for now.


edited to add: of course, now Sian has her licence, I could always get her to drive down the road with me hanging out the bonnet to tweak it ;D

[daf44]

hi

it may be worth trying so called "super" unleaded for a week or two as this has a higher octane rating and may run easier with the emission control and timing settings you have.

keep trying.

paul44

[Bob Scrivens]

Hi Joe
Had the same problem with my 33
The sticker and markings on the pulley showed 5 degs after TDC.
Have had the timing light and other test tools check the system, and it does not work with the max vacuum idea.
I have found that the advance induced by the vacuum and weights is about 40 degs if you put your foot down.
I have now back mine off to about 2 deg ATDC
and it seems to run OK, and still has the pulling power.
Still found that these engines have to run on a bit rich on idle to tick over when at stand still.
Funny old game these engines!

Regards Bob.

[starider]

Hi,ought to add my "two penneth",have always set my Daf's using the timing marks.Quite right you use the 2nd of the two marks,the first is TDC the 2nd 5 degrees after.The way I set up is firstly to set the points gap using a dwell meter,this ballances out any wear in the distributor mechanism.I then use a touch of Tippex to highlight the timing marks and use a strobe to set the timing[disconnect vacuum pipe first].I have had few problems with ignition timing,except of course when the points gap closes.Ensure when you have everything set as per.manuals,the engine revs when you brake to a standstill,the revs should drop back to tick-over when the brake pedal is released.The reason this should happen is to keep the clutch engaged to give engine braking almost to a standstill. Hope some of this helps. starider.

[jeremy]

Just when you all thought it was safe to go back in the water... I've set mine at about 4 degrees before and it seems to like it. The book figures assume 88octane 2 star and boggo unleaded now is 95.
Like Bob, I found that it needs to be set at about 3.5% CO at idle to be comfortable.

Jeremy.

[spunkymonkey]

Thanks for all the feedback. She seems happy "on the mark", although I really have to treat myself to a timing light to set it dynamically (drove diesels for the past 10 years or so and lost my old one somewhere along the way )

No idea what the CO levels are at because I've always had a problem with these damn carbs that have volume screws rather than mixture - they just seem so insensitive. May have to make friends with our local garage and beg a few minutes on their analyser instead of relying on my ageing ears

[jeremy]

I used a strobe but the main thing I noted was how quickly the timing advances with revs (and vacuum) I'm not sure how accurate setting it by strobe would be, particularly without a rev counter to set a speed.
Does anyone have a dynamic timing figure for the 33?

Re the analyser, I set the mixture pretty much by ear and observed that it was a plausible 3.5%, ie a little rich by todays, or even the day before yesterday's standards.

Jeremy

[daf44]

at least high co2 levels will not fail an mot.
the nearest dafs get to an emissions test is that you will pass if the car driving behind you can still see through your smoke. ;D ;D

[starider]

Hi,after reading these posts, I have "dug out" my set of DAF 33 Service Bulletins,these figures and script are directly from those bulletins.
E. 0-032 July 1973 Eindhoven. Engine type BM 74 E. Idling speed 900+/-25. Angle of contact [degrees] 57-61. Ignition timing[degrees] 5 after TDC. Vol % CO 3.5 --4.4[measure with a warm engine with the oil at a temp. of at least 60 degrees C]. Four ways valve setting 2700 +/- 50 rpm. Vacuum limit for changing up 2-- 2.5 MWC[Metre of Water Column].
{Angle of contact measured at 2000 rpm engine speed. CO measured at special tube on cross silencer}.
Part of Service Bulletin E. 0 - 026. "the engine is equipped with a modified distributor which,to conform with the air pollution requirements, must be adjusted at tickover to 5 degrees after TDC.The adjustment can be made statically or stroboscopically:in the latter case the number of revolutions must not exceed 950 r.p.m.When the distributor is adjusted using a stroboscope,it is recommended that the vacuum connection to the distributor is disconnected.When re-connecting the vacuum pipe there should be no change in the ignition timing". Hope this helps!! starider.

[spunkymonkey]

Helps a lot, Star - especially the 4-way setting that's 300rpm lower than Autodata specifies. Would be interested in the "on-the-road" method for that sometime!

Nice to have a factory dwell angle (which also disagrees with Autodata), although gap-setting should be close enough on an engine like this I guess.

[daf44]

hi.

just goes to show that you cannot trust timing figures.

set the car up by the book... then go back and set it up by the performance.

[spunkymonkey]

Only trouble with that is actually measuring the performance. Don't think Betty warrants a set of dyno runs & the difference over a few degrees either way isn't exactly noticable on the road with her. 0 - 60 in sometime today is about as good as she gets

[Onne]

0-60 in due time

I'm sure it'll beat my sidevalve Minor though, that takes about 50 seconds to get to 60 I think.

[veeruk]

I set my Little Belter by ear when I got it. I'm being honest, just like my dad, I can have a heavy foot at the lights. I just love it that my 30 year old 2 cylinder jumps off before a modern fast car. It leaves them baffled lol. She pulls off fantastically, however she is missing the little pipe that goes from the exhaust to the carb. I guess it must have rotted and somebody cut it off at some point. So, I need to get her a new inlet manifold unless I can get it welded up again. No probs with that in the summer, but I took her out to Ikea when we had the first cold snap. That is when I noticed that she hesitates every time you want to pull off. I was a bit nervous as I expected the carburettor to freeze up and make the engine die on me. She held up fine though. And, I was impressed that the heater still makes the car cozy(ish) even when it's cold.

[littlebelter]

L.O. Veeruk.

There's a thread about these Manifolds on page 7 of this section (DAF discussion).

You might find it interesting.

Cheers.

Pete H.