I am sorry if this has been covered already, but my search revealed nothing.

I am wondering about the timing for carbs on 1.7 / 2.0 motors. I have read that some use 27 other use 35. What kind of difference should I expect and which is the correct setting for different applications.

For me, I have a 1.7 with and an unknown (carb friendly) cam.

thanks

Using 35 or there abouts may provide for a "peppier" engine, but it will also heat up the heads faster and they will run at a higher temperature which may lead to a dropped valve seat.

I've lost three engines and they were timed at 34, but I cannot place the blame solely on "overadvance" as "overrev" came into play. All were FI too.

i use 28 with my mallory dizzy....

General rule is to advance it till it pings and then back off a few degrees. If you can't hear the pings (loud exhaust or old ears, for example) then you'll generally be safe at 30 degrees. Some engines want more advance, some less, so that's a real general rule of thumb.

Ron's absolutely right, too much advance will make it run hot, and if your carbs are running lean at the same time it will kill it pretty quick. So keep an eye on the cylinder head temperatures and plug colors until you find the right timing for your engine.

Thanks boys!

Just a question on this. When setting timing for carbs should it be set at 3500 rpm?

Depends on the advance curve in the dizzy you're running, compression ratio, fuel type, blah, blah, blah ...

Someone posted a good list of dizzy specs for different displacement engines (Bowlsby?). Then you can have a speed shop with a distributor test machine check it out.

I am using an old 009 dizzy. I am not able to find that list you are talking about. I set it last night to about 27 degrees at 3000rpm and it seemed to run really well. I guess a plug test will tell

Depending upon which 009 you are using, the advance curve may be to short for the Type 4 engine, so your initial advance is high.

The popular 009 used in VWs was used on static engines that ran at a constant speed (powering water pumps, generators, etc).

But if yours runs good, ignore what I said.

i had my engine on the dyno 3 weeks ago and we were playing around with the timing. 27 degrees gave me the highest hp reading.

Still looking for the list I was thinking about, but found another chart in a timing tech article on the Bird Board Click here

How can I tell which dizzy I have? I don't see any markings on it anywhere?

If it is a Bosch ... it will have a number stamped into the case like 0 231 178 009. Even the Brazilian Bosch had it. The 009 was strictly mechanical advance and did not have a vacuum pot attached to it.

At this point, I wouldn't worry to much about it. If you want to read, there are a bunch of threads on this board that define the 009 as better used in a float test in a lake.

I have no dog in this hunt and have never used one when I had 4 cyl engines.

Haha okay then having said that, what would be a good dizzy for me to get given my current setup? I have a 2.0 with what I think is stock cam and dual weber 40s

Could be dangerous advice.

I'd not go above 28 degrees unless you know what pinging sounds like and are able to hear it, or have gauges on the car to tell you where to tune to.

It depends heavily on the engine. On my car, 30 was pinging.

Zach

Just to clarify, you mean 28 measured at 3000rpm or idle?

3000.

I was just rereading the timing procedure and I'm wondering if im even doin it right. I have an adjustable timing light and I just set it to 27 and revved warm engine to 3k and turned distributor until painted mark lined up with notch. However, I am wondering if the painted mark indicates tdc (0 degrees) or if it was put there to indicate 27 degrees in which case I should set light to zero and rotate distributor until it lines up with notch. How can I tell what painted mark indicates easiest?

Found it Click here

If it's a stock 2.0L FI engine, it should be either a 039 905 205 or 039 905 205A depending on the year of the car (actually year of engine and FI system). The 009 shouldn't be used on a Type-4 engine.

There is a mark on mine at 0 tdc and another one for 27. There is another mark. You have to get under the car and look through the hole where the trans mates to the engine (I think). When you can see that mark, look at the indicator on the top of the fan and whatever mark is showing at that time is 0 tdc. The mark not far from it is 27. Clear as mudd??

Right on, flyboy.

When say mark do you mean a notch or a painted mark?

If you are lucky, TDC was painted white (notch, groove, 0 stamped into fan rim) and 27 degrees would be painted red.

If you find TDC, 27 degrees is 55.5 mm to the right of TDC on the circumference of the fan with the fan facing you or about 4 fan blades to the right and near one of the large bosses for the thru bolts that hold the fan assembly together.

Using your adjustable timing light, your procedure is correct. You have already set the timing so turn the light back to zero and see if a red mark shows in the timing window @ 3000 rpm.

Well I did this tonight and although there was no red paint on TDC, I was able to find the groove. When the groove was lined up the rotor was pointing almost right at the grove in the dizzy so it looks good. I turned engine a bit more and sure enough there was the white painted mark at what I am assuming is 27 degrees. It seems to be just like I have seen in this pic http://www.thesamba.com/vw/forum/album_pag...p?pic_id=985064

My question is this, I thought that 27 degrees was BTDC. If that is the case, why does the painted mark at 27 show up after the rotor has passed the groove in the dizzy where the number one spark plug would be? It seems like it would be before spark plug number one. Can someone explain this?

In the Samba fan pic, you see the BTDC advance mark OR slit (no association to SLITS) off to the left of TDC (0) mark. From this angle, the crankshaft rotates toward the left so the 'red' mark will show up in the inspection hole X number of degrees before the '0' (TDC) mark does.

Note, not all fans are marked and not all are marked at 27 degrees. They should have a mark for TDC though. After close to 40 years since the original date of manufacture, many engines don't have the original parts on them. There is a possibility that your fan may not be the original one

You should verify and mark your fan for the advance that your particular engine requires. For example, the full advance on a 039 905 205 dizzy is 20~24 degrees BTDC @3000 RPM ... the full advance on a 039 905 205A dizzy is only 22 degrees BTDC @3000 RPM.

The correct BTDC mark on the fan and the slit in the body (under the cap) of the dizzy should line up at specified full advance if everything is correct. Of course, unless you have a clear dizzy cap and very fast eyes, you'll never see the rotor pass over the slit at the precise time it fires anyway. That's why we have timing lights

What year is your engine?

My engine is a '73 2.0. I have some pics of what I found below. The white paint mark is 4 fan blades from the slit just as in the image from samba. So are u saying the slit is TDC and the white Mark is 27 degrees or is it the other way around? It would make sense that the slit (which apparently should be painted red) Since that comes before the mark painted white but it runs well with white mark set at 27 degrees so i'm confused.

Click to view attachment
Click to view attachment

Hi,

I believe you have timed your car correctly. Pic number one is the 27 btdc mark. It looks red to me.
Pic 2 is in the tdc neighborhood.

Your adjustable timing light delays the stobe by the setting on the dial. If you set it to zero you would see the red mark @ 3000 rpm.

Carlos

Thanks for the reply I guess I just dont understand why the red mark comes before the white mark though. It seems like the white mark (being 27 degrees BTDC) would be before TDC.

The red mark is supposed to come first. It is 27 BTDC. The white mark is TDC. If you did not have n adjustable timing light, you would be seeing the red mark in the notch @ 3k rpm. Since you dialed 27 on your timing light, the stobe is delayed 27 degrees, therefore you see the white TDC mark. If you set the timing light to zero, you would be seeing the red mark. Try it tonight

Carlos

Okay, I got it. So since I have set my timing light to 27 and adjusted for white mark (which indicates TDC) at 3000rpm I have in essence set the engine to 27 degrees. If I didnt have an adjustable timing light I would use the red mark (indicating 27 degrees BTDC). Am I right?

Yes.