Does anyone hav ethe stock timing curves for a 73 b20f. By timming curves I meen a chart or similar document that gives the ignition timming with all vac hoses hooked up at different rpm points. A good diagnostic tool to have for your dizzy, I suspect that mine is sick, so I would just like to check. If such a list doesn't exist, and you would like to make one,knowing that you engine is in a great state of tune, the next time you are under the hood and have a few miniutes to spare hook up your timming light and take readings at every 250 or 500 rpm. This can serve you well in the future.

Thanks for any info
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65 122s/73 1800es/80 262c(350ci v8)/89 745t/87 780/89 740/89 740t/ 86 745

I have a 72' 140 Green Book (Genuine Volvo Manual)

B20E&F
Bosch JFURX4
Cenrifugal Advance:
Total 12.0 +/- 1 degrees at distributor.
Begins at---------- 375-550 distrib. RPMs
5 distib. degrees at 610-800 distrib. RPMs
7 distib. degrees at 970-1140 distrib. RPMs
9 distib. degrees at 1200-1375 distrib. RPMs
11 distib. degrees at 1300-1450 distrib. RPMs
12 distib. degrees at 1500 distrib. RPMs

Vacuum Retard:
Total 5 +/- 1 degrees at distributor.
Begins at 30-110mm Hg
3 distib. degrees at 80-125mm Hg
Finishes at 130mm Hg


As Rhys says, don't bother connecting the vacuum.


Cheers,
Paul.

Thank you very very much, When is the brickboard going to have a faq for classic volvo's(mind you a 84 740 is now considered an antique )
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65 122s/73 1800es/80 262c(350ci v8)/89 745t/87 780/89 740/89 740t/ 86 745

Aside from my message below, re that emission testers may not like your aftermarket equipment...

I recalled that, when I used to have a 1973 164, B30F engine, I had worked out the advance curve. Realize that I measured it (with a timing light, as was suggested -- mine had an advance "wheel" that I could turn to rezero at each rpm, hopefully for more accuracy -- but it was a home-made unit, a "HeathKit" electronic project kit, so I can't promise exact accuracy.
But I've found the graph that I made and kept tucked inside my '73's "green manual" (I never throw things away).
So if a B30F (instead of your B20F) is of any help:
[Note: I did not record the overall BTDC, but only the amount of advance, or how much BEYOND the BTDC at idle -- I was planning to fiddle with the advance curve using different springs]
Here are the empirical data points from my graph:
At 400 distributor rpm (double this for engine rpm), 0 deg advance (over idle advance).
at 500 " " , 1.5 deg. more
at 750 " " , 5.0 deg. more
at 1000 " " , 7.5 deg. more
at 1250 " " , 9.0 deg. more
at 1600 " " , 10.2 deg. more
and it leveled off beyond that rpm.

Even if not exact, it should be within the ballpark, I think.

Thank You very much, I also have a problem giving good stuff to the weakly collection people, you never know when and why you will need it.

Thanks
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65 122s/73 1800es/80 262c(350ci v8)/89 745t/87 780/89 740/89 740t/ 86 745

It's actually quite simple to check without factory data. At the crank, the engine sees 10 degrees or so BTDC at idle speed. At 3000-3200 RPM there should be 34-36 degrees at the crank. There it stays all the way to whatever redline you choose. With a primary and secondary spring there will be a small bump or flat spot in the curve as one gives way to the other, and all you can really change is the rate at which each achieves its full travel.
A sick distributor probably has some spark scatter, resulting from a worn cam or bushings. It may also have sticky weights and not retard or advance reliably. Spin it on a distributor machine and measure the angular variation, and plot the curve. If it runs out about 12-14 degrees on the distributor, all is well. The vacuum retard function is brutally simple and simply takes out about 7-10 degrees of advance under conditions of low manifold pressure. Don't even connect it.

As Rhys says make sure you are getting 34 at 3000+ rpms

Also, check it on number 4 as well, this will give you some idea of how worn the dizzy is, if it is bent, if the cam is worn funny.

Cheers,
Paul.

I've heared of a handfull of people that have changed B20's over to MegaSquirt, an electronic hobbiest FI system. Since they have done it, they will be able to provide you with a timing curve and a vacuum advance curve. Being hobbiests, they would also have experimented with optimum curves. Just do a Google search for "MegaSquirt Volvo".

Niel Thanks for the info, I am seriosly considering megasquirt for enviromental reasons, Since it uses on o2 sensor, it is compatible with a catylitic convertor. People think I am crazy wanting to add a catylitic convertor to a classic car, but hey I want to be able to drive it in 10 years when polution laws will be harsher to us oldtimers! Also since i drive 40-50k a year a little less polution can't hurt.
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65 122s/73 1800es/80 262c(350ci v8)/89 745t/87 780/89 740/89 740t/ 86 745

re: "...I want to be able to drive it in 10 years when polution laws will be harsher to us oldtimers...."

Hi.
One of the things that are examined (in some states, like CA, I've heard) is that the automobile be 'stock'. Cars with aftermarket modifications (e.g., high performance ignition systems) can be rejected -- the automatic assumption is that the modifications increase pollutants (kind of like guilty until proven innocent) unless the product has been pre-approved (you may need a certificate for this). You might have to invest a LOT of money to get your car tested -- if you're even offered that defense, which they may not.
So cobbling together your own "advanced" emission control system may not be appreciated by the authorities 10 years from now. You'd first better look into this with your local authorities.
On the other hand, the authorities cannot make emission requirements for your model year that's stricter than the limits that the car was originally designed to meet -- in fact, most states actually loosen the standards a bit to accommodate the effects of age on such older models. If you've got a car so old that it was built before there were any emission standards, you're probably "home free."
And, on the other hand, there might come a time when you don't want to drive your old car 50,000 miles a year, but nevertheless want to keep it for sentimental reasons. I have a '75 Volvo (a 164) that I had registered as a "collector" car (based on its age, >25 yrs), and here in N.J. it is exempt from all emission and safety examination. The only downside, for you if you want to use it as a daily driver (which I don't), is that I have to show up at the inspection station to show that my annual mileage is less than 3,000 miles per year [and I have to drive around the block of the inspection station, to show that the odometer is hooked up and working :-) ].

Hi Here in Quebec they are talking that they will force cars more that 20 years old off the road, or for special use only, ie: 3000 miles or less per year with a yearly safety inspection. If your car passes emision testing of a car less than 20 years old (ie1984 emissions standards) you are home free to drive when and where you want, my goal!

Thanks
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65 122s/73 1800es/80 262c(350ci v8)/89 745t/87 780/89 740/89 740t/ 86 745

That's very hard! But I would be able to pass the 3000mi limit, as I drive about 3mi to work each day...

Here in New Zealand they do a safety inspection every year, or every 6 months if your car is older than 6 years. There is talk of introducing emission testing, but for cars before I think '75 it will only be a visual (smoke) test.

I really hope that they do not get so hard in Quebec.

I am for some type of testing. At the moment there is only a manditory instection if the car is importesd from another province or country, or if the car has been unlicenced for more than a year. The condition of some of the cars on the road is pittyfull to say the least. The police have the authorisation to stop a vehicule for obvious saftey discrepencies(ie burnt out lights ect.) but this doesn't give them any revenue so it falls to the bottom of the list(understandably, as they are already overworked and under funded). The exception to this is the local police force in Granby Quebec, they are to say the least over-zealous. They are on a anti harley,honda, V8 anything, lowered crusade. They regularly harass the local motorcycle comunity to the point that last summer during a fund-raiser for the hospital, in which people pay for a ride on a bike, they stopped a large percentage of the volenteers to give them tickets for excessive noise(personally if I were to take a ride on a Harley I would want the full experiance, give me noise vibration and insects on my glasses). Extreemes are everyware.
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65 122s/73 1800es/80 262c(350ci v8)/89 745t/87 780/89 740/89 740t/ 86 745

Here in New Zealand we get almost all TV programs late, so please excuse me if you have seen this Top Gear episode ages ago: Last night the presenter said that in London you get a ticket for improper parking. That is if you are parked over the line or at a slight angle to the line. The problem was he got a ticket, but the box was too small for his car to fit in! Another interesting one is that at a city center parking building you pay 20 pounds for the first hour, and 40 pounds for 1 hour and 5 minutes (i.e. for the second hour). So ghe parked illegally in the road, went to the movies and shops for 5 hours with his family, and the parking ticket was only 48 pounds (or something like that). Sometimes crime pays!

Wow, my '71 144 has 115 000km (70 000mi) on the clock, that's what you do in less than 2 years! I've been looking at both MS and ignition ionisation current sensing, as I've been into electronics for 18 years and currently work in electric fence R&D (play with 10kV sparks). MS is an excelent design.

I'm not an oldtimer, I'm 30 years old. But I own my father's 33 year old car and have now started listening to his music (The Mills Brothers, The Ink Spots, etc.) because I enjoy the good stuff.

Hope you manage to find all the info you're after.

Old is a relative term, I was once told you are only as old as you think you are. I'm 36 but have been around the track a few times(people think I am at least 45, the grey beard and volvo's will do that to a person). When I was younger(when boosting a car didn't involve watts, amps, and woofersb but cams, sway bars, and cubic inches) I amazed my friends to no end with my volvo's(Camaro's and Mustangs were of choice then, pre-lowered rice rockets) handling. As I put it a big engine won't always get you there faster, just more expensive, I prefer lateral G's to inline.

Have fun
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65 122s/73 1800es/80 262c(350ci v8)/89 745t/87 780/89 740/89 740t/ 86 745