1800: Setting Points - Why is it so difficult?

[swedishandgerman]

Originally Posted by fishyboy

Then I set the static timing to 10º at 800rpm, which gave around 17º at 1500rpm and 30º at 2500rpm.

You will get so, SO much more out of that car with a good few more degrees advance at 2500rpm. Fuel consumption, power, response, smooth running and so on

[Clan]

Originally Posted by fishyboy

Hi all,
Why do I find setting point so difficult in my 1968 1800S?

I have always found it really difficult to set the points gap accurately. It seems such a poor set up having to physically rotate the base of the points with a screwdriver. Must have had 4 or 5 separate attempts yesterday before giving up with a dwell reading of 56degrees (from a 0.015inch gap).

I have set Lucas style points with the eccentric screw many times and got it right first time. The Bosch system seems so unrefined.

Am I missing something and is there a better way to set the points gap correctly.

I am tempted to go down the electronic ignition set up (Accuspark) but have been put off due to issues of integration with the armored cable/coil set-up! Maybe its time to bight the bullet.

Phil

Have you still got the genuine points adjusting screw with the built in spring wavy washer ? That is the secret to tightening the screw without the adjustment changing .......

I have heard accuspark units can and do fail from contacts in other classic car clubs .
I have always said that with a carburettor and set of points and a screw driver you can always get the engine going again if it gives trouble , but with electronic devices you stay where you stop until the tow truck arrives .

[fishyboy]

Swedishandgerman
How high should I go at 2500 rpm? I think you mentioned 36º (with no pinking). I think when i tried it this high it was much higher than 9º at idle. I'll have another go tomorrow and record the numbers. If I can't get 9/36º then ther might be something wrong with the advance weights (no vacuum advance on my JF4U 0 231 170 085 which I think is off a B20A engine).

Clan
Not sure what the "genuine points adjusting screw with the built in spring wavy washer: looks like. The screw looks fairly old but there is no washer. Checked on Brookhouse and in the parts catalogue but couldn't find anything? Any chance of photo to help?

Phil

[swedishandgerman]

It’s more specific to the engine Phil, so if it’s not a b20a that the 085 is fitted to, you should do well with incrementally adjusting so that you get the results! If you see what I mean

Definitely try it at 36 dogs or so at 2500. If it pinks under load (it probably won’t) then turn it back. I would say usually I set things to 34 ish.

I am much more concerned about the full speed advance than what it does at idle. After all, most of the driving you do is up around 2500 rather than 850 rpm!

For your info, I think 085 advance at idle is something like 12 to 14 degrees. From memory.

[arcturus]

After having so much trouble with the standard dizy and condenser failures. I am changing to a 123 system. No more points or condenser problems on my B16. Will still carry the old dizy as spare in boot in case of failure. belt and braces!

[fishyboy]

Hi all,
Damn, damn, damn!

Set advance to around 34º at 2750 rpm, but was then 14º at 800rpm. Fairly happy so tried to tighten bolt on distributor clamp and of course the bolt snapped! Found a temporary replacement nut and bolt, but it requires a spanner on both the nut and the bolt head, which is challenging. I assume that the correct size bolt is somehow held in position by the clamp.

I probably should have made it clear that my 1968 1800S is a B18 engine with a JFU 4 0 231 170 085 dizzy, which apparently was used on a B20A engine (https://www.volvoforums.org.uk/showthread.php?t=196277). There is no vacuum advance.

I have got myself a bit confused and have a few questions-

1) Is the ignition timing dependent on the engine (B18 or B20A), the Dizzy (JFR4 or JFU 4) or a combination of both? Should I be using the ignition timing of 17-19º BTDC (100octane) or 14-19º BTDC (97octane) quoted in the 18B service manual or the 21-23º at 1500rpm quoted in the B20A service manual.

2) What advance should I be looking for at idle? 9º (18B JFR4) or something more like 12-14º (B20A/JRU 4) as suggested by "swedishandgerman"?

2) Does anyone know what the max advance should be for the JFU 4 dizzy- should I be working at 32-36º?

3) Finally, does anyone know what the where I can get a replacement bolt from?

Thanks

Phil

[Laird Scooby]

Phil - is it a B18A (single carb) or B18B (twin carb) or are you really lucky and have a B18E EFi?

Second question is what fuel are you running it on? If you're running it on BP Ultimate or Shell V-Power then set the timing for 98 octane - sadly 100 octane or (as it was known) 5-star petrol went out long ago.

If you're running it on ordinary unleaded that's 95 octane so that will have to be a "suck it and see" exercise - advance it as far as you can without pinking.

Also what fluid do you use in the carb dashpots?

If memory serves, the nut and bolt for the dizzy clamp were designed so the nut sat inside one half and had a flat on its body so it wouldn't turn while the bolt was being tightened or maybe it was the head of the bolt that had the flat so the nut could be done up - it's over 30 years since i had a B20A in a 144 and before that, a 145.

I've had (and worked on) a lot more cars since, last count of cars i'd owned was in the region of 235 about 10 years ago. It's not gone up much since though!

[Clan]

Originally Posted by fishyboy

Swedishandgerman
How high should I go at 2500 rpm? I think you mentioned 36º (with no pinking). I think when i tried it this high it was much higher than 9º at idle. I'll have another go tomorrow and record the numbers. If I can't get 9/36º then ther might be something wrong with the advance weights (no vacuum advance on my JF4U 0 231 170 085 which I think is off a B20A engine).

Clan
Not sure what the "genuine points adjusting screw with the built in spring wavy washer: looks like. The screw looks fairly old but there is no washer. Checked on Brookhouse and in the parts catalogue but couldn't find anything? Any chance of photo to help?

Phil

I found this .. see the screw with spring washer ? It is probably the same screw/washer that holds the cap clips to the distributor body ...

[fishyboy]

Laid Scooby
Mine is a twin carb B18B car.
Normally I put in Shell V-power which I believe is 98 oct, but current tank is regular unleaded at 95oct. Might try to use that up before I try again.

I'm using the SU dashpot oil from Burlen so it should be the right stuff (http://burlen.co.uk/dashpot-oil-light.html).

Clan
Thanks for the picture? Can I ask where it comes from?

Thanks all
Phil

[Laird Scooby]

Originally Posted by fishyboy

Laid Scooby

I'm using the SU dashpot oil from Burlen so it should be the right stuff (http://burlen.co.uk/dashpot-oil-light.html).

Phil

No point setting the timing right yet then. Volvo dashpots should have ATF in, it's slightly thicker and the viscosity remains more constant through temperature changes. If you look at this pdf, on Pg9 there is a "sideways" page with specifications and at what would be the bottom of the page, the carb dashpot oil is shown as being ATF* and the "*" refers to a note saying "Automatic transmission fluid, Type A".

http://www.myvolvolibrary.info/Tech_...vice_hints.pdf

Once you've changed the BFS dashpot oil for ATF, then you can have a good go at the timing.