Changing from 95 Ron to 98 Ron

[Chris A]

My 13/60 is currently set to run on 95, there is no problem with it and I am quite happy as it is. However, I am thinking of resetting it to run on 98 so I looked at the manual to see what is involved. As I see it all the needs to be adjusted is the static timing and this is set with the knurled adjuster on the dizzy and by looking at the number of divisions visible at the vacuum end?

I have no idea how many degrees BTDC it is set at so I thought – if I look at how many divisions are visible that gives me the setting, 1 division = 4° according to the hand book.

Snag is as can be seen in the photo there are no divisions visible so I guess when the timing was set whoever did it simply turned the dizzy body until they got a smooth running engine on 95.

Does this mean I need to go the complicated route and have the timing checked with a strobe and then reset it to run on 98?

A previous owner also decided the dizzy looked better painted black, I have cleaned a bit off so as to be able to see the divisions easier, had there been any to see.

I’m sure I can rely on you guys to come up with various methods, preferably including one that doesn’t require anything more than turning the adjuster a little. Fingers crossed.

[Pete Lewis]

your dic=visions on the vac unit are hidden as its screwed right in if you undo the knurled ring they will apppear

they wont help you as you dont know what the static timing is at present 

do you have the marks on the crank pulley and the timing cover ???

easy to diy a simple check on static setting 

get a small bulb and wire  or circuit tester etc  connect on the coil to dizzy 12v terminal and earth 

discon the coil or remove dizzy cap .

ign on and in top gear 

push/ nudge car till  rotor is  nearing to pointing at no1 ht lead position

as the cam rotates in the dizzy it opens the points as soon as they 'break' the lamp will light up

so a gentle re nudge to getit just on , look at the timing cover and crank pulley marks , see what you have 

the worst situation is some 13/60 dont have a mark on the crank pulley they use a hole which is as much use as a chocolate tea pot 

daft but there can be timing marks on the flywheel but hidden within the clutch hsg.  most useful !!

then you are back to turn the dizzy to get the fastest idle and back it off a bit , you dont want  'best'

take for a run pull in 4th at 40mph if she 'Pinks'  retard till the the pull is pink free 

Pete

 

 

 

[NonMember]

With the adjuster screwed all the way in, like you have, you are maximally retarded for the position the distributor is clamped in. To convert to 98RON you'll want to advance it a fraction.

Don't get hung up on official static advance figures. What your engine needs will depend on the condition of the engine and the characteristics of the fuel you put in. Both are likely very different from what they were in 1970. I'd turn the knob to get a bit more advance then try the 40mph in 4th test.

[Chris A]

Pete, as usual a very well detailed answer to a question asked here, however NonMember's answer is much more in keeping with my technical abilities .

"A bit more advance"? what a couple of degrees? 3 revolutions of the knob?

Thanks to both of you.

[NonMember]

The Vitesse manual suggests 3 degrees between 4* and 5* (97 vs 100 octane) so a couple or three degrees is probably about right. However, the fact that somebody has turned your adjuster all the way might suggest it's not quite as retarded as they intended, so maybe 2 rather than 3. At the end of the day, though, if you can dial in 3 degrees without making it knock at 40mph in 4th then I'd go with that. If it does knock, dial it back a little.

[RogerH]

Hi Chris,

    why are you changing from 95 to 98.?

 

Roger

[Chris A]

Hi Roger, you get the prize for asking this question I expected someone to ask.

Having read about the levels of "additives" in 95 that don't sit well with our beloved motors, that 95 causes higher running temperatures and that 98 has less of them( I believe) I thought I might go that route. I'm not looking ( well a bit maybe) for increased performance, the car can still give moderns plodding along our rural roads a shock as I overtake them.

The car, as I said runs well on 95 and I don't have any overheating problems as a rule. I just thought I would float the idea.

[Chris A]

An update on where I am with the change from 95 To 98.

Having run the 95 petrol in the tank down to virtually empty and filled with 98 I have been gragually advancing the ignition via the knurled nut on the distributor by 1 revolution increments. After each change I drove the car until fully warmed up and them did the "40mph in 4th" test as recommended by members on here.

Well, the timing has gone from the fully retarded position on this adjuster to the fully advanced and I don't seem to have  any running problems doing the test. although I have to say that the last run with it fully advanced did give my the feeling it wasn't running as smoothly as the previous setting, fully advanced minus 1 revolution so I have reset it to fully advanced minus 1 revolution ready for my next outing, which will be sunday for a club run at the latest.

I gather that the marks on the shaft by the vacuum unit are at 4° intervals, ther seems to be 4 or maybe 5 intervals, so 16 to 20 degrees of adjustment if this is correct.

I really find it hard to believe that the timing can be advanced this much without getting severe running issues. Maybe even though the shaft is moving there is something wrong internally and the timing hasn't been changed.

Any comments, thoughts or advice?

Baffled in Normandie.

P.S. The Sunday run should give plenty of time to do the 40 in 4th test as one of the cars will be a 1937 Peugeot which 'cruises' at 30 to 40....

Thanks all

[NonMember]

If you've managed to get past the point of noticing a deterioration in the running, then you're probably several degrees over-advanced even if it's not pinking. Depending on the original market, some Herald engines were quite low compression (for the old 2-star fuel) and might not pink on 98 RON even if over-advanced.

I think I would get it nicely warmed up then, at idle, retard it until the revs just start to drop off.

[johny]

Im afraid I think you really need to find where your timing setting is either using Petes method above or if possible with a timing strobe light. With a bit of luck you can run your engine on 98 at the standard timing so avoiding any retard but note: theres no use in advancing more than the recommended value even if theres no knocking....

[Chris A]

2 hours ago, NonMember said:

If you've managed to get past the point of noticing a deterioration in the running, then you're probably several degrees over-advanced even if it's not pinking. Depending on the original market, some Herald engines were quite low compression (for the old 2-star fuel) and might not pink on 98 RON even if over-advanced.

I think I would get it nicely warmed up then, at idle, retard it until the revs just start to drop off.

The car and engine is a standard UK model.

I'll try your method when the weather permits.

Thanks for the help

[Chris A]

3 hours ago, johny said:

Im afraid I think you really need to find where your timing setting is either using Petes method above or if possible with a timing strobe light. With a bit of luck you can run your engine on 98 at the standard timing so avoiding any retard but note: theres no use in advancing more than the recommended value even if theres no knocking....

Thanks for the input. If I am still strugling after Pete's method I'll go round to my local mechanic who has done other work on it and get him to check it.