unleade or not unleaded

[MJ]

Well our 89 1.7 runs happy on unleaded, I think it likes Optimax a bit more though

[shimon340]

Cars that used to run on leaded fuel have a "leaded memory" ie a build up of lead based compounds on the valve seats. This material stops the local 'sticking' or spot welding of the valve to the seat. The continuous contact and breaking contact with the tiny local weld sticking effect is what causes valve seat recession if the valve seat isnt sufficiently hard material. The lead compounds deposit on the valve seat and prevent the wear of the valve seat ie valve seat recession. This wasnt an intentional design nor a direct use for lead in fuel ( it was added to increase octane number and reduce pinking or detonation ). Once discovered, manufactures used the fact the lead was in the fuel... ie they relied on the lead to prevent valve seat recession and didnt bother fitting harder valve seats.

The lead memory takes about 10,000 miles to degrade fully.. after this you get valve seat recession. Hence this is why some people who change from leaded fuel to unleaded report "no problems with starting etc" and "the engine runs better" The first comment is due to the fact the engine is still relying on the lead memory and the second one is most likely due to the comprehensive detergents in modern fuels which have probably cleaned up the carb and fuel system including valve deposits....

The best thing is to use a phosphorus based lead replacement additive like castrol. I need to check what Millers additive is based on....

Volvo personally had trouble with LRP lead replacement petrol. This isnt made anymore and had a relatively short market life... it was potassium based and caused problems!! Volvo inadvertantly discovered this when Shell accidently delivered some LRP to volvos engine test labs.... oops.... the LRP damaged some prototype engines especially the turbos! This is why volvo advised against LRP

The fuel issue for older cars is either or both of the following

1) engine has soft valve seats... therefore needs lead or a suitable replacement to protect the valve seats

2) engine compression... like the 240 2.1 or B14.1E

These need a higher octane fuel ( unleaded is 95 and leaded is 98. Super unleaded is 98 ( not available anymore )

Shell optimax and BP ultimate are 97. My 240 wouldnt start on 97 octane but did on 98.

If your cars compression ratio is too high for 95 unleaded, then you need an octane booster only to bring the octane up to 98.

In volvo 66s, they have high compresion and soft valve seats so need Catrol additive plus octane boost ( comes in one bottle from halfords )

B14 1E has soft valve seats

B14 4E has hard valve seats and lower compression. Timing needs to be changed on breaker system or on Renix. For Renix ground B pin ( second pin when counting from the right most pin of the 8...

I need to check the ignition changes for the breaker ignition

For B14 2E and B14 3E ... bit of confusion. Volvo introduced hardened valve seats at some point so these cars could run on LPG ( no additive so engine needs harder seats )

However, compression is a problem.

Ive heard conflicting info on these engines regarding over heating valves, pistons etc....

The valve sizes were changed during the development of the B14 .. not sure if the B14 2E or 3E got the bigger valves... need green book to check


Interesting that your A reg has a B142E... my A reg is a 1983 August car and has the B14 4E

My 343 has a B13 1E engine.... and is a special edition... most likely it was "special" as they were trying to get rid of the older stock of B14 1E engines........


hope this helps everyone!!!!

Shimon

I research all this when working at a fuel additive company...However, at some point Id like to look into it a bit more as Ive heard many times that the compression is too high on volvo 66s and early 340s. Compression ratio for the B13 engine is 8:1, B14 0E is 9.5:1 and for B14 1E, 2E and 3E its all 9.25:1 Hence the problems with the early 343s seem to be heat problems with running on leaded fuel. Hence, the safer thing to do is run as if they were using 98 octane leaded fuel ie an additive plus octane boost.

PS... there are also issues with carb needles relying on leaded additive as in the case of the B21A engine.......

Enjoy....

Shimon

[foggyjames]

I can't quite work out why your 240 would fail to start on 97 octane. Which year is it? I know of a number of late 70s and early 80s 240s running around quite happily on 95 octane with B21s! Optimax is still 98 octane.

cheers

James

[redline]

shimon thats all very interesting ,but more importantly .
when are you going to leave me ebay feedback for the other two switches I sold you LOL

seriously though thanks for all the help , I have passed it on to my new admirer

[antiekeradio]

B14.3 = B14.4 with other manifolds/carb/exhaust.

compression, valve sizes, valve seats, valve timing, all identical.



grounding pin 2 on connector B = retard 3 degrees.
ground pin 2 AND pin 3 on connector B = retard 6 degrees

[antiekeradio]

PS afaik the B13 engine was only sold in Italy and Finland, for fiscal reasons.

it is the same block/head as the 1289 cc volvo 66 GL engine, wich had been sold in the DAF 66 1300 'marathon' since 1973

the manifolds and carburettor are identical to the non-B14.3 1400's.
(don't know wich carb revision), power is comparable to B14.3

Greetings Wouter

[shimon340]

cheers wouter for the extra info!! very interesting!!

Redline... Im so sorry about the feedback I thought Id left some... I'll hav a look thru my Ebay and leave the feedback for you. Cheers for those switches... very useful!!!

Foggy.. yeah the 240 was a mystery. I had been standing a while and the tank was full of 98 octane LRP -lead replacement petrol. I filled it up with some shell optimax and it would NOT fire.. it coughed and you could hear it firing on one maybe two cylinders as it ran on the starter.....it was soooo annoying!! I was leaving for a year abroad the next day so put it down to the 97 octane LRP. About 6 months later on a visit home i started it no problem after filling up with some unleaded plus castrol lead replacement additive plus octane boost.... bit odd eh????


I think this engine cant run on unleaded as the compression is two high. volvo advise fitting two head gaskets to reduce the compression. Every mechanic I asked about this cringed at the idea of fitting two!! I think the carb needle needs lead so Im just running it on unleaded plus castrol lead replacement additive plus octane boost... cant wait to get it on the road!!!

[classicswede]

The B21's run very well on unleaded. We have been running them on unleaded ever since it became available. All that does need doing is slight adjustment to timing.
The non start could be due to stale petrol. Todays petrol only lasts a max of 3 months.

[shimon340]

hi Dai!

running my 1984 240 2.1 on unleaded would make life easier!

do you know what the change to the timing is?

cheers mate!

shimon

[classicswede]

Retard by 2-3 deg. It is mostly a case of ear realy that is the way my brother always does it.

[340GLT]

Reading properly what you put earlier Shimon could this be the reason my car is a bitch to start once left overnight? Because of the octane in the fuel??? If so thats an interesting thought. I believed it was/still is the fuel pump. But as i have nothing to lose i may try a octane booster.
Although the age of my car should be fine i would have thought?????
Cheers Adam

[classicswede]

Do you ever get pinking under load? that is the real sign of insuficent octane.

[340GLT]

Cant say i have but what are the real tell tail signs if i was???
Cheers Adam

[classicswede]

You would normaly hear it. The octane booster could be worth a try but I would try krypton tuning to make sure all is well.

[340GLT]

Damn gud point we have a krypton at the garage, *must get manual out*
Cheers Mate!!!
Adam