Hi everybody, my name is Joaquin Novara and live on Peru (Southamerica). previously month I buy two 121 volvos (B18A engine) from the original owners (more precise, from the sons of the late owners). Both was on bad shape.

In Peru we don´t have supplies for these old machines, and due it (with the help a retired mechanic, an ex-worker from a local Volvo representative), we merge both card and produced a single volvo 122 (engine, brakes, suspension are Ok, and we are working now on doors and seats - both cars has a single row front seat - a rarity, also the car have a Stomberg SU2 carburator, and the distributor was taken from a old VW beetle).

We have leaded gas with 84 RON octane, and non-leaded 90 RON octane (in Peru). Both gas make some pinging on the engine. ¿Somebody are coped with this problem?. I am open to suggestions (the compression is Ok - based on the Hayes Volvo 120 manual, and the timing are setting to the norm).

Also, ¿somebody have a copy of the original Amazon users manual on pdf (computer) format or like so?. If yes (and if in your country is not against law) can be kindly of send a copy to my e-mail (yogui@upch.edu.pe).

Thanks very much,


Joaquin Novara

In theory lower octane means faster ignition (counter-intuitive but true) so... retard the ignition untill you get rid of it (maybe 5-8 BTDC) , also make sure the exhaust valves have clearance per specs. I ran a B18D in Mexico/Guatemala and I managed a reasonable performance no pinging. Oh yeah, keep the revs (revolution de motor) up. I also would suggest finding better carbs for this but that won't be easy in Peru i imagine, poor fuel mix can cause pre ignition or late ignition (burnt valves). Good luck.

p.s. try volvoworld.com he has lots of stuff digitized and if you tell him your situation he'll probably give you a good price (maybe free).
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Disclaimer: be careful, work safely!!! If you have any doubts as to the safety of the work you are doing, consult a proffessional before you hurt yourself or others!!! I'm not a licensed mechanic, I have just been fixing stuff my whole life, patrick of

Joaquin,

Welcome to the board. Most of the B18 engines I have ever owned have some pinging due to the lower octane fuels.

Suggest you check the valves are adjusted correctly per the Haynes manual. Also check your timing again, if you retard the timing more than about 20 degrees you will get more pinging. (The more you retard the timing the hotter the engine will run.) And finally make sure that you have a good weight of motor oil, 10W40 or 20W50 if possible.

Good luck...

Oliver

Faling the above tips you could also try a thicker head gasket to lower the compression ratio. There are special ones made to lower the compression on B20 engines - I don't know if they would work on a B18 or not. www.ipdusa.com sells them. Otherwise you might try to get s thcik solid copper gasket made - there are several companies around that can make them in any thickness when provided with a template.

Hi!, I´m here again...

... I buy a thick gasket from IPD, but (my error) this was for the B20 engine (piston diameter higher than B18). Luckily, my mechanic found a local gasket makers store, and they are making a hand-made new thick gasket, sized for the B18 engine.

In other side, digging on the database of www.alldata.com, I found a reference about a Volvo's technical note: "TSB# 20101 July 1981 L4-1.8l VIN B18 155 2x1-bbb Engine : Modification for low grade fuel usage". Somebody know some way for request this tech note from Volvo or another source?

btw: alldata.com support a very good tech docs database for any type of car used on USA from the 80´s - bad luck they don´t have records for 60's and 70's cars.

Thanks to all for your help!

Joaquin