An emissions controlled PV
or
How Cats do it

English translation of the story "PV med avgasrening eller Rent utav katten" in the PV-Entusisten # 3 1998 pages 20-21.

By Erik Gustavsson

The environmental struggle of Svenska Volvo PV-klubben continues. Last summer a catalytic converter was fitted on a PV. In this text you can find out how it was done, and what we achieved.

Every now and then, since PV-klubben began selling lead-converted heads, the board discusses what to do next. Both catalytic converters and bi-fuel have been on the agenda at several occasions. The most serious effort was when we offered some members, who had changed to lead-converted heads (that is converted to enable the use of lead-free gas), an electrical fuel-pump to enable them to try E 85-fuel (85% ethanol and 15% gasonline). But due to the many questions surrounding what to do and what to change in order to use E 85, no-one was interested.

More publicity
When Jan Broman last July re-wrote PV-klubbens environmental policy, which states that PV-klubben will try both catalytic converter and bi-fuel, many reporters got so interested that the story was featured in reports both by local media and the official Swedish press-agency TT. At the time I was examining if and how hoses and membranes in my 1957 PV 444 was affected by ethanol. But that particular car was actually too much of a heap to be a serious alternative for legal every-day use, although it was perfectly suited for various experiments. In mid-July Lasse Dunå at Amerikan Racing called me and offered our club-members a good discount on their catalytic converters. He replied positively to my question if he was willing to supply PV-klubben with a complimentary cat in order to evaluate their effectiveness. So by now, no further doubt dwelt in my mind - the time was right and I was ready!

Shopping for cars - again!
I had received some photos of a PV 544 F which seemed reasonably well-maintained and negotiations were initiated. Claes Magnbrant of Volvo promised to find out if it was possible to have a laboratory appointment to evaluate emissions - with and without the catalytic converter. A few days later Claes called back and said that an appointment could be made at short notice. Therefore we decided to do the test in connection to VROM, because that would be the perfect occasion to break the (hopefully) good news that emissions faced a 50% reduction when using a catalytic converter. For that reason I bought a fair 1965 PV 544 F. I immedeatly undertook some minor (?) welding operations. And simultaneously I tried to find out what the actual fitting of the cat would include. The following plan shaped:

• fitting a lead-converted head
• ignition system maintenance (re-placing all worn parts)
• carburettor fine-tuning (obtaining optimum mixture)
• fine-tuning of the entire engine (ignition and camshaft timing, setting CO-level etc)
• fitting the catalytic converter (as close to the engine as possible)

Fitting the cat
In order to obtain best possible effect, the catalytic converter should be fitted as close to the engine as possible. On a B18 engine, that means immediately after the exhaust pipe’s first bend. I rotated the oval cat, that American Racing had given me, a couple of degrees which gave a perfect fit between engine and firewall. But the angular sheet-metal protection had to be cut out or even removed. By fitting the cat in the engine compartment, the need for heat-protection devices was reduced. And the crowning procedure was completed when the engine oil was changed to Biosyntet, a straight synthetic vegetable oil, and by doing so I knew that I had done everything I could.

En route to the laboratory
The journey to Gothenburg went smoothly. I was originally planning to write an entire article on this adventurous trip, but such an article will never surface due to the fact that nothing happened. I arrived a little bit late to the laboratory and handed over the car to total strangers. I thought for myself: "That car’ll probably end up for sale as scrap metal on the Sunday market"! Notwithstanding, this is how the laboratory procedures went on:
Wednesday afternoon: The fuel tank was drained and its content was replaced by unleaded gas of know specifications. Thereafter the car underwent a short running-in period (some ten or twenty kilometres) on this new fuel and afterwards it was parked in a temperature-controlled room (20 centigrades) for the rest of the day. Thursday morning: The car was first driven according to a fixed programme without the catalytic converter. All in order to measure the CO, HC, NOx contents as well as fuel consumption. In the afternoon a cat with an adapter for an external lambda sensor was fitted. Thereafter a test-drive similar to Wednesday’s was made.
Friday morning:
The PV was driven with catalytic converter fitted. The emissions were measured both directly before and after the cat, in order to obtain as accurate results as possible. Afterwards I realised that the entire test had taken some 100 kms all-in-all.

An amazing outcome
So, what can be concluded regarding the result? CO 15%, HC 38% and NOx 63%. Gas consumption 8.5 liters / 100 kms. These results correspond well to those achieved when Volvo performed similar tests on the 240- and 740-series with carburettor and catalytic converter in the late 1980ies. The outcome was so good that we intend to sell these catalytic converters to our members from now on. For more information, please see ads in our newsletter PV-Notiser.

Original text by Erik Gustavsson
Translation by John Boija