Spark plug surprise

Buying parts before doing the research is always a bit risky. This I recently learnt when trying to put new spark plugs in the Okrasa heads.

The manual for Okrasa exchange engines mention: "When delivered the Okrasa exchange engine type TSV-1300/30 and TSV-1300/34 are equipped with Champion L87Y and L85 spark plugs". The interesting thing is that the L85 is a normal plug-type for the VW engine, but the L87Y has an extended tip. When first reading it I found it a bit strange. Why do they mention two different types?

But, when I tried to assemble "normal" spark plugs in my Okrasa heads I notice that they sat a bit deep. I asked fellow Okrasa builder Bengt H for advise and he mentioned the extended tip plug as a mean of getting the gap more into the combustion chamber. Thus I guess the correct interpretation of the text from the Okrasa manual is that the extended type was to be used in the TSV-1300/30 and that the L85 was used in the TSV-1300/34. (If you have more info about this, please contact me)

If you want to find the extended type in a specific brand look in the catalogue for Volvo 140 with B20 engine, they use the same. If you want to go one notch colder for your race engine, then plugs from Volvo 123GT will work fine.

The upside of buying the wrong parts was that I got a reason to change spark plugs in my Ghia. A long overdue activity.