Thread: Opal fuel in old 2 1/4

ummm...don't know who nay is ..but has anyone used it.Opal fuel that is.....

considering the grades of petrol the 2.25 can deal with, I wouldn't have thought opal would be a problem. might be wrong though.

I run Opal in my Rover V8 without issue. You should consider the original market for the 2.25 was in third world where the fuel quality was crap.
Opal I think falls into this category. I would wonder if over time the head would suffer valve seat recession as it probably would on unleaded??
Duane

Opal fuel is simply petrol with very low aromatic content, adequate octane rating being achieved by use of appropriate branched chain hydrocarbons. On the face of it there should be no reason why it would perform any worse in a 2.25 than ordinary unleaded. As others have pointed out the 2.25 was designed to be tolerant of poor fuel, and its low compression (even the 8:1, and most are 7:1) would enable it to tolerate the perhaps optimistic octane rating of the Opal fuel.

I had the head of my 2.25 last year after several years running on unleaded and there was no signs of valve seat recession. Overseas experience, particularly in Canada, where this engine was sold into a market with only unleaded available, suggests that the engine will only suffer valve seat recession when subjected to sustained high power use over long periods (for example freeway driving).

John