Volvo RWD 120-130 Forum

Hmm.. I think that setting the timing by making the engine sound like it did last time the timing was set by something other than how it sounds will, at best, get you to the point that it runs well enough to drive around. I don't think anyone out there can optimize their ignition timing this way.

After installing headers and tuning the engine, timing needs may or may not be what they were before, and the sound the engine makes may or may not be the same as what it seemed like it was... you get where I'm going...

I'd get a timing light on it and ensure that the ignition is as perfect as you can make it before doing anything with the carbs. Maladjusted timing can lead you very astray when you face the SUs and problems compound readily.

I don't have phenolic spacers, but if I did, I'd go ahead and use them to prevent heat convection from the intake manifold to the carbs. I haven't had any trouble, but it doesn't really get all that hot here very often and I don't push this tired old engine very hard. In fact, it's coming out of the car in the very near future.

If you can see a gap between the carbs and the intake manifold (do I understand this correctly?), then there MUST be false air - which ruins the mixture and throws off the sound of the engine such that timing by sound becomes less possible.

Bottom line - I doubt you really 'need' phenolic spacers; but you certainly need to not have any vacuum leaks and I'd definately set the timing with a light so that you know it's correct. Only then can you really address the carbs with any confidence.

Best,

Cameron
444,122SC
Rose City