[Thomas]

Ah, it's a Model 90. For that model the book says 5/8 inch or 50° which matches well with your 0.63 inch. I presume that highest accuracy is not required, anyway, considerung the recent 1mm carbon layer on my piston. 

Cheers, Thomas

[Alex]

Hi Thomas,

thanks, sounds good, I was just wondering if anyone has any other conclusions about igniton advance other then the std mentioned in the books. I assume the fuel quality was quiet different some 90 years ago, but if that works fine still why not.
It's for a M90 and I saw that the advance is slightly more compared to the M9, maybe it's mentioned in the book somewhere why but didn't see it yet? I would like to use regular 100oct. as it's easy to get for racing purpose, so I was thinking about 16mm (0,63in), possible slightly more depending a bit on where I would end up when retarding to also keep it firing up well.

BR
Alex

[Thomas]

Hi Alex,

I suppose you talk about a Model 9. I don't know what you mean with "best ignition advance" The Book of the Sunbeam says 9/16 inch BTDC or 43° at the crank shaft (right when the points open at advance position). Monograde oil is required. I use Castrol XXL 30 to 50 (mostly 40). I think a NGK7 might be a better choice, but you can try with a NGK8. It's not too big a difference.

Cheers, Thomas

[Alex]

Hello,

I would be interested what are the experience from any of you regarding ignition timing and oil us.
For my 1929 500 ohv I would like to know:

- Ignition advance, what's best from your experience?
- Engine oil, which oil are you using (summer)
- Which spark plug are you using? I think I will go for NGK8ES

Thanks. Alex