Timeing my 348

[dunhamfield]

OK guys, I have read all timeing threads and I understand how you all come up with basically the same numbers.
Heres my problem.
While timeing my 348, my light went south on me. I sent it off for repair.
I adjusted the timeing by feel, many black marking runs down the street and found the best performance setting.
I got my timeing light back today and checked to see where I was at.
With vaccum line off and plugged and idleing at 850 rpm I am reading 17 btdc.
With vaccum line connected and idleing 900 rpm I am reading 40 btdc.
With vaccum line connected and 3000 rpm I am reading 60 btdc.
These numbers are higher than what I have seen recommended but the engine runs great at this setting.
Yes I checked and highlighted my timing marks during assembly.
I guess my question is, will these numbers hurt my engine or have any effect on any thing else?????

[Ronnie Russell]

Terry, I love it!!!!! Old school all the way!! Nothing wrong with 17 deg, if motor starts hot without kick back and no detonation. I think all would agree that an adjustable vacuum control would be good addition, so you could restrict cruise timing to 45 to 48 degrees. 50 is common , so you can be the judge. 60 sounds like too much. Glad you are having fun with the 348. Good luck..........:)

[fatride]

I agree with Ronnie. Cool, I would like to see you run a bit less on the light load cruise though. 60 is a bit much and I would be afraid you would be in detonation most of the time and not be able to hear it. Make a vacuum advance stop and limit your light load advance to 50 dgs max.

[dunhamfield]

Thanks for the advise. I have noticed that in cruise at 65 mph and 3000 rpm that my EGT's climb quickly to 1300. I havent allowed the EGT's to exceed 1300 but that just means that I cant cruise at a higher rpm.
I dont hear any detonation but the plugs are reading to the lean side.
Maybe I'll put a mark where its at now and then retard back to specs for just runnin around. If I'm gonna show off a bit I could just drag it back to the mark.
Maybe a valve inline to vaccum advance that is cockpit adjustable?
I do take detonation very seriously as I have seen holes in pistons before.
What gets me is that it starts and runs great.....