It doesn't idle at 8 degrees base timing on my 355. What is the proper base timing, it sounds crazy.

 

the actual HOT cam, or an LT4 cam?
when i had the HOT cam kit (including the 1.6 roller rockers and LT4 valve springs) in the vortec headed 355 in my Nova, i wound up at18 degrees initial, 36 total, with about 20 degrees of vacuum advance hooked up to a port on the carb with full manifold vacuum.. it idled smooth at 800, slight lope at 750, 17" of vacuum at idle..

 

haha - why would you want to 'tame' it?

i was told by a 'gm performance' guy to set my timing at '0' and it seems to run fine - for now. but i will also say that it isn't tuned yet. once i get the oil consumption figured out, then it'll be off to the dyno...

 

Assuming this is efi car...If it doesnt idle at 8 deg base with est disconnected, increase until it does hold idle. May be 10-14 degs, shouldnt be more than that for base.

Once thats set, reconnect est and rework the tune to stabilize idle further. Give it a fair amount of idle timing. 24-28 deg. Work the fuel tables, tune for max vacuum and even check plugs. Should be slight tan at idle

If its not efi, bump initial to 15-20 deg depending on your distributor. Vacuum advance is nice. Keep timing at wot 32-36 depending on heads. May want more may need less. Gotta verify fuel curve at wot too

 

I found out it eventually likes the base timing at 8 after advancing the timing on the spark tables at around 4-10 deg. I'll be hooking up the auto prom to see what I can do. Another problem happened when I went to break in the new Hastings piston rings, I gave it close to full throttle from 35-60mph (around 5 times), and developed a small oil leak coming from the rear main seal area. So now that problem needs to be fixed.