Hi everyone, I was playing with my distributor the other day. I replaced my holley metering blocks with some off an old demon that i had laying around and lost my vacuum advance in the process (demons get vacuum advance from the base plate, holleys get it through the metering block). To make up for this, i put lighter springs on the advance and moved the piece that the springs attach to 180 degrees so that it has more total advance (i put it on the wider slot...anyone who has taken apart a stock distributor should know what i'm talking about). My question is, with 15 degrees of initial timing, this puts my total timing at about 40 degrees. I get no knocking or pinging (aluminum heads, 302, flat tops, high elevation, etc.). I use strictly 91 octane, they highest they sell here. I have read that most of our engines like 35 degrees total. Am i going to lose power with that extra five degrees? Would i be better off with 10 degrees initial and 35 total, or leaving it like it is? I have a feeling this is something i'll have to find out on the dyno, but i thought i'd find out what you all thought first. Oh, also...do i need to stabilize my pickup now that there is no vacuum running to it? Thanks!
You might lose a bit of power on the top end with that much timing, but only a dragstrip timeslip will tell you. Many moons ago, I ran 42* total timing on the little 302 in my race mav. Ran like that all season, til one fall day it was getting a little tougher to start, so I retarded it 4 degrees. Picked up .1 second/1 mph. Retarded it another 4 degrees, picked up another .1/1mph. Got all the way back to 32 total, then leaned out the carb slightly and gained a grand total of .35/3 mph. That being said, the 351 I have now "likes" about 24* total, locked (24* all in by 1000 rpm.) I don't quite know why it slows down with more, but I'll live with it. You just have to play with it until you get it right.
does anybody really know " what timing it is anyway"? i had to say that. my 302, flat top and small cam likes 12 degrees and no vac...frank...:bananaman :bananaman L.T.N.G.
So i guess the general consensus is that i probably have too much timing, but the only way to know for sure is to play with it, on the dyno or at the track. Unfortunately, my car isn't consistent enough to find out these things at the track, so on the dyno it goes!
Go on Ebay and buy a G-Tech for $40. Once you know your baseline you can see what difference the timing changes make.
