Thread: BBC Ignition Timing

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Hi guys,

I lost the distributor timing on my 454 Chevy recently and had to re-time it. Here is what I did. Question: did I do anything wrong??

Engine dyno sheet showed best hp/torque with total timing was with total timing at 3800 (I thought that a little high with an efficient engine?)
So... I disconnected and plugged vacuum advance, put the strobe light on it, ran it up to 4000 and locked the distributor down when it was all in and I had a reading of 3800. Should I have kept the vacuum advance hooked up, or wouldn't it matter at those revs? BTW, this is a street car.

I have an MSD Pro Billet distributor with 6AL box. Am running it with 2 light blue springs and silver (25 crank degs) advance-stop bush. According to the instructions, that should start advance at 1500 and be all in by 3400.

Engine is 454+.030", 9.8:1, Edelbrock Performer RPM heads, headers, hydraulic roller 218/226 w 112 lc's & mid-.500 lift. Dyno test gave 463hp at 5400, & 522 ft lb at 3800.

I only ran it up the road to get gas (98 RON octane) and it fely noticeably livelier than before. Am I in the ball-park, or have I goofed somewhere? I don't want to burn any holes in pistons...

Any thoughts very welcome!

Chris

do you know how much you pulling with the vac pull hook up ? i like the curve faster but you are running vac pull so you may not need it to come in faster i would try one lite sliver and one blue spring that will make come in faster if that is what you want ? 38 is abit more then i think you need but there is way to many thing s and we are only talking 2 from were i would think it should be