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View Full Version : Initial timing for BBC with FI and Small Cap MSD?



strangler
01-14-2008, 09:58 AM
Hello. I have a 396 that I am retrofitting with Holley Projection and a New, Small Cap (7 pin) Distributor. Right now, I installed the distributor and twisted it to be as close to 18* BTDC. I am getting really close to trying to start this and lately I have been second guessing myself, wondering if I should install it straight-up, and let the computer do all of the timing.

Where should I start?

At what timing would a person install the dist. for any computer controlled SBC/BBC with TBI, TP, or MPI?

Thanks in advance (pun intended =) Scott

powerjames
01-14-2008, 12:19 PM
Every different engine will respond different to different timing curves. There really isn't "one" timing setting which might be optimum for every engine without knowing all of the specs.

If my memory serves correct, the Holley Projection recommends setting your timing at ZERO degrees, and inputting the timing controls in the Holley unit.

I'd shoot for something around 12-18 degrees at idle and 32-36 degrees at WOT. Is this a new engine or just a retrofit on an older engine?

The best thing would be for you to have your vehicle tuned on a Dynojet once you have it running in decent condition.

-James

strangler
01-14-2008, 12:38 PM
Not yet looking for every last HP, just looking to get it started. This is an all new engine, so I need it to start right away. You suggestion to install at 0* is what I'm looking for. Are you pretty confident that that suggestion is correct? Thanks. -Scott

powerjames
01-14-2008, 12:45 PM
Scott, you can look at Holley's web site - and download the instructions from the Projection. I'd double check them before trusting my memory 100%.

They have exact instructions on setting up the ignition timing in the EFI unit.

-James

powerjames
01-14-2008, 12:46 PM
The instructions are here (http://209.85.173.104/search?q=cache:f0iWNzAC5AIJ:www.holley.com/data/TechService/Technical/R10022.pdf+holley+projection+timing+adjusting&hl=en&ct=clnk&cd=4&gl=us&client=firefox-a)

strangler
01-14-2008, 12:54 PM
Thanks James, but those are the same directions I have and all it tells me to do is hook the harness to the distributor.

Using that as a reference, assuming most people are retro-fitting this system to an already tested although carburated engine (most of which would have had the initial timing set to 16-18* BTDC) and Holley's directions make no note of altering that setting, I chose to set mine up that way. Even with that reason, I fear that I am wrong. Any suggestions?

powerjames
01-14-2008, 12:56 PM
I read the directions pretty quickly - but there is a section under timing which says to set the timing at zero degrees.

Here's from Section 8:


Use this paragraph only if spark control will be used. Now is
the time to adjust base spark timing. Follow the
manufacturers recommendations for connecting a timing light
to the engine. With the engine running at idle, disconnect the
TPS connector at the throttle body. Set the ignition timing to 0
by rotating the distributor. Disconnect the timing light and
reconnect the TPS connector at the throttle body.

strangler
01-14-2008, 01:00 PM
Thanks, didn't see that part or have it in my set of directions at home. Looks like I'm supposed to have the engine running before making adjustments. Kind of a chicken or the egg question for BBC buildups.

Im really leaning toward putting my old 750, mechanical pum and points dist. back on just to break this in. I'd hate to wipe out my cam just because I'm an idiot.