Spark plug gap?

[steves66]

I need to find out what plug gap I should be using. My build is a 493 stroker with 10.5:1 compression ratio, .570 solid lift cam 260 duration @ .050, edelbrock heads stage II ported, Holley street dominator intake, Holley 850 carb, MP electronic ignition conversion kit with orange box, Accel plug wires and coil, NGK plugs, TTI 2" headers with 3" exhaust and X pipe. I have read somewhere that with electronic ignition that you should run a wider gap somewhere in the neighborhood of .45 or .50??? I am at the stock .35 now. What gap should I set my plugs at? One more thing, if anyone wants to through any timing suggestions at me, as where it should be set at, I would appreciate it.

[firefighter3931]

Steve, with the MP ingition .035 is fine....you can go wider if you're using an MSD or other high energy box. As for timing, that combo will like 18-20* base timing and ~35-36* total all in by 2800-3000 rpm. Try mapping out the curve once the base timing is set and post the numbers in 200 rpm increments so we can look at the curve. The new MP distributors are made by Mallory and can be tuned with the Mallory tuning kit. Depending on where the curve is now it might need a spring swap and adjustment to the plate to limit mechanical advance.

Basicly you want to shorten the mechanical advance (if needed) to fall within those parameters. 

Ron

[steves66]

Thanks Ron!
I have my base set at 16* right now. Trying to get everything buttoned up right now to hopefully get to drive her this weekend! What do you think about setting the initial timing with the vaccum gauge method? I have a timing light, but it is pretty old. I don't have one of those fancy smanshy one's with the dial.

I have been working with kamkuda tying to get him my cam break-in video. The video file must be too big because he is not getting it. I tried to send it to his work email this morning. Haven't heard anything yet.

[firefighter3931]

Thanks Ron!
I have my base set at 16* right now. Trying to get everything buttoned up right now to hopefully get to drive her this weekend! What do you think about setting the initial timing with the vaccum gauge method? I have a timing light, but it is pretty old. I don't have one of those fancy smanshy one's with the dial.

I have been working with kamkuda tying to get him my cam break-in video. The video file must be too big because he is not getting it. I tried to send it to his work email this morning. Haven't heard anything yet.

Sure the vacuum guage works but it would be nice to see where it actually is.  You also want to know what the total is in degrees so that there's not too much  spark lead. Anything more than 35-36* with an aluminum head is counterproductive and can cause issues with pre-ignition. Time for a trip to Sears for a new light. 

Ron


Ps. Lookin forward to that vid....Rob'll get it figured out.

[steves66]

I've been needing to go to Sears anyway to replace some tools. Guess I will pick me up one of them there lights with the dial! I can hear my wife now when I tell her, "honey remember that guy Ron that persuaded me to spend all our money on this stroker, well now he's telling me I need a new timing light!"   ;)That's my story and I'm sticking to it, hopefully you have my back!

[firefighter3931]

I've been needing to go to Sears anyway to replace some tools. Guess I will pick me up one of them there lights with the dial! I can hear my wife now when I tell her, "honey remember that guy Ron that persuaded me to spend all our money on this stroker, well now he's telling me I need a new timing light!"   ;)That's my story and I'm sticking to it, hopefully you have my back!

Sure thing, i got ya covered, lol ! Hey, it's easy to rationalize....several grand for an engine that you don't want to frag because it's out of tune.  I'm sure Farrah will understand  she's very 

Ron

[steves66]

Yah she's pretty awsome! She's been very supportive since day one of this restoration, almost 3 years now! Lucky to have her.

[Chryco Psycho]

you can also put a mark on the damper 2 3/8" clockwise from the TDC mark & use a normal timing light the mark will be 36* at zero on the scale on teh timing cover 

[steves66]

you can also put a mark on the damper 2 3/8" clockwise from the TDC mark & use a normal timing light the mark will be 36* at zero on the scale on teh timing cover 

Man, learn something new everyday from you guys. Thanks Chryco! Should the vacuum advance be connected or disconnected with the rpm's at about 2800 to get my total?

[Chryco Psycho]

time it as you will normally be running it  so connected If you are going to use the vacuum advance
that should save you $50 on a timing light !!