Foxy Green Foxbody Build

89 Fox 427 said:
Another member was giving me timing advice. Never new you could program timing with an msd box and a laptop. Might have some spring upgrades

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Locking it out and programming a curve sure sounds easier than messing with springs.
I tried different springs and bushings, even made custom ones and didn't notice a difference so I leave mine locked out at 31.
This was trying to get rid of a surge that turned out to be a lean carb. I never had it at the track and changed springs though so no idea. As far as racing it's always up in rpm so I see no need for a curve. This should get some comments 😆
 
These are my only current options with the setup I have. Using the black bushing (bottom dashed line in each graph) adds 17-18 degrees to initial. I'm running 16 initial right now with vacuum advance plugged. If I hook up vacuum advance I could probably back initial to 13 or so with these fast burn chambers. Might be a decent starting point at the track or dyno and see what happens

 
Trying to decide what rpm to be all in. Based on the charts my "all in" rpm options are:

1600
2100
2500
3000
3200
3400
 
89 Fox 427 said:
Trying to decide what rpm to be all in. Based on the charts my "all in" rpm options are:

1600
2100
2500
3000
3200
3400
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Exactly my point, when the fuck am I below 3400 rpm 😆🤣. That's why I made custom bushings but....
Lock the fucker out, nice stable timing 👍

But really you will be running lower rpm in cruise mode with the OD, mine has no OD with 4.10's and going to even lower gear. I know people have found gains and make a car more streetable with a good curve and having it "all in" much later than 3400. Big part of making a street engine last is the tune, no detonation and not being in peak torque rpm. That programmable box sounded good. I think Itey may be knowledgeable on timing curves iirc 🤔
 
Go back and read that team chevelle link that someone posted, timing 101 I think. It actually had some solid info and explanation in it. As for the laptop MSD setup, that's pretty cool, didn't know they had those. I've said for years now, these laptop tuner guys understand timing curves way more than old school hot rodders do, they just don't know how to apply that knowledge to a distributor.

Find someone with a distributor machine, way easier to setup than having to lean over a fender and do it.
 
kilowattkid said:
Go back and read that team chevelle link that someone posted, timing 101 I think. It actually had some solid info and explanation in it. As for the laptop MSD setup, that's pretty cool, didn't know they had those. I've said for years now, these laptop tuner guys understand timing curves way more than old school hot rodders do, they just don't know how to apply that knowledge to a distributor.

Find someone with a distributor machine, way easier to setup than having to lean over a fender and do it.
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The thread is "Ignition 101" on Team Chevelle. Thanks for the heads up on that.
 
The ignition 101 thread is good knowledge, though a lot not applicable entirely to my setup. I understand a lot of what is being achieved with timing and vacuum advance, I will just have to find a different way to go about getting there. Without dyno or track time, and with only springs, weights, bushings, and a non adjustable vacuum can, there's only so much I can do to try and protect this engine best I can for longevity.

Ideally I would be able to adjust timing at in ranges. 2k to 3k, 3k to 4k, 4k to 5k, and so on. But currently my options are "when is it all in, and how fast does it get there?"

Paying more attention to my idle characteristics (vacuum advance plugged) 14 degrees initial sounds off to my ears. 16 is good. 18 is better, but too high for my total timing. I haven't tried above that because that puts my total timing astronomically too high for my heads (so it would seem). 30-34* seems to be a pretty sweet spot total for similar combos.

The next issue would be 11" vacuum at idle, but 22" at 1800rpm cruise. My distributor needs 15 inches before it adds timing, so at idle it's worthless in my application. This if course is if I'm using manifold vs ported. I think I can swap the canister, but need more driving time to pay more attention to where my vacuum is, when it is, how it responds, etc.

I am the computer controller here.

So far, I fuckin love this stuff. Learning more, I realize i was born in the wrong era... this shit is cool as fuck
 
And another question here. Is vacuum advance timing numbers listed in distributor degrees, or crankshaft degrees? If it's distributor degrees, then I might be all fucked up here to begin with
 
Another "ah ha!" Moment.

More initial timing makes it hard to crank because with the low engine speeds the charge fires off and creates enough pressure to want to make the cylinder go back down the hole instead of finishing its stroke.
 
89 Fox 427 said:
Another "ah ha!" Moment.

More initial timing makes it hard to crank because with the low engine speeds the charge fires off and creates enough pressure to want to make the cylinder go back down the hole instead of finishing its stroke.
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Not enough and anything with any amount of cam won't even start. And your headers will turn orange while your exhaust valves try to, lol.
 
89 Fox 427 said:
And another question here. Is vacuum advance timing numbers listed in distributor degrees, or crankshaft degrees? If it's distributor degrees, then I might be all fucked up here to begin with
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Distributor degrees, but you generally check it with the timing light, so I think of it at the crank.

Read the post after JohnZ's in "Ignition 101" if you haven't.
It's the one by Lars that talks about vacuum advance.
 
89 Fox 427 said:
Paying more attention to my idle characteristics (vacuum advance plugged) 14 degrees initial sounds off to my ears. 16 is good. 18 is better, but too high for my total timing. I haven't tried above that because that puts my total timing astronomically too high for my heads (so it would seem). 30-34* seems to be a pretty sweet spot total for similar combos.
Click to expand...

As somebody mentioned, there are bushing you can buy that limit the advance more that the MSD bushings.
Here's the site (their tech talk on that page is pretty good):


Also, I found the thread by "Tuner" that describes how (and why) to bend the weights to limit advance:

www.tapatalk.com

racingfuelsystems-MSD-Delco Distributor Weight Modification For Less Advance

Using a big bushing to limit travel in an MSD stops the travel of the weight lever arm at a location on the advance cam further from the distributor s
www.tapatalk.com www.tapatalk.com
 
Steve439 said:
As somebody mentioned, there are bushing you can buy that limit the advance more that the MSD bushings.
Here's the site (their tech talk on that page is pretty good):


Also, I found the thread by "Tuner" that describes how (and why) to bend the weights to limit advance:

www.tapatalk.com

racingfuelsystems-MSD-Delco Distributor Weight Modification For Less Advance

Using a big bushing to limit travel in an MSD stops the travel of the weight lever arm at a location on the advance cam further from the distributor s
www.tapatalk.com www.tapatalk.com
Click to expand...

My thought would be with vacuum advance pulled from manifold vac I wouldn't need a different bushing as it would advance the timing at idle and not have to deal with that.

Lots of ways to skin the cat here I think
 
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