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You have big port head’s and tight LSA cam it isn’t all that huge a cam especially on such a big engine with 234 degrees .556 lift intake and 244degrees .581lift. The cam itself isn’t so damn mean but that tight LSA will bring out a lot of bad traits in the attempt to make the idle sound like a racer cam. Idle should be 900-1000 RPM. You most likely should use a four corner idle Holley . Given the bore size and overlap that the tight LSA portends the base timing should be 19-20 degrees. If you can get 5 to 7 of those with vacuum advance it would make the engine easier to get started when using a lot of advance.

The Edelbrock head uses 95cc chambers, the original Ford head used 88. Unless something was done to compensate for those extra 7cc’s you might not have enough compression for the cam on a 429 as the 2045 kit is really aimed at the 460 and larger builds.

I’d put some money into a decent timing light and a vacuum gauge and a shop tach you need to gather some info.


Bogie
 

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Discussion Starter · #22 ·
Thanks I'll try POS 2 this weekend. The carb change also caused it to (sometimes) run on briefly. Only a second when it happens. Am I stuck with that? Will it cause any damage? Engine doesn't seem overly hot, hits about 185 and goes no higher, has electric fan already. I didn't see this with timing changes but happened with my earlier carb (nozzle) changes as well.
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I haven't read every post on this thread ,but in case it wasn't mentioned ,you must set / adjust your TOTAL advance , initial plus mechanical , too much total has a tendency to burn pistons , listening for it isn't good enough .
 

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Discussion Starter · #25 ·
Thanks, I have a tach coming Tuesday. So when I get it, I just make sure when I bring up rpm it doesn't go above 35 or so right?
 

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The run-on is more likely to be the electric fan backfeeding the wiring when you kill the ignition and harness power. It's a somewhat common issue. As the electric fan winds down it keeps enough voltage back into the system to keep a aftermarket ignition box active.

It's not a carburetor or timing thing because if there is no spark then the carb and timing settings don't matter, it won't run-on if no spark is present, no matter how much timing or fuel might be there.

Modern chamber aluminum heads on a lower compression 429 might need to be up near 40° Total Timing on pump gas.
35-36° is a good safe spot to sort out the rest of the engine tune first.
 

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Discussion Starter · #28 ·
Thanks so much! So, swapped cams, then put orange (now on primary) into position 2 and it's perfect!
I also went to check full advance timing though. We starting bringing RPMs up slowly and hit 40 around 2800k rpm and got scared we'd blow something. I backed it off to 14 (from 16) initial and now we got to about [email protected] How do I now make it so I can go to full 16 and get max power? I heard about weights or something but does my Unilite even have that? I popped the cap and I see nothing like that, just a red rotor, perhaps that stuff is further down into the distributor? I know @ericnova72 mentioned full timing 36-40 but at 3.5k so we were afraid to push past 3k with hitting 40 already.
It runs fine at 14 degrees and the carb settings now, has power, no hesitation, just don't want to be loosing any power that might still be in there either!
 

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I wish I could help you with the Unilite advance internals, but I am not a fan of the Unilite electronic system and have never had one completely apart. Since you said nothing is visible from above, like the GM distributors are, it sounds like it is based on the stock Ford design, with all the advance mechanism down inside it, which in the case of stock Fords is somewhat more a PITA to manipulate.

Looking at current Mallory listings, they still sell the 351C/M/400/429/460 Unilite, #3756701.
if that is what you've got, the instructions PDF show it has an "easily"(their words) fully adjustable mechanical advance mechanism.
Mallory 3756701 Mallory Unilite Distributor Ford 351C-460 (holley.com)

They also show a spring and limiter bushing kit, but with Holley having bought up both MSD and Mallory it is hard to say if the parts supplied are actually for a Mallory and not an MSD distributor design....maybe the spring/bushing kit fits both but I have no clue on that.
The PDF drawing for the distributor shows the GM design, but with Holley muckin' up so much of what they touch it could just be a printing oversight.

It doesn't hurt anything to rev it in park/neutral in order to map the timing curve and figure out total added, you can only hurt it with too much advance when it is under a load, heavy throttle opening, moving the vehicle. Free rev won't hurt it.

According to the Mallory PDF, all Unilite distributors with part # ending in "1" come with the limit bushing installed that provides 24° added.
That would jive with 16° initial giving you 40° total

Also according to the PDF, there are limit bushings clear up to 28° added, or as little as 18°

I guess I would say all you can do is dive into it if you want to tune it further, or leave it as-is.
it's not terribly hard, but some mechanical ability is needed, so it will depend on your comfort level with snap rings, springs, and bushings.

I will say that chasing the last 2-4° in a timing curve usually doesn't turn up a ton of lost HP, once you get close to ideal the gains get really small.
 

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Agree with Eric....
I'd set it at 14 initial, 38 total and worry about something else for now. Come back and revisit when you can test with a dyno or timed passes.
 

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Eric’s on it, the Unilite is built like the classic Ford and many other distributor designs with the weights and springs index what was the breaker now sensor plate.

The caution of over advancing the top end at max RPM as has been said is detonation. There really is a situation where you need to probe what the engine needs to stay just under that point. In general different engines will want different values. The numbers you see typically here are for small block Chevies and while a reasonable safe point for most any engine are not necessarily specific goals for other engines.

You also should find that aluminum head’s are much more tolerant of excesses than are iron head’s.

Bogie
 

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when setting up squirts, ANY movement of the throttle should cause some discharge. I use large tube type nozzles, solder closed and drill to normal size for carb, per Holley specs. Then road test, if still have hesitation, drill to next wire drill size, retest. do this till goes away. if gets too rich will puff black smoke on hit, if that happens remelt solder and go back one step. then replace with closest size nozzles (have read posts about brass tubes falling out of nozzle, although has never happened to me - don't want to be the next one it happens to) without brass tubes. has ALWAYS worked for me in the past.
 

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Discussion Starter · #33 ·
Bad but great news. I didn't get the XL after all. Still in the family so I appreciate the fix, I can drive it when I want.
But... it got the motor running. My dream car was always an early Nova. I once had a 63 I never got to finish restoring, lost it. Missed just having a classic and wrenching, so I started shopping.
Well, yesterday I pulled the trigger and am a VERY proud owner of a 1966 Nova, super clean and a BEAST! But I could user your help again if willing. This may be too much for my knowledge though in which case I'd be happy to take it to a tuner (if I can find one!) instead, depending on what you all think.
So, it's a 383 with a 671 blower, dual Holley Performance (that's all I can find thus far on them) carbs, looks vacuum secondaries this time. Before I get into any detail, ya'll think this is something I can tackle or should I find a tuner with this beast?
Here's some pics, I LOVE this thing. I'm told about 600HP at the wheels and it sure feels like it.
Wheel Tire Car Vehicle Land vehicle
Wheel Car Tire Land vehicle Vehicle
Car Vehicle Motor vehicle Steering part Hood
Grille Motor vehicle Hood Automotive tire Automotive lighting
 

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Nice looking new ride!(y) Two door Post cars don't get seen as much as the hardtops.

there are a few tricks to using Vacuum secondary carbs on a supercharger, but nothing we can't guide you through, it's all relatively simple.

First thing is to get the scoop off and get any identifying numbers off the carbs, so we can see what you've got and look up the carb original settings and spec's.

You'll never get it hooked up on those weeny rear tires LOL.

What's the trans and rear axle under it?

Come on over and join Steve's Nova Site, some good forums over there.
(8) Chevy Nova Forum (stevesnovasite.com)
www.novaresource.org is another good resource for info.
 

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Discussion Starter · #35 ·
Thanks! I did join steves novas, only posted under the newbie/welcome page so far.
I pulled the scoop today. They are Holley 80457 carbs which I looked up to be Street Warrior 600cfm carbs.
Definitely upgrades to do once I pay it off, lol. I can do about half throttle and it's straight as an arrow and fast. Past that she breaks loose and can go sideways. Turbo 400 trans, Chevy 10 bolt with what seems like lower gears but not sure what. Down the line i will probably do front clip and a Ford 9 mini tub in the back, as long as I have some back seat.
Here's my problems, which im actually wondering if I just don't understand supercharged engines and the "trick" because the last owner didn't seem to have them. Maybe just starting it wrong?
So...
Went to look at it, guy started it right up. Shut it off and we talked quite a while, cool guy. Knew I was serious so he was now ok with a drive. Started right up again. Did some putting and hot rodding. Came back to buy it next day and after paperwork he said it was ready and keys in the car. Started right up again for me.
Now I drive home about 10-15m, first half 65 highway then some back roads. Shut her off so my mother who drove me could park then go for a ride. Had a hell of a time starting back up. Flooded it.
Now this is what it seems to do every time, if I'm under say 30-40, I can smell fuel and when I **** it off and try to start it back up, acts like it's flooded, have to put pedal to the floor and crank until it stumbles and starts. Did this about 4-5 times yesterday (everyone wanted a ride). Come out today, started right up. Drove it around the neighborhood, stopped, same thing. Seemed flooded. Then I had this bright idea maybe the supercharger is still pulling so I should let it idle a bit in park before I shut it off? Did that and shut it off a minute, started right up! Problem solved? Nope, friend came over a couple hours later and same thing, had to put pedal to floor and crank.
So, I don't know if its tuning or me never having a roots blown engine and starting/stopping wrong?
There's also the hesitation thing again, but not like the XL. If I get going gradually, or get on it from say 30mph+, it's fine. But if I get on it less than that there's a pause.
Probably tried to give so much info it's too much. Oh yeah, both carbs have orange cans in position 2. Didn't check nozzles yet. And both had choke plates completely removed, that another supercharger thing?
 

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With the supercharger involved, you'll probably be better off starting a new thread specific to the new car and engine set-up

I think you'll get more info that way, the guys that know Roots set-ups will see it and respond
 
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