about 5 minutes after start....

Alright, great input.

I have a Pro-Comp distributor (thru 440Source) and a Mallory Hyfire VI with the Map sensor. It will let me set a "retard at start". It's at 5 degrees now.
The retard for boost is set 1 degree per pound.

Do those numbers sound about right?

And I'll definitely get more advance at start.

I'll be able to post some more Saturday evening.

And let me thank everyone for easing my worry that I may have installed the cam wrong.

you wont see any boost untel you power brake it realy hard.we could use some engine info just to get an idea of what you have.welcome to boost!

Quick lesson/info on map sensors from last weekends personal experience!!

First how many bar map do you have.

Does it read in psiA or psiG

This will make a huge difference.

psiA does not factor in atmospheric pressure, so 1 pound of boost isnt infact 1 pound until about 15.7 on the igntion


Also, im not sure your initial timing, but 1 degree per pound is a really to much at low boost levels I wouldnt look to pull much of anything until 6-7 pounds of boost
if it reads psiG than infact 1lb is a true 1 pound of boost.

Mine is a 3 bar map and 0-14.7 is truly vaccum. Also How are you adjusting this/

Glowing tubes indicates retarded timing as stated. 1 degree per 1psi is a safe way to start, but wont put you where you really should be.
Your question about fuel pressure leads me to believe your regulator reference port is plumbed below the carb's throttle plates (vacuum applied to the regulator will decrease fuel pressure). Move the reference line to a place in the air stream before the carb.
Timing with forced induction and a distributor can be tricky. You need to remember a few things.
1- Distributors have a limited phasing range.
2- Electronic timing controls combined with mechanical advance can really screw you up.
3- 100% rotor phasing should occur at peak torque rpm/ max boost. This is where most people fail.

Answers in no particular order.

3 bar MAP sensor from Mallory plugs into the Hyfire box. I don't know which of those two measurements it's doing. The hose is plumbed to a port on the BDS intake manifold.

A separate mechanical Autometer boost gauge is also plumbed to the BDS manifold. It shows about 15 lbs when I'm running about 2500 RPM. I understand that turbos won't boost until a load but this is a Dyer's 671 roots supercharger. Wouldn't they be compressing the air anytime the screws are turning?

The distributor has no port for vacuum advance. I only see a magnetic pickup and the star wheel under the rotor. Would any centrifugal advance be further underneath the plate holding the pickup component? If it's there, your recommendation is to tighten it so I'm not pitting the Hyfire input with the mechanical input?

I ran it for about 10 minutes today after turning the distributor housing clockwise until the engine started bucking (then backed off just a bit). The headers weren't glowing, at least where I could see them outside in the sun, but the water temp got to about 220 and was holding steady. I figure thats still too hot but shouldn't be causing any damage, right?

I had also installed the exhaust and muffler that I had on it when it was just a N/A 440. I think it is 2 1/2 inch. I'll step up to 3 inch later.

It is built with the 440Source 500 cubic inch kit.
Bored 0.055 over with the dished Ross pistons so the compression would be low. I forgot to look back for my cam info. It also ran today with the Superchiller intercooler hooked up using water through a garden hose (I don't have a pump yet).

The #1 plug shows a black deposit on about 1/3 of the side of the insulator. The rest is bright white. Nothing remarkable about the electrode. The plugs are Champion R12YC (IIRC)

It seems to start best with a few pumps to the carbs (2 Edelbrock 1405s, one with manual choke) and then setting the choke to full. Then I have to gradually open the throttle to get to up to 2000 just as soon as it fires. Opening the throttle quickly bogs it down and usually stops it. I haven't let it idle yet but I think it's had at least 20 minutes of run time so I think the cam should be broken in.

I've verified that the March serpentine belt kit effectively hides the timing marks. There is no way to get the timing light at an angle that will light up the balancer and get an eyeball at the same time. I plan on getting a balancer tape and adding a reference point to the other side of the engine where there is plenty of room beneath the lower radiator hose.

The oil pressure was holding at 59 pounds at the mechanical gauge. I have a small oil leak along the passenger side valve cover to fix.

I appreciate the help.

Any gurus near Marshall, Texas who want to stop in for some personal input?

Roy

I don't think there's anybody near Marshall. It's just a wee little town in the grand scheme of things.

I think you'll get it with a little fiddling. Get the car to idle first and tune it from there.
Don't make yourself hate life. Only change one thing at a time.

keep at it. good luck with the timing mar change.i would think you could run the engine without the belt for 30 sec to adjust the timing,do it cold to keep the heat down.i have a blowershop A/W cooler with 3 gall tank behind passinger seat with a boat washdown pump for water flow.i have a higher flow pump to install about 300GPM [wp136]i think it is.if you want pics to see let me know.

How do you adjust the amount of retard your pulling per pound of boost? do you hook up a laptop, or use a handheld?

A 3 bar map sensor is good for 30lbs of boost as you probably already know. Simple thing to check is does the graph or scale for the retard read 0-30 or does it read 0-45....

If it reads to 45 than like I said in the earlier post, 15.7 is really 1 pound. Make sure you check that out first.

The Mallory Hyfire VI, model 685, has programable settings built into the box.
10 modes to control rev limits, activate additional equipment, test the tach, etc.
One setting will let you retard the ignition at very low RPM (starting the engine is easier)
Another setting sets how many degrees are retarded for each pound of boost. You have to have their MAP sensor. A 2 BAR or 3 Bar is available.

I've got 9 degrees of retard on start.

The 1 degree per pound was posted somewhere else but can be changed easily by scrolling though the modes and then pressing up/down arrows.

I've also just read through my Edelbrock PDF and I'll get around to some adjustments later.

The car, a '74 Charger, isn't ready for the engine yet so I have time to play.

Roy