The reason I was changing over to a new distributor was that with the old Motorcraft one, on the truck now, the timing had a tendency to drift.
Make sure your existing timing gun can function with an MSD box..... not all can. A sure thing is noticing the timing bouncing ALL over the place below 3000rpms as the MSD (hence the name) throws out multiple sparks. If you cannot afford a fancy msd compliant gun, just use any old ancient gun and mark the balancer where you want idle and max advance.
When I restarted the engine yesterday I checked the timing and it was back down around 14 with the vacuum attached. Given the previous history I wasn't surprised.
To keep things simple, why not just cap the vacuum advance until your initial tuning is good? If running ported vacuum it's only real function is to give you a lil better economy at cruise.
Staying with setting the timing, I want to make sure I really get this - with no vacuum attached the base timing should be between 18 to 20 degrees and total advance should be 32?
Tis a wildassedguess based on comparable engines. Your engine will tell you what it wants, and your starting system will tell you what it allows
I'll get the carb off and look at this again, I know we started with too much primary when we first started it just to keep it running. The primary was open much to much and the secondary was closed. I backed the primary down so the transition slot showed a square and opened the secondary a similar amount. Prior to this the engine had not been responsive to the mixture screws, after it was responsive but I can't say how sensitive since that was last year and I don't remember. If I'm going to pull the carb and set the primary and secondary when I can see them, is it your advice to close the primary so no transition slot is visible? While the carb is off I'll make sure the link closes the secondary, if not I'll adjust the link bar.
Slot on the primary needs to be a square (ideally). Too little and you stumble off idle, too much and you pull too much fuel at idle. Ok, looking under a carburetor, you'll see a round hole and a slot. The round hole is from the idle screw. The slot is from the transfer slot. Really until the main metering system comes online you are running only on these, so it's setting is pretty critical. Engines vary, but you aren't really pulling from the boosters (main metering) until 2000-2800rpms (totally dependent on several variables I'm not gonna get into right now). With a QF I normally just set the primaries, check the secondary link, use a wrench to bend it so it stays shut fully. Don't get crazy, but it needs to shut it..... I know I know it's supposed to shut on it's own, but well it doesn't always. This is typically the issue where you leave the house at 900rpms go for a vigorous ride and the car idles at 1100rpms.
I'll let someone more qualified discuss the oiling system.
I will close off the PCV for the moment and then re-think what I'm doing. Question: how do you size a PCV valve? Maybe I'll leave that for the moment because I don't understand how to create a PCV system that will work and I've seen a bunch of different thoughts on it.
Well here is the deal..... a stock engine makes 18-20 inches of vac. These keeps the PCV closed or mostly closed at idle and during cruise. Maybe not closed, but it isn't flowing much. Your engine makes 10inches of vac ideally, 6 at the moment. Do you think the intake vac is pulling the pcv shut?
What happens if the pcv isnt' shut?
Chain reaction..... it stay open, you get a gulp of unmetered air, this raises idle speed, and due to the engine being somewhat randomly lean it makes adding fuel troublesome because at different rpm the engine is taking in different amounts of unmetered air. Adding a restriction lessens this swing by only allowing so much in during low vac situations.
I liked your comment about "you built the performance engine, now go ahead and build a performance starting system", by "build a performance starting system" I gather you are suggesting I may need a new starter at some point. I'm running a very old Ford stock starter and for now it is working fine, but I hear you. Burning out the starter is an acceptable risk.
Most factory starters will crank the engine hot at up to 18 degrees of advance. Some may not. Good battery, good cables, good starter, possible start/retard function are all part of the game.
The specs from QFT for the SS 830 don't mention the IFR, and I have no idea what they are, but I'll ask. Below are the specs they provided, and I changed the primary jets to compensate for the altitude based on QFT's advice.
High Speed Air Bleed 28
Idle Air Bleed Size 70
Primary Main Jet 78
Ohh boy, a carb lesson. Ok well power valve opening point is determined really by your cruise vacuum (mostly just that you don't want it opening at cruise). Ignore that for now. Jet size is strictly for cruising on the main circuit. High speed bleed and idle bleed, well.... lets avoid those right now so we don't get too confused, same with emulsion bleeds.... those aren't the current issue, so lets put that off until another day.
As mentioned at idle and up until the mains come online you are driving on JUST the transfer slot and the idle feed hole.
If you have no idle screw adjustability or it is very desensitized you either have too much transfer slot showing, OR you are feeding way too much fuel at idle.
This is dictated by the Idle Feed Restriction (IFR)
On your quickfuel it'll be here:
On one of my carbs or on an older Holley it'll be in the low position:
Notice on the bottom photo with the IFR at the low position? Ok, fuel from the main well flows from the cross drilled hole that is next to where I have that 6-32 restriction. The restriction is for the fuel that flows into the idle well. In the high position it pretty much does the same thing as fuel flows up the backside of the metering block to the top of the well through the high IFR hole. Now look at the idle slot on the metering block. Two holes..... one is for the transfer slot one is for the idle screw. These two holes flow into the main body and to that round hole and transfer slot you see under the butterflies. Obviously, you can only adjust one externally.... the idle screw.
Main well:
Idle well:
People like to say "well jus change da jets"
You can take the jets out... throw them in the trash and idle the engine just fine
They only really come into play at higher rpm and are for cruising.
The power valve is held shut by vacuum (in your case til 6.5inch)
When vacuum drops below that it begins to open.... fully open a lil later as the vacuum drops.
For acceleration only are the PVCR (power valve channel restrictors) The power valve feeds directly into the main well which is going to the boosters.
and for reference, even tho I said I wasn't gonna go into it, the emulsion bleeds:
until you get the timing sorted and perfect, I wouldn't mess with this.
But...... once timing is sorted, and primary transfer slot is perfect, if you still lack adjustability with the idle screws, you *may* need to change that IFR to a smaller one. The idle screws are good, but not if so much fuel is pouring in via the slot that they are but a drop in the bucket. I'm sure others will argue, but I find most new carbs come too rich in this department. The idle circuit is always working really, it just becomes obsolete once there is so much air flowing into the carburetor that the fuel it provides doesn't matter.
Drew