Now I have a new problem. I replaced the wretched Autolite 1100 finally with the Carter YF. With a carburetor that actually puts out correct vacuum to the dis. I now have an advance problem. I noticed quickly that I had a noticeable hesitation only at a certain point of acceleration. It felt like an ignition issue but on the other hand I had just put on a rebuilt carb. Tonight I unplugged the advance hose and she ran perfectly or at least as good as an engine can run without proper advance curve.

Earlier in this thread I mentioned my timing being set around 8 deg. Since then I had moved it up to around 10 deg. That was no problem with the Loadomatic carb that seemed to produce little or no vacuum to the distributor. Now, with the Carter I think I need to set the timing back to near what savage066 mentioned, 4-6 deg. That way I should not be running off the scale when I have high vacuum. For the record I am fairly certain that I do not have a LoADOMATIC distributor. I have read about some of the problems mixing and matching Loadomatic parts can cause. With this problem I have at least given it a second thought. To my knowledge the LM should have a rigid shaft as opposed to the more normal springy shaft. When I say springy I mean you can turn the rotor a bit by hand and it kind of has a spring action. My dis. actually has a non fixed shaft position but the rotor does not really spring back. If it were not for the tention of the points I dont think there would be any spring back, or very little. Maybe I have a broken Loadomatic dis. Who knows? Seems like the two types would be easier to visually identify. I have a feeling that either way I need a new distributor. Then I start thinking of a whole other can of worms. Electronic ignition. I guess I could go buy a probably needed point dis. and get the Pertronix setup. I keep my truck mostly stock and hate to visually change anything. I must say I would much rather have the super durable Duraspark setup but that would not look the same. With all this Loadomatic confusion I think the easiest thing will be some kind of replacement if nothing else just know what I have for sure........

 

I replaced the wretched Autolite 1100 finally with the Carter YF. With a carburetor that actually puts out correct vacuum to the dis. I now have an advance problem. I noticed quickly that I had a noticeable hesitation only at a certain point of acceleration. It felt like an ignition issue but on the other hand I had just put on a rebuilt carb. Tonight I unplugged the advance hose and she ran perfectly or at least as good as an engine can run without proper advance curve.

You are aware that the "dist" port will show little to
no vacuum at idle, but increase as you give it gas...
The dist port on the carter should have little to no
vacuum at idle. Make sure you are on the right port.
Some are marked "dist", but some may not be.

Earlier in this thread I mentioned my timing being set around 8 deg. Since then I had moved it up to around 10 deg. That was no problem with the Loadomatic carb that seemed to produce little or no vacuum to the distributor.

Again, did you check that port at various RPMS's?
It might not have been as dead as you think at
higher rpms...8-10 deg is normally pretty close for
many 300's...
Now, with the Carter I think I need to set the timing back to near what savage066 mentioned, 4-6 deg.

You could do that if it doesn't ping...I have to wonder
about timing settings of 12-14 btdc....????
How do they have any power set that high???
Gads....Seems like it would having trouble tearing
pants off a clothesline...
6-10 deg is the normal range for most 240's-300s..
Maybe some of the newest models went a tad higher,
but they are the exception to the rule...
If you want the most power, set low...I'd try 6 deg..
If it doesn't ping, fine...If it does, you have two choices.
A better grade of gas, or set the timing up to 8 deg, or
so until it quits pinging...I agree with some...There is
no "exact" best timing...It will vary to location, alt, fuel,
etc, etc...If you set it using pinging as a guide, or use
the vacuum gauge, etc, you are getting as close as you
can get...Remember...The higher the number, the less
power in general, although some may "feel" better at
high RPM's when set up a bit higher...

Electronic ignition. I guess I could go buy a probably needed point dis. and get the Pertronix setup. I keep my truck mostly stock and hate to visually change anything. I must say I would much rather have the super durable Duraspark setup but that would not look the same.

I have the duraspark setup on my 74 F-100..."240".
I think the parts came from a 79 ford van...
It's great, and all stock, so parts can be had anywhere.
The only difference in looks is the slightly larger cap, etc..
Who cares....I have points in my 68, and I'd switch it to
a duraspark in a second....It's worth it for the lack of point
changeouts, adjusting, etc...You get a hotter spark too...
Myself, I would not waste the money on the high $$$
ignition stuff, unless it's a hotrod...Unless you actually use
a wider plug gap, raising the voltage is useless...It adds
nothing really...The stock ignition is fine for any general
use engine...
MK

 

I am sure that the smaller vacuum port is the correct distributor connection since there is some restriction (metered) there as opposed to the other larger unrestricted port.

What I did was jack the idle speed way up until I heard the hesitation. At that time I turned the distributor clockwise until it went away. Then of course I readjusted the idle speed. I did not have time to drive it. I'll get back soon as I do.

 

On a stock EFI intake, where would I hook up a vacuum gauge for timing adjustment. Ive been looking for a way to accurately set the timing.
You say set for max vaccuum at idel, then advance or retard it just a bit? Is a bit 1-2 degrees? and is that clockwise or counterclockwise?

 

I wanted to revive this thread because there was a lot of great input throughout and the last question was never answered.

Also, I finally have no Loadomatic issues at all. I have the Cater YF and stock point distributor. I'm hoping with the recent fuel cost increases that some more good ideas may have come about concerning setting timing for maximum fuel efficiency. Right now I am at about 10. I was around 8 but it kind of felt like something was holding the engine back so I went up a bit. I havent tried one of these wild 14 deg settings yet. Still not sure about that. If I had a light I would just go try everything and tell everyone instead of ask questions. Unfortunately I have to borrow one. Why? I have never needed one. I have always done it by feel (power) and had good luck. Now with the price of gas I want to be more precise, and efficient.

 

I've been running my new set up for about 8 months now. Fuel economy has been terrific since I put the Holly 390 on it. My timing is still set at 12* advance. If I remember right, advance is counter-clockwise. I don't think 14* is wild, the shop manual says 10* +/- 2*. 14 probably isn't so far out there. My truck was on 18* before I started putting stuff on it. That setting was the 'tuning by ear' method. The truck just seemed to run better that way. After I changed the manifolds, I found out there had been some leaks, and that's probably to blame for the huge advance. My truck won't run worth a toot at 10, but at 12, she purrs like a kitten!

If fuel efficiency is your goal, then I think you should change the carb. A properly tuned four barrel like the Holly 390 will improve fuel economy if you drive conservatively. On the same token, if you're like me and you just like to hear the sound of the pipes when that power valve opens, you can romp it and have some power to play with! Another thing is, if you really want to be precise, you'll have to spring for that timing light! I got one for about $40 at Advance Auto. In my limited experience, eyeballing or 'tuning by ear' can get you power, but it won't help fuel economy.

 

Yeah I guess 14 deg isnt all that wild. I guess I was just thinking that twice the AutoZone factory recomended setting seemed like a lot. My engine seems to do better the further I advance it. I think I will break out the vacuum gauge soon and give that a whirl. Some people swear by the the use of a vacuum gauge.

Now, a four barrel on a six to save gas sounds a little extream. I know people do it but I just think its overkill. Seems like a two barrel would be more like it for a six. Really its all about what the owner wants out of his/her ride as far as mods go. I pretty much stay stock, in apearance at least. The struggle of justifying keeping insurance on a gas hog that I love to drive has definitly made me consider any mod that will increase efficiency.

 

FYI....

I've been keeping up with my mpg since March '05. In late April, I installed the EFI manifolds and walker downpipe. And I got a new gas cap... the old one allowed fuel to siphon out, dripping along the side of the truck.

Prior to these changes my mpg was 11.6. Now it is 12.85.

 

I thought a four barrel would be too much for this 'little' motor, too. But the Holley 390 really operates on two barrels until the engine NEEDS the extra power, then the secondaries and powervalve open as required. It may be ridiculous to think that a four barrel carb will give you better mileage, but it will increase performance on the 300 rather nicely!

I didn't know about the vacuum guage thing until I upgraded to my current setup. I must say that it worked out really well. It's a lengthy process, though. Once you get max vacuum at the manifold by tweaking your carb, you have to set the timing and re-tweak the carb, reset the timing, recheck the carb, etc. They are so dependant on each other, that any changes you make to either means you need to go back and check the other.