Carb or ignition first?

J

Jason Schulz

New member
Hi everybody!

I am new to this forum, and internationals!

I got a great deal on a 72 Scout 11, with a 304.

I have gotten it running , but I need help with some very basic questions.

1> should I set ignition dwell and timing first, or get carb setting spot on?

2> I have been reading threads, and I am wondering if there is a way to tell if my distributer is 180 out or not?


I have rebuilt the carb, and now she runs but not great?


I live at 6600 ft elevation, and know that needs to be taken into account during engine tuning!
 
Congrats.
1. Look up the power tune by mr mayben. I believe in it he specifically states what should happen before messing with timing.
2. Your distributor being 180 or the cap or the way you have your wires plugged in? I can’t imagine any of them being that far off but I could be wrong. I’ve only replaced my cap, rotor, plug wires, plugs, and some other wiring up there.

I’m in denver and know what you’re dealing with at altitude. It wasn’t until a few runs around 10k feet that I realized how much better it ran up there.
 
Jason, do you know which carb is on the engine? If the engine 'runs', the distributor must be pretty close to correct. If it was 180* out, it wouldn't start at all. Set the point gap before messing further with the carb. Use a 'dwell meter' if the distributor is the 'points' style. The correct setting will be between 28* to 32* or try 18/1000 with new points. Be sure to lube the rubbing block of the points where it rides against the distributor cam. When the point gap has been set, check the base timing again as changing the dwell will change the timing.
Verify the plug wires are in the correct holes. The IH fireing order begins with the #8 cyl. That is 'rear on passenger side'. The fireing order is cast on the intake manifold near the thermostat housing. The cyls are numbered on the intake manifold runners just above where the manifold bolts to the heads.
Look for m. Maybens writeup on 'power timing'.
 
Thanks aubrey and bill!

I am not sure what exact distributer I have.

But after opening 100 boxes of points, I was able to find the ones I needed!

I do not have a dwell meter available, but I can gap them properly with a snug feeler guage.

Will this be accurate enough to insure an accurate time?

Or should I get a dwell meter?

Also does anyone agree with advancing 1 degree per 1200 ft of altitude, or should I set at tdc and test drive? Thanks!
 
A 'dwell meter' is the better way to set points, but if you don't have one - you just get close! The 18/1000 will be good enough to start. The dwell meter will also show if the timing is 'even' at each cyl. For the timing, 'advancing' for higher elevation does help, but you won't know the base timing till after the point gap is set. Do look for Mike Maybens thread on setting timing for best results when a timing light is not available.
Setting point gap in the Holley points dist is at 'very light drag' on the thickness gauge. (that is what I have) other distributors have different methods to set dwell.
 
Thanks alot bll!

I will set my points with a guage, and start looking for a dwell meter.

Any suggestions on a good meter? And where to get it?
 
I haven't looked at or used dwell meters for a long time. I have 2meters and don't think either work. The trick is that if you can borrow a dwell meter to get the 'feel' for setting points and verify with the dwell meter, you can get pretty close with the thickness gauge. The IH engines were designed to be used by a farmer or non-techie driver with minimum tuneup equipment. Some just use a standard 'business card' to set the point gap. Of course, having the correct equipment to do the tuneup does give better results to begin with. I like to remove the distributor from the engine and set the points with the distributor in my bench vice. Gives me the opportunity to check each lobe of the distributor cam for wear and I can check the dist shaft wear at the same time. It is much easier to check and set the point gap out of the engine than trying to 'bump' the starter to get the distributor to hit directly at the high point of the distributor cam. Trying to hit the 'point' of the cam on each lobe to check wear would be next to impossible with the distributor 'in' the engine. The trick is to get the distributor back in the engine in the correct position so the engine can be restarted. Just takes a little 'cheating' to make the reinstall a 'drop in' task. :winky:
 
I read somewhere,credit card is .030,and the good ole matchbook cover is .020...back in the day,matches were everywhere,thats what was used,was no credit cards.Jeff
 
So,

I set the gap to a lightly snug .017. And it obviously made a positive change to the happiness of the 304!

I then started playing
with the carb, I was adjusting the two screws in the baseplate. I have them at 3.5 turns out?

I was told that these two screws only change the idle mixture, but they also seem to affect the response throughout the range?

I was set at 3 degrees advanced, I am now at 8 degrees advanced because it just seem to be happy there?

I am going to check your thread recomendation for power timing right now!!!!
 
'cheating', means I made a small 'pointer' that attaches to the back side of the water pump and extends to the base of the dist cap. There is a short painted line the same width as the notch on the pointer. The width of the notch is close to 5* worth of advancement. About the amout needed for local mountains =6000 ft. Before removing the dist, I remove the cap and rotate the engine/distributor so the dist rotor is direct in line with the pointer. I made a Mark on the dist housing as well. Remove the dist for whatever service is needed and re-install the dist so the housing and rotor are in line with the pointer. The cap (with Mark) should drop right back in as it was originally. Of course, if the engine is cranked while the dist is out of the engine, all bets are off! While the point setting May have been adjusted, the timing will only have changed a couple degrees. Should have no problem re starting the motor.
If a picture would help, send a e-mail to :winky:
mrbillb 'at' yahoo 'dot' com
 
jason schulz said:
so,

I set the gap to a lightly snug .017. And it obviously made a positive change to the happiness of the 304!

I then started playing
with the carb, I was adjusting the two screws in the baseplate. I have them at 3.5 turns out?

I was told that these two screws only change the idle mixture, but they also seem to affect the response throughout the range?

I was set at 3 degrees advanced, I am now at 8 degrees advanced because it just seem to be happy there?

I am going to check your thread recomendation for power timing right now!!!!
Click to expand...

Good job on setting the point gap and the timing advance. Since you're playing at high elevation and this is a 304, you can likely get away with even more advance, but do so in small increments with test drives under hard accel up a hill after each adjustment to make sure you're engine doesn't ping. This is explained in greater detail in the "power timing" thread. The mixture adjustments are primarily for idle quality. Turning them out enriches the mixture. Generally speaking, the ideal setting for most folks is usually between 1.5 to 2 turns out from lightly seated. The best way to adjust these is with a vacuum gauge connected to monitor manifold vacuum at idle on a warm engine. You want the highest number possible in hg's with a smooth idle for your elevation. At or near sea level for a stock 304 in a good state of tune would be roughly 20 hg on the vac gauge, but the number will be gradually lower the higher the elevation is.
 
Thanks everyone!
I went to the [ power timing thread ] And it really helped.
I ended up at 11 degrees, with more power, a much smoother rev, and a better hot start!

Now I will go bug all the guys on the carb thread!

Thanks again everyone!
 
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