Header Glowing Red! 2.4 Conversion

[CDN OpelNut]

I've managed to fix most of my assembly snafu's. Noting dire and easy to fix mostly. I ordered a new water pump from OGTS today as I don't like the noise coming from the old one.

I still can't get the idle down although I did find and replace the pictured volume control screw that was broken in half.

Anyway, despite the fact that the temp gauge is reading normal and creeps to just above normal after running for a while, in the dimly lit garage tonight I could see that the header is glowing bright red within a minute of sustained idle at 2000 rpm. I mean glowing enough to light up the engine bay. Every cylinder, right down to the exhaust connection. I knew it felt hot in there and the plastic screws on the OP sender have already melted.

I poked around the 'net and found that likely causes are advanced timing and running to lean. Any other hints?

Any suggestion on a systematic investigation?

I did have to advance the hell out of the timing to get it to start and stay running. But that was before I found the broken volume screw. If the timing is too advanced, will that affect both the idle and the temp?

Help!

[Azgt]

I would say its the advanced timing.The one time ive seen this myself was on my 79 blazer and i had the distributor too advanced and the headers were glowing red.

[CDN OpelNut]

Perhaps this is a problem. Hopefully you guys with Compufire can verify.

The Compufire instructions say to line up the dot on the trigger with the notch in the distributor shaft. This is impossible on mine. The notch is directly over a shaft lobe and the trigger will only fit in 4 spots due the the shape. See my pictures. first one is of the rotor in #3 firing location. If I put the trigger on in the closest of the 4 options, the magnet is way off. Seems to me this is going to bugger up timing and account for the large amount of counter-clockwise turn necessary to get the engine to fire.

Does this seem logical and for those of you with compufire, does your magnet line up with the shaft notch?

[RallyBob]

Originally Posted by CDN OpelNut I poked around the 'net and found that likely causes are advanced timing and running to lean. Any other hints? Any suggestion on a systematic investigation? I did have to advance the hell out of the timing to get it to start and stay running. But that was before I found the broken volume screw. If the timing is too advanced, will that affect both the idle and the temp? Help!

Either overly advanced OR overly retarded timing can cause the high EGT's you are seeing.

But more likely it's due to the carburetor being jetted for a MUCH tamer and smaller displacement engine. Probably dead-lean.

Are you running an exhaust on the car during the critical break-in period? It's always a good idea to do this (although for some reason people tend to like to start new engines with open exhaust!?), as the lack of muffling often hides obscure engine noises, and will make the engine run even leaner than usual.

[CDN OpelNut]

Bob - Thanks.

I had the exhaust installed before I did the break-in. 2.25" all the way back through a Magnaflow and two pacesetter tips. No funny sounds outside of the squeaky water pump.

I told the supplier of the jets that I was running a single carb into a 125hp engine and went with the jets he suggested. I have a few spares and if I can't solve it through timing, I post what's there.

Corey

[RallyBob]

Originally Posted by CDN OpelNut I told the supplier of the jets that I was running a single carb into a 125hp engine and went with the jets he suggested. I have a few spares and if I can't solve it through timing, I post what's there. Corey

What do your plugs look like? That would be a tell-tale for sure. Check #2 cylinder, it generally runs the hottest therefore the leanest.

Bob

[CDN OpelNut]

Originally Posted by RallyBob What do your plugs look like? That would be a tell-tale for sure. Check #2 cylinder, it generally runs the hottest therefore the leanest. Bob

I took the plugs out last night. They are all the same. Black electrode with some oil on the threads. I was worried about that but the Chilton manual has a photo of exactly how the plugs look and said that it is normal in a new rebuild.

Any thoughts on the Compufire trigger?

[hrcollinsjr]

One last question that everyone seems to have forgotten to ask, "Do you have a fan or blower of some sort in front of the car for additional cooling?" I installed a VERY mild cam (probably a waste of $) in a Dodge Ramcharger years ago and when breaking it in noticed that the exhaust was glowing because of the lack of air flow across the exhaust.

HTH,

Harold

[Tru-Craft]

Lean and timing off sounds like the problem.
What is your initial timing set at?
Like Bob said plugs tell the story.
Put some clean plugs in, run it at 2,000-3,000 for a couple minutes and shut off.
Then see what the plugs look like.

How about an exhaust header gasket blocking flow or leaking?
Collector gasket?
I have a 20 year old quick trip header on my GT. It has very thin wall primary tubes. At night mine glows red at higher rpm. I can't put my hand near the header for long, even at idle adjusting the carb is a pain.
How red is too red?
Lyle

[CDN OpelNut]

Originally Posted by hrcollinsjr One last question that everyone seems to have forgotten to ask, "Do you have a fan or blower of some sort in front of the car for additional cooling?" I installed a VERY mild cam (probably a waste of $) in a Dodge Ramcharger years ago and when breaking it in noticed that the exhaust was glowing because of the lack of air flow across the exhaust. HTH, Harold

Short answer - nope. The temp gage stays pretty good. I did have a bucket of ice and fan when I did the break-in, but other than the header, no issues.

I am hoping that if I can get the advance fixed, it'll cure itself.

[wrench459]

Originally Posted by CDN OpelNut I took the plugs out last night. They are all the same. Black electrode with some oil on the threads. I was worried about that but the Chilton manual has a photo of exactly how the plugs look and said that it is normal in a new rebuild.

The chilton manual was based on leaded fuel.
The brown circle aint there.
I'm having a major problem with reading spark plugs with no lead fuel. They all look lean. Did you index the flywheel?

[oldopelguy]

If you just can't get enough adjustment out of the distributor you can always move it 90* and then swap the spark plug wires to compensate. That is, if you need to advance it (counter-clockwise) more than you can get before the vacuum advance hits the block you instead retard the distributor 90* (clockwise) then swap all the plug wires one later in the correct firing order. (The plug wire currently on #1 moves over to 3, the one on 3 moves to 4, etc.) Basically you get to decide which hole in distributor or magnet on the trigger is for #1, move the housing around as needed and line up the closest one.

This is why it's so important to find the ball on the flywheel and the actual TDC for the motor. The relationship between that ball and whatever wire is firing #1 cylinder is the only really important relationship as long as the firing order is correct. Everything else can be changed as needed as long as that relationship is held correct.

[CDN OpelNut]

Thanks everyone for your help so far. In looking at the picture of the Compufire trigger in post #3, I can see that in order for the motor to run, I'm having to rotate the dizzy counterclockwise until the normal cylinder #3 firing position on the dizzy housing is beneath the pick-up on the trigger.

Makes sense I guess. RallyBob's posts in the Compufire installation thread only mention rotating the housing to the #3 position while the engine is at #1TDC firing position. Maybe this is the 30* phasing issue?

It would be helpful if someone with the Compufire installed could tell me if their trigger position relative to the shaft notch looks different than mine.

Tomorrow I'm going to replace my 160 Luftkorrekturduse (air correction jet) with 80's to try to enrich things a bit. In looking at my notes, 80 was originally recommended.

[trlmr]

Maybe you should put a timing light on it if you haven't already. It won't be exact since you are running 2000 rpms. But you can get it somewhat close even with the distributor adding advance at that rpm. I'm thinking, as I'm sure you are, that the idling problems are related to the hot pipe. If nothing else works, keep in mind that there is always a possibility of the cam not being timed right.
Good luck

[broszzy]

I'm running a stock 1.9 with the compufire and my rotor is in the same position as yours but my distributor is retarded to where the snap clips are straight up and down and the wires out of the pick up are coming straight out the front towards the radiator if that helps u at all. Do you know where the end of the broken needle valve is? hope its note still in the carb.

Pat

[broszzy]

Do you have your vacuum lines pluged? I pluged mine and took the diagram right off the dissy and sealed the holes since it has no effect on the timing any more, it looks really clean that way too.

Pat

[CDN OpelNut]

I went back to square one. Checked the #1TDC. All good. Reinstalled the Compufire. I decided that you simply have go by ear. Once I lined the dizzy up for #3 fire I still had to rotate it CC alot in order for it to smooth out.

But what seems to have done the trick was switching the air correction jet/emulsion tube (they're a single unit on this carb). I changed to one half as big, 160 down to 80, and I'm sure the A/F ratio is much better now. I'll let it run in the dark tonight and see about the glowing but I can feel that it is not as hot.

I may get another dizzy and try it without the vacuum advance. I've got the mechanical advance limited to 25* so we'll see how it drives.

Anyway, I got it to idle at about 1000-1100 rpm. It's pretty lumpy below that with the combo cam.

I have to hook up a manual choke and set the throttle cable then I'm on the road.