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Discussion Starter · #21 ·
No. It won't run for even a second if you're 180 deg off. Are you trying to break in an engine with a new carburetor? It's preferable to use one that you know ran OK even if it's too small for your engine.
Well that's good news about being 180⁰ out. It's the carb I took off the old 400. It ran fine and it's probably 2-3 years old. It's a 750 holley, should be a good fit for this engine. My dad suggested having someone crank the engine while I slowly adjust the dizzy until i have some success. I told him I'm going to reach out to you all first haha.
 

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Hey all,

Update: I've been chasing gas, oil, and coolant leaks since my last post. Today I attempted engine break in. The car fired up immediately and died. I advanced the timing a bit and it was experiencing hard sluggish sounds as the engine turned over. I retarted the timing and it fired up but backfired. I richened up the air fuel screws and it did the same on the next attempt. Would I even get this far if the dizzy was 180⁰ out? I hooked up my timing light so I can see what rpms i was running at since I do not have a tach and the timing light for the first time showed me what degree the timing was at when the key was on and it was counting down from 90⁰ to 0⁰ I'm not sure if that's just a default feature of the timing light but my gut tells me something Is off with my timing the light is a innova 3568a If that helps.

Thanks for the help!
X2 if it is out 180 it would not run. Since it seemed to run it is more likely the timing. Have experienced this myself. Hard start typically means to far advanced. Then you probably retarded it too much and got the fire - and an engine retarded too much will spike up in temperature. Keep in mind that you may have loaded up the intake/cylinders with gas trying to get it to start if you pumped the pedal a few times.

I have had the experience in trying to get the engine to fire up by moving the distributor that you only want to go a small amount each move or you can be chasing the correct timing as you go too far one way and then too far the other way. You can leave the dist. hold-down bolt/clamp snug, but enough to rotate the dist.. You can turn it while someone is cranking the engine and listen to the engine and it will tell you by sound when you are getting it right. Just keep your face away from the carb and have the fire extinguisher handy.

Some timing lights, which seem to be some of the "dial-back" timing lights, don't work with an HEI dist.. I do not recall if this applies to other electronic distributors or not - you will have to do a search to find out.
 

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Discussion Starter · #23 ·
X2 if it is out 180 it would not run. Since it seemed to run it is more likely the timing. Have experienced this myself. Hard start typically means to far advanced. Then you probably retarded it too much and got the fire - and an engine retarded too much will spike up in temperature. Keep in mind that you may have loaded up the intake/cylinders with gas trying to get it to start if you pumped the pedal a few times.

I have had the experience in trying to get the engine to fire up by moving the distributor that you only want to go a small amount each move or you can be chasing the correct timing as you go too far one way and then too far the other way. You can leave the dist. hold-down bolt/clamp snug, but enough to rotate the dist.. You can turn it while someone is cranking the engine and listen to the engine and it will tell you by sound when you are getting it right. Just keep your face away from the carb and have the fire extinguisher handy.

Some timing lights, which seem to be some of the "dial-back" timing lights, don't work with an HEI dist.. I do not recall if this applies to other electronic distributors or not - you will have to do a search to find out.
I'll try that tomorrow! Thank you! My old man will be pleased that his idea was the right one.
 

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Discussion Starter · #25 ·
Humor me... I think I've stated before about my lack of knowledge with electricity/ignition. I did a simple Google search about the firing order of a pontiac 400 (image below) I was not even sure if I had points or an HEI dizzy in my car and a previous post someone uploaded a firing order from I assume points dizzy and I just followed that orientation of wires (my fault for not knowing, not who posted it) do I need to go back and re route my wires to match what is below for my HEI distributor? Could that be why my carb is backfiring? I can reassemble an engine (enjoy the hell outta it doing it too) but I just can't seem to understand igniton related topics I ruined the MSD ignition system my car came with when i bought it from running wires where they weren't supposed to go and caught my other car on fire messing with the relays. Be gentle, my name is Goat noob for a reason :)
Font Circle Event Electric blue Science
 

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You need to turn the engine over to find top dead center (TDC) for the number 1 cylinder, then remove the distributor cap and see where the rotor is pointing and then attach the spark plug wires to cap in the firing order starting where your rotor is pointing, depending on your distributor you may need to pull it and rotate it if you vacuum advance doesn't let you rotate it enough

You can pull the valve cover to watch the rockers to help get you close to TDC watch for both number 1 cylinder rockers to be closed (up) at the same time and the piston will travel up a little more to reach TDC

If you pull all the spark plugs it will make it a lot easier to turn the engine over with a ratchet on the crank bolt by hand

The engine will show TDC or 0 on your timing mark once at TDC exhaust (one rocker arm down) and TDC compression (both rocker arms up) you want TDC compression both valve closed (both rocker arms up)

HEI or points same process
 

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Cameo Ivory 1967
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Firing order is the same for both unless you used a non-standard camshaft. There is a cam profile that will change the firing order. I t5hink the typical is a 4&7 swap but don't quote me on it. I think @armyadarkness was running one of these before he installed his current cam.
I was going to ask about that earlier, but I didnt see where he added a new cam.

I was having his exact issues.
 

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Discussion Starter · #31 ·
I was going to ask about that earlier, but I didnt see where he added a new cam.

I was having his exact issues.
I Installed a Comp Cams XTREME ENERGY XE268H Hydraulic Flat Tappet Cam. It was butlers recommendation for the biggest cam without getting into a stall convertor. I'll pull the cap and check my firing order hopefully tonight. Thank you for your help everyone.
 

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Discussion Starter · #33 ·
Found TDC on the compression stroke pulled the cap and the rotor was pointing at #1. Double checked my wires and they looked good. The motor fired right up. I'm going to attempt break in tomorrow. My heater core is leaking at the head. Can I just throw a cap on the piece coming from the head and cut off heat to the car. I don't drive the car during the winter months in PA, is that an option for me to elimate the need for the heater core hose? I put just shy of 4 gallons of coolant in the car and removed the thermostat for break in? I had my heads checked and rebuilt by my machinist prior to all this, I'm running the stock #16 72cc heads from the original 68 block that came with the car by sadly the original block was damaged, the ring that holds the distributor was broken and could not be repaired so I have a 71 400 from a GTO in the car now. Good thing I got the car cheap or I would have loved to have the original engine in the car. Not that I plan on ever parting with it. I built this engine for about 2k, I'm proud of doing it so cheap (for a pontiac) wish me luck. The rear main is leaking a bit but I hope it gets better once the engine gets up to temp.
 

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Found TDC on the compression stroke pulled the cap and the rotor was pointing at #1. Double checked my wires and they looked good. The motor fired right up. I'm going to attempt break in tomorrow. My heater core is leaking at the head. Can I just throw a cap on the piece coming from the head and cut off heat to the car. I don't drive the car during the winter months in PA, is that an option for me to elimate the need for the heater core hose? I put just shy of 4 gallons of coolant in the car and removed the thermostat for break in? I had my heads checked and rebuilt by my machinist prior to all this, I'm running the stock #16 72cc heads from the original 68 block that came with the car by sadly the original block was damaged, the ring that holds the distributor was broken and could not be repaired so I have a 71 400 from a GTO in the car now. Good thing I got the car cheap or I would have loved to have the original engine in the car. Not that I plan on ever parting with it. I built this engine for about 2k, I'm proud of doing it so cheap (for a pontiac) wish me luck. The rear main is leaking a bit but I hope it gets better once the engine gets up to temp.
You will be using high octane gas with the #16 heads, so keep that in mind so you don't allow the engine to ping/detonate or you will damage the engine.
 

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Discussion Starter · #36 ·
You will be using high octane gas with the #16 heads, so keep that in mind so you don't allow the engine to ping/detonate or you will damage the engine.
According to butler performance compression calculator I'm at 9.5:1. I have it filled up with 93 octane currently and all I'll run in it. I actually tracked my oil leak to the oil filter. I snugged the filter and I'll keep an eye on it tomorrow.
 

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Discussion Starter · #37 ·
Fired it up today and about 5 minutes into the breakin in had a substantial coolant leak under the car. It's coming from the back of the block so I'm thinking freeze plug or head gasket isn't seated properly maybe. I'm going to jack it up and get under it and see if I can find it.
 

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Discussion Starter · #39 ·
You can't catch a break on this. Hopefully it's something simple. Good luck!
Both heads are wet at the bottom and I assume it's something headgasket/surface related. I'll probably pull The heads and intake and order new head gaskets to be safe and see what happens. For the 5 minutes it ran it sounded good and oil pressure stayed at 800psi the entire time. I torqued the heads to spec and tightened them in the correct orientation. I did use the 50+ year old bolts. I reused everything I could in this build (even the rods...gasp) wish me luck.
 

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Discussion Starter · #40 ·
Both heads are wet at the bottom and I assume it's something headgasket/surface related. I'll probably pull The heads and intake and order new head gaskets to be safe and see what happens. For the 5 minutes it ran it sounded good and oil pressure stayed at 800psi the entire time. I torqued the heads to spec and tightened them in the correct orientation. I did use the 50+ year old bolts. I reused everything I could in this build (even the rods...gasp) wish me luck.
80* lol. Freeze plugs were dry.
 
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