If it is backfiring something is way off. One way to find approx TDC is have the valve cover off and watch for both valves to be closed on #1 (rocker arms up). Then stick the distrib
in so the rotor points to #1 on the cap.
Attached pictures showing #1 on a couple of Poly’s. You can see number one on the cap is 3 terminals over from the clip. The krusty engine was mine when I got it, still with Grandpa’s
clothes pin on #1. Don’t let the wires crossing under the heater hoses fool you in that pic. And another nice Poly showing same orientation and you can trace the wire to #1 cylinder in that pic. Of course you can use any wire on the cap, as long the distrib
is stuck in there so the rotor points to whatever terminal is wired as #1, and the firing order is correct. 1-8-4-3-6-5-7-2
Your distributor clocking can be just a couple notches off and cause the backfiring. Be glad you don’t have mufflers on there - you can blow them up. Summer of 2012 I was starting
a ’72 Cadillac 472 after sitting 20 years. It started right up and ran 15 mins, had to shut it down for a fuel leak from the fuel pump when diaphragm split. Next time trying to start the distributor jumped a couple of gears and it backfired - it did expand
a muffler! Still running that muffler, drove the rig with that engine in it today in fact. Figured timing chain, opened up the timing chain area to find the stripped distributor gear. (150,000 mile engine with oiling problems in timing chain area).
From: 1962to1965mopars@xxxxxxxxxxxxxxxx [mailto:1962to1965mopars@xxxxxxxxxxxxxxxx]
On Behalf Of dennis.1963ply
Sent: Tuesday, November 11, 2014 9:45 PM
Subject: Re: Timing on New Engine?
I'm sure you are going to get better answers with more detail than mine but here is a start:
You need to get #1 piston coming up on the compression stroke, you can check the valves, use a finger to tell when it is on compression or I have a screw-in compression gauge, I use it to tell when #1 is coming up.
You can buy or make a piston stop. With it you can roll the engine forwards and backwards, mark where it hits the stop, in the middle will be Top Dead Center.
When I have TDC and I am on compression I rotate back about a quarter of a turn and come back up to 10 Degrees on the harmonic balancer aligned with the TDC I found.
I set the distributor to #1 and rotate the distributor until the points just open for a point distributor.
It should fire.
I know I didn't provide enough details, I'm sure you will get more answers. This is the way I started the engine in my attachment. I used a point distributor, easy to tell when the points open with a meter or test light.
On Tuesday, November 11, 2014 10:08:01 PM UTC-7, Bubba wrote:
I am finally trying to get my 318 poly engine started after a full rebuild, and am not sure that I have the distributor dialed in close enough to get it firing. Definitely getting fuel and spark, as it has backfired
through the carb and out the exhaust manifold (no exhaust on it right now, as the old exhaust was toast).
Nice flame through the carb, and out the exhaust manifold, but no sign that it is going to start. Tried to see if I could use the timing light, but could not find the timing tab (maybe they left it off or lost
it?). I can see the timing mark on the damper, but without a timing tab, doesn't seem to be much help. Tried moving the distributor, but not really successful. Might be 180 degrees out?
Engine is a newly-rebuilt 318 poly, new 4bbl Edelbrock Performance carb, factory iron intake/exhaust.
Thoughts? Really wanted to get it going before the cold came through, but it's rolling into Ohio tonight.