351 Windsor Timing Help
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Mountain Pass
Joined: Feb 2020
Posts: 101
Likes: 7
351 Windsor Timing Help
I just got my 351 Windsor "running" but something is off with the timing. I wanted to see if anyone had any advice until I can get home and look at it myself. We had a timing light on it and it showed that the timing was correct and it idles fine but would backfire thorough the manifold if I gave it any gas. A week later I tried to start it and it struggled and I only got it to start once very briefly. It backfires out of the manifold when it cranks. I haven't changed the timing since I had it running before and now it doesn't want to start. People have told me it could be be off 180 but it doesn't make sense that it would idle perfectly fine and even rev up fine sometimes and be 180 off. It would only backfire sometimes but not every time it would rev up. Could it just be slightly off
Post Fiend
Joined: Apr 2002
Posts: 19,311
Likes: 97
From: Waterloo, Iowa
It is common for older crank balancers, made with an outer steel inertia weight, to slip off its "clock" due to the rubber bonding dry rotting. Always verify true TDC with a piston stop tool, and see that it coincides with the pointer and "0" mark on the balancer.
FTE Legend
Joined: Nov 2015
Posts: 30,940
Likes: 4,125
From: Angier, NC
Get a wooden rod, remove #1 plug and by hand crank the motor till the timing mark is at 0.
Now with the rod in the hole turn the motor by hand and the rod should drop in more.
Now turn the motor back and the rod should push up and just after TDC drop back down again.
Now go back the other way so the rod gets pushed out and just as the rod drops check the timing mark.
If it has not slipped it should point to 0.
If it is off a little say 5* it should not make it run that bad but may get pinging and hard start when hot.
Now what is the story on this motor?
Junk yard find, you rebuilt it, it ran fine till you did plug wires & cap?
Check your firing order it sounds like you have 2 wires swapped.
Now the 351 is a 302 and I have seen it posted the 302 has 2 different firing orders.
Normal 302 and H.O. 302 so check this out and I think the 351 uses the HO firing order but not 100% sure.
Maybe for S&G swap the firing order to see what happens?
Dave ----
Moderator
Joined: Jan 2001
Posts: 56,997
Likes: 2,744
From: Virginia
I think the timing is fine. I think the accelerator pump is gone in his carb. That explains why he can't get it started cold, and why it spits back up through the carb when he nails the throttle.
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