Backfiring
#11
RE: Backfiring
What does your timing light say? It'll let you know what your timing is even if the engine doesnt' run.
Do you have the cam part number handy? Look it up and make sure it's for an older 302, vs a newer 302/351.
Do you have the cam part number handy? Look it up and make sure it's for an older 302, vs a newer 302/351.
#12
RE: Backfiring
I did the same thing on my 351C now are you certain of which way the rotor spins on the distributor? i wired mine backwards and had the same problem...actually started some fuzz on fire from my hood . simple fix if that is the case
#13
RE: Backfiring
All good points. Check the firing order of the cam. It should be on the cam spec sheet. Make sure you used the firing order for the cam you have.(That one kicked my but cus I had a 5.0HO cam and didn't know). Make sure you wired the dizzy wires for a counter clock wise rotation. Try those things and I'll bet you figure it out.
#14
RE: Backfiring
Thanks everybody!!
I did some more playing with it last night and found I was wrong. Ihad tryed to eyeball the location of the rotor at #1 compression time by having my son turn over the engine while I felt for the compression stroke and hollered stop when it hit. Then pulled the cap and checked the position of the rotor. Problem is, by time I holler stop and he lets off the key, the rotor has already turned an additional 180 degrees or so.
Last night, I pulled the cap off and tested it again, watching the rotor spin with my finger over #1 hole, while my son turned it over. It's actually firing at the 7:00 position instead of 1:00.
That sounds like I've dufused the timing chain. I will double check the doc on the camI added, though, to make of the firing order for it. I would sure love to find it's something like that instead of having to tear that engine back down again.
So, just a theortical question, if I did dufus the timing chain and have it 180 degrees off, what would happen if I wired the distributor by starting my #1 wire at the 7:00oclock position and then #5, and then #2, etc., going counter clockwise. Would that sync everything back up? Just pondering...
I did some more playing with it last night and found I was wrong. Ihad tryed to eyeball the location of the rotor at #1 compression time by having my son turn over the engine while I felt for the compression stroke and hollered stop when it hit. Then pulled the cap and checked the position of the rotor. Problem is, by time I holler stop and he lets off the key, the rotor has already turned an additional 180 degrees or so.
Last night, I pulled the cap off and tested it again, watching the rotor spin with my finger over #1 hole, while my son turned it over. It's actually firing at the 7:00 position instead of 1:00.
That sounds like I've dufused the timing chain. I will double check the doc on the camI added, though, to make of the firing order for it. I would sure love to find it's something like that instead of having to tear that engine back down again.
So, just a theortical question, if I did dufus the timing chain and have it 180 degrees off, what would happen if I wired the distributor by starting my #1 wire at the 7:00oclock position and then #5, and then #2, etc., going counter clockwise. Would that sync everything back up? Just pondering...
#15
RE: Backfiring
So, just a theortical question, if I did dufus the timing chain and have it 180 degrees off, what would happen if I wired the distributor by starting my #1 wire at the 7:00oclock position and then #5, and then #2, etc., going counter clockwise. Would that sync everything back up? Just pondering...
keep in mind different engines from different manufactures use the timing marks different. some are "dot to dot", some are "both dots up" so dont feel bad!
you'll just have to remember thats how its setup when you do a tune up later down the road. pretend 7:00 is 1:00 and you'll be perfect
#16
RE: Backfiring
I may just wuss and do that then.I just checked the Edelbrock Tech site for the cam/lifter kit I got (part 7122) and it says to go with the 289-302 order... 15426379... so I guess the 351 firing order is out. That leaves the gears flipped around. I hang my head in shame and gonna go try rewiring it starting at the 7o'clock position. I'm sure I'll be back in the engine sometime down the road and can flip it then.
Thanks for all the info. At least I'm learning a lot.
Thanks for all the info. At least I'm learning a lot.
#17
RE: Backfiring
You're gonna be grinning from ear to ear when that sucker pops and sputters and then starts and runs. When she finally starts and runs, let her idle for about 20 minutes or so, then start adjusting the timing and carb, etc.
#18
RE: Backfiring
IT'S ALIVE!!! [sm=groupwave.gif]
I went with the 180 degree swap with the wires and got it going. Then my Pop told me it's be lots easier just to pull up the distributor and spin the rotor button/shaft around 180 degrees and bolt it down there. That way I could keep my wiring order by the book. So I went back and reworked it that way and it worked as well.
Oh man, you're right Soaring, it sure was nice to drive it around the block one time.I need to do a little adjusting on the valves, they're rattling a good bit, then some adjusting on the clutch to get it feeling better and some tweeking on the carb and I believe I'm back in business!!
Thanks again for everyone's suggestions!! [sm=hail.gif]
I went with the 180 degree swap with the wires and got it going. Then my Pop told me it's be lots easier just to pull up the distributor and spin the rotor button/shaft around 180 degrees and bolt it down there. That way I could keep my wiring order by the book. So I went back and reworked it that way and it worked as well.
Oh man, you're right Soaring, it sure was nice to drive it around the block one time.I need to do a little adjusting on the valves, they're rattling a good bit, then some adjusting on the clutch to get it feeling better and some tweeking on the carb and I believe I'm back in business!!
Thanks again for everyone's suggestions!! [sm=hail.gif]
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