52 Coronet....Help! I think I F'd it up bad.

Ok sorry I haven't been here in awhile fellas but i need help again. 52 Coronet 230 Flathead Straight 6. I had the biggest backfiring issue forever went threw pretty much all the easy troubleshooting. Wound up rebuilding the distributor and the carb (single Carter)......twice to no avail. Got to the point that the timing chain was determined to be the culprit. Jacked the motor, pulled the mount, pulled the cover, pulled the chain (hella slop), replaced the gears and new chain, forgot to line up the punch marks. So, pulled it all back off and very stupidly aligned the marks on each gear independantly...... so now there outta whack....right? I dont have the shop manual either so that brings me back here. looking for that old skool gear head that has actually worked on one of these motors. If someone out there can actually help get this things back in order, I would appreciate it. Im waiting on the new gaskets anyway before I can button it up. Trying to get it road ready for Huff a rama.......Help!!!

 

Bring it up to TDC on the number one cylinder. line up the marks, and you should be good

 

Did you alter the distributor at all? If not you could wind the cam around until the points open and assume about 8 degrees of timing. Then line the crank up from that. I did this on a friends car that they pulled apart once, that had no timing marks. Of course this assumes that the timing was ok before you started...

 

The Dodge flatheads set up their timing off of TDC on #6, there's actually a little pipe plug in the head over that cylinder you can remove to check to see if you're at TDC.

But you should just need to line up the dots. This is taken from a '53 Dodge truck manual, but the 218's and 230's are pretty similar.

 

Thanks for the help guys. Gonna give it a shot today. So Moparmonkey, any idea why #6? That actually helps a lot cuz youd assume #1 since its right there in front

 

I do believe that 1# and 6# TDC at the same time

 

Okay, finally had some time to put it all back together and with the second turn of the key, it fired up. Yay!!! but (always a but) It's still back firing. But now its different, It idles great but as soon as I put it in gear it starts stuttering and popping. Would it backfire if the engine is struggling to work that tranny? yeah....right? I tried to drive it down the block and I had it in first and it actually slammed into gear as if I nuetral dropped it. WTF is going on fellas?

 

If the idle is nice, and it backfires up the carb when you drive, it could be a carb issue causing it to need more fuel....or could be lack of advance on timing.

If it is backfiring through the carb, try giving it some choke if you can find a way to do that. If there is something wrong with the carb causing lean, choking it a bit would help diagnose it, if it does get better with some choke on.


If it's backfiring out the tailpipe instead, I'd be looking at ignition. cracked cap, crossfiring wires, etc

 

Have you done a compression test? Ever had the head off the motor? Have you ever adjusted the valve lash? Does it run OK cold but start backfiring after it's warmed up?

Helped a friend get her old Dodge pick up with a flat 6 running years ago. It would backfire thru the intake after warmed up and actually had a burned intake valve. Which sounded a bit unusual, but I had an old timer explain to me that it wasn't uncommon if the valves had been adjusted a bit on the tight side of the specs. When things got really hot the lash would go away and it would hold the valve open just enough to backfire thru the intake and eventually burn the valve.

We fixed the valve and then I ran the valves about .003" looser than the specs called for. There was maybe just a little more valve train noise but it ran fine and didn't backfire anymore.