got a 54 inline 6 ran good when got it when driving saturday it started missing a little at first then it got bad I found rotor had chipped and brass tip had turned so I changed plugs rotor cap wires and points and condenser it is still missing very bad and backfire through carb.it had 6 volt coil on it and I put a msd coil I had in its place w/no help.car is a 12 volt system now.I reinstalled 6 volt coil and no change any ideas on curing this back fire and missing?
Yes i would say also say to check out Petronics elctronic set with a flame thrower coil. they replace the points and condensor and really work very well. They also are easy to install into your stock Distributor. Good Luck
The rotor usually breaks because it is hitting the cap. On a 6 that would probably be because it wasn't on straight. As Old dirt tracker said. Check the firing order. Also make sure that the condenser is tight in it's holder and that the screw is tight.
check timing. vac adv. Vac leaks? very basic motor. mines still apart re-grind cam here in the morrning.
i had the same problem and found the bushings in the dist were worn badly. ran good when i first got it and after a week it started poping thru the carb. i quess the old grease in the dist softened up and started letting it walk around in the housing
notice my dist.is NOT turning when RPM's increase I am going to check when I get home today.hvychvy put new vac advanc on around 3 yrs ago but parts go bad plus I'll check for leaks...any other idea's?I also noticed slight fuel leak on front of carb at base where buterfly is connected(nipple on side of carb)it is close to where vac is connected for vac adv. would this cause loss of vac to advance?
If you can find one, drop in a hei from a 250/292. They fit with a minor mod, and will help you diagnose the problem. You can always switch back once you get the other issues sorted. What part of OK are you in? I know where a replacement points dizzy is.
popping on decelleration would indicate a vac leak. Take a close look at the valve springs. Maybe one is broken. Also, since its a new motor (to you anyway) do a compression test on it, so you know what shape its in. Since its 12 volts and running points, you should have a resistor before the coil, otherwise you run the risk of burning the points. There is no resistor wire present, as it was a 6v car originally. Is the motor grounded to the frame good? A worn out dizzy is a possibility, as mentioned. If you pull out the dizzy, take a look at the cam gear. It should be centered in the hole. If its towards the rear, it may have slid out of the cam gear, which screws up the timing. I've run many miles with a disconnected vac advance, and a little more initial timing. I don't see how an inoperatable vac advance woud cause anything, unless you end up with a vac leak, in which case see point #1.
found last rocker(closest to firewall)lose and adjuster backed out almost completly...hope this will fix,once I adjust valve that is...
ok,I adjusted valves,I reinstalled 6 volt coil as the msd blaster 2 coil got to hot(I'm assuming)and poped the top spewing what ever is inside all over my arm, car and my bike...after cleanup I gave up for night.but next day and a good battery charge I ran car idled great no popping or missing.drove for awhile and ounce warmed up it started missing when accelarating,not so bad if you hardly apply gas but very bad if driving normal shifting through gears..but still idles great...vacuum advance still does not work,and i went through valves again while motor was hot....any ideas?
the coil is not different on 6v or 12v, what matters is the resistor in fron t of it on a 12v system. vacuum advance needs to work, get a different dizzy to try. HEI doesn't need the resistor, BTW. How is the fuel filter? clogged? Sounds like you have multiple problems all with similar symptoms.
Humor me for a moment. Disconnect your vac advance, plug the carb connection, and bump up the timing to get back to the regular idle rpms. Take it for a drive... I'm not saying you should run it that way, I'm just saying that it isn't causing the popping, etc... I used to run a dual point Mallory that had no vac advance on it...
THIS^^^is a real common issue. This allows the dist shaft to move around, this changes the timing and dwell and will act OK sometimes and run like shit other times. Please check into this before you get into expensive other things that are not the problem. Frank
yea I will check into some of the above(compresion test,fuel filter,etc.)still not giving up or discouraged.... but I'm asking with dan above what or how can I upgrade to a better dist. setup?I was planing on keeping motor if ran ok,but may be easier and cheaper in long run to go to 350/350.if nothing else parts for that would be at local parts store...but still like the idea of a hot rodded original 6 motor??????but for know would just like to drive for awhile.if I can get it drivable...
http://www.stovebolt.com/techtips/hei_conversion.htm This link covers it in general, but I would add that the tip of the shaft usually needs to be shortened also. Just compare the 235 and 250 dizzys side by side, with them lined up on the center of the gear. What needs to be done will be obvious. Reusing the clamp setup from the 235 is the easier than making one from scratch, but I have done the 2 piece clamp collar method on mine. One keyed 12ga wire to the coil, no resistor or resistor wire.
ok checked,fuel filterits ok,pulled dizzy,how do u check bushing?I don't feel any side to side playin shaft,there is some play in up/down,also under clampthere is 2 groves is there a O-ring that goes there? also if I upgrade to hei as above what about vac advanc do I have to put this on or what.....Yes I'm green.......
If the shaft doesn't wobble, its fine. No O rings required. The stock HEI has a vac advance on it. Yes, you would hook it up.
I'm having the same ,problem. I have 2 235 motors. I one Chevy 235 the I changed to a 12 volt, put a electronic disrtibutor. I have a presure test gage, and all the valves read, 75+ Presure. they are all equal in presure. This motor is a 235, 1 barel carb. The next thing I'm going to do, I have two cars that are 1954 Chevy bell air's. 'm going to take the carburator, out of the other Chevy, and put in the one that is mising, and see if it makes the car run better. If it doe's that means it could be the Carburator, I hope. Any suggestion any of you ? Please help, I'm in dire needs here. Thank you Guys. I wait you're help. You can send me a private message if you like. I live in Southern California, Los Angeles.
I converted mine using an s10 dizzy. It takes a little machining, but they're cheap at a Junkyard and because they use a small cap they fit better than the large cap 250, they look almost stock, and advance internally.
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