Technical Timing? help, possibly worse?

I have a ‘58 283
Ran perfectly for a long time. Couple years. Out of the blue the distributor came loose, timing out of wack. Reset timing, tightened down, now the darn thing works itself loose every day.
Get a new hold down, no help. Timing seems to be all out of wack consistency now. today I was test driving, running good. After a mile on the freeway I took the exit and at the stop light it dies and won’t re start. I had to advance the timing a ton to get it going, now runs like garbage at the 10 degrees it historically loved.

New plugs (same plugs it ran great with)
Wires all seem good
MSD box the has blue spark and zapped the hell out of me while I was check king all the connections into the cap
could The timing chain have too much slack? Possibly bad distributor? Just all happened at once. I’m at a loss. Checked everything I know how to. Wondering if I should do a leak down test to see if I bend a push rod?
Any next step advice would be a huge help
Thanks

 

I wonder if a bushing went out in the distributor, and it's seizing?

 

My only next clue is to pull it. Not sure who can test MSD distributors. Pretty spendy to replace without knowing though

 

The distributor works, doesn't it, since the engine runs. So you need to see how it turns, is it grabbing, or rough? Is the shaft loose side to side?

 

Ok. I’ll pull it and see what I can find out. Thx

 

At some stage it hasn't had one of them plastic cam timing gears fitted, and now jumped a tooth??

 

Un Sure. I have been thinking through this whole mess, it may be worth a gear drive to nip any slippage in the bud. At some point I’m afraid I’m gunna have to dig deeper than surface stuff. For what it’s worth, the timing marks are dead smooth in the light. No jumping around at all

 

Is the distributor off a tooth or two from when it was loose?
In other words, is rotor still pointing at number one plug wire on distributor cap when piston #1 is at top dead center?

 

Slow down and take a deep breath, Is the car running now? is it popping back through the carb or muffler? If it has a fiber or plastic cam sprocket it could have broke, but a gear drive is over kill just get a steel timing set. With the timing light on the motor does the timing mark move up (advance) when you Raise the RPM's ? Does it have a wire style hold down or a flat steel fist. hold down, I find the solid steel work better. Do this by the numbers before you sink stupid money on it. 283's are great engines no matter what the Jags and Summit hot rodders say.

Pat

 

Is the distributor physically moving that you have to move it back to where it was?

 

You'll hate a gear drive , extremely noisy & less accurate than a chain ..like 1934coupe says , slow down & do some diagnosis before you test it down . Start with pulling the plugs , take off the dist cap & check if your on no.1 , then rotate the crank forward then backward to see how much slop is in the chain/ gears .

 

Yes, physical mobility. For some reason I get it real tight so I can’t move it with my hand, 30 minutes driving it loose and timing is out, with all the drivability issues to follow. I’ve been carrying a timing light with me. I’ll try a new hold down, go test and have issues.

 

Car will start and drive, at least up until tonight, not sure about now, but I was able to re time it and drive well. It will pop slightly out the pipes coming down off high rpm (5000 ish). Never have backfired
I’m getting some black smoke now, which I was never getting before. Have always been solid steel hold down. On my 3rd one. Had 2 after market and one factory. All same issue. It never moved at all for over a year, or all the sudden. Real weird. I really like this little motor. Plenty of power for this little roadster. Good looking too.

 

Thanks. I tend to react fairly abruptly. I’ll check play in the rotor 1st thing. Distributor only has 1200 miles on it, but that doesn’t mean much these days I guess

 

Has the intake been cut? [for milled heads /block]
If so install a spacer between the distributor and intake

I had this same issue with a BBC [with a HEI]

 

It sure possible. It’s an early aluminum. Front oil fill like the factory cast one. It easily could have been milled over the years by someone. I can try a spacer for sure. Just strange that it just now getting loose after a year and a half of no issues.

 

I’m wondering if for something odd has happened with the drive shaft from the oil pump and you’re now clamping the distributor down on to that rather than the manifold or if the manifold/heads have been skimmed as Kerry said.

 

PS is the distributor itself moving or is it the timing alone that is changing? Have you marked the distributor body against the intake to check?

 

Is the distributor clamp held down with a long stud and a nut? If so, make sure that the stud is not physically pulling the threads out of the intake. That would have the sensation of being tight and randomly coming loose, until the threads leave the party altogether.

 

I haven’t made a mark, but that’s a really good idea. My hunch is that it’s physically moving since it keeps coming loose, but definitely a box to check. Good idea

 

No, it’s a bolt. I was going to try a stud to see if it helped

 

I think at some point soon I’m going to have to pull the distributor. I’ll make sure to look. Oil pressure is normal luckily

 

@OZCAST
First thing I would do is check play in chain , cap off , watch rotor button , back & forth on crank, or
If stick transmission , 1st gear rock roaster back & forth .
If play looks Marginal,

"" Is the Collar on Distributor adjustable ??? """"
If No or Yes still do whats below ,

Then I would pull distributor out ,
Take gasket off , drop back in & see how much of a gap between base & intake .
Should set on Intake with No Gap with Out a Gasket . If there is a gap , it's
More likely pushing on Oil Pump .....
Or Very close unless gasket in use is
.065 to .100 thou Thick !

If that checks out Ok,
Then I would start looking @ distributor
Pin , Not sheard & that gear not spinning / slipping on shaft ,
Then Shaft &
To pick up wheel Not slipping / spinning ,
Then the weight plate where Cap bolts / screws to
To make sure its not slipping / spinning.

If shaft , pick up or weight plate Is slipping / spinning it will change timing in distributor relation to poles for each cylinder Before spark plug wires to plugs to piston & so on ...

Report back what you see /find

Also Mark distributor base & on intake to see if distributor housing is turning
When clamped down after your Drive ..

 

Hurry up & Fuck up .... Are the hold down threads in the manifold still good ? Try some blue loctite on the bolt ..

 

Is there a gasket under the distributor? I’ve found sometimes I needed 2 as the unit was going to far on to the oil pump drive. Good luck

 

some MSD distributors have an adjustable lock collar around the stem. If that is loose it could be the cause....

 

I go with Squirrel's suggestion, the shaft in the distributor may be seazing to the distributor body due to lack of lube and turning the distributor.

 

If the distributor has been undisturbed and functional I would suggest that there may be varnish buildup on the shaft causing drag.

Clean up the shaft and install a new distributor gasket.

Verify the dist gear is not too close to the housing, binding.

Verify the distributor clamp is also installed correctly. It can be flipped upside down which may look as though it is clamping the distributor, but it is not.
Verify the bolt is not too long or missing a washer.
Some later model clamps and aftermarket pieces work only when installed 'upside down'.

To check timing chain slop;
Rotate engine to TDC.
Remove distributor cap.
Manually rotate crank backwards while watching rotor.
When rotor begins to move STOP.
Look at timing tab mark.
<5° You're OK.
>5° Start gathering parts for timing chain replacement .
>10° Timing chain should have been replaced last year.

 

What kind of distributor is it? Pick up a new one for about $60 and stab it in and see what happens. Or borrow one if you don't want to buy one.

 

Good call! I’ll check that right away. Thanks!