Timing and dwell on a 304

Heath M

Heath M

Member
I have a 304 that idles great, but once I hit the road, it beats the crap out of ya. It backfires while on the road too. I understand I need to set the dwell and timing. I could not find a step-by-step in the forums. Is there one?

I thought I remember I need to not set it to tc. Also, tc or 0 doesn't seem to have a line on the engine, kind of off a bit.

I know that I need to time to #8 (I have the service manual, but didn't help here), but that is about it.

Any help or guidance is much appreciated. I plan on running down to harbor freight to get a timing light w/advance.

Thanks!
 
Heath!

What ya need is 'splained in this thread, what I call the redneck way:

http://www.forums.IHPartsAmerica.co...es-pertronix-require-timing-readjustment.html

Also, since you are a local dude....and ya have a major IH player right there in harrisburg also (I have a fresh Holley 2300 carb hanging on the wall waiting for him to come up and install!), both of ya need to plan to be up here at binder university on March 28th for a full day of scruuin' with this stuff including an engine analyzer session! The "power timing" technology will be a highlight!

Here's a link to the club calendar just posted today, keep tabs on the IHSTO goings on in our sub-forum there:

http://www.forums.IHPartsAmerica.com/I-h-s-t-o/1421-IHSTO-calendar-events.html

No matter which distributor you have in yore motor, the "dwell" setting is a nominal 30*, that translates to a breaker point gap of 0.017" average, depending upon amount of distributor wear.

That harbor freight "dialback" timing light is what I keep here at the shop, if it gets run over or wrapped up inna fan blade, no great loss! I quit using the highdollar timing lights years ago as they just seem to disappear too easily and make very expensive crunching sounds when the fan eats 'em.

Yore scoutneighbor there in h-burg is wes, or better known here as "wbrent 7766".
 
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Well, I got the dwell to 24, but thats the best I could get out of it. The diz is stuck and won't budge, even after liquid wrench and wd40. The timing Mark jumps all over the place (using #8). She seems to idle somewhat fine, but click it into drive and something in there feels like it is hittin' or something. It seems like a cross between constant backfiring or maybe a piston slamming (not experienced enough to tell).:confused:

I got to get this thing runnin', my other car is about to poop out on me. I guess it is back to a bicycle. This economy has wiped us out (as far as income goes).

Suggestions?
 
Ahhh yes...the frozen distributor syndrome...we see that way too often! Rats nested down in there for years, pissin' on everything, that welds the distributor to the block! Rats are the politicians of the underworld, what they can't crap on, they eat.

Ya just gotta keep soaking in penetrant...it also helps to "tap" around the hold-down flange with a large drift and hammer, not too hard or you will break the housing. Tap and soak, tap and soak, etc.

I can tell ya from much experience, that distributor needs to come out and be disassembled, cleaned and "rebuilt" to an extent. If ya can't get the dwell to set properly, then the breaker points are toast and need to be replaced, the rubbing block is worn completely down.

If it's a Holley distributor (ya need to tell us which one ya are dealing with), there were two different units used, a "straight point" with points mounted to a phenolic insulator, and the curved point (much more common and easy to find points for).

If it's a delco distributor, then a "uniset" for any older v8 GM motor (bop/chev) will work.

But even if ya get the dwell set, then the timing can be anywhere...so ya must free it up for rotation.

In extreme cases like this, I use the oxy-acetylene torch and heat that area, but that is very dangerous to do and ya must remove all traces of wiring, fuel, fuel lines, carb, etc. From the area and have someone standing by with a fire extinguisher.
 
michael mayben said:
I can tell ya from much experience, that distributor needs to come out and be disassembled, cleaned and "rebuilt" to an extent. If ya can't get the dwell to set properly, then the breaker points are toast and need to be replaced, the rubbing block is worn completely down.

If it's a Holley distributor (ya need to tell us which one ya are dealing with), there were two different units used, a "straight point" with points mounted to a phenolic insulator, and the curved point (much more common and easy to find points for).

If it's a delco distributor, then a "uniset" for any older v8 GM motor (bop/chev) will work.

But even if ya get the dwell set, then the timing can be anywhere...so ya must free it up for rotation.

In extreme cases like this, I use the oxy-acetylene torch and heat that area, but that is very dangerous to do and ya must remove all traces of wiring, fuel, fuel lines, carb, etc. From the area and have someone standing by with a fire extinguisher.
Click to expand...

This problem all started when I put a new set of points, wires, rotor and cap. I was truckin on the binderbulletin. I tried firing it up again recently, however they have been down for days. It is as though I have to start over.

My distrib is a curved points I believe (see pix).
 

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Ok, ya gotta curved point Holley...that's good (at least for a start!).

The points do look fresh, so there is no reason ya can't set the dwell to spec...which 28*>32*. Are you certain you have the calibration switch set properly on your dwell meter and you are reading the correct scale? I always shoot for the middle. With new points, you should be able to set within a dwell range between 0* and about 48*...but 30* is correct. The engine will only "try" to start and run between a dwell of about 15* and say 38*, if out of that range ignition coil saturation will be crap and the effective timing will be greatly out of range.

If you prefer to use the feeler gauge method, then use 0.017" and make it a snug fit. That will give you 30* dwell. Unless the distributor mechanical advance is completely worn out.

The dwell must be set and locked down first, then ya adjust the static and dynamic timing. But if you can't rotate the distributor, you will never be able to bring the timing in.

No telling what the "old" dwell setting (or timing) was. And the distributor/timing was set for whatever that factor was also, dwell and timing are correlated but not the same thing. If you get the points/dwell set to spec now, the timing will be way off. This is the same thing I explained in that thread regarding the pertronix conversion...no different!
 
michael mayben said:
Are you certain you have the calibration switch set properly on your dwell meter and you are reading the correct scale?
Click to expand...

The dwell section of the meter settings are by how many cylinders you have. I set it to 8 of course. It is another harbor freight special.

I will fool with it again tomorrow.

What about the plugs being 180˚ out?is that possible?
 
My hf dwell meter got run over years ago...but all the cheepies I keep here work the same, there is an 8 cylinder scale which is a direct read. Be sure to not use the 6 cylinder scale. For a four cylinder engine, ya double the 8 cylinder reading.

Ya can take all the plug wires off and throw inna pile, that has nothing to do with "dwell" setting, only the plug firing order. But yes, the firing order must be correct as relative to the cap terminal and rotor phase inside the cap.

Since you did not remove or even move the distributor (yet), then it's simple to wire the cap correctly..see this thread for how to do that:

http://www.forums.IHPartsAmerica.com/ignition-tech/640-new-guy-clueless-about-ignition.html
 
What a duffus! I can tell you that I checked my wires at least 12 times since I replaced everything... #1 and #2 were switched. The knock is gone.

As far as moving the diz... When I went out this morning, I was able to turn it with no hassles. As the engine warmed up it began to lock up again.

I did get the dwell to 30˚. Now all need is that distrib to loosen while the engines warm. The timing is at 15˚ btc.
 
All I can say is...the sparkfairee came out from under yore pillow last night and did sum shit!

If the dwell is correct, then leave it alone now!!!

If you used the "power timing" method, with "regular" grade e10, and the timing still reads 15* btdc on the timing light at 600rpm curb idle, then ya still have issues!

No way a 266/304/345 or a 392 can run 15* btdc base timing and not detonate like a bitch!! Even under the lightest load, just wingin' the throttle in the driveway.

Walkin' away from stuff is sumtime the best fix ya can employ. Tomorrow is always better than today 'cause it's another chance!
 
michael mayben said:
all

if you used the "power timing" method, with "regular" grade e10, and the timing still reads 15* btdc on the timing light at 600rpm curb idle, then ya still have issues!

No way a 266/304/345 or a 392 can run 15* btdc base timing and not detonate like a bitch!! Even under the lightest load, just wingin' the throttle in the driveway.!
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Not sure I follow you on the "power timing" method. I search, but found nothing on the forum.

The 15˚ is the Mark on the engine case. That would be the number 15 before or counter-clock-wise of tc. This is where it is at, although I had to have a stick on the pedal to keep the engine revved high enough to keep it running long enough (maybe that is what you mean by "no way it can run") to time gun it, other wise it dies.

I also want to say a big thanks for all your input.
 
You are very welcome heath...and it saves me a housecall to bail ya out! But we still expect ta see ya up here March 28 for a followup session!

Look at this thread:

http://www.forums.IHPartsAmerica.co...es-pertronix-require-timing-readjustment.html

Don't let the title fool ya...start at the top, at some point you will be doing this same thing most likely unless the fairees take yore ride away from ya and ground ya. Pay close attention to post #10, that is the "power timing" methodology. If lou can understand that...then anyone outside of washington d.c. Or salem can too!

You keep lernin' stuff, we'll keep kickstartin' yore azz!
 
I am fed up with this crap!!! I wish this thing would work right.

So today I go out and try to start the Scout. It takes a lot. Then the carb catches on fire. Ahhhh!:mad5: I had to use the fire extinguisher.

I am tired of not knowing enough and want to give up on this piece of junk. Unfortunately I can't afford to take it to a real mechanic and have to press on because I need it to run before the other car kicks the bucket.
 
Backfire in the carb indicates very retarded timing.

If the timing is too far advanced, the engine will crank slowly like the battery capacity is diminished which means it's "kicking back" when it fires the cylinders, that will break a starter drive.

You simply must get that distributor broken loose so ya can rotate it bring the timing in. Your issue will be solved.
 
I got "oiler" to fire up pretty regularly, but she won't stay running without pumping the gas.

I still cannot rotate the distributor once the engine gets a little warm, no matter what gunk I use. It does move a bit when the engine is cold though.

Other than that, I am stuck. Don't know what else to try. I did get the dwell set.
 
I asked wes (your scoutneighbor there in harrisburg) if he'd ever hooked up with ya just two weeks ago! Too bad ya missed the all day event we had here at binder u., we coulda fixed the rig once and for all!

Ya simply must get the distributor to rotate or remove it for freshening! No way around it!!
 
michael mayben said:
I asked wes (your scoutneighbor there in harrisburg) if he'd ever hooked up with ya just two weeks ago! Too bad ya missed the all day event we had here at binder u., we coulda fixed the rig once and for all!
Click to expand...

I got a pm from him in February. I replied immediately with my email and phone, but haven't heard from him yet. I sent him a new pm today.
 
Well, wes came over and gave me a hand yesterday (thanks wes). We got it running. I even took it for a drive.

Now I will adjust the dwell, which is currently at 33˚to 30˚ and adjust the timing, which is so far off it doesn't even show up.

Maybe I will get this thing running safely enough to make it up the river one of these days.
 
heath m said:
well, wes came over and gave me a hand yesterday (thanks wes). We got it running. I even took it for a drive.

Now I will adjust the dwell, which is currently at 33˚to 30˚ and adjust the timing, which is so far off it doesn't even show up.

Maybe I will get this thing running safely enough to make it up the river one of these days.
Click to expand...

Great!!!!

Both you and wes need to make a Saturday trip up here! We need to install that fresh carb for wes and get it tweeked! Bring both rigs (one can push the other??) and we'll put both on the diagnostic analyzer and look at their heart and lungs!

My wife showed me that you had signed on with IHSTO (she's the club secretary). Thanks for joining us, it's the best money ya could spend considering we charge nothing for joining!!! But she didn't know we were already communicating on the forum here!
 
So, I set the dwell to 30˚, but the timing... Well, I have turned the distributor until the advance?? Hits and won't turn any more. I almost have the Mark showing up on the tick marks. Could it be possible that when we pulled the distributor, it got put back one off or something.

To reiterate, at this point, I cannot dial it in because I need to rotate it clockwise, but have run out of room. Ideas??
 
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