View Full Version : More on timing......


dbx1969
Aug 5th, 07, 12:56 PM
I finally got an MSD timing gun and tried it out today. It's no wonder my car had trouble starting, as the damper mark wasn't even visible until I turned it quite a bit. It must have been advanced at around 22+...and this might have happened when I installed a new trannny and jacked the engine up & down. Anyway, I backed it down to around 18 (after searching many threads here I decided to start here) and bingo, my car started in a nanosecond after. Like, instant detonation after turning the key. I had set the idle at 800 and it idled fine. While it idles and seems to throttle fine in neutral in my driveway, I took it around the block and it doesn't respond well to any acceleration. It wants to choke and sputter when just trying to get from 1st to 2nd...2nd to 3rd. I was even concerned I didn't have enough momentum to climb a neighborhood hill, but barely made it. I returned home and set it back to 16...then 14, driving it around both times. It seems like it ran slightly better at 18 & 16 than it did at 14, but not where it was standout noticeable. But it starts up instantly and seems to idle fine at 800 with any of those settings.

Am I back to looking at my "newly cleaned & adjusted" carb? And no, I haven't received my vacuum gauge yet, so I can't check vacuum. I was out of town and apparently, I have to sign for this $20 gauge I ordered, unlike the $120 gun:confused:.

I'm hoping to take it to a shop tomorrow to get the manifold/exhaust connection fixed (problem since installing new X-member), and they said they'd set my timing curve for only like, $27, which I thought was awesome. But the point is, I want to learn how to fix these problems on my own when they arise....but I'm so far back, knowledge-wise, that I need lots of help to steer me:)

One other question while I'm at it: A dust shield rubbing against the flywheel isn't something to worry about is it? I know it's not supposed to, lol, but I didn't feel like taking the starter out again at present time. You can hear it slightly rubbing against it. (I had to hammer down a raised part of the shield to accommodate a new starter, and I guess it "warped" it a bit)

kustomwerker
Aug 5th, 07, 01:53 PM
it could be that the damper mark is incorrect due to age...the damper ring is rubber mounted on the center flange, which is attached to the crank...when the rubber deteriorates over time, the outer ring can move, giving you false timing marks...

dbx1969
Aug 5th, 07, 02:12 PM
it could be that the damper mark is incorrect due to age...the damper ring is rubber mounted on the center flange, which is attached to the crank...when the rubber deteriorates over time, the outer ring can move, giving you false timing marks...

The engine is a newly rebuilt 350, .030 over. And it makes sense that it was off due to jarring the dizzy when installing the tran. AND....that when I retarded the timing... the car starts right up.

Basically, by changing the timing myself...I got it to start up in a split second. The problem I face is that it doesn't appear to drive much different. In other words, ever since I "fixed" the carb and installed a new tranny (done at the same time), I haven't had it running properly. But why is it now choking when a load is put on it? Again, idling and throttling it while in neutral/parked seems fine. The problem is when I drive it.

kustomwerker
Aug 5th, 07, 03:14 PM
so the car ran fine until you pulled the carb and did the trans???plenty of power before the swaps???

dbx1969
Aug 5th, 07, 05:13 PM
so the car ran fine until you pulled the carb and did the trans???plenty of power before the swaps???

Yes.

dbx1969
Aug 5th, 07, 07:53 PM
Shameless bump and an embarrassing follow-up question: As already stated, my 350 engine is rebuilt. The firing order on dist/engine are that of what my Chilton's manual says is a 75'-81' engine configuration. I don't see any vacuum hose/cannister attached to my distributor, but this is normal, right? LOL, be nice....I've already admitted I don't know squat about engines. I started wondering how I could have possibly knocked the timing out so much while bumping the dist when working on the tran. So I started thinking that if I was checking the timing today without disconnecting a vacuum hose....that that's why it was so far advanced.

And while I wouldn't think of my engine to be timed under a racing application, the MSD manual suggests to time it at around 3K rpms. And I am having issues when it's under load....not while idling or being throttled in neutral.

Yes, I'm lost here:)

JimM
Aug 5th, 07, 09:24 PM
1 if the distributor was installed and the cap on when you changed the trans, you probably at least cracked the cap, may even have tweaked the distributor body. Take the cap off and check it out.

2 Initial timing is at idle with the distributors vac hose disconnected and pluged. stock was 4-12 depending on the engine, most performance motors are happier at 16-18.

3 total timing is initial plus mechanical advance. most SBC's are at 34-36 degrees, don't exceed 38. check at 3000 rpm or more, with the vac hose disconnected and plugged. (yes, just reved up in neutral)

4 vacuum advance helps cruise economy and response, connect the hose to a port with full time vacuum. finger the port at idle, it should suck.

dbx1969
Aug 5th, 07, 09:29 PM
1 if the distributor was installed and the cap on when you changed the trans, you probably at least cracked the cap, may even have tweaked the distributor body. Take the cap off and check it out.

2 Initial timing is at idle with the distributors vac hose disconnected and pluged. stock was 4-12 depending on the engine, most performance motors are happier at 16-18.

3 total timing is initial plus mechanical advance. most SBC's are at 34-36 degrees, don't exceed 38. check at 3000 rpm or more, with the vac hose disconnected and plugged. (yes, just reved up in neutral)

4 vacuum advance helps cruise economy and response, connect the hose to a port with full time vacuum. finger the port at idle, it should suck.

Jim, I removed the cap when tilting the engine, but just figure MAYBE I still bumped the assembly.

Again, I don't see a vac hose on the dist :confused:. I also read about "total" timing, but again, I don't have a vac gauge right now either (ordered).

dbx1969
Aug 6th, 07, 06:54 AM
Jim, I removed the cap when tilting the engine, but just figure MAYBE I still bumped the assembly.

Again, I don't see a vac hose on the dist :confused:. I also read about "total" timing, but again, I don't have a vac gauge right now either (ordered).

It is a Mallory/Unilite 3748201D dist. with no vacuum advance. In this case, would initial still be set at 16-18?